Alector, Inc.
For the period ended Dec 31, 2025. Filed Feb 25, 2026.
View on SEC.govAbout this filing
A company's yearly report to the SEC, with audited financial statements. It is the fullest account a company gives of its business, its finances and the risks it sees.
FY2025 · Filed Feb 25, 2026
ALEC$2.29+9.6%Stored close · as of Nov 6, 2026
What changed in Risk Factors?
Read the current filingPrevious report: 10-K
Period ended 2024-12-31; filed 2025-02-26.
0000950170-25-027758
Item 1A. Risk FactorsCurrent report: 10-K
Period ended 2025-12-31; filed 2026-02-25.
0001193125-26-071593
Item 1A. Risk FactorsThe baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.
Compared 394 previous paragraphs and 413 current paragraphs.
274 unchanged; 99 reworded; 38 added; 17 removed; 4 previous and 2 current paragraphs rearranged.
Tables are not compared: 0 previous and 0 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.
A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.
Added paragraphs (38)
Current report
Changes or reductions in the FDA’s or other government agencies’ management and personnel, or changes in such agencies’ funding, could impact their ability to hire and retain key leadership and other personnel, impact the timing for development or commercialization of new products and services, or otherwise impact those agencies’ performance of historically typical functions upon which the operation of our business may rely, which could negatively impact our business.
Current report
In October 2025, we decided to stop the open label extension portion of the INFRONT-3 trial and the continuation study of our product candidate latozinemab based on the results of the INFRONT-3 Phase 3 clinical trial evaluating the safety and efficacy of latozinemab in slowing disease progression in individuals with frontotemporal dementia due to a progranulin gene mutation (FTD-GRN). Latozinemab failed to meet the clinical co-primary endpoint in that trial.
Current report
In November 2024, our AL002 program was terminated, based on the results of the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD, in which AL002 failed to meet the primary endpoint. In 2022, we and AbbVie concluded that further development of our product candidate AL003 was not warranted. We previously decided to close the Phase 1 clinical trial for our AL044 product candidate based on initial pharmacokinetics and tolerability data.
Current report
withstand high rates or sustained periods of inflation; and
Current report
To date, clinical development of four of our product candidates has been terminated. In October 2025, we decided to stop the open label extension portion of INFRONT-3 and the continuation study of our product candidate latozinemab based on the results of the INFRONT-3 Phase 3 clinical trial evaluating the safety and efficacy of latozinemab in slowing disease progression in individuals with FTD-GRN. Latozinemab failed to meet the clinical co-primary endpoint in that trial. In November 2024, our AL002 program was terminated, based on the results of the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD, in which AL002 failed to meet the primary endpoint. In 2022, we and AbbVie concluded that further development of our product candidate AL003 was not warranted. Additionally, we decided to close the Phase 1 clinical trial for our AL044 product candidate based on initial pharmacokinetics and tolerability data.
Current report
We cannot be certain that any of our product candidates will be successful in this or any other future clinical trials. Our current or future clinical trials of our product candidates may not demonstrate their safety or efficacy, either in the indications currently being tested or in any other indications, or either as single agent therapies or in combination with other therapeutics. For example, we were developing our product candidate latozinemab with GSK to treat patients with FTD-GRN. Latozinemab was an investigational human monoclonal antibody (mAb) designed to block and internalize the sortilin receptor (SORT1) to elevate PGRN levels in the brain. In October 2025, we decided to stop the open label extension portion of the Phase 3 study and the continuation study of latozinemab based on the results of the INFRONT-3 Phase 3 clinical trial evaluating the safety and efficacy of latozinemab in slowing disease progression. Latozinemab failed to meet the clinical co-primary endpoint in that trial. Our product candidate nivisnebart, which is being tested in the PROGRESS-AD Phase 2 clinical trial, is an investigational human mAb designed to block and downregulate SORT1 to elevate the level of PGRN in the brain in a manner that is similar to latozinemab, but with different pharmacokinetic and pharmacodynamic properties. An independent interim futility analysis is planned for PROGRESS-AD for the first half of 2026.
Current report
In November 2024, our AL002 program was terminated based on the results of the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD, in which AL002 failed to meet the primary endpoint. In 2022, we and AbbVie concluded that further development of our product candidate AL003 was not warranted. In the future, GSK or any other collaboration partner may decide to terminate a collaboration program based on, among other things, our clinical trial data.
Current report
inability to generate sufficient preclinical, toxicology, or other in vivo or in vitro data to support the submission of an IND or initiation or continuation of clinical trials;
Current report
the cost of clinical trials of our product candidates being greater than we anticipate, including costs associated with tariffs or other import or export restrictions;
Current report
delays in correspondence from, reviews by, or other interactions with the FDA or regulatory agencies in other countries;
Current report
interim analyses of clinical trials that result in a decision to terminate those trials due to failure of our product candidates to meet certain criteria; and
Current report
There are competing pharmaceutical and biotechnology companies, such as Denali Therapeutics, Inc. (“Denali”), F. Hoffman La Roche Ltd. (“Roche”), Aliada Therapeutics, Inc. (acquired by AbbVie), Eli Lilly, BioArctic, JCR Pharmaceuticals, Arrowhead, and Ossianix, who have developed and continue to develop technologies for the transport of products across the blood-brain barrier using transferrin receptor (TfR)-based transfer mechanisms. Other companies may successfully develop technologies for blood-brain barrier transport that are based on mechanisms other than TfR and that effectively compete with TfR-based mechanisms. Our ABC platform, which uses a TfR-based transfer mechanism, faces competition from such third party technologies.
Current report
Additionally, those competing blood-brain barrier transport technologies are being applied to antibodies and product candidates that act on the same disease targets as we are pursuing. For example, Denali and Roche are advancing antibody candidates, both of which target A-beta and incorporate blood-brain barrier transport mechanisms that act through TfR, and Arrowhead is advancing a tau-siRNA candidate with a TfR binding antibody fragment. Other companies, including Bial, Vanqua Bio, Inc., Gain Therapeutics, Inc., Prevail, Spur Therapeutics,
Current report
Voyager Therapeutics, Inc., Denali, and Roche have clinical or pre-clinical programs targeting GCase through allosteric activation, gene therapy, or enzyme replacement, with the latter approach incorporating TfR-based blood-brain barrier transfer mechanisms. Those and other competitors are pursuing product candidates that act on some of the same targets or through comparable mechanisms of action as we are pursuing.
Current report
Several companies are employing nucleic acid-based strategies, such as anti-sense oligonucleotides and siRNA, directed to neurodegenerative disease targets in conjunction with TfR-based blood-brain barrier technologies. Certain of those companies, including Eli Lilly, Arrowhead, Novartis, Denali, Roche and Manifold Bio, are applying this approach to some of the same targets that we are pursuing, including tau and alpha-synuclein.
Current report
Current or potential competitors may develop products with a market advantage due to their mode of delivery, such as oral small molecule or subcutaneous formulation. For example, Eisai received FDA approval for a subcutaneous formulation of lecanemab in August 2025, and Bial, Vanqua Bio, and Gain Therapeutics are developing small molecule allosteric activators of GCase.
Current report
In addition, we could face litigation or other proceedings with respect to the scope, ownership, validity, and/or enforceability of our patents relating to our competitors’ products. Furthermore, our competitors may allege that our products infringe, misappropriate, or otherwise violate their intellectual property. The availability of our competitors’ products could limit the demand, and the price we are able to charge, for any products that we may develop and commercialize.
Current report
our inability to recruit and retain adequate numbers of effective sales, marketing, reimbursement, customer service, medical affairs, and other personnel;
Current report
If we enter into arrangements with third parties to perform sales, marketing, commercial support, and distribution services, our product or royalty revenue or the profitability of such revenue may be lower than if we were to market and sell any product we may develop ourselves. In addition, we may not be successful in entering into arrangements with third parties to commercialize our product candidates or may be unable to do so on terms that are favorable to us. We may have little control over such third parties, and any of them may fail to devote the necessary resources and attention to sell and market our products effectively. If we do not establish commercialization capabilities successfully, either on our own or in collaboration with third parties, we will not be successful in commercializing our product candidates if approved.
Current report
Further, the current administration has issued an executive order focused on decreasing prescription drug prices, which directs the Secretary of Health and Human Services (HHS) to establish a mechanism through which American patients can buy drugs directly from manufacturers who sell at a most-favored-nation price. The order further directs the U.S. Trade Representative and Secretary of Commerce to take action to ensure foreign countries are not engaged in practices that purposefully and unfairly undercut market prices and drive price hikes in the United States. If HHS sets most-favored-nation pricing targets for prescription drugs or increases generic and biosimilar drug entry sooner than expected, then those actions could have a material adverse effect on our ability to set adequate pricing, recoup our investment in R&D, and commercialize our product candidates, if approved. We cannot predict the full impact of this executive order, its implementation, or other measures that may be implemented by the current administration related to drug pricing.
Current report
Additionally, reorganization of the U.S. Department of Health and Human Services (HHS) under its current leadership, changes in the current administration’s focus and policies, departure of senior leadership at the FDA and other agencies under HHS, and reductions in staffing at HHS may impact operations at the FDA as well as other federal agencies. Government shutdown, staff departures at the FDA, lapses in government appropriations, and changes in the staffing and resourcing levels at the FDA may impact the FDA’s ability to meet current review, approval, and inspection schedules, as well as our ongoing correspondence with the FDA, including correspondence regarding progression to the next phases of development. Likewise, restructuring, downsizing, and decreased funding of federal agencies including the FDA may result in our not realizing all the benefits of Breakthrough Designation and Fast Track designation, particularly benefits related to priority review, frequent communications with the FDA, and intensive guidance from the FDA, to the extent such benefits are applicable to any of our product candidates. Any of the above impacts could in turn delay our anticipated timelines, which can increase the cost of clinical development of our product candidates. Other policy changes may lead to fewer agency guidance documents, which could result in changes to FDA programs or possible delays or refusals to approve products. Further, FDA’s “real-time” release of newly issued Complete Response Letters associated with withdrawn or abandoned applications, if applicable to any of our product candidates, can materially impact our competitive advantage and intellectual property. It is unclear how our industry and our clinical programs will be impacted by policies or regulations implemented under the current administration and the new FDA commissioner or other executive orders. To the extent the agency's reduction in force and other agency changes lead to disruptions in the FDA’s operations, our interactions, correspondence, and regulatory review processes with the FDA may be delayed.
Current report
Healthcare legislative and executive measures aimed at reducing healthcare costs may have a material adverse effect on our business and results of operations.
Current report
Further, the current administration has issued executive orders focused on decreasing prescription drug prices, including directing the Secretary of Health and Human Services to establish a mechanism through which American patients can buy drugs directly from manufacturers who sell at a most-favored-nation (MFN) price and directing the U.S. Trade Representative and Secretary of Commerce to take action to ensure foreign countries are not engaged in practices that purposefully and unfairly undercut market prices and drive price hikes in the United States. The OBBBA includes provisions that will impact the U.S. healthcare system in various ways, including by cuts to Medicaid and introducing new participant work and eligibility requirements for Medicaid coverage, which are expected to significantly change the administration and applicability of Medicaid coverage. In November 2025, CMS announced a voluntary initiative called the GENEROUS Model (GENErating cost Reductions fOr U.S. Medicaid Model) to introduce the option of most-favored-nation pricing to the Medicaid program, whereby a drug manufacturer may voluntarily offer supplemental rebates to participating state Medicaid programs for a manufacturer’s covered outpatient drugs.
Current report
significant reductions in federal funding, such as research grants, to academic and other institutions may result in reduced opportunities to collaborate with such institutions;
Current report
We may not realize the benefit of collaborations if we or our collaborator are unable to successfully develop a product candidate and commercialize it upon approval or integrate a product candidate into existing operations and company culture. For example, in January 2025, AbbVie decided to terminate the TREM2 collaboration program, which resulted in termination of the AbbVie Agreement, after the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD failed to meet the primary endpoint. Therefore, we did not receive a $250.0 million milestone payment for AbbVie’s opting into the AL002 program or any future payments, and all rights to the TREM2 program have reverted back to us. In October 2025, we announced that latozinemab failed to meet the clinical co-primary endpoint in the INFRONT-3 Phase 3 clinical trial. As a result, we will not be seeking approval for and commercializing latozinemab in FTD-GRN, and certain milestone payments ($160 million for the first US commercial sale and $90 million for the first commercial sale in two or more EU countries) will not be achieved through commercialization of latozinemab in FTD-GRN, and our receipt of such milestones will therefore be delayed, or may not occur at all.
Current report
Further, FDA’s policy to release in “real time” newly issued Complete Response Letters associated with withdrawn or abandoned applications for approval of drug or biological products, if applicable to any of our product candidates, could materially impact our intellectual property by publicly disclosing our trade secrets or other confidential information in the absence of an opportunity to redact or otherwise protect such information contained in such applications.
Current report
As of December 31, 2025, we had 103 full-time employees.
Current report
Our future financial performance and our ability to continue to develop and, if approved, commercialize our product candidates will depend, in part, on our ability to effectively manage any future growth.
Current report
Any future reductions in or restructurings of our workforce may generate severance and other costs that may cause our business and operating results to suffer. Future reductions in force or restructuring of our workforce may occur as a result of market downturns, uncertainty in capital markets, or other macroeconomic changes, or may occur if we are unable to obtain additional capital to develop our product candidates or fund operations or if our clinical trials are not successful. Future reductions in force may require the company to manage significant personnel and operational changes, which may negatively impact our business.
Current report
We currently rely, and for the foreseeable future will continue to rely, in substantial part on certain independent contractors, advisors, and consultants to provide certain services. There can be no assurance that the services of these independent contractors, advisors, and consultants will continue to be available to us on a timely basis when needed, or that we can find qualified replacements. In addition, if we are unable to effectively manage our outsourced activities or if the quality or accuracy of the services provided is compromised for any reason, our research, preclinical development and clinical trials may be negatively impacted, and we may not be able to advance our programs or obtain regulatory approval of or successfully commercialize our product candidates or otherwise advance our business. There can be no assurance that we will be able to manage our existing independent contractors, advisors or consultants or find other competent outside contractors and consultants on economically reasonable terms, if at all.
Current report
The use of new and evolving technologies, such as AI, in our operations may require us to expend resources and may present risks and challenges that can impact our business, including by posing security and other risks to our proprietary and personal information, any of which may result in reputational harm and liability, or otherwise adversely affect our business.
Current report
We may choose to integrate AI into our operations, and this innovation presents risks and challenges that could affect its adoption, and therefore our business. Although AI has the potential to help advance our business, t here are risks involved in utilizing AI, and no assurance can be provided that the use of AI will enhance our business or assist our business in becoming more efficient or profitable. The use of certain AI technology can give rise to intellectual property risks, including compromises to proprietary intellectual property and intellectual property infringement and misappropriation. Other known risks of AI currently include inaccuracy, bias, toxicity, data privacy and cybersecurity issues, and data provenance disputes. In addition, AI may have errors or inadequacies that are not easily detectable. AI may also be subject to data herding and interconnectedness (i.e., multiple market participants utilizing the same data). If the data used to train AI or the content, analyses, or recommendations that AI applications assist in producing are or are alleged to be deficient, inaccurate, incomplete, overbroad or biased, our business, financial condition, and results of operations may be adversely affected.
Current report
Additionally, we expect to see increasing government and supranational regulation related to AI use, which may also significantly increase the burden and cost of research, development and compliance in this area. For example, the EU’s Artificial Intelligence Act (AI Act), which imposes significant obligations on providers and deployers of AI systems, entered into force on August 1, 2024 and, with some exceptions, will become effective 24 months thereafter. The rapid evolution of AI will require the expenditure of resources to design, develop, test and/or maintain our technology and products to help ensure that AI is implemented in accordance with applicable laws and regulations and in a socially responsible manner and to minimize any real or perceived unintended harmful impacts. The legal landscape and subsequent legal protection for the use of AI remains uncertain, and development of the law in this area could impact our ability to enforce our proprietary rights or protect against infringing uses. If we do not have sufficient rights to use the data on which AI relies or to the outputs produced by AI applications, we may incur liability through the violation of certain laws, third-party privacy or other rights or contracts to which we are a party. Our use of AI applications may also, in the future, result in cybersecurity incidents that implicate personal data. Any such cybersecurity incidents related to our use of AI applications could adversely affect our reputation and results of operations.
Current report
Our collaborators or other third-party service providers may also incorporate AI tools into their own offerings, and the providers of those AI tools may not meet existing or rapidly evolving regulatory or industry standards, including with respect to intellectual property, data privacy, and cybersecurity. Further, bad actors around the world use increasingly sophisticated methods, including the use of AI, to engage in illegal activities involving the theft and misuse of personal information, confidential information and intellectual property. Any of these effects could damage our reputation, result in the loss of valuable property and information, cause us to breach applicable laws and regulations, or otherwise adversely impact our business.
Current report
trade protection measures, import or export licensing requirements, trade tariffs, or other restrictive actions by U.S. or non-U.S. governments;
Current report
If we fail to comply with the continued listing requirements of the Nasdaq Stock Market, it could result in our common stock being delisted, which could adversely affect the market price and liquidity of our securities and could have other adverse effects.
Current report
Our common stock is currently listed for trading on The Nasdaq Global Select Market. We must satisfy Nasdaq’s continued listing requirements, including a minimum bid price for our common stock of $1.00 per share. Given the current market environment and despite our cash position, our common stock has traded for less than $1.00 per share, during the second quarter of 2025, and our aggregate market capitalization over the last several quarters has valued below the total value of our cash, cash equivalents, and investments. If we do not meet these requirements, we risk possible delisting from Nasdaq, which could have a material adverse effect on our business.
Current report
A delisting could make it more difficult to buy or sell our securities and to obtain accurate quotations, and the price of our common stock could be adversely affected. In addition, a delisting would impair our ability to raise capital through the public markets, could deter broker-dealers from making a market in or otherwise seeking or generating interest in our securities, and might deter certain institutions and persons from investing in our securities.
Removed paragraphs (17)
Previous report
We and our collaboration partners rely on service providers, including CDMOs and contract research organizations (CROs), for our research and product development activities and product candidates. If we cannot obtain products or use services from these CDMOs and CROs at an acceptable cost or at all, our business would be adversely affected.
Previous report
We are highly dependent on our key personnel, and if we are not successful in attracting, motivating, and retaining highly qualified personnel, including as a result of layoffs and furloughs, pausing of recruiting efforts, or regrettable employee attrition, we may not be able to successfully implement our business strategy.
Previous report
Our existing cash, cash equivalents, and marketable securities may not be sufficient to fund our future operating expenses and capital expenditure requirements.
Previous report
On July 1, 2021, we entered into an agreement with GSK to collaborate on the global development and commercialization of progranulin-elevating monoclonal antibodies, including latozinemab and AL101. Under the terms of the GSK Agreement, we received $700 million in upfront payments, of which $500 million was received in August 2021 and $200 million was received in January 2022. In addition, we will be eligible to receive up to an additional $1.5 billion in clinical development, regulatory, and commercial launch-related milestone payments for latozinemab and AL101.
Previous report
withstand periods of high rates of inflation; and
Previous report
Reimbursement may impact the demand for, or the price of, any product candidate for which we obtain marketing approval. In order to get reimbursement, physicians may need to show that patients have superior treatment outcomes with our products compared to standard of care drugs, including lower-priced generic versions of standard of care drugs. If reimbursement is not available or is available only to limited levels, we may not be able to successfully commercialize any product candidate for which we obtain marketing approval. In the United States, no uniform policy of coverage and reimbursement for products exists among third-party payors, and coverage and reimbursement levels for products can differ significantly from payor to payor. As a result, the coverage determination process is often a time consuming and costly process that may require us to provide scientific and clinical support for the use of our products to each payor separately, with no assurance that coverage and adequate reimbursement will be applied consistently or obtained in the first instance.
Previous report
Our inability to obtain sufficient product liability insurance at an acceptable cost to protect against potential product liability claims could prevent or inhibit the commercialization of products we develop, alone or with collaborators. Our insurance policies may have various exclusions, and we may be subject to a product liability claim for which we have no coverage. We may have to pay any amounts awarded by a court or negotiated in a settlement that exceed our coverage limitations or that are not covered by our insurance, and we may not have, or be able to obtain, sufficient capital to pay such amounts. Even if our agreements with any future corporate collaborators entitle us to indemnification against losses, such indemnification may not be available or adequate should any claim arise.
Previous report
Additionally, changes in the leadership at the FDA under the new presidential administration may lead to further changes in FDA’s policies and regulations. To the extent the transition to the new administration leads to disruptions in FDA’s operations, such as a result of executive orders that impose a freeze on hiring, federal funding, and external communications, and return-to-office policy, or changes in funding for certain programs at the FDA, correspondence and regulatory review processes with the FDA may be delayed.
Previous report
We have obtained Fast Track designation and Breakthrough Therapy designation from the FDA for latozinemab for the treatment of patients with FTD carrying specific genetic mutations in the granulin gene, but we may be unable to obtain or maintain the benefits associated with those designations.
Previous report
Fast Track designation is designed to facilitate the development and expedite the review of therapies which treat serious conditions and fill an unmet medical need. Programs with Fast Track designation may benefit from early and frequent communications with the FDA, potential priority review, and the ability to submit a rolling application for regulatory review. Fast Track designation applies to both the product and the specific indication for which it is being studied.
Previous report
In December 2019, the FDA granted Fast Track designation for latozinemab, and in January 2020, the FDA granted Fast Track designation for AL101, each for the treatment of patients with FTD carrying specific genetic mutations in the granulin gene. If our clinical development program does not continue to meet the criteria for Fast Track designation, or if our clinical trials are suspended or terminated, or put on clinical hold due to unexpected adverse events or issues with clinical supply, we may not realize all the benefits associated with the Fast Track program. For example, we inactivated the AL101 IND for FTD in the third quarter of 2023, and therefore Fast Track designation no longer applies. Furthermore, Fast Track designation does not change the standards for approval. Fast Track designation alone does not guarantee qualification for the FDA’s priority review procedures.
Previous report
In February 2024, the FDA granted Breakthrough Therapy Designation to latozinemab for the treatment of FTD-GRN. The benefits of Breakthrough Therapy designation include the same benefits as Fast Track designation, plus intensive guidance from the FDA to ensure an efficient drug development program.
Previous report
As of December 31, 2024, we had 238 full-time employees. As our development plans and strategies develop, and as we progress development of our product candidates and move towards commercialization, we will be required to add additional managerial, operational, financial, and other personnel. We will need to effectively manage the size and capabilities of our organization and any future growth through significant responsibilities on members of management, including:
Previous report
identifying, recruiting, integrating, retaining, and motivating employees;
Previous report
managing our internal development efforts effectively, including the clinical and FDA review process for our current and future product candidates, while complying with our contractual obligations to collaborators and other third parties;
Previous report
expanding our operational, financial and management controls, reporting systems, and procedures; and
Previous report
managing increasing operational and managerial complexity.
Reworded paragraphs (99)
Previous wording
We have concentrated a substantial portion of our research and development efforts on the treatment of neurodegenerative diseases, a field that has seen both limited success in drug development and evolving standards for regulatory approval.
Current wording
We have concentrated our research and development efforts on the treatment of neurodegenerative diseases, a field that has seen both limited success in drug development and evolving standards for regulatory approval. Further, our product candidates are based on innovative approaches and technologies, making it difficult to predict the time and cost of product candidate development and subsequent regulatory approval.
Previous wording
Our operations and financial results could be adversely impacted by the effects of worldwide economic conditions, including macroeconomic downturns stemming from increased inflation, supply chain and other economic impacts of pandemics or other public health outbreaks and geopolitical events and conflicts.
Current wording
Our operations, financial results, and the market price of our common stock could be adversely impacted by the effects of worldwide economic conditions, including macroeconomic downturns, global recessions, increased inflation, supply chain disruptions, trade tariffs or other disruptions in global trade, pandemics or other public health outbreaks, and geopolitical events and conflicts.
Previous wording
Our existing or future indebtedness and any associated debt covenants on our business and growth prospects.
Current wording
Our existing or future indebtedness and any associated debt covenants may impact our business and growth prospects.
Previous wording
We are a late-stage clinical biotechnology company with a limited operating history, focused primarily on developing therapeutics for neurodegenerative diseases, including FTD, Alzheimer’s disease, and Parkinson’s disease. We commenced operations in May 2013. To date, we have financed our operations primarily through equity and debt financings and upfront payments received in connection with the GSK Agreement and our collaboration agreement with AbbVie Biotechnology, Ltd. (AbbVie) to co-develop antibodies to two program targets in preclinical development (AbbVie Agreement) entered into in October 2017. We have no products approved for commercial sale and have not generated any revenue from product sales. Drug development is a highly uncertain undertaking and involves a substantial degree of risk. Our product candidate latozinemab is in a Phase 3 clinical trial and our product candidate AL101 is in a Phase 2 clinical trial. In November 2024, we decided to stop the long term extension study of our product candidate AL002 based on the results of the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD. AL002 failed to meet the primary endpoint in that trial. In January 2025, AbbVie decided to terminate the TREM2 collaboration program, under which AL002 was being developed, which resulted in termination of the AbbVie Agreement. AbbVie had previously decided in 2022 to terminate the CD33 collaboration program, after we and AbbVie concluded that further development of AL003, the asset being developed under that program, was not warranted. In the third quarter of 2023, we inactivated the IND application for AL101 in FTD, given that we and GSK plan to develop AL101 for the potential treatment of larger indications, including Alzheimer’s disease and Parkinson’s disease. We previously decided to close the Phase 1 clinical trial for our AL044 product candidate based on initial pharmacokinetics and tolerability data. We inactivated the IND for AL044 in the third quarter of 2023. To date, we have not completed a pivotal clinical trial, obtained marketing approval for any product candidates, manufactured a commercial scale product, or arranged for a third party to do so on our behalf, or conducted sales and marketing activities necessary for successful product commercialization. Our limited operating history as a company makes any assessment of our future success and viability subject to significant uncertainty.
Current wording
We are a biotechnology company with both preclinical and clinical stage programs, focused on developing therapeutics for neurodegenerative diseases, including Alzheimer’s disease and Parkinson’s disease. We commenced operations in May 2013. To date, we have financed our operations primarily through equity and debt financings and upfront payments received in connection with the GSK Agreement and previously, our October 2017 collaboration agreement with AbbVie Biotechnology, Ltd. (AbbVie Agreement). We currently have one product candidate, nivisnebart, in a Phase 2 clinical trial. We have no products approved for commercial sale and have not generated any revenue from product sales. Drug development is a highly uncertain undertaking and involves a substantial degree of risk.
Previous wording
We will encounter risks and difficulties frequently experienced by clinical-stage biotechnology companies in rapidly evolving fields, and we have not yet demonstrated an ability to successfully overcome such risks and difficulties. If we do not address these risks and difficulties successfully, our business will suffer.
Current wording
We will encounter risks and difficulties frequently experienced by biotechnology companies in rapidly evolving fields, and we have not yet demonstrated an ability to successfully overcome such risks and difficulties. If we do not address these risks and difficulties successfully, our business will suffer.
Previous wording
We have incurred net losses in each year since our inception. We incurred net losses of $119.0 million, $130.4 million, and $133.3 million for the years ended December 31, 2024, 2023, and 2022, respectively. As of December 31, 2024, we had an accumulated deficit of $829.1 million.
Current wording
We have incurred net losses in each year since our inception. We incurred net losses of $142.9 million, and $119.0 million, for the years ended December 31, 2025, and 2024, respectively. As of December 31, 2025, we had an accumulated deficit of $972.1 million.
Previous wording
We have invested significant financial resources in research and development activities, including for our preclinical and clinical product candidates. We do not expect to generate revenue from product sales for several years, if at all. The revenue we have generated from our collaboration arrangements with AbbVie and GSK has been, and from our collaboration arrangement with GSK is expected to continue to be, variable and limited in amount. For our collaborations with AbbVie and GSK, we have recognized, and for our collaboration with GSK we will continue to recognize, collaboration revenue by measuring the progress towards complete satisfaction of each performance obligation measured as the program costs are incurred. The amount of our future net losses will depend, in part, on the level of our future expenditures and revenue. Moreover, our net losses may fluctuate significantly from quarter to quarter and year to year, such that a period-to-period comparison of our results of operations may not be a good indication of our future performance.
Current wording
We have invested significant financial resources in research and development activities, including for our preclinical and clinical product candidates. We do not expect to generate revenue from product sales for several years, if at all. The revenue we have generated from our collaboration arrangements with GSK, and previously, AbbVie, has been, and from our collaboration arrangement with GSK, is expected to continue to be, variable and limited in amount.
Previous wording
Developing our product candidates is expensive, and we expect to continue to spend substantial amounts as we fund our early-stage research projects and continue to advance our programs through preclinical and clinical development. Even if we are successful in developing our product candidates and obtaining regulatory approvals, launching and commercializing any product candidate will require substantial additional funding.
Current wording
Developing our product candidates is expensive, and we expect to continue to spend substantial amounts as we fund our early-stage research projects and continue to advance our programs through preclinical and clinical development. Even if we are successful in developing our product candidates and obtaining regulatory approvals, launching and commercializing any product candidate will require substantial additional funding as we continue to advance other candidates in our pipeline.
Previous wording
work with our CDMOs to scale up the manufacturing processes for our product candidates or, in the future, establish and operate a manufacturing facility;
Current wording
work with our CDMOs to develop and scale up the manufacturing processes for our product candidates or, in the future, establish and operate a manufacturing facility;
Previous wording
make required payments under the Loan Agreement (defined below);
Current wording
make required payments under the Loan Agreement;
Previous wording
addressing impacts on our clinical trials resulting from factors related to the effects of worldwide economic conditions, including macroeconomic downturns stemming from increased inflation, supply chain disruption and other economic impacts of pandemics or other public health outbreaks and geopolitical events and conflicts;
Current wording
addressing impacts on our clinical trials resulting from factors related to the effects of U.S. and worldwide economic conditions, including macroeconomic downturns or global recessions stemming from the economic impacts of increased inflation, supply chain disruption, trade tariffs, pandemics or other public health outbreaks, and geopolitical events and conflicts;
Previous wording
attracting, hiring, and retaining qualified personnel in a competitive compensation environment.
Current wording
attracting, hiring, and retaining qualified personnel in the face of reductions in force, layoffs, hiring freezes, employee attrition, policy changes for foreign worker visas, or a competitive compensation environment.
Previous wording
To date, clinical development of three of our product candidates has been terminated. In November 2024, we decided to stop the long term extension study of our product candidate AL002 based on the results of the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD. AL002 failed to meet the primary endpoint in that trial. In January 2025, AbbVie decided to terminate the TREM2 collaboration program, under which AL002 was being developed. AbbVie had previously decided in 2022 to terminate our CD33 collaboration program, after we and AbbVie concluded that further development of AL003, the asset being developed under that program, was not warranted. Additionally, we decided to close the Phase 1 clinical trial for our AL044 product candidate based on initial pharmacokinetics and tolerability data. Because of the numerous risks and uncertainties associated with drug development, we are unable to predict the timing or amount of our expenses, or when we will be able to generate any meaningful revenue or achieve or maintain profitability, if ever. In addition, our expenses could increase beyond our current expectations if we are required by the FDA or foreign regulatory agencies to perform studies in addition to those that we currently anticipate, or if there are any delays in any of our or our current or future collaborators’ clinical trials or the development of any of our product candidates. Even if one or more of our product candidates is approved for commercial sale, we anticipate incurring significant costs associated with launching and commercializing any approved product candidate and ongoing compliance efforts.
Current wording
Because of the numerous risks and uncertainties associated with drug development, we are unable to predict the timing or amount of our expenses, or when we will be able to generate any meaningful revenue or achieve or maintain profitability, if ever. In addition, our expenses could increase beyond our current expectations if we are required by the FDA or foreign regulatory agencies to perform studies in addition to those that we currently anticipate, or if there are any delays in any of our or our current or future collaborators’ clinical trials or the development of any of our product candidates. Even if one or more of our product candidates is approved for commercial sale, we anticipate incurring significant costs associated with launching and commercializing any approved product candidate and ongoing compliance efforts.
Previous wording
Our operations have required substantial amounts of cash since inception, and we expect our expenses to increase significantly in the foreseeable future. To date, we have financed our operations primarily through the sale of equity securities and upfront payments received in connection with our collaboration arrangements with AbbVie and GSK. Developing our product candidates and conducting clinical trials for the treatment of neurodegenerative diseases, including FTD, Alzheimer’s disease, and Parkinson’s disease, will require substantial amounts of capital. Even if our clinical trials are successful, preparing for and applying for regulatory approval of our product candidates will require a significant amount of capital, and if we do not have sufficient capital, we may be unable to seek regulatory approval, or regulatory approval may be significantly delayed, in any or all desired markets. Likewise, even if our product candidates are approved, commercialization of our product candidates will require a significant amount of capital, and if we do not have sufficient capital, we may be unable to commercialize our approved products, or commercialization of such products may be significantly delayed, in any or all desired markets.
Current wording
Our operations have required substantial amounts of cash since inception. We expect our expenses relating to latozinemab and AL002 to decrease in the foreseeable future as a result of the discontinuation and wind-down of clinical trials for latozinemab and AL002. However, we continue to invest in research and development activities related to programs in our research and preclinical pipeline and to the advancement of those programs into clinical trials. To date, we have financed our operations primarily through the sale of equity securities and upfront payments received in connection with our collaboration arrangements with GSK, and previously, AbbVie. Developing our product candidates and conducting clinical trials for the treatment of neurodegenerative diseases, including Alzheimer’s disease, and Parkinson’s disease, will require substantial amounts of capital. Even if our clinical trials are successful, preparing for and applying for regulatory approval of our product candidates will require a significant amount of capital, and if we do not have sufficient capital, we may be unable to seek regulatory approval, or regulatory approval may be significantly delayed, in any or all desired markets. Likewise, even if our product candidates are approved, commercialization of our product candidates will require a significant amount of capital, and if we do not have sufficient capital, we may be unable to commercialize our approved products, or commercialization of such products may be significantly delayed, in any or all desired markets.
Previous wording
As of December 31, 2024, we had cash, cash equivalents, and marketable securities of $413.4 million, which we anticipate provides runway through 2026. Our estimate as to how long we expect our existing cash, cash equivalents, and marketable securities to be available to fund our operations is based on assumptions that may prove to be inaccurate, and we could use our available capital resources sooner than we currently expect. In addition, changing circumstances, including periods of rising inflation, may cause us to increase our spending significantly faster than we currently anticipate, and we may need to spend more money than currently expected because of circumstances beyond our control. We may need to raise additional funds sooner than we anticipate if we choose to grow more rapidly than we presently anticipate.
Current wording
As of December 31, 2025, we had cash, cash equivalents, and marketable securities of $256.0 million, which we anticipate provides runway at least through 2027. Our estimate as to how long we expect our existing cash, cash equivalents, and marketable securities to be available to fund our operations is based on assumptions that may prove to be inaccurate, and we could use our available capital resources sooner than we currently expect. In addition, changing circumstances, including periods of rising inflation, may cause us to increase our spending significantly faster than we currently anticipate, and we may need to spend more money than currently expected because of circumstances beyond our control. We may need to raise additional funds sooner than we anticipate if we choose to grow more than we presently anticipate.
Previous wording
Global markets recently have experienced volatility and instability in connection with macroeconomic downturns stemming from increased inflation, supply chain disruption and other economic impacts of pandemics or other public health outbreaks and geopolitical events, including the ongoing conflict between Russia and Ukraine, associated sanctions targeting Russia, and the ongoing conflict in the Middle East, among other matters. In addition, the public market for and stock prices of biotechnology companies have experienced significant downturns over the last few years. Our ability to raise money in the public markets may be severely impacted for the foreseeable future due to these factors. Additional capital may not be available when we need it, on terms acceptable to us, or at all. If adequate capital is not available to us on a timely basis, we may be required to significantly delay, scale back, or discontinue our research and development programs or the commercialization of any product candidates, if approved, or be unable to continue or expand our operations, or otherwise capitalize on our business opportunities, as desired, which could materially affect our business, financial condition, results of operations, and growth prospects and cause the price of our common stock to decline.
Current wording
Global markets recently have experienced volatility and instability in connection with macroeconomic downturns stemming from tariffs and global trade uncertainties, increased inflation, supply chain disruption and economic impacts of pandemics or other public health outbreaks and geopolitical events, including the ongoing conflict between Russia and Ukraine, associated sanctions targeting Russia, and the ongoing conflict in the Middle East, among other matters. In addition, the public market for and stock prices of biotechnology companies have experienced significant downturns over the last few years. Our ability to raise money in the public markets may be severely impacted for the foreseeable future due to these factors. Additional capital may not be available when we need it, on terms acceptable to us, or at all. If adequate capital is not available to us on a timely basis, we may be required to significantly delay, scale back, or discontinue our research and development programs or the commercialization of any product candidates, if approved, or be unable to continue or expand our operations, or otherwise capitalize on our business opportunities, as desired, which could materially affect our business, financial condition, results of operations, and growth prospects and cause the price of our common stock to decline.
Previous wording
Two of our product candidates, latozinemab and AL101, are in clinical development, and we continue to develop our research pipeline, including our ABC technology platform. Together, the development of these programs and product candidates and this platform requires significant capital investment. Due to the significant resources required, we must focus our programs and product candidates on specific diseases and disease pathways and decide which product candidates to pursue and advance and the amount of resources to allocate to each. One aspect of our drug development strategy is to clinically test and seek regulatory approval for our product candidates in indications in which we believe there is the most evidence that we will be able to quickly generate proof-of-concept data. For certain product candidates, we may choose to expand clinical testing and seek regulatory approvals in other neurodegenerative indications based on genetic and mechanistic overlap with the primary indication.
Current wording
Our product candidate, nivisnebart is in clinical development, and we continue to develop our research and preclinical pipeline, including our ABC technology platform and ABC-enabled product candidates. Together, the development of these programs and product candidates and this platform requires significant capital investment. Due to the significant resources required, we must focus our programs and product candidates on specific diseases and disease pathways and decide which product candidates to pursue and advance and the amount of resources to allocate to each. One aspect of our drug development strategy is to clinically test and seek regulatory approval for our product candidates in indications in which we believe there is the most evidence that we will be able to quickly generate proof-of-concept data. For certain product candidates, we may choose to expand clinical testing and seek regulatory approvals in other neurodegenerative indications based on genetic and mechanistic overlap with the primary indication.
Previous wording
However, even if our product candidates are able to gain regulatory approval in one indication, there is no guarantee that we will be able to obtain approval in other indications, and we may expend significant resources in seeking such approvals. Our decisions concerning the allocation of research, development, collaboration, management, and financial resources toward particular technology, product candidates or therapeutic areas may not lead to the development of any viable commercial product and may divert resources away from better opportunities. Similarly, our potential decisions to delay, terminate, or collaborate with third parties in respect of certain programs may subsequently also prove to be suboptimal and could cause us to miss valuable opportunities. If we make incorrect determinations regarding the viability or market potential of any of our programs or product candidates or misread trends in the biopharmaceutical industry, in particular for neurodegenerative diseases, such events could have a material adverse effect on our business, financial condition, and results of operations. As a result, we may fail to capitalize on viable commercial products or profitable market opportunities, be required to forego or delay opportunities with other product candidates or other diseases and disease pathways that may later prove to have greater commercial potential than those we choose to pursue, or relinquish valuable rights to such product candidates through collaboration, licensing, or other royalty arrangements in cases in which it would have been advantageous for us to invest additional resources to retain sole development and commercialization rights. Our reliance on genetic screening and use of biomarkers to align patient risk profiles with targeted intervention may eventually require us to develop and use companion diagnostics, which could impact product development costs and timelines depending on the specific diagnostic test and any applicable regulatory requirements that would need to be met to enable its use.
Current wording
However, even if our product candidates are able to gain regulatory approval in one indication, there is no guarantee that we will be able to obtain approval in other indications, and we may expend significant resources in seeking such approvals. Our decisions concerning the allocation of research, development, collaboration, management, and financial resources toward particular technologies, product candidates or therapeutic areas may not lead to the development of any viable commercial product and may divert resources away from better opportunities. Similarly, our potential decisions to delay, terminate, or collaborate with third parties in respect of certain programs may subsequently also prove to be suboptimal and could cause us to miss valuable opportunities. If we make incorrect determinations regarding the viability or market potential of any of our programs or product candidates or misread trends in the biopharmaceutical industry, in particular for neurodegenerative diseases, such events could have a material adverse effect on our business, financial condition, and results of operations. As a result, we may fail to capitalize on viable commercial products or profitable market opportunities, be required to forego or delay opportunities with other product candidates or other diseases and disease pathways that may later prove to have greater commercial potential than those we choose to pursue, or relinquish valuable rights to such product candidates through collaboration, licensing, or other royalty arrangements in cases in which it would have been advantageous for us to invest additional resources to retain sole development and commercialization rights. Our reliance on genetics and use of biomarkers to align patient risk profiles with targeted intervention may eventually require us to develop and use companion diagnostics, which could impact product development costs and timelines depending on the specific diagnostic test and any applicable regulatory requirements that would need to be met to enable its use.
Previous wording
On November 14, 2024, we entered into a loan and security agreement (the Loan Agreement) with our subsidiary, Alector LLC, as a co-borrower, several banks and other financial institutions from time to time party thereto (collectively, the Lenders), and Hercules Capital, Inc. (Hercules), in its capacity as administrative agent and collateral agent for itself and the Lenders, pursuant to which we may access up to two tranches of term loans in an aggregate principal amount of up to $50,000,000 (the Term Loans). The Loan Agreement provides for an initial $25.0 million tranche of Term Loans available through June 30, 2026, $10.0 million of which we borrowed at closing. Our ability to borrow an additional tranche of $25.0 million is subject to agreement on the terms and conditions thereof and the sole discretion of the Lenders. As security for our obligations under the Loan Agreement, we granted the collateral agent a first priority security interest on substantially all of our assets, subject to certain exceptions. We intend to satisfy our future debt service obligations with our existing cash and cash equivalents. However, we may not have sufficient funds or may be unable to arrange for additional financing to pay the amounts due under our outstanding debt. Funds from external sources may not be available on acceptable terms, if at all.
Current wording
On November 14, 2024, we entered into a loan and security agreement (the Loan Agreement) with our subsidiary, Alector LLC, as a co-borrower, the lenders from time to time party thereto (the Lenders), and Hercules Capital, Inc. (Hercules), in its capacity as administrative agent and collateral agent for itself and the Lenders, pursuant to which we may access up to two tranches of term loans in an aggregate principal amount of up to $50,000,000 (the Term Loans). The Loan Agreement provides for an initial $25.0 million tranche of Term Loans available through June 30, 2026, $10.0 million of which we borrowed at closing. Our ability to borrow an additional tranche of $25.0 million is subject to the terms and conditions of the Loan Agreement and at the sole discretion of the Lenders. As security for our obligations under the Loan Agreement, we granted the collateral agent a first priority security interest on substantially all of our assets, subject to certain exceptions. We intend to satisfy our future debt service obligations with our existing cash and cash equivalents. However, we may not have sufficient funds or may be unable to arrange for additional financing to pay the amounts due under our outstanding debt. Funds from external sources may not be available on acceptable terms, if at all.
Previous wording
We are in the clinical stages of development for certain product candidates currently in our pipeline. To date, we have invested substantially in our efforts and financial resources to identify, procure intellectual property for, and develop our programs, product candidates, and ABC technology platform, and provide general and administrative support for these operations. Our future success is dependent on our ability to successfully develop, obtain regulatory approval for, and then successfully commercialize our product candidates, and we may fail to do so for many reasons, including the following:
Current wording
We are in Phase 2 for nivisnebart. To date, we have invested substantially in our efforts and financial resources to identify, procure intellectual property for, and develop our programs, product candidates, and ABC technology platform, and provide general and administrative support for these operations. Our future success is dependent on our ability to successfully develop, obtain regulatory approval for, and then successfully commercialize our product candidates, and we may fail to do so for many reasons, including the following:
Previous wording
a product candidate may on further study be shown to have harmful side effects or other characteristics that indicate it is unlikely to have an acceptable safety profile or be sufficiently effective or otherwise does not meet applicable regulatory criteria;
Current wording
a product candidate may upon further study be shown to have harmful side effects or other characteristics that indicate it is unlikely to have an acceptable safety profile or be sufficiently effective or otherwise does not meet applicable regulatory criteria;
Previous wording
We may not be successful in our efforts to further develop our current product candidates. For example, our clinical trials of our product candidates may not demonstrate their safety or efficacy, e.g., the trials may not meet their primary endpoints or otherwise demonstrate evidence of clinical benefit. We are not permitted to market or promote any of our product candidates before we receive regulatory approval from the FDA or comparable foreign regulatory authorities, and we may never receive such regulatory approval for any of our product candidates. We have product candidates in development, and all will require significant additional clinical development, management of preclinical, clinical, and manufacturing activities, regulatory approval, adequate manufacturing supply, a commercial organization, and significant marketing efforts before we generate any revenue from product sales, if at all.
Current wording
We may not be successful in our efforts to further develop our current product candidates. For example, clinical trials of our product candidates may not demonstrate their safety or efficacy, e.g., the trials may not meet their primary endpoints or otherwise demonstrate evidence of clinical benefit, or interim analyses of our clinical trials may result in a decision to terminate such trials due to failure of our product candidates to meet certain criteria. We are not permitted to market or promote any of our product candidates before we receive regulatory approval from the FDA or comparable foreign regulatory authorities, and we may never receive such regulatory approval for any of our product candidates. We have product candidates in development, and all will require significant additional clinical development, management of preclinical, clinical, and manufacturing activities, regulatory approval, adequate manufacturing supply, a commercial organization, and significant marketing efforts before we generate any revenue from product sales, if at all.
Previous wording
We have never completed a clinical development program. Our product candidate latozinemab is in a Phase 3 clinical trial and our product candidate AL101 is in a Phase 2 clinical trial. We cannot be certain that any of our product candidates will be successful in these or any other future clinical trials. For example, our current or future clinical trials of our product candidates may not demonstrate their safety or efficacy, either in the indications currently being tested or in any other indications, or either as single agent therapies or in combination with other therapeutics, such as anti-amyloid beta antibodies or other therapies that may be available for indications relevant to our development programs. For any product candidates that have advanced into clinical trials, we may terminate such trials or the clinical program prior to their completion. For example, in November 2024, we announced that we decided to stop the long term extension study of our product candidate AL002 after results from the INVOKE-2 Phase 2 clinical trial showed that AL002 failed to meet the primary endpoint.
Current wording
For any product candidates that have advanced into clinical trials, we may terminate such trials or the clinical program prior to their completion. For example, we decided to close the Phase 1 clinical trial for our AL044 product candidate based on initial pharmacokinetics and tolerability data.
Previous wording
If any of our product candidates successfully complete clinical trials, we generally plan to seek regulatory approval to market our product candidates in the United States, the European Union, and in additional foreign countries where we believe there is a viable commercial opportunity. We have never commenced, compiled, or submitted an application seeking regulatory approval to market any product candidate. We may never receive regulatory approval to market any product candidates even if such product candidates successfully complete clinical trials, which would adversely affect our viability. To obtain regulatory approval in countries outside the United States, we must comply with numerous and varying regulatory requirements of such countries regarding safety, efficacy, manufacturing and controls, clinical trials, commercial sales, pricing, and distribution of our product candidates. We may also rely on our collaborators or partners to conduct the required activities to support an application for regulatory approval, and to seek approval, for one or more of our product candidates. We cannot be sure that our collaborators or partners will conduct these activities or do so within the timeframe we desire. Even if we (or our collaborators or partners) are successful in obtaining approval in one jurisdiction, we cannot ensure that we will obtain approval in any other jurisdiction. If we are unable to obtain approval for our product candidates in multiple jurisdictions, our business, financial condition, results of operations, and our growth prospects could be negatively affected.
Current wording
If any of our product candidates successfully complete clinical trials, we generally plan to seek regulatory approval to market our product candidates in the United States, the European Union, and in additional foreign countries where we believe there is a viable commercial opportunity. We have never commenced, compiled, or submitted an application seeking regulatory approval to market any product candidate and we may encounter difficulties or delays in doing so, even if such product candidate successfully completed clinical trials. We may never receive regulatory approval, or we may not receive approval in the desired timeframe, to market any product candidates even if such product candidates successfully complete clinical trials, which would adversely affect our viability. To obtain regulatory approval in countries outside the United States, we must comply with numerous and varying regulatory requirements of such countries regarding safety, efficacy, manufacturing and controls, clinical trials, commercial sales, pricing, and distribution of our product candidates. We may also rely on our collaborators or partners to conduct the required activities to support an application for regulatory approval, and to seek approval, for one or more of our product candidates. We cannot be sure that our collaborators or partners will conduct these activities or do so within the timeframe we desire. Even if we (or our collaborators or partners) are successful in obtaining approval in one jurisdiction, we cannot ensure that we will obtain approval in any other jurisdiction. If we are unable to obtain approval for our product candidates in multiple jurisdictions, our business, financial condition, results of operations, and our growth prospects could be negatively affected.
Previous wording
For example, we are developing our proprietary BBB technology platform (Alector Brain Carrier, or ABC) to support selected next-generation product candidates. The goal of our technology is to deliver therapeutic candidates at a lower dose and provide deeper blood-brain barrier penetration while optimizing efficacy, safety and cost. If we are unable to successfully develop and apply our ABC technology as intended, our future pipeline opportunities may be reduced.
Current wording
For example, we are developing our proprietary BBB technology platform (Alector Brain Carrier, or ABC) to support selected product candidates. The goal of our technology is to deliver therapeutic candidates at a lower dose and provide deeper blood-brain barrier penetration while optimizing efficacy, safety and cost. If we are unable to successfully develop and apply our ABC technology as intended, our future pipeline opportunities may be reduced.
Previous wording
We also seek to develop product candidates against targets in our preclinical and research pipeline, with certain candidates incorporating our ABC technology, for a range of neurodegenerative diseases. If we are unable to advance such preclinical and research candidates, our future pipeline opportunities may be reduced.
Current wording
We also seek to develop product candidates incorporating our ABC technology in our preclinical and research pipeline for a range of neurodegenerative diseases. For example, we are currently pursuing AL137 (and a back-up candidate), our brain-penetrant anti-amyloid beta antibody in AD; AL050, our brain-penetrant GCase enzyme replacement therapy, in Parkinson’s disease; and AL064, our brain-penetrant tau siRNA, in AD, all of which are enabled by ABC using a TfR-based transport mechanism. Those product candidates have complex structures and multiple functional elements, relative to the standard antibody candidates that have previously been our main focus. Therefore, those product candidates may pose additional challenges, including with respect to their manufacture and their ability to function as intended. If we are unable to advance those programs or other preclinical or research candidates, our future pipeline opportunities may be reduced.
Previous wording
We are focusing our research and development efforts on addressing neurodegenerative diseases. Collectively, efforts by biopharmaceutical companies in the field of neurodegenerative diseases have seen limited success in drug development. There are currently limited approved therapeutic options available for patients with FTD, Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative diseases. Recently approved therapies for the treatment of Alzheimer’s disease target a specific pathology (amyloid plaques). Our future success is highly dependent on the successful development of our product candidates for treating neurodegenerative diseases. Developing product candidates and, if approved, commercializing our products for treatment of neurodegenerative diseases subject us to a number of challenges, including obtaining disease modifying activity and efficacious dose in target tissue and obtaining regulatory approval from the FDA and other regulatory authorities who have only a limited set of precedents to rely on.
Current wording
We are focusing our research and development efforts on addressing neurodegenerative diseases. Collectively, efforts by biopharmaceutical companies in the field of neurodegenerative diseases have seen limited success in drug development. There are currently limited approved therapeutic options available for patients with Alzheimer’s disease, Parkinson’s disease, and other neurodegenerative diseases. Recently approved therapies for the treatment of Alzheimer’s disease target a specific pathology (amyloid plaques). Our future success is highly dependent on the successful development of our product candidates for treating neurodegenerative diseases. Developing product candidates and, if approved, commercializing our products for treatment of neurodegenerative diseases subject us to a number of challenges, including obtaining disease modifying activity and efficacious dosing and obtaining regulatory approval from the FDA and other regulatory authorities who have only a limited set of precedents to rely on.
Previous wording
Our approach to developing treatments for neurodegenerative diseases is based on understanding the complex mechanisms underlying neurodegeneration, including the roles of misfolded proteins, deficient proteins, and lysosomal, immune system, and neuronal dysfunction. Our approach further leverages our understanding of the genetic associations with disease. Through this approach, our product candidates seek to remove toxic proteins, replace critical deficient proteins, and restore immune and nerve cells to normal function. One aspect of this approach is to identify and select targets enriched in microglia and other myeloid immune cells which are genetically associated with neurodegenerative diseases. We identify and develop product candidates, including candidates that utilize our ABC technology, that are designed to cross the blood-brain barrier in sufficient quantity and potency to enable efficacious delivery to the brain and engage the intended target. We seek to identify and develop biomarkers and biomarker assays that can accurately identify signs of a disease or condition, assist us in selecting the right patient population, demonstrate target and pathway engagement, and measure the impact on disease progression of our product candidates. This strategy may not prove to be successful. We cannot be sure that our approach will yield satisfactory therapeutic products that are safe and effective, scalable, or profitable.
Current wording
Our approach to developing treatments for neurodegenerative diseases is based on understanding the complex mechanisms underlying neurodegeneration, including the roles of misfolded proteins, deficient proteins, and dysfunctional immune cells and neurons. Our approach further leverages our understanding of the genetic associations with disease. Through this approach, our product candidates seek to remove toxic proteins, replace critical deficient proteins, and restore immune and nerve cells to normal function. One aspect of this approach is to identify and select targets enriched in microglia and other myeloid immune cells which are genetically associated with neurodegenerative diseases. We identify and develop product candidates, including candidates that utilize our ABC technology, that are designed to cross the blood-brain barrier in sufficient quantity and potency to enable efficacious delivery to the brain and engage the intended target. We seek to identify and develop biomarkers and biomarker assays that can accurately identify signs of a disease or condition, assist us in selecting the right patient population, demonstrate target and pathway engagement, and measure the impact on disease progression of our product candidates. This strategy may not prove to be successful. We cannot be sure that our approach will yield satisfactory therapeutic products that are safe and effective, scalable, or profitable.
Previous wording
imposition of delays to clinical trials, including as a result of temporary or permanent clinical hold by regulatory agencies for any number of reasons (see for example our discussions of ARIA in other risks described in this “Risk Factors” section), including:
Current wording
imposition of delays to clinical trials, including as a result of temporary or permanent clinical hold by regulatory agencies for any number of reasons (see for example our discussions of ARIA and other risks described in this “Risk Factors” section), including:
Previous wording
Any inability to successfully initiate or complete clinical trials could result in additional costs to us or impair our ability to generate revenue. In addition, if we make manufacturing or formulation changes to our product candidates, we may be required to or we may elect to conduct additional studies to bridge our modified product candidates to earlier versions. Clinical trial delays could also shorten any periods during which our products have patent protection and may allow our competitors to bring products to market before we do or sooner than anticipated, which could impair our ability to successfully commercialize our product candidates and may harm our business and results of operations. For example, we had been developing AL002 with AbbVie to treat patients with early Alzheimer’s disease (AD). In November 2024, we announced that AL002 failed to meet the primary endpoint in the INVOKE-2 Phase 2 clinical trial evaluating the safety and efficacy of AL002 in slowing disease progression in individuals with early AD. In January 2025, AbbVie decided to terminate the TREM2 collaboration program, under which AL002 was being developed, which resulted in termination of the AbbVie Agreement. Previously, we had been developing AL003 with AbbVie to treat patients with Alzheimer’s disease but on June 30, 2022, AbbVie provided written notice to us formalizing the decision to terminate the CD33 collaboration program under which AL003 was being developed. GSK, or any other collaboration partner may, in the future decide to terminate collaboration programs based on, among other things, our clinical trial data.
Current wording
Any inability to successfully initiate or complete clinical trials could result in additional costs to us or impair our ability to generate revenue. In addition, if we make manufacturing or formulation changes to our product candidates, we may be required to or we may elect to conduct additional studies to bridge our modified product candidates to earlier versions. Clinical trial delays could also shorten any periods during which our products have patent protection and may allow our competitors to bring products to market before we do or sooner than anticipated, which could impair our ability to successfully commercialize our product candidates and may harm our business and results of operations.
Previous wording
We could also encounter delays if a clinical trial is suspended or terminated by us, by the data safety monitoring board for such trial or by the FDA, EMA, or any other regulatory authority, or if the IRBs of the institutions in which such trials are being conducted suspend or terminate the participation of their clinical investigators and sites subject to their review. Such authorities may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA, EMA, or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a product candidate, changes in governmental regulations or administrative actions, lack of adequate funding to continue the clinical trial, and impacts of worldwide economic conditions, and other public health outbreaks and geopolitical events. Should the FDA or other government agency issue additional guidance that mandates material changes to our clinical trials in response to a pandemic or other public health outbreak, the costs of such clinical trials may increase.
Current wording
We could also encounter delays if a clinical trial is suspended or terminated by us, by the data safety monitoring board for such trial or by the FDA, EMA, or any other regulatory authority, or if the IRBs of the institutions in which such trials are being conducted suspend or terminate the participation of their clinical investigators and sites subject to their review. Such authorities may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA, EMA, or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a product candidate, changes in governmental regulations or administrative actions, decreases in regulatory agency funding, staffing, or operations, lack of adequate funding to continue the clinical trial, and impacts of worldwide economic conditions, including trade tariffs, public health outbreaks and geopolitical events. Should the FDA or other government agency issue additional guidance that mandates material changes to our clinical trials, e.g., in response to a pandemic or other public health outbreak, the costs of such clinical trials may increase.
Previous wording
We may in the future advance product candidates into clinical trials and terminate such trials prior to their completion, which could adversely affect our business.
Current wording
We may in the future advance product candidates into clinical trials and terminate such trials prior to their completion, which could adversely affect our business. Further, FDA’s policy to release in “real time” newly issued Complete Response Letters associated with withdrawn or abandoned applications for approval of drug or biological products, if applicable to any of our product candidates, could materially impact our competitive advantage and intellectual property.
Previous wording
The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the trial until its conclusion. We pursued measures to enroll our Phase 3 INFRONT-3 and Phase 2 INVOKE-2 trials, for example, by opening additional clinical trial sites and expanding recruitment efforts to enroll the INFRONT-3 trial. We completed enrollment in those trials in the second half of 2023. However, we may experience difficulties in patient enrollment in other clinical trials for a variety of reasons, including:
Current wording
The timely completion of clinical trials in accordance with their protocols depends, among other things, on our ability to enroll a sufficient number of patients who remain in the trial until its conclusion. We may experience difficulties in patient enrollment in other clinical trials for a variety of reasons, including:
Previous wording
Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy profile despite having progressed through preclinical studies and initial clinical trials. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or unacceptable safety issues, notwithstanding promising results in earlier trials. This is particularly true in neurodegenerative diseases, where failure rates historically have been higher than in many other disease areas. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization. For example, in November 2024, we decided to stop the long term extension study of our product candidate AL002 after results from the INVOKE-2 Phase 2 clinical trial showed that AL002 failed to meet the primary endpoint.
Current wording
Product candidates in later stages of clinical trials may fail to show the desired safety and efficacy profile despite having progressed through preclinical studies and initial clinical trials. A number of companies in the biopharmaceutical industry have suffered significant setbacks in advanced clinical trials due to lack of efficacy or unacceptable safety issues, notwithstanding promising results in earlier trials. This is particularly true in neurodegenerative diseases, where failure rates historically have been higher than in many other disease areas. Most product candidates that begin clinical trials are never approved by regulatory authorities for commercialization. For example, in October 2025, because latozinemab did not meet the clinical co-primary endpoint in the INFRONT-3 Phase 3 clinical trial, we decided to stop the open label portion of that trial and the continuation study for latozinemab. In November 2024, we decided to stop the long term extension study of our product candidate AL002 after results from the INVOKE-2 Phase 2 clinical trial showed that AL002 failed to meet the primary endpoint.
Previous wording
Moreover, in our INVOKE-2 Phase 2 clinical trial in Alzheimer’s disease, treatment-emergent MRI findings resembling ARIA were observed. ARIA are MRI findings that may include vasogenic edema, sulcal effusions, microhemorrhages and/or superficial siderosis. To mitigate the associated risks, we stopped enrolling patients that were most at risk and implemented additional monitoring procedures, and the trial continued to completion. However, if those measures are not successful in managing ARIA like events, if any arise in our future clinical trials, then the FDA, EMA or other regulatory authority may suspend such trials, delay or deny approval, or require a more restrictive label or box warning on an approved product.
Current wording
In addition, in our INVOKE-2 Phase 2 clinical trial in Alzheimer’s disease, treatment-emergent MRI findings resembling ARIA were observed. ARIA are MRI findings that may include vasogenic edema, sulcal effusions, microhemorrhages and/or superficial siderosis. To mitigate the associated risks, we stopped enrolling patients that were most at risk and implemented additional monitoring procedures, and the trial continued to completion.
Previous wording
We have limited experience in designing clinical trials and may be unable to design and execute a clinical trial that generates data sufficient to support continued clinical development or marketing approval of any of our product candidates. We cannot be certain that our current clinical trials or any other future clinical trials will be successful. Additionally, any safety concerns observed in any one of our clinical trials in our targeted indications could limit the prospects for regulatory approval of our product candidates in those and other indications, which could have a material adverse effect on our business, financial condition, and results of operations.
Current wording
We have limited experience in designing clinical trials and may be unable to design and execute a clinical trial that generates data sufficient to support continued clinical development or marketing approval of any of our product candidates. We cannot be certain that any of our clinical trials will be successful. Additionally, any safety concerns observed in any one of our clinical trials in our targeted indications could limit the prospects for regulatory approval of our product candidates in those and other indications, which could have a material adverse effect on our business, financial condition, and results of operations.
Previous wording
In addition, even if such clinical trials are successfully completed, we cannot guarantee that the FDA or foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit our product candidates for approval. To the extent that the results of the trials are not satisfactory to the FDA or foreign regulatory authorities for support of a marketing application, we may be required to expend significant resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates. Even if regulatory approval is secured for any of our product candidates, the terms of such approval may limit the scope and use of our product candidates, which may also limit its commercial potential. Further, even if regulatory approval is secured for any of our product candidates, we cannot be assured that a federal court will not modify, invalidate, or revoke such approval.
Current wording
In addition, even if any of our clinical trials are successfully completed, we cannot guarantee that the FDA or foreign regulatory authorities will interpret the results as we do, and more trials could be required before we submit our product candidates for approval. To the extent that the results of the trials are not satisfactory to the FDA or foreign regulatory authorities for support of a marketing application, we may be required to expend significant resources, which may not be available to us, to conduct additional trials in support of potential approval of our product candidates. Even if regulatory approval is secured for any of our product candidates, the terms of such approval may limit the scope and use of our product candidates, which may also limit its commercial potential. Further, even if regulatory approval is secured for any of our product candidates, we cannot be assured that a federal court will not modify, invalidate, or revoke such approval.
Previous wording
There are a number of large pharmaceutical and biotechnology companies that are currently pursuing the development of products for the treatment of neurodegenerative diseases, including FTD, Alzheimer’s disease, and Parkinson's disease. Many of these current or potential competitors, either alone or with their strategic partners, have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals, and marketing approved products than we do. For example, in July 2024, the FDA approved donanemab, which was developed by Eli Lilly and Company, for the treatment of Alzheimer’s disease. Donanemab targets amyloid plaques by binding to insoluble N-truncated pyroglutamate amyloid beta. In January 2023, the FDA granted accelerated approval, and in July 2023, the FDA granted full approval to lecanemab, an anti-amyloid beta protofibril antibody for the treatment of Alzheimer’s disease developed by Eisai Co., Ltd. (Eisai) and Biogen Inc. (Biogen). Lecanemab has been approved as a treatment for slowing progression of mild cognitive impairment and mild dementia due to Alzheimer’s disease in Japan, and in November 2024, a committee of the EMA recommended approval of lecanemab in Europe. Eisai also initiated submission for a Biologics License Application for a subcutaneous formulation of lecanemab in May 2024. In addition, companies such as Prevail Therapeutics, Inc. and Passage Bio, Inc. are developing gene therapy based products (PR006 and PBFT02, respectively) for the treatment of FTD-GRN. Vigil Therapeutics is developing small molecule (VG-3927) and antibody (iluzanebart) candidates targeting TREM2. There are also pharmaceutical and biotechnology companies, such as Denali Therapeutics, Inc., F. Hoffman La Roche Ltd., and Aliada Therapeutics, Inc. (acquired by AbbVie), that are developing technologies for the transport of products, including anti-A-beta and other antibodies and product candidates, across the blood-brain barrier. Those and other competitors are pursuing product candidates that act on some of the same targets or through comparable mechanisms of action.
Current wording
There are a number of large pharmaceutical and biotechnology companies that are currently pursuing the development of products for the treatment of neurodegenerative diseases, including Alzheimer’s disease and Parkinsons disease. Many of these current or potential competitors, either alone or with their strategic partners, have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals, and marketing approved products than we do. For example, in July 2024, the FDA approved donanemab, which was developed by Eli Lilly and Company, for the treatment of Alzheimer’s disease. Donanemab targets amyloid plaques by binding to insoluble N-truncated pyroglutamate amyloid beta. In January 2023, the FDA granted accelerated approval, and in July 2023, the FDA granted full approval to lecanemab, an anti-amyloid beta protofibril antibody for the treatment of Alzheimer’s disease developed by Eisai Co., Ltd. (Eisai) and Biogen Inc. (Biogen). Lecanemab has been approved as a treatment for slowing progression of mild cognitive impairment and mild dementia due to Alzheimer’s disease in Japan, and in April 2025, lecanemab received final marketing authorization in Europe for treating mild cognitive impairment or mild dementia due to Alzheimer’s disease in patients who have only one or no copy of the ApoE4 allele.
Previous wording
The processes involved in manufacturing our product candidates are complex, expensive, highly regulated, and subject to multiple risks. Further, as product candidates are developed through preclinical studies to late-stage clinical trials towards approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods, are altered along the way in an effort to optimize processes and results. Such changes carry the risk that they will not achieve these intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials.
Current wording
The processes involved in manufacturing our product candidates are complex, expensive, highly-regulated, and subject to multiple risks. Manufacturing certain product candidates, such as non-antibody protein product candidates or product candidates incorporating ABC and other active components, may be especially challenging and may require complex and integrated supply chains and CDMO networks. Further, as product candidates are developed through preclinical studies to late-stage clinical trials towards approval and commercialization, it is common that various aspects of the development program, such as manufacturing methods, are altered along the way in an effort to scale processes and optimize results. Such changes carry the risk that they will not achieve these intended objectives, and any of these changes could cause our product candidates to perform differently and affect the results of planned clinical trials or other future clinical trials.
Previous wording
In order to conduct clinical trials of our product candidates, or supply commercial products, if approved, we will need to manufacture them in large quantities. Our CDMOs may be unable to successfully produce or increase the manufacturing scale or capacity for any of our product candidates in a timely or cost-effective manner, or at all. In addition, quality issues may arise during scale-up activities. If any of the foregoing occurs, the development, testing, and clinical trials of that product candidate may be delayed or become infeasible, and regulatory approval or commercial launch of any resulting product may be delayed or not obtained in any or all jurisdictions in which such approval or launch is intended, which could significantly harm our business. The same risk would apply to our own manufacturing facilities, should we in the future decide to build our own manufacturing capacity. In addition, building such manufacturing capacity would carry significant risks in terms of being able to plan, design, and execute on a complex project to build manufacturing facilities in a timely and cost-efficient manner.
Current wording
In order to conduct clinical trials of our product candidates, or supply commercial products, if approved, we will need to manufacture them in large quantities. Our CDMOs may be unable to successfully produce or increase the manufacturing scale or capacity for any of our product candidates in a timely or cost-effective manner, or at all. In addition, quality issues may arise during scale-up activities or in connection with production of commercial supply. If any of the foregoing occurs, the development, testing, and clinical trials of that product candidate may be delayed or become infeasible, and/or regulatory approval or commercial launch of any resulting product may be delayed or not obtained in any or all jurisdictions in which such approval or launch is intended, which could significantly harm our business. The same risks would apply to our own manufacturing facilities, should we in the future decide to build our own manufacturing capacity, which would carry significant risks in terms of being able to plan, design, and execute on a complex project to build manufacturing facilities in a timely and cost-efficient manner. Likewise, the same risks would apply to a collaboration partner manufacturing our product candidates or commercial products, if approved, using their CDMOs or their own facilities, and that partner may be unable to maintain a commercially viable cost structure.
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Rearranged current paragraphs (2)
Current report — wording carried from elsewhere
To date, we have not obtained a positive readout from a pivotal clinical trial, obtained marketing approval for any product candidates, manufactured a commercial scale product or arranged for a third party to do so on our behalf, or conducted sales and marketing activities necessary for successful product commercialization. Our limited operating history as a company makes any assessment of our future success and viability subject to significant uncertainty.
Current report — wording carried from elsewhere
Such MFN pricing agreements and other government measures that use most-favored-nation pricing targets for prescription drugs, including the use of international pricing references to set drug prices in the United States, or increased and earlier generic and biosimilar drug entry, can have a material adverse effect on our industry, including the ability to set adequate pricing for new drugs to recover research and development costs, and the ability to attract potential investors and potential buyers in the future. We cannot predict the full impact of these and other measures that may be implemented by the current administration related to drug pricing. The impact of ongoing judicial challenges against provisions of the Inflation Reduction Act as well as future legislative, executive, and administrative actions under the current presidential administration, including changes in leadership at HHS, CMS, and FDA, and new agency rules implemented by the government on us and the pharmaceutical industry as a whole is unclear. The implementation of cost containment measures or other healthcare reforms may prevent us from being able to generate revenue, attain profitability, or commercialize our product candidates if approved.
Rearranged previous paragraphs (4)
Previous report — wording carried elsewhere
We may not accurately predict the time and cost of development and subsequent regulatory approval for our product candidates, which are based on innovative approaches and technologies to address the complex mechanisms underlying neurodegeneration.
Previous report — wording carried elsewhere
The market price of our common stock has been, and may continue to be, volatile, which could result in substantial losses for investors and could negatively impact our ability to conduct additional fundraising in the public markets.
Previous report — wording carried elsewhere
section also apply to the activities of our collaborators and any negative impact on our collaborators may adversely affect us.
Previous report — wording carried elsewhere
Periodic maintenance fees, renewal fees, annuity fees, and various other government fees on patents and applications will be due to the USPTO and various government patent agencies outside of the United States over the lifetime of our owned or licensed patents and applications. In certain circumstances, we rely on our collaborators or licensing partners to pay these fees due to U.S. and non-U.S. patent agencies. The USPTO and various non-U.S.