Rapport Therapeutics, Inc.

Previous wording

We are a clinical-stage biotechnology company dedicated to discovering and developing small molecule precision medicines for patients with neurological or psychiatric disorders. Our foundational science has elucidated complexities of neuronal receptor biology and enables us to map and target certain neuronal receptor complexes. Neuronal receptors are complex assemblies of proteins, comprising receptor principal subunits and their receptor associated proteins (“RAPs”), the latter of which play crucial roles in regulating receptor expression and function. We believe that our deep expertise in RAP biology provides an opportunity for us to interrogate previously inaccessible targets and develop neurological and psychiatric drugs that are specific for receptor variants and neuroanatomical regions associated with certain diseases. Most neuroactive drugs lack this specificity, often resulting in undesired and intolerable side effects. Leveraging our expertise, we are developing a portfolio of precision product candidates that we believe has the potential to transform the standard of care of many neurological and psychiatric disorders.

Current wording

We are a clinical-stage biotechnology company dedicated to the discovery and development of small molecule precision medicines for patients with neurological or psychiatric disorders. Our foundational science has elucidated complexities of neuronal receptor biology and enables us to map and target certain neuronal receptor complexes. Neuronal receptors are complex assemblies of proteins, comprising receptor principal subunits and their receptor associated proteins (“RAPs”), the latter of which play crucial roles in regulating receptor expression and function. We believe that our deep expertise in RAP biology provides an opportunity for us to interrogate previously inaccessible targets and develop neurological and psychiatric drugs that are specific for receptor variants and neuroanatomical regions associated with certain diseases. Most neuroactive drugs lack this specificity, often resulting in undesired and intolerable side effects. Leveraging our expertise, we are developing a portfolio of precision product candidates that we believe has the potential to transform the standard of care of many neurological and psychiatric disorders.

Previous wording

Our founders have made pioneering discoveries related to the function of RAPs in the brain. Their findings form the basis of our RAP technology platform, which enables a differentiated approach to generate precision small molecule product candidates with the potential to overcome many limitations of conventional neurology drug discovery. RAP-219, our most advanced product candidate, is an AMPA receptor (“AMPAR”) negative allosteric modulator (“NAM”). RAP-219 is designed to achieve neuroanatomical specificity through its selective targeting of a RAP known as TARP8, which is associated with the neuronal AMPARs. Whereas AMPARs are distributed widely in the central nervous system (“CNS”), TARP8 is expressed only in discrete regions, including the hippocampus and neocortex, where focal seizures often originate. By contrast, TARP8 has minimal expression in the hindbrain, where drug effects are often associated with adverse events. As such, we believe RAP-219 has the potential for a differentiated profile as compared to traditional neuroscience medications. Due to the role of AMPA biology in various neurological disorders and our precision approach of selectively targeting TARP8, we believe RAP-219 has pipeline-in-a-product potential and we are evaluating it as a potentially transformational treatment for patients with focal epilepsy, bipolar disorder, and peripheral neuropathic pain.

Current wording

Our founders have made pioneering discoveries related to the function of RAPs in the brain. Their findings form the basis of our RAP technology platform, which enables a differentiated approach to generate precision small molecule product candidates with the potential to overcome many limitations of conventional neurology drug discovery. RAP-219, our most advanced product candidate, is an AMPA receptor (“AMPAR”) negative allosteric modulator (“NAM”). RAP-219 is designed to achieve neuroanatomical specificity through its selective targeting of a RAP known as TARP8, which is associated with the neuronal AMPARs. Whereas AMPARs are distributed widely in the central nervous system (“CNS”), TARP8 is expressed only in discrete regions, including the neocortex and mesial temporal lobe, where focal onset seizures (“FOS”) often originate. By contrast, TARP8 has minimal expression in the hindbrain, where drug effects are often associated with adverse events. As such, we believe RAP-219 has the potential for a differentiated profile as compared to traditional neuroscience medications. Due to the role of AMPA biology in various neurological disorders and our precision approach of selectively targeting TARP8, we believe RAP-219 has pipeline-in-a-product potential and we are evaluating it as a potentially transformational treatment for patients with FOS, primary generalized tonic-clonic seizures (“PGTCS”), and bipolar mania.

Previous wording

A total of four Phase 1 trials in RAP-219 have been conducted to date in healthy adult volunteers: a single ascending dose (“SAD”) trial; a multiple ascending dose (“MAD”) trial; a second MAD trial (“MAD-2”), to assess dosing regimens that may accelerate time to reach therapeutic exposure; and a human positron emission tomography (“PET”) trial, which utilized a companion PET radiotracer to confirm brain target receptor occupancy and brain region specificity across a range of dosing and exposure levels. In January 2025, we announced results from our PET and MAD-2 trials of RAP-219. Data demonstrated that neuroanatomical specificity can be achieved through RAP-219’s selective targeting of TARPγ8. In Cohort 1 ofthe human PET trial, which used the dosing regimen utilized in our ongoing Phase 2a trial in patients with refractory focal epilepsy, RAP-219 achieved target receptor occupancy associated with maximal seizure protection in preclinical models within five days and was generally well tolerated, which we believe further supportsthe use of such dosing regimen in the Phase 2a trial in patients with refractory focal epilepsy.

Current wording

Several Phase 1 trials in RAP-219 have been conducted in healthy adult volunteers, including a single ascending dose (“SAD”) trial; a multiple ascending dose (“MAD”) trial; a second MAD trial (“MAD-2”), to assess alternative dosing regimens that may accelerate time to reach therapeutic exposure; a positron emission tomography (“PET”) trial, which utilized a companion PET radiotracer to confirm brain target receptor occupancy (“RO”) and brain region specificity across a range of dosing and exposure levels.

Previous wording

We are currently conducting a Phase 2a proof-of-concept trial in adult patients with refractory focal epilepsy, for which we expect to report topline results in the third quarter of 2025. We believe RAP-219 also has therapeutic potential in bipolar disorder and peripheral neuropathic pain, and we intend to initiate a Phase 2a proof-of-concept trial in bipolar mania in the third quarter of 2025 with topline results expected in the first half of 2027. We were notified in the fourth quarter of 2024 by the U.S. Food and Drug Administration (“FDA”) that the Investigational New Drug (“IND”) submitted for the initiation of a Phase 2a proof-of-concept trial of RAP-219 for the treatment of diabetic peripheral neuropathic pain (“DPNP”) was placed on clinical hold. The FDA requested additional information and amendments specific to the protocol design. The clinical hold is specific to the IND for DPNP and has not impacted our ongoing Phase 2a trial in refractory focal epilepsy or planned proof-of-concept trial in bipolar mania. We believe in our ability to advance the clinical development of RAP-219 for DPNP and will provide an update on the anticipated timing of the Phase 2a trial initiation once available.

Current wording

We believe RAP-219 also has therapeutic potential in bipolar disorder. Our Phase 2 proof-of-concept trial in bipolar mania is currently enrolling patients, with topline results expected in the first half of 2027.

Previous wording

Beyond TARP8, we have two advanced discovery-stage nicotinic acetylcholine receptor (“nAChR”) programs stemming from our RAP technology platform. The first comprises modulators of6 nAChRs that we are developing in chronic pain; and the second comprises modulators of910 nAChRs that we are developing in hearing disorders. Third-party genetic data suggest that these nAChR subtypes could be attractive drug targets for these diseases. We continue to leverage our RAP technology platform to discover additional product candidates that we believe have the potential to provide a transformative benefit for large patient populations with neurological or psychiatric diseases with unmet needs.

Current wording

We also have two advanced discovery-stage nicotinic acetylcholine receptor (“nAChR”) programs stemming from our RAP technology platform. nAChRs have been clinically validated in patient-reported neuropathic pain and our first advanced discovery-stage nAChR program comprises agonists of the α6ß4 nAChR. α6ß4 nAChRs are selectively expressed in sensory neurons, while the α6 subunit has human genetic validation in chronic pain. We have initiated IND-enabling activities for our α6ß4 nAChR agonist development candidate, RAP-641, a genetically validated precision target that we are pursuing as a potential novel non-opiate, non-CNS approach for chronic pain and migraine. The second advanced discovery-stage nAChR program comprises modulators of the α9α10 nAChR. Third-party preclinical genetic data suggest that this nAChR could be an attractive target in treating hearing and vestibular disorders. We continue to leverage our RAP technology platform to discover additional product candidates that we believe have the potential to provide transformative benefits for large patient populations with neurological or psychiatric diseases.

Previous wording

We have incurred significant operating losses in each year since our inception. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of any product candidates we may develop. Our net losses were $78.3 million and $34.8 million for the years ended December 31, 2024 and 2023, respectively. As of December 31, 2024, we had an accumulated deficit of $123.7 million. We expect our expenses and operating losses will increase substantially as we:

Current wording

We have incurred significant operating losses in each year since our inception. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of any product candidates we may develop. Our net losses were $111.5 million and $78.3 million for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, we had an accumulated deficit of $235.2 million. We expect our expenses and operating losses will increase substantially as we:

Previous wording

In addition, we have several preclinical and clinical development, regulatory, and commercial milestone payment obligations under our licensing arrangements. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies and planned clinical trials and our expenditures on other research and development activities.

Current wording

In addition, we have several preclinical and clinical development, regulatory, and commercial milestone payment obligations under our licensing arrangements. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending on the timing of our preclinical studies, clinical trials and our expenditures on other research and development activities.

Previous wording

We believe that our existing cash and cash equivalents, and short-term investments will enable us to fund our operating expenses and capital expenditure requirements through the end of 2026. See the sections titled “—Liquidity and Capital Resources” and “Risk Factors—Risks Related to Our Limited Operating History, Financial Condition and Need for Additional Capital” included elsewhere in this Annual Report.

Current wording

We believe that our existing cash and cash equivalents, and short-term investments will enable us to fund our operating expenses and capital expenditure requirements into the second half of 2029. See the sections titled “—Liquidity and Capital Resources” and “Risk Factors—Risks Related to Our Limited Operating History, Financial Condition and Need for Additional Capital” included elsewhere in this Annual Report.

Previous wording

In November 2023, we entered into a master services agreement (the “NeuroPace Agreement”) with NeuroPace Inc. (“NeuroPace”), the manufacturer and distributor of the responsive neurostimulation (“RNS”) system. Pursuant to the NeuroPace Agreement and in accordance with statement of work agreements entered into from time to time, NeuroPace provides us with certain services with respect to data from the RNS systems used in our clinical trials. The NeuroPace Agreement also grants us a royalty-free, worldwide, exclusive, non-transferable license to all data collected by the RNS systems in our Phase 2a clinical trial and the outcomes of algorithms that are applied to such data, as well as the ability to publish the outcomes of algorithms, subject to certain conditions. The consideration we will pay to NeuroPace for such services is set out in each statement of work agreement.

Current wording

In November 2023, we entered into a master services agreement (the “NeuroPace Agreement”) with NeuroPace Inc. (“NeuroPace”), the manufacturer and distributor of the responsive neurostimulation (“RNS”) system. Pursuant to the NeuroPace Agreement and in accordance with statement of work agreements entered into from time to time, NeuroPace provides us with certain services with respect to data from the RNS systems used in our clinical trials. The NeuroPace Agreement also grants us a royalty-free, worldwide, exclusive, non-transferable license to all data collected by the RNS systems in our RAP-219 clinical trials in drug-resistant FOS and the outcomes of algorithms that are applied to such data, as well as the ability to publish the outcomes of algorithms, subject to certain conditions. The consideration we will pay to NeuroPace for such services is set out in each statement of work agreement.

Previous wording

Concurrently with the execution of the NeuroPace Agreement, the parties also entered into an initial statement of work, as amended in March 2024 (the “NeuroPace SOW”), under the NeuroPace Agreement, pursuant to which NeuroPace agreed to provide services related to our Phase 2a clinical trial of RAP-219, including, among other things, clinical trial readiness support, identification of potential patients satisfying the enrollment criteria and RNS system data reporting and data analysis. Pursuant to the payment schedule set out in the NeuroPace SOW, we will pay NeuroPace an aggregate of up to $3.7 million over a period of approximately two years in connection with NeuroPace’s provision of services and achievement of certain patient enrollment and deliverable milestones.

Current wording

Concurrently with the execution of the NeuroPace Agreement, the parties also entered into an initial statement of work, as amended in March 2024, and a second SOW in July 2025 (collectively, the “NeuroPace SOWs”) under the NeuroPace Agreement, pursuant to which NeuroPace agreed to provide services related to our RAP-219 Phase 2a clinical trial and planned open-label long term safety trial in RAP-219 for FOS, including, among other things, clinical trial readiness support, identification of potential patients satisfying the enrollment criteria and RNS system data reporting and data analysis. Pursuant to the payment schedule set out in the NeuroPace SOWs, the Company will pay NeuroPace an aggregate of up to $5.3 million over a period of approximately four years in connection with NeuroPace’s provision of services and achievement of certain patient enrollment and deliverable milestones. During the year ended December 31, 2024, we paid NeuroPace $0.6 million and recognized $1.8 million in research and development expense for services performed, resulting in a prepaid expense balance of $0.3 million as of December 31, 2024. The Company has incurred cumulative expenses of $4.2 million on both NeuroPace SOWs through December 31, 2025.

Previous wording

Interest income consists of interest earned from our cash, cash equivalents and short-term investments.

Current wording

Interest income consists of interest earned from our cash, cash equivalents and short-term and long-term investments.

Previous wording

Our Series A and Series B convertible preferred stock purchase agreements provided the investors the obligation to participate in subsequent offerings of Series A and Series B convertible preferred stock upon achievement of certain specified milestones, upon the waiver of such milestone achievement by a majority vote of the respective series convertible preferred stockholders, or with respect to the Series B convertible preferred stock, upon exercise of the stockholders right to early exercise the preferred stock tranche right. The preferred stock tranche rights are classified as liabilities and initially recorded at fair value upon the issuance date of the rights. The liabilities were subsequently remeasured to fair value at each reporting date and immediately prior to being settled, and changes in fair value of the preferred stock tranche right liabilities were recognized as a component of other income (expense), net in our consolidated statements of operations and comprehensive loss. In February 2023, we closed the Series A second and third financings, resulting in full settlement of the tranche right, upon both of which we issued additional shares of Series A convertible preferred stock. Immediately prior to the issuance of such shares, the preferred stock tranche right liability was remeasured to fair value with the change in fair value recognized as a component of other income (expense), net. As a result of the Series A preferred stock tranche right settlement in February 2023, we will no longer recognize changes in the fair value of the Series A preferred stock tranche liability in our consolidated statements of operations and comprehensive loss. In March 2024, we closed the Series B second financing, resulting in full settlement of the tranche right, upon which we issued additional shares of Series B convertible preferred stock. Immediately prior to the issuance of such shares, the preferred stock tranche right liability was remeasured to fair value with the change in fair value recognized as a component of other income (expense), net. As a result of the Series B preferred stock tranche right settlement in March 2024, we will no longer recognize changes in the fair value of the Series B preferred stock tranche liability in our consolidated statements of operations and comprehensive loss.

Current wording

Our Series B convertible preferred stock purchase agreements provided the investors the obligation to participate in subsequent offerings of Series B convertible preferred stock upon achievement of certain specified milestones, upon the waiver of such milestone achievement by a majority vote of the respective series convertible preferred stockholders, or with respect to the Series B convertible preferred stock, upon exercise of the stockholders right to early exercise the preferred stock tranche right. The preferred stock tranche rights are classified as liabilities and initially recorded at fair value upon the issuance date of the rights. The liabilities were subsequently remeasured to fair value at each reporting date and immediately prior to being settled, and changes in fair value of the preferred stock tranche right liabilities were recognized as a component of other income (expense), net in our condensed consolidated statements of operations and comprehensive loss. In March 2024, we closed the Series B second financing, resulting in full settlement of the tranche right, upon which we issued additional shares of Series B convertible preferred stock. Immediately prior to the issuance of such shares, the preferred stock tranche right liability was remeasured to fair value with the change in fair value recognized as a component of other income (expense), net. As a result of the Series B preferred stock tranche right settlement in March 2024, we will no longer recognize changes in the fair value of the Series B preferred stock tranche liability in our condensed consolidated statements of operations and comprehensive loss.

Previous wording

For the years ended December 31, 2024 and 2023, we recorded an income tax provision of zero and $10 thousand, respectively. As of December 31, 2024 and 2023, we recorded a full valuation allowance of our net deferred tax assets, as we believed it was more likely than not we would not be able to utilize our deferred tax assets prior to their expiration.

Current wording

For each of the years ended December 31, 2025 and 2024, we recorded an income tax provision of zero. As of December 31, 2025 and 2024, we recorded a full valuation allowance of our net deferred tax assets, as we believed it was more likely than not we would not be able to realize our deferred tax assets prior to their expiration. The income tax provision reflects the changes to tax law that was enacted during 2025.

Previous wording

Since our inception, we have not recorded any income tax benefits for the net losses we have incurred in each year or for our research and development tax credits, as we believe, based upon the weight of available evidence, that it is more likely than not that all of our net operating losses (“NOLs”), carryforwards and tax credits will be not realized. As of December 31, 2024, we had federal NOL carryforwards of approximately $13.7 million and state NOL carryforwards of approximately $12.0 million, respectively. Federal losses have an indefinite carryforward period, but can only offset 80% of federal taxable income in a given year. Losses for state purposes begin to expire in 2043. As of December 31, 2024, we also had federal and state tax research and development credit carryforwards of approximately $3.8 million and $1.6 million, respectively, to offset future tax liabilities, which begin to expire in 2042 and 2037, respectively. We have recorded a full valuation allowance against our net deferred tax assets at December 31, 2024. As of December 31, 2024, we had no unrecognized tax benefits.

Current wording

Since our inception, we have not recorded any income tax benefits for the net losses we have incurred in each year or for our research and development tax credits, as we believe, based upon the weight of available evidence, that it is more likely than not that all of our net operating losses (“NOLs”), carryforwards and tax credits will be not realized. As of December 31, 2025, we had federal NOL carryforwards of approximately $46.1 million and state NOL carryforwards of approximately $15.1 million, respectively. Federal losses have an indefinite carryforward period, but can only offset 80% of federal taxable income in a given year. Losses for state purposes begin to expire in 2043. As of December 31, 2025, we also had federal and state tax research and development credit carryforwards of approximately $8.0 million and $3.2 million, respectively, to offset future tax liabilities, which begin to expire in 2042 and 2037, respectively. We have recorded a full valuation allowance against our net deferred tax assets at December 31, 2025. As of December 31, 2025, we had no unrecognized tax benefits.

Previous wording

Research and development expenses were $60.9 million for the year ended December 31, 2024, as compared to $28.0 million for the year ended December 31, 2023. The increase of $32.9 million consisted of the following:

Current wording

Research and development expenses were $94.8 million for the year ended December 31, 2025, as compared to $60.9 million for the year ended December 31, 2024. The increase of $33.9 million consisted of the following:

Previous wording

an $11.9 million increase in RAP-219 program costs, which consisted primarily of an increase of $7.4 million in clinical trial costs primarily driven by costs for our Phase 2a trial in refractory focal epilepsy, start-up costs for our Phase 2a proof-of-concept trial in DPNP, costs from our MAD-2 trial, costs from our PET trial, and costs from our human absorption, distribution, metabolism, and excretion study, a $1.7 million increase in preclinical toxicology studies driven by initiation of long-term toxicology work, a $2.4 million increase in contract manufacturing costs related to the production of materials to support our additional Phase 1 and 2 trials, and an increase of $0.2 million for consulting related to the DPNP program;

Current wording

a $19.1 million increase in RAP-219 program costs, which consisted of an increase of $17.0 million in clinical trial costs, primarily driven by costs for our Phase 2a trial, open-label long term safety trial, start-up costs for our Phase 3 trials in drug-resistant FOS, and costs for our Phase 2 proof-of-concept trial in bipolar mania, a $2.0 million increase in contract manufacturing costs related to the production of clinical trial supply, and a $0.8 million increase in RAP-219 consulting costs. These increases were offset by a $0.7 million decrease in preclinical toxicology studies related to long-term toxicology work;

Previous wording

a $9.6 million increase in personnel-related costs due to an increase in headcount, which consisted primarily of salaries, bonuses, and other compensation-related costs of $7.7 million, and stock-based compensation of $2.2 million. These increases were partially offset by a decrease in general research and development consulting costs of $0.3 million; and

Current wording

a $10.9 million increase in personnel-related costs due to an increase in headcount, which consisted primarily of salaries, bonuses, and other compensation-related costs of $7.7 million, and stock-based compensation of $3.2 million; and

Previous wording

a $1.3 million increase in other costs, consisting of research and development facilities expenses and depreciation expense related to opening our Boston office in September 2023, and continuing to expand our San Diego site.

Current wording

a $3.9 million increase in other costs, consisting primarily of research and development facilities, information technology, and depreciation expenses related to increased headcount and continued expansion of our Boston and San Diego sites.

Previous wording

General and administrative expense were $22.1 million for the year ended December 31, 2024, as compared to $8.2 million for the year ended December 31, 2023. The increase of $13.9 million consisted of the following:

Current wording

General and administrative expense were $30.3 million for the year ended December 31, 2025, as compared to $22.1 million for the year ended December 31, 2024. The increase of $8.2 million consisted of the following:

Previous wording

$9.7 million increase in workforce expense due to an increase in headcount, consisting of salaries, bonuses, and other compensation-related costs of $5.1 million and stock-based compensation of $4.6 million;

Current wording

a $7.5 million increase in workforce expense primarily due to an increase in headcount, consisting of salaries, bonuses, and other compensation-related costs of $2.2 million and stock-based compensation of $5.4 million;

Previous wording

$1.9 million increase in other expenses, consisting primarily of administrative expenses due to increased business activities, and expanded general and administrative support in connection with operating as a public company.

Current wording

a $0.9 million increase in facility and other expenses, consisting of administrative expenses due to increased business activities and expanded general and administrative support in connection with operating as a public company; partially offset by

Previous wording

Interest income was $12.1 million for the year ended December 31, 2024, as compared to $2.5 million for the year ended December 31, 2023. The increase of $9.6 million is primarily due to opening additional interest-bearing accounts in December 2023, in addition to the increased cash, cash equivalent and short-term investments balances from the Series B convertible preferred stock financing in August 2023 and February 2024, and our initial public offering (“IPO”) in June 2024.

Current wording

Other income (expense) was $13.6 million for the year ended December 31, 2025, as compared to $4.7 million for the year ended December 31, 2024. The $7.4 million decrease in the expense from the change in fair value of preferred stock tranche right liability was due to the settlement of the Series B preferred stock tranche right liability in March 2024. The $1.5 million increase in interest income is due to the increased cash, cash equivalent and short-term investments balances from the IPO and concurrent private placement in June 2024 and the September 2025 Offering.

Previous wording

For the years ended December 31, 2024 and 2023 we recorded an income tax provision of zero and $10 thousand, respectively.

Current wording

For the years ended December 31, 2025 and 2024 we recorded an income tax provision of zero.

Previous wording

Since our inception in February 2022, we have not generated any revenue from any sources and have incurred significant operating losses and negative cash flows from operations. We expect to incur significant expenses and operating losses for the foreseeable future as we advance the clinical development of our product candidates and pipeline. Further, we expect to continue to incur additional costs associated with operating as a public company. To date, we have funded our operations with proceeds from the sale of convertible notes, convertible preferred stock, and the issuance of common stock in our IPO and concurrent private placement. Through December 31, 2024, we received aggregate gross proceeds of $424.4 million from the issuance of convertible promissory notes and the sale of our convertible preferred stock and common stock. As of December 31, 2024, we had cash and cash equivalents of $56.8 million and short-term investments of $248.5 million.

Current wording

Since our inception in February 2022, we have not generated any revenue from any sources and have incurred significant operating losses and negative cash flows from operations. We expect to incur significant expenses and operating losses for the foreseeable future as we advance the clinical development of our product candidates and pipeline. Further, we expect to continue to incur additional costs associated with operating as a public company. Historically, we have funded our operations with proceeds from the sale of convertible notes, convertible preferred stock, the issuance of common stock in our IPO and concurrent private placement, and the September 2025 Offering. Through December 31, 2025, we received aggregate gross proceeds of $711.9 million from the issuance of convertible promissory notes and the sale of our convertible preferred stock and common stock. As of December 31, 2025, we had cash and cash equivalents of $52.6 million and short-term investments of $437.9 million.

Previous wording

During the year ended December 31, 2023, net cash used in investing activities was $78.9 million, primarily consisting of purchases of short-term investments of $77.2 million and purchases of property and equipment of $1.6 million.

Current wording

During the year ended December 31, 2025, net cash used in investing activities was $187.5 million, primarily consisting of purchases of short-term investments of $354.8 million and purchases of property and equipment of $0.6 million, partially offset by maturities of short-term investments of $167.9 million.

Previous wording

During the year ended December 31, 2023, net cash provided by financing activities was $145.1 million, primarily consisting of net proceeds of $59.9 million from our additional issuance of Series A convertible preferred stock, and net proceeds of $85.3 million from our initial issuance of Series B convertible preferred stock, including tranche rights.

Current wording

During the year ended December 31, 2025, net cash provided by financing activities was $270.8 million, primarily consisting of net proceeds from the September 2025 Offering in the aggregate amount of $269.4 million and proceeds from exercise of stock options of $1.3 million.

Previous wording

As of December 31, 2024, we had cash, cash equivalents and short-term investments of $305.3 million, excluding our restricted cash. As of the issuance date of the consolidated financial statements for the year ended December 31, 2024, we expect that our cash, cash equivalents and short-term investments will be sufficient to fund our operating expenses and capital expenditure requirements through at least 12 months from the issuance of the consolidated financial statements. We believe that our existing cash, cash equivalents and short-term investments will enable us to fund our operating expenses and capital expenditure requirements through the end of 2026. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. However, our forecast for the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. Additionally, the process of conducting preclinical studies and testing potential future product candidates in clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain. We will need to raise substantial additional capital in the future.

Current wording

As of December 31, 2025, we had cash, cash equivalents and short-term investments of $490.5 million, excluding our restricted cash. As of the issuance date of the consolidated financial statements for the year ended December 31, 2025, we expect that our cash, cash equivalents and short-term investments will be sufficient to fund our operating expenses and capital expenditure requirements through at least 12 months from the issuance of the consolidated financial statements. We believe that our existing cash, cash equivalents and short-term investments will enable us to fund our operating expenses and capital expenditure requirements into the second half of 2029. We have based this estimate on assumptions that may prove to be wrong, and we could exhaust our available capital resources sooner than we expect. However, our forecast for the period of time through which our financial resources will be adequate to support our operations is a forward-looking statement that involves risks and uncertainties, and actual results could vary materially. Additionally, the process of conducting preclinical studies and testing potential future product candidates in clinical trials is costly, and the timing of progress and expenses in these studies and trials is uncertain. We will need to raise substantial additional capital in the future.

Previous wording

Until such time, if ever, as we can generate substantial product revenue to support our cost structure, we expect to finance our cash needs through equity offerings, debt financings, or other capital sources, potentially including collaborations, licenses, and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, your ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our common stockholders. Additional debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends. If we raise funds through collaborations, license arrangements, or other similar arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or potential future product candidates or grant licenses on terms that may not be favorable to us and/or may reduce the value of our common stock. Our failure to raise capital or enter into such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional funds through equity or debt financings, or through other sources when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market our product candidates and potential future product candidates even if we would otherwise prefer to develop and market such potential future product candidates ourselves.

Current wording

Until such time, if ever, as we can generate substantial product revenue to support our cost structure, we expect to finance our cash needs through equity offerings, debt financings, or other capital sources, potentially including collaborations, licenses, and other similar arrangements. However, we may be unable to raise additional funds or enter into such other arrangements when needed on favorable terms or at all. To the extent that we raise additional capital through the sale of equity or convertible debt securities, ownership interests will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our common stockholders. Additional debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends. If we raise funds through collaborations, license arrangements, or other similar arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or potential future product candidates or grant licenses on terms that may not be favorable to us and/or may reduce the value of our common stock. Our failure to raise capital or enter into such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional funds through equity or debt financings, or through other sources when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts or grant rights to develop and market our product candidates and potential future product candidates even if we would otherwise prefer to develop and market such potential future product candidates ourselves.

Previous wording

As of the December 31, 2024, we had future minimum operating lease payments under non-cancelable leases of $1.8 million related to leases we have recognized on our consolidated balance sheet, which are due over the following 2.5 years. In addition, we have one lease in San Diego that has been entered into but has not yet commenced, for which we expect to pay approximately $9.6 million over the five-year lease term. We also entered into a sublease agreement for a facility in Boston, for which we expect to pay approximately $5.2 million over the six and a half-year sublease term.

Current wording

As of the December 31, 2025, we had future minimum operating lease payments under non-cancelable leases of $13.4 million related to leases we have recognized on our consolidated balance sheet, which included existing laboratory and office leases and the new corporate headquarters lease that commenced June 1, 2025 in Boston, Massachusetts. The future minimum operating lease payments under these non-cancelable leases are due over a weighted average remaining lease term of 4.6 years.

Previous wording

In connection with the execution of the NeuroPace Agreement, the parties also entered into an initial statement of work under the NeuroPace Agreement, pursuant to which NeuroPace agreed to provide services related to our Phase 2a proof-of-concept clinical trial of RAP-219, including, among other things, clinical trial readiness support, data analysis and data reporting. Pursuant to the payment schedule set out in the statement of work, we will pay NeuroPace an aggregate of up to $3.7 million over a period of approximately two years in connection with NeuroPace’s provision of services and achievement of certain patient enrollment and deliverable milestones.

Current wording

In connection with the execution of the NeuroPace Agreement, the parties also entered into an initial statement of work (“SOW”), as amended in March 2024, and a second SOW in July 2025 (collectively, the “NeuroPace SOWs”) under the NeuroPace Agreement, pursuant to which NeuroPace agreed to provide services related to the RAP-219 Phase 2a proof-of-concept clinical trial and planned open-label long term safety trial in RAP-219 for FOS, including, among other things, clinical trial readiness support, identification of potential patients satisfying the enrollment criteria and RNS system data reporting and data analysis. Pursuant to the payment schedule set out in the NeuroPace SOWs, the Company will pay NeuroPace an aggregate of up to $5.3 million over a period of approximately four years in connection with NeuroPace’s provision of services and achievement of certain patient enrollment and deliverable milestones. During the year ended December 31, 2024, we paid NeuroPace $0.6 million and recognized $1.8 million in research and development expense for services performed, resulting in a prepaid expense balance of $0.3 million as of December 31, 2024. The Company has incurred cumulative expenses of $4.2 million on both NeuroPace SOWs through December 31, 2025.

Previous wording

the likelihood of achieving a liquidity event, such as an initial public offering (“IPO”) or sale of our company in light of prevailing market conditions; and

Current wording

the likelihood of achieving a liquidity event, such as an IPO or sale of our company in light of prevailing market conditions; and

Previous wording

Our Series A and Series B convertible preferred stock purchase agreements obligated the Series A and Series B investors to participate in a subsequent offering of Series A and Series B convertible preferred stock upon certain conditions being met, which we referred to as the preferred stock tranche rights. We determined that the preferred stock tranche rights were required to be recorded as liabilities because they were freestanding financial instruments that would require us to transfer assets upon exercises of the right. The preferred stock tranche rights met the definition of a freestanding financial instrument because they were legally detachable and separately exercisable from the Series A and Series B convertible preferred stock. The preferred stock tranche rights were classified as a liability and initially recorded at fair value upon the issuance date of the right. The liabilities were remeasured to fair value at each reporting date until settled, and changes in the fair value of the preferred stock tranche right liabilities were recognized as a component of other income (expense) in our consolidated statements of operations and comprehensive loss.

Current wording

Our Series B convertible preferred stock purchase agreements obligated the Series B investors to participate in a subsequent offering of Series B convertible preferred stock upon certain conditions being met, which we referred to as the preferred stock tranche rights. We determined that the preferred stock tranche rights were required to be recorded as a liability because it was a freestanding financial instrument that would require us to transfer assets upon exercises of the right. The preferred stock tranche rights met the definition of a freestanding financial instrument because they were legally detachable and separately exercisable from the Series B convertible preferred stock. The preferred stock tranche rights were classified as a liability and initially recorded at fair value upon the issuance date of the right. The liability was remeasured to fair value at each reporting date until settled, and changes in the fair value of the preferred stock tranche right liability was recognized as a component of other income (expense) in our consolidated statements of operations and comprehensive loss.

Previous wording

Subsequent to the original issuance, one stockholder exercised its right to early exercise the Series B preferred stock tranche right and purchased 4,769,655 shares of Series B convertible preferred stock for cash proceeds of $8.0 million. The fair value of the associated tranche right liability that was settled at the time of the sale of $0.5 million was recognized in additional paid-in capital. Additionally, the investor paid a premium of $0.8 million for these shares over their fair value which was also recorded in additional paid-in capital.

Current wording

Subsequent to the original issuance, one stockholder exercised its right to early exercise the Series B preferred stock tranche right and purchased shares of Series B convertible preferred stock for cash proceeds of $8.0 million. The fair value of the associated tranche right liability that was settled at the time of the sale of $0.5 million was recognized in additional paid-in capital. Additionally, the investor paid a premium of $0.8 million for these shares over their fair value which was also recorded in additional paid-in capital.

Previous wording

The fair value of the tranche right liabilities was determined based on significant inputs not observable in the market, which represented a Level 3 measurement within the fair value hierarchy. The fair value of the tranche right liabilities was determined using a Contingent Forward Analysis, which is a scenario-based lattice model that accounts for the different possible milestone scenarios and their associated probabilities, as estimated by us. The valuation model considered the probability of closing the tranche, the estimated future value of the convertible preferred stock to be issued at each closing and the investment required at each closing. Future values were converted to present value using a discount rate appropriate for probability-adjusted cash flows. The most significant assumptions in the Contingent Forward Analysis impacting the fair value of the preferred stock tranche rights were the fair value of the Series A and Series B convertible preferred stock as of each remeasurement date, the estimated remaining term of the tranche right as of each remeasurement date, and the probabilities of success for each tranche milestone as of each measurement date. We determined the fair value per share of the underlying convertible preferred stock by taking into consideration the most recent sales of our convertible preferred stock as well as additional factors that we deemed relevant. We assessed these assumptions and estimates on a quarterly basis as additional information impacting the assumptions was obtained. The risk-free rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining estimated time to each tranche closing.

Current wording

The fair value of the tranche right liability was determined based on significant inputs not observable in the market, which represented a Level 3 measurement within the fair value hierarchy. The fair value of the tranche right liability was determined using a Contingent Forward Analysis, which is a scenario-based lattice model that accounts for the different possible milestone scenarios and their associated probabilities, as estimated by us. The valuation model considered the probability of closing the tranche, the estimated future value of the convertible preferred stock to be issued at each closing and the investment required at each closing. Future values were converted to present value using a discount rate appropriate for probability-adjusted cash flows. The most significant assumptions in the Contingent Forward Analysis impacting the fair value of the preferred stock tranche rights were the fair value of the Series B convertible preferred stock as of each remeasurement date, the estimated remaining term of the tranche right as of each remeasurement date, and the probabilities of success for each tranche milestone as of each measurement date. We determined the fair value per share of the underlying convertible preferred stock by taking into consideration the most recent sales of our convertible preferred stock as well as additional factors that we deemed relevant. We assessed these assumptions and estimates on a quarterly basis as additional information impacting the assumptions was obtained. The risk-free rate was determined by reference to the U.S. Treasury yield curve for time periods approximately equal to the remaining estimated time to each tranche closing.