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 TARPγ8, which is associated with the neuronal AMPARs. Whereas AMPARs are distributed widely in the central nervous system (“CNS”), TARPγ8 is expressed only in discrete regions, including the hippocampus and neocortex, where focal onset seizures often originate. By contrast, TARPγ8 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 TARPγ8, we believe RAP-219 has pipeline-in-a-product potential and we are evaluating it as a potentially transformational treatment for patients with focal onset seizures, 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 TARPγ8, which is associated with the neuronal AMPARs. Whereas AMPARs are distributed widely in the central nervous system (“CNS”), TARPγ8 is expressed only in discrete regions, including the neocortex and mesial temporal lobe, where focal onset seizures (“FOS”) often originate. By contrast, TARPγ8 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 TARPγ8, 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 of the human PET trial, which used the dosing regimen utilized in our Phase 2a trial in patients with drug-resistant focal onset seizures, RAP-219 achieved target receptor occupancy associated with maximal seizure protection in preclinical models within five days and was generally well tolerated, which supported the use of such dosing regimen in the Phase 2a trial in drug-resistant focal onset seizures.

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

In September 2025, we announced positive topline results from our Phase 2a proof-of-concept trial of RAP-219 in adult patients with drug-resistant focal onset seizures. The trial met its primary and secondary endpoints. The trial demonstrated a statistically significant reduction in long episodes – an objective electrographic biomarker for clinical seizure reduction – compared with baseline over the 8-week treatment period. In the trial, RAP-219 also demonstrated a statistically significant and clinically meaningful reduction in clinical seizures compared with baseline. RAP-219 was generally well tolerated. We expect to present additional efficacy analyses later in 2025, as well as 8-week follow-up results in 2026. By the end of 2025, we plan to initiate an open-label long term safety trial to allow patients enrolled in our Phase 2a focal onset seizure trial to resume taking RAP-219. Preliminary results of the trial are expected in the second half of 2026. We plan to hold an end-of-Phase 2 meeting with the U.S. Food and Drug Administration (“FDA”) in the fourth quarter of 2025, and move into two Phase 3 trials, with initiation expected in the third quarter of 2026.

Current wording

In September 2025, we announced positive topline results from our Phase 2a proof-of-concept trial of RAP-219 in adult patients with drug-resistant FOS. The trial met its primary and secondary endpoints. The trial demonstrated a statistically significant reduction in long episodes (“LEs”) – an objective electrographic biomarker for clinical seizure reduction – compared with baseline over the 8-week treatment period. In the trial, RAP-219 also demonstrated a statistically significant and clinically meaningful reduction in clinical seizures compared with baseline. RAP-219 was generally well tolerated. In December 2025, we presented post-hoc analysis from the Phase 2a proof-of-concept trial showing treatment with RAP-219 had consistent effects in the first (weeks 1-4) and second (weeks 5-9) four-week segments of the treatment period. This demonstrates that there was a rapid onset of efficacy, and a consistent reduction in LEs, and a consistent, clinically meaningful reduction in clinical seizures throughout the 8-week treatment period. Following 8-weeks of RAP-219 treatment in the Phase 2a trial, patients entered an 8-week follow-up period to assess the durability effect on LEs and clinical seizures. In April 2026, we presented results from the 8-week follow-up period. Based on pharmacokinetic (“PK”) data collected across the Company’s Phase 1 and Phase 2 trials and further supported by population PK modeling, RAP-219 is now estimated to have a 22-day half-life, compared to the prior reported estimate of 14 days. Due to the long half-life, plasma concentrations of RAP-219 remained within the receptor occupancy therapeutic levels over the 8-week follow-up period, resulting in sustained biomarker and clinical responses consistent with the 8-week treatment period. In the first four weeks of follow-up (weeks 9-12), RAP-219 showed even greater reductions in LEs and clinical seizures than were observed during the 8-week treatment period. Clinically meaningful improvements over baseline continued through the second four weeks of follow-up (weeks 13-16).

Previous wording

Additionally, we continue to develop a long-acting injectable (“LAI”) formulation of RAP-219. We believe an LAI formulation has the potential to improve patient adherence and expand the potential clinical utility across all of the RAP-219 indications.

Current wording

Additionally, we continue to develop a long-acting injectable (“LAI”) formulation of RAP-219. We believe an LAI formulation has the potential to improve patient adherence and expand the potential clinical utility across all of the RAP-219 indications. IND-enabling activities are underway and initial Phase 1 PK data is expected in 2027.

Previous wording

Beyond TARPγ8, 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, and the α6 subunit has human genetic validation in chronic pain. We have initiated IND-enabling activities for our α6β4 nAChR agonist development candidate, RAP-641, directed at 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 $26.9 million and $17.5 million for the three months ended September 30, 2025 and 2024, respectively, and $77.7 million and $58.3 million for the nine months ended September 30, 2025 and 2024, respectively. As of

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 $19.9 million and $24.1 million for the three months ended March 31, 2026 and 2025, respectively. As of March 31, 2026, we had an accumulated deficit of $255.1 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

In August 2022, we entered into an option and license agreement with Janssen Pharmaceutical NV, as amended on April 3, 2023, April 18, 2023, May 2, 2023, October 2, 2023, and April 9, 2024 (collectively, the “Janssen License”), under which we received an exclusive option to obtain from Janssen (a) a worldwide exclusive license for the research, development, and commercialization of transmembrane TARPg 8 AMPAR products for the diagnosis, treatment, prophylaxis or palliation of any disease or condition in humans or other animals (the “Field”) and (b) an assignment of certain patents related to TARPg 8, in each case of (a)-(b), subject to certain retained rights by Janssen. Pursuant to the Janssen License, we also received a worldwide, royalty-free, non-exclusive license

Current wording

In August 2022, we entered into an option and license agreement with Janssen Pharmaceutical NV, as amended on April 3, 2023, April 18, 2023, May 2, 2023, October 2, 2023, and April 9, 2024 (collectively, the “Janssen License”), under which we received an exclusive option to obtain from Janssen (a) a worldwide exclusive license for the research, development, and commercialization of transmembrane TARPγ8 AMPAR products for the diagnosis, treatment, prophylaxis or palliation of any disease or condition in humans or other animals (the “Field”) and (b) an assignment of certain patents related to TARPγ8, in each case of (a)-(b), subject to certain retained rights by Janssen. Pursuant to the Janssen License, we also received a worldwide, royalty-free, non-exclusive license (exclusive under certain joint patents) for the research, development, and commercialization of certain neuronal nicotinic acetylcholine (“nACh”) products in the Field.

Previous wording

We made a non-refundable, non-creditable upfront payment of $1.0 million to Janssen after we entered into the Janssen License. In October 2022, we exercised the option and paid a non-refundable, non-creditable option fee of $4.0 million to Janssen. If we succeed in developing and commercializing TARPg 8 products, Janssen will be eligible to receive (i) up to $76.0 million in development milestone payments and up to $40.0 million sales milestone payments for the product containing the lead TARPg 8 development candidate, and (ii) up to $25.0 million in development milestone payments and up to $42.0 million sales milestone payments for other TARPg 8 products containing a non-lead TARPg 8 development candidate.

Current wording

We made a non-refundable, non-creditable upfront payment of $1.0 million to Janssen after we entered into the Janssen License. In October 2022, we exercised the option and paid a non-refundable, non-creditable option fee of $4.0 million to Janssen. If we succeed in developing and commercializing TARPγ8 products, Janssen will be eligible to receive (i) up to $76.0 million in development milestone payments and up to $40.0 million sales milestone payments for the product containing the lead TARPγ8 development candidate, and (ii) up to $25.0 million in development milestone payments and up to $42.0 million sales milestone payments for other TARPγ8 products containing a non-lead TARPγ8 development candidate.

Previous wording

Janssen is also eligible to receive (a) royalties ranging from mid to high-single digit percentages on worldwide net sales of any products containing a TARPg 8 development candidate and (b) royalties ranging from low to mid-single digit percentages for other TARPg 8 products that do not contain a TARPg 8 development candidate, in each case of (a) and (b), subject to potential reductions following the expiration of valid claims and regulatory exclusivity covering such TARPg 8 products, the launch of certain generic products and the application of certain anti-stacking reductions for third party intellectual property payments, subject to a customary reduction floor. The royalties for any TARPg 8 product will expire on a country-by-country basis upon the latest to occur of (i) the expiration of all valid patent claims covering such product in such country, (ii) the expiration of all regulatory exclusivities in such country, and (iii) a specified number of years following the first commercial sale of such product in such country. The Janssen License provides us with certain other exclusive rights with respect to small molecules with activity against TARPg 8 and nACh.

Current wording

Janssen is also eligible to receive (a) royalties ranging from mid to high-single digit percentages on worldwide net sales of any products containing a TARPγ8 development candidate and (b) royalties ranging from low to mid-single digit percentages for other TARPγ8 products that do not contain a TARPγ8 development candidate, in each case of (a) and (b), subject to potential reductions following the expiration of valid claims and regulatory exclusivity covering such TARPγ8 products, the launch of certain generic products and the application of certain anti-stacking reductions for third party intellectual property payments, subject to a customary reduction floor. The royalties for any TARPγ8 product will expire on a country-by-country basis upon the latest to occur of (i) the expiration of all valid patent claims covering such product in such country, (ii) the expiration of all regulatory exclusivities in such country, and (iii) a specified number of years following the first commercial sale of such product in such country. The Janssen License provides us with certain other exclusive rights with respect to small molecules with activity against TARPγ8 and nACh.

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, 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 focal onset seizures, 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.

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 statement of work, as amended in February 2026 (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, we will pay NeuroPace an aggregate of up to $5.8 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. As of March 31, 2026, we have incurred cumulative expenses of $4.5 million on both NeuroPace SOWs.

Previous wording

For the three and nine months ended September 30, 2025 and 2024, we recorded no income tax provision. As of September 30, 2025 and December 31, 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 utilize our deferred tax assets prior to their expiration.

Current wording

For the three months ended March 31, 2026 and 2025, we recorded no income tax provision. As of March 31, 2026 and December 31, 2025, 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.

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. During the nine months ended September 30, 2025, we utilized $0.5 million of research and development tax credits as a reduction of payroll expenses to offset our payroll tax expenses.

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. As of December 31, 2025, we had no unrecognized tax benefits.

Previous wording

On July 4, 2025, new U.S tax legislation was signed into law (known as the “One Big Beautiful Bill Act” or “OBBBA”) which makes permanent many of the tax provisions enacted in 2017 as part of the Tax Cuts and Jobs Act that were set to expire at the end of 2025. In addition, the OBBBA makes changes to certain U.S. corporate tax provisions, but many are generally not effective until 2026. The impacts of OBBBA are not expected to be material to the 2025 consolidated balance sheet or statements of operations and comprehensive loss.

Current wording

On July 4, 2025, new U.S tax legislation was signed into law (known as the “One Big Beautiful Bill Act” or “OBBBA”) which makes permanent many of the tax provisions enacted in 2017 as part of the Tax Cuts and Jobs Act that were set to expire at the end of 2025. The impacts of OBBBA are not expected to be material to the 2026 consolidated balance sheet or statements of operations and comprehensive loss.

Previous wording

a $12.0 million increase in RAP-219 program costs, which consisted primarily of an increase of $11.5 million in clinical trial costs primarily driven by costs for our Phase 2a trial and planned open-label long term safety trial in drug-resistant focal onset seizures, costs for our Phase 2 proof-of-concept trial in bipolar mania, start-up costs for our Phase 2 proof-of-concept trial in DPNP, and a $1.1 million increase in contract manufacturing costs related to the production of clinical trial supply. These increases were offset by a $0.5 million decrease in preclinical toxicology studies related to long-term toxicology work;

Current wording

a $7.9 million increase in RAP-219 program costs, which consisted primarily of an increase of $6.8 million in clinical trial costs primarily driven by start-up costs for our Phase 3 trials in drug-resistant FOS, costs for our Phase 2 proof-of-concept trial in bipolar mania, costs for IND-enabling activities for our Phase 1 trial for our LAI program, and a $1.0 million increase in contract manufacturing costs related to the production of clinical supply.

Previous wording

a $2.0 million increase in personnel-related costs due to an increase in headcount, which consisted primarily of salaries, bonuses, and other compensation-related costs of $1.5 million, and stock-based compensation of $0.5 million;

Current wording

a $3.9 million increase in personnel-related costs due to an increase in headcount, which consisted primarily of salaries, bonuses, and other compensation-related costs of $2.4 million, and stock-based compensation of $1.5 million;

Previous wording

a $0.8 million increase in preclinical program costs, which consisted primarily of a $0.4 million increase in toxicology and animal studies related to our discovery programs, a $0.2 million increase in external chemistry efforts, and a $0.1 million increase in contract manufacturing costs related to the production of materials for use in our preclinical studies.

Current wording

a $1.0 million increase in preclinical program costs, which consisted primarily of a $1.2 million increase in toxicology and animal studies related to our discovery programs, offset by a $0.2 million decrease in external chemistry efforts; and

Previous wording

a $0.9 million increase in other costs, consisting of research and development facilities, information technology, and depreciation expense related to increased headcount and continued expansion of our Boston and San Diego sites; and

Current wording

a $0.4 million increase in other costs, consisting of research and development facilities, information technology, and depreciation expense related to increased headcount and continued expansion of our Boston and San Diego sites.

Previous wording

a $1.4 million increase in workforce expense due to an increase in headcount, consisting primarily of salaries, bonuses, and other compensation-related costs of $0.4 million and stock-based compensation of $1.0 million; and

Current wording

a $2.0 million increase in workforce expense due to an increase in headcount, consisting primarily of salaries, bonuses, and other compensation-related costs of $0.7 million and stock-based compensation of $1.4 million.

Previous wording

a $0.2 million increase in professional and consulting costs primarily associated with the September 2025 Offering and the ATM Program.

Current wording

a $2.0 million increase in professional and consulting costs primarily associated with increases of $2.2 million in consulting costs and $0.3 million in legal costs primarily due to the execution of the Tenacia License Agreement. These increases were offset by a $0.4 million decrease in accounting consulting costs.

Previous wording

Other income was $3.1 million for the three months ended September 30, 2025, as compared to $4.1 million for the three months ended September 30, 2024. The decrease in interest income was due to the decreased cash, cash equivalent and short-term investments balances for most of the three months ended September 30, 2025 due to continued spend on operations.

Current wording

Other income was $4.4 million for the three months ended March 31, 2026, as compared to $3.0 million for the three months ended March 31, 2025. The increase in interest income was due to the increased cash, cash equivalent and short-term investments balances for most of the three months ended March 31, 2026 due to proceeds from the September 2025 Offering.

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. Historically, 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, concurrent private placement and the September 2025 Offering. To date, we have received aggregate gross proceeds of $711.9 million from the issuance of common stock, convertible promissory notes and the sale of our convertible preferred stock. As of September 30, 2025, we had cash and cash equivalents and short-term investments of $513.0 million, excluding our restricted cash.

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, and the issuance of common stock in our IPO, concurrent private placement, September 2025 Offering, and collaboration agreements. To date, we have received aggregate gross proceeds of $731.9 million from these sources. As of March 31, 2026, we had cash and cash equivalents and short-term investments of $476.8 million, excluding our restricted cash.

Previous wording

In July 2025, we filed a registration statement on Form S-3 (File No. 333-288444) (the “Registration Statement”) with the U.S. Securities and Exchange Commission (the “SEC”) pursuant to which we may issue up to $400.0 million in shares of our common stock, preferred stock, debt securities, warrants and/or units. As market conditions permit, we may offer and sell securities under the Registration Statement in order to fund our operations or provide additional liquidity. Concurrent with the filing of the Registration Statement, we entered into a common stock sales agreement, dated July 1, 2025, by and between the Company and Leerink Partners LLC and Cantor Fitzgerald & Co., acting as sales agents (the “Sales Agreement”), which established an at-the-market offering program pursuant to which we may offer and sell shares of our common stock from time to time (the “ATM Program”). In connection with the ATM Program, we also filed a prospectus with the Registration Statement for the offer and sale of up to $150.0 million of shares of common stock from time to time through the sales agents (the “ATM Prospectus”). Effective September 8, 2025, we terminated the ATM Prospectus, and as a result, we will not make any sales of common stock pursuant to the Sales Agreement, unless and until a new prospectus supplement or a new registration statement is filed. The Sales Agreement remains in full force and effect. As of September 8, 2025, we had not issued and sold any shares of common stock under the Sales Agreement.

Current wording

We previously entered into a common stock sales agreement (the “Sales Agreement”), dated July 1, 2025, by and between the Company and Leerink Partners LLC and Cantor Fitzgerald & Co., acting as sales agents, which established an at-the-market offering program pursuant to which we may offer and sell shares of our common stock from time to time (the “ATM Program”).

Previous wording

During the nine months ended September 30, 2025, operating activities used $62.8 million of cash, resulting primarily from our net loss of $77.7 million, non-cash accretion of investments in marketable securities of $0.3 million, and changes in operating assets and liabilities of $0.1 million, partially offset by $13.2 million of non-cash stock-based compensation expense, $0.8 million of non-cash depreciation expense, and $1.5 million of non-cash lease expense. The $0.1 million change in operating assets and liabilities is primarily driven by an increase in prepaid expenses and other current assets of $2.6 million, primarily due to advanced payments on new contracts related to our clinical trials, a $0.1 million decrease in operating lease liabilities, and an increase in other assets of $0.9 million due to the payment of the security deposit for our new corporate headquarters lease and an up-front long-term clinical trial payment, partially offset by increases in accounts payable of $1.0 million and accrued expenses of $2.5 million due to increased expenditures and timing of payments to vendors.

Current wording

During the three months ended March 31, 2026, operating activities used $13.1 million of cash, resulting primarily from our net loss of $19.9 million, non-cash accretion of investments in marketable securities of $0.4 million, and changes in operating assets and liabilities of $0.8 million, partially offset by $7.0 million of non-cash stock-based compensation expense, $0.2 million of non-cash depreciation expense, and $0.6 million of non-cash lease expense. The $0.8 million change in operating assets and liabilities is primarily driven by a decrease in prepaid expenses and other current assets of $0.8 million, primarily due to recognition of advanced payments on contracts related to our clinical trials, a $0.7 million decrease in operating lease liabilities, and a decease in other assets of $0.3 million due to the movement of an upfront long-term prepaid clinical trial payment from long-term to short term, and a decrease in accrued expenses of $3.5 million due to timing of payments to vendors, partially offset by increases in accounts payable of $2.3 million due to financial advisory fees due in connection with the Tenacia License Agreement.

Previous wording

During the nine months ended September 30, 2024, operating activities used $50.4 million of cash, resulting primarily from our net loss of $58.3 million, non-cash accretion of investments in marketable securities of $3.8 million, and changes in operating assets and liabilities of $3.8 million, partially offset by $7.0 million of non-cash stock-based compensation expense, non-cash change in fair value of preferred stock tranche right liability of $7.4 million, $0.6 million of non-cash depreciation expense, and $0.5 million of non-cash lease expense. The $3.8 million change in operating assets and liabilities is primarily driven by an increase in prepaid expenses and other current assets of $1.8 million, primarily due to advanced payments on new contracts related to our clinical trials, a decrease in accounts payable of $1.0 million and accrued expenses of $0.5 million due to payments to vendors, and $0.5 million decrease in operating lease liabilities.

Current wording

During the three months ended March 31, 2025, operating activities used $20.2 million of cash, resulting primarily from our net loss of $24.1 million, non-cash accretion of investments in marketable securities of $0.4 million, and changes in operating assets and liabilities of $0.4 million, partially offset by $4.0 million of non-cash stock-based compensation expense, $0.2 million of non-cash depreciation expense, and $0.4 million of non-cash lease expense. The $0.4 million change in operating assets and liabilities is primarily driven by an increase in prepaid expenses and other current assets of $0.8 million, primarily due to advanced payments on new contracts related to our clinical trials, a $0.1 million decrease in operating lease liabilities, partially offset by an increase in accounts payable of $0.2 million and accrued expenses of $0.3 million due to timing of payments to vendors.

Previous wording

During the nine months ended September 30, 2024, net cash used in investing activities was $202.1 million, primarily consisting of purchases of short-term investments of $293.0 million and purchases of property and equipment of $2.2 million, partially offset by maturities of short-term investments of $93.1 million.

Current wording

During the three months ended March 31, 2026, net cash provided by investing activities was $37.9 million, primarily consisting of maturities of short-term investments of $58.3 million and sales of short-term investments of $10.1 million, partially offset by purchases of short-term investments of $30.4 million and purchases of property and equipment of $0.1 million.

Previous wording

During the nine months ended September 30, 2025, net cash used in investing activities was $13.1 million, primarily consisting of maturities of short-term investments of $145.0 million partially offset by purchases of short-term investments of $157.7 million and purchases of property and equipment of $0.4 million.

Current wording

During the three months ended March 31, 2025, net cash provided by investing activities was $21.0 million, primarily consisting of maturities of short-term investments of $64.6 million, partially offset by purchases of short-term investments of $43.2 million and purchases of property and equipment of $0.3 million.

Previous wording

During the nine months ended September 30, 2025, net cash provided by financing activities was $270.5 million, primarily consisting of net proceeds from the September 2025 Offering in the aggregate amount of $269.8 million and proceeds from exercise of stock options of $0.6 million.

Current wording

During the three months ended March 31, 2026, net cash provided by financing activities was $0.5 million, primarily consisting of proceeds from exercise of stock options of $0.8 million, partially offset by payment of deferred offering costs of $0.3 million in connection with the preparation and filing of the 2026 Registration Statement.

Previous wording

As of September 30, 2025, we had cash, cash equivalents and short-term investments of $513.0 million, excluding our restricted cash. As of the issuance date of the condensed consolidated financial statements for the nine months ended September 30, 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 condensed 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.

Current wording

As of March 31, 2026, we had cash, cash equivalents and short-term investments of $476.8 million, excluding our restricted cash. As of the issuance date of the condensed consolidated financial statements for the three months ended March 31, 2026, 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 condensed 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 September 30, 2025, we had future minimum operating lease payments under non-cancelable leases of $14.0 million related to leases we have recognized on our condensed 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 4.8 years.

Current wording

As of the March 31, 2026, we had future minimum operating lease payments under non-cancelable leases of $12.5 million related to leases we have recognized on our condensed 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 4.4 years.

Previous wording

We made an upfront non-refundable, non-creditable payment of $1.0 million to Janssen after we entered into the Janssen License. In October 2022, we exercised the option and made a non-refundable, non-creditable option fee of $4.0 million to Janssen. If we succeed in developing and commercializing TARPg 8 products, Janssen will be eligible to receive (i) up to $76.0 million in development milestone payments and up to $40.0 million sales milestone payments for the product containing the lead TARPg 8 development candidate and (ii) up to $25.0 million in development milestone payments and up to $42.0 million sales milestone payments for the other products containing a non-lead TARPg 8 development candidate. We are also required to pay tiered royalties related to the TARPg 8 development candidate of a mid to high single-digit percentage on worldwide net sales and tiered royalties related to the TARPg 8 products that do not contain a TARPg 8 development candidate of low to mid single-digit percentages on annual net sales of the products covered by the license.

Current wording

We made an upfront non-refundable, non-creditable payment of $1.0 million to Janssen after we entered into the Janssen License. In October 2022, we exercised the option and made a non-refundable, non-creditable option fee of $4.0 million to Janssen. If we succeed in developing and commercializing TARPγ8 products, Janssen will be eligible to receive (i) up to $76.0 million in development milestone payments and up to $40.0 million sales milestone payments for the product containing the lead TARPγ8 development candidate and (ii) up to $25.0 million in development milestone payments and up to $42.0 million sales milestone payments for the other products containing a non-lead TARPg 8 development candidate. We are also required to pay tiered royalties related to the TARPγ8 development candidate of a mid to high single-digit percentage on worldwide net sales and tiered royalties related to the TARPγ8 products that do not contain a TARPγ8 development candidate of low to mid single-digit percentages on annual net sales of the products covered by the license.

Previous wording

NeuroPace Master Services Agreement and Statement of Work

Current wording

NeuroPace Master Services Agreement and Statements of Work

Previous 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 focal onset seizures, 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. The Company has incurred cumulative expenses of $3.4 million on both NeuroPace SOWs through September 30, 2025.

Current wording

In connection 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 statement of work, as amended in February 2026, (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 $5.8 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. The Company has incurred cumulative expenses of $4.5 million on the NeuroPace SOWs through March 31, 2026.

Previous wording

During the nine months ended September 30, 2025, there were no material changes to our critical accounting policies and estimates described under Management’s Discussion and Analysis of Critical Accounting Policies and Estimates which were included in our Annual Report on Form 10-K filed with the SEC on March 11, 2025.

Current wording

For information regarding our critical accounting policies and estimates, please refer to Note 2, “Summary of Significant Accounting Policies” contained in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025. The critical accounting policy below supplements the critical accounting policies discussed in our Annual Report on Form 10-K filed with the SEC on March 10, 2026.