Rapport Therapeutics Announces Accelerated Initiation of RAP-219 Phase 3 Program, Expansion of Epilepsy Portfolio, and Continued Progress Across the Pipeline

Rhea-AI Summary

Rapport Therapeutics (Nasdaq: RAPP) announced accelerated initiation of its RAP-219 Phase 3 focal onset seizures (FOS) program, expected to begin in Q2 2026 after an End-of-Phase-2 meeting with the FDA that allows registrational trials. The company is expanding its epilepsy portfolio into primary generalized tonic-clonic seizures (PGTCS) with a planned Phase 3 start in H1 2027.

Other pipeline updates: an open-label long-term safety trial for RAP-219 is enrolling (initial data expected H2 2026), Phase 2 bipolar mania trial remains enrolling with topline expected H1 2027, IND-enabling for a long-acting injectable starts Q1 2026, and the FDA lifted the clinical hold on the RAP-219 DPNP IND while the company defers further DPNP investment to prioritize an α6β4 pain program. Cash was $513.0M at quarter end, which management says funds operations into H2 2029.

Positive

• FDA allowed advancement of RAP-219 into registrational FOS trials
• Phase 3 FOS initiation accelerated to Q2 2026
• Planned Phase 3 start in PGTCS in H1 2027
• Open-label long-term safety trial enrolling; initial data expected H2 2026
• Cash position of $513.0M funds operations into H2 2029

Negative

• Company deferring further investment in RAP-219 DPNP program
• Topline results for RAP-219 bipolar mania trial not expected until H1 2027
• Initial PK results for long-acting injectable not expected until 2027

Key Figures

RAP-219 U.S. opportunity >$2B Market research estimate for focal onset seizures, if approved

FOS Phase 3 start Q2 2026 Initiation of RAP-219 Phase 3 program in focal onset seizures

PGTCS Phase 3 start H1 2027 Planned Phase 3 RAP-219 trial in primary generalized tonic-clonic seizures

Bipolar mania topline H1 2027 Expected topline data from RAP-219 Phase 2 bipolar mania trial

LAI IND-enabling start Q1 2026 Planned start of IND-enabling activities for long-acting injectable RAP-219

Open-label FOS data H2 2026 Initial data from long-term safety open-label FOS trial

Cash & investments $513.0M Cash, cash equivalents and short-term investments at Q3 end

Runway guidance Into H2 2029 Management expectation for funding of planned operations

Market Reality Check

$28.96 Last Close

Volume Volume 275,293 is below the 20-day average of 400,146 (relative volume 0.69x), indicating subdued trading ahead of this news. low

Technical Shares at $27.66 were trading above the 200-day MA $18.62, reflecting a pre-existing uptrend before this update.

Peers on Argus

Key biotech peers showed mixed moves (e.g., ORIC +0.49%, TRVI -3.6%, DNTH -0.85%), suggesting RAPP’s setup was more stock-specific than part of a broad sector trend.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Dec 18	Conference presentation	Neutral	+3.4%	J.P. Morgan conference presentation announcement with webcast access details.
Dec 05	Clinical data update	Positive	+2.6%	New post‑hoc Phase 2a RAP-219 data in focal onset seizures at AES.
Nov 25	Upcoming data presentation	Neutral	+0.9%	Notice of upcoming Phase 2a RAP-219 data presentations at AES 2025.
Nov 06	Earnings and pipeline	Positive	-3.1%	Q3 2025 results, follow-on offering, and positive RAP-219 Phase 2a topline data.
Nov 05	Investor conferences	Neutral	-3.1%	Participation in Stifel and Jefferies healthcare investor conferences.

Pattern Detected

News on RAP-219 clinical data and presentations has often seen positive price reactions, while broader business or conference updates have sometimes coincided with negative or divergent moves.

Recent Company History

Over the past few months, Rapport has steadily built the RAP-219 story. Positive Phase 2a focal onset seizure data and detailed analyses in Nov–Dec 2025 produced modest gains, while Q3 2025 financials and offering details on Nov 6 coincided with a -3.1% move. Conference-related announcements on Nov 5 and Dec 18 had mixed reactions. Today’s announcement advances that clinical trajectory by accelerating Phase 3 timing, broadening epilepsy indications, and updating cash runway beyond 2029, extending themes from prior updates.

Regulatory & Risk Context

Active S-3 Shelf Registration 2025-07-01

$8 million registered capacity

An effective Form S-3 covers 470,589 existing shares for resale by a venture investor. The filing provides no proceeds to Rapport, does not create new shares, and is largely administrative. It has seen 2 recorded 424B5 usages.

Market Pulse Summary

The stock moved +8.9% in the session following this news. A strong positive reaction aligns with prior RAP-219 clinical milestones, which previously saw large moves around data catalysts. The update combines FDA alignment, accelerated Phase 3 timing, and expansion into PGTCS and bipolar mania, supported by cash of $513.0M and runway into H2 2029. However, an existing resale shelf and recent insider sales introduce overhang risks that could temper follow-through if enthusiasm fades.

Key Terms

focal onset seizures medical

"registrational trials for focal onset seizures (FOS); accelerated initiation"

Focal onset seizures are seizures that begin in a specific part of the brain and can cause localized symptoms such as brief changes in awareness, unusual sensations, or jerking in one limb; they can sometimes spread to affect the whole brain. Investors care because these seizures define patient groups, influence how drugs and devices are tested and approved, and shape market size, pricing and risk — like a localized outage that requires a targeted fix rather than a whole-system replacement.

primary generalized tonic-clonic seizures medical

"expanded with new program in primary generalized tonic-clonic seizures (PGTCS)"

A primary generalized tonic-clonic seizure is a type of epileptic event that starts across both sides of the brain at once and causes a sudden loss of awareness, stiffening (tonic) followed by rhythmic jerking (clonic) of the body—think of it like a brief, widespread electrical storm that shuts down normal brain control. Investors care because the frequency and severity of these seizures drive demand, safety profiles, and regulatory outcomes for epilepsy treatments, influencing clinical trial endpoints, market size, and revenue potential.

Phase 3 medical

"initiate its Phase 3 program for RAP-219 in FOS in the second quarter of 2026"

Phase 3 is the late-stage clinical testing step for a new drug or medical treatment, where the product is given to large groups of patients to confirm effectiveness, monitor side effects, and compare it to standard care. Successful Phase 3 results are often the final scientific hurdle before regulators decide on approval and market launch—like passing a final exam before graduation—and can sharply change a company's valuation and future revenue prospects.

Phase 2a medical

"On strength of RAP-219 Phase 2a FOS data, epilepsy portfolio expanded"

Phase 2a is an early stage in testing a new medical treatment or drug, where the main goal is to assess its safety and find the right dosage. For investors, this stage indicates whether the treatment shows initial promise before moving on to larger, more definitive studies; progress here can influence expectations for future development and potential success.

open-label medical

"begun enrolling patients into an open-label, long-term safety trial"

Open-label describes a situation where everyone involved in a study or process knows the full details, such as who is receiving a treatment or intervention. For investors, understanding whether a project or product is open-label helps gauge the level of transparency and potential biases, influencing trust and decision-making. It’s like knowing whether a test or experiment is conducted openly or behind closed doors.

long-acting injectable medical

"long-acting injectable development, FDA’s removal of the clinical hold"

A long-acting injectable is a medication formulated to be given by shot that releases its active ingredient slowly over weeks or months so a patient needs fewer doses. For investors, these products can change a drug’s market value by improving patient convenience and adherence, extending patent life or pricing opportunities, and requiring different manufacturing and regulatory steps compared with daily pills — much like swapping many small payments for a single, larger subscription.

investigational new drug (IND) regulatory

"Investigational New Drug (IND)-enabling activities are expected to start"

An investigational new drug (IND) is a drug or biologic that is being tested but has not yet been approved for general use; it is the application and formal status that allows a company to begin human clinical trials under regulator oversight. Investors care because an IND marks the transition from lab work to human testing — like getting a permit to run real-world experiments — which creates important milestones, costs, timelines and regulatory risk that drive a development-stage company's value.

AI-generated analysis. Not financial advice.

U.S. Food and Drug Administration (FDA) allows advancement of RAP-219 into registrational trials for focal onset seizures (FOS); accelerated initiation of Phase 3 program expected in the second quarter of 2026 

On strength of RAP-219 Phase 2a FOS data, epilepsy portfolio expanded with new program in primary generalized tonic-clonic seizures (PGTCS)

Phase 2 trial in bipolar mania, long-acting injectable, and other pipeline programs continuing to progress

BOSTON and SAN DIEGO, Jan. 07, 2026 (GLOBE NEWSWIRE) -- Rapport Therapeutics, Inc. (Nasdaq: RAPP) (“Rapport” or the “Company”), a clinical-stage biotechnology company dedicated to the discovery and development of small molecule precision medicines for patients with neurological and psychiatric disorders, today announced plans to initiate its Phase 3 program for RAP-219 in FOS in the second quarter of 2026 and expand its epilepsy portfolio with a new program in PGTCS. Additionally, the Company announced progress across its pipeline, including its Phase 2 bipolar mania trial, long-acting injectable development, FDA’s removal of the clinical hold on its Phase 2 diabetic peripheral neuropathic pain (DPNP) trial, and advancement of additional pipeline programs.

“Aligned with the FDA and supported by robust Phase 2a data in focal onset seizures, where we believe RAP-219 potentially represents a multi-billion-dollar market opportunity, we are initiating our Phase 3 trials in FOS ahead of plan,” said Abraham N. Ceesay, chief executive officer of Rapport. “We are excited to expand clinical development into primary generalized tonic-clonic seizures, reflecting our focus on building a growing epilepsy portfolio with a potential best-in-class profile in RAP-219 that will serve as a core strategic pillar for the Company. We are also advancing other important opportunities, including our Phase 2 trial in bipolar mania, long-acting injectable, and additional pipeline programs, applying our precision medicine approach to high unmet-need indications.”

“We are focusing resources on the programs we believe are best positioned to drive impact and value creation. As we advance our strategy in pain, we plan to prioritize our promising α6β4 program in chronic pain and migraine and are deferring investment in the DPNP program for RAP-219 at this time. As we look to the new year ahead, we expect to build on the strong foundation we put in place in 2025, including our robust clinical data in FOS and our successful follow-on offering, and we are focused on disciplined execution to deliver a catalyst-rich 2026 and beyond as we advance key milestones across the portfolio.”

CLINICAL AND PIPELINE UPDATES

Rapport is prioritizing programs it believes have the greatest potential to deliver meaningful impact for patients and long-term value for the Company. This disciplined approach positions the Company for a strong cadence of milestones throughout 2026 and beyond as it advances its pipeline.

RAP-219 Epilepsy Portfolio

• Robust Phase 2a Data in FOS Supports a Multi-Billion Market Opportunity, if Approved. Market research indicates epileptologists and neurologists view RAP-219’s potential best-in-class profile as highly favorable, suggesting a greater than $2B commercial opportunity in the U.S., if approved.
• Updating Guidance on Start of Phase 3 Program in FOS. Following Rapport’s End-of-Phase-2 meeting with the FDA in December, the Company is accelerating the initiation of its Phase 3 program in FOS to begin in the second quarter of 2026, updated from its previous guidance of initiation in the third quarter of 2026.
• Open-label Trial Initiated. The Company has begun enrolling patients into an open-label, long-term safety trial, enabling participants from its recently completed Phase 2a FOS trial to resume RAP-219 treatment. Initial data from the trial is expected to be shared in the second half of 2026.
• Expansion into PGTCS. Building on the robust clinical data from RAP-219’s Phase 2a clinical trial in FOS, Rapport is expanding its epilepsy portfolio into PGTCS, the most common type of generalized seizure and an important next step in addressing unmet need across the epilepsy spectrum. With proof-of-concept established in FOS, Rapport plans to initiate a Phase 3 trial of RAP-219 in PGTCS in the first half of 2027.

Additional RAP-219 Updates

• Bipolar Mania Phase 2 Trial Progress. The Company’s Phase 2 trial of RAP-219 in bipolar mania continues to enroll patients and remains on track to report topline results in the first half of 2027.
• Long-Acting Injectable Development. Development of a long-acting injectable for RAP-219, a key potential differentiator in the epilepsy space, continues to progress. Investigational New Drug (IND)-enabling activities are expected to start in the first quarter of 2026 to support a Phase 1 clinical study in healthy volunteers, with initial pharmacokinetic results expected in 2027.
• DPNP Trial Clinical Hold Lifted. Following further discussions with the FDA in December, the FDA removed its clinical hold on the DPNP IND. The Company is deferring further investment in the RAP-219 DPNP program as it prioritizes its α6β4 program, which it believes has significant potential in chronic pain and migraine.
  

Other Pipeline Updates

• α6β4 Investigational New Drug (IND)-Enabling Activities Underway. Rapport has initiated IND-enabling activities for its development candidate agonist of the α6β4 nAChR, a clinically-validated target the Company is pursuing as a potential novel non-opioid, non-CNS approach for chronic pain and migraine.
  

BUSINESS UPDATES

• Presentation at the 44th Annual J.P. Morgan Healthcare Conference. Rapport Therapeutics will present at the 44th Annual J.P. Morgan Healthcare Conference, being held next week in San Francisco, CA. The Company is scheduled to present on Wednesday, January 14, 2026, at 11:15 a.m. PST. Interested parties may access a live and archived webcast of the presentation in the “Investors” section of the Company’s website at: https://investors.rapportrx.com.
• Cash Position. The Company ended the third quarter with $513.0 million in cash, cash equivalents and short-term investments. Management expects this will be sufficient to fund the Company’s planned operations into the second half of 2029.

About Rapport Therapeutics
Rapport Therapeutics is a clinical-stage biotechnology company dedicated to discovering and developing small molecule precision medicines for patients with neurological and psychiatric disorders. The Company’s founders made pioneering discoveries related to the function of receptor associated proteins (RAPs) in the brain, which form the basis of Rapport’s RAP technology platform. The platform enables a differentiated approach to generate precision small molecule product candidates with the potential to overcome many limitations of conventional neurology drug discovery. Rapport’s precision neuroscience pipeline is anchored by its epilepsy portfolio, including focal onset seizures and primary generalized tonic-clonic seizures, in addition to bipolar mania. The Company is also advancing additional discovery and preclinical programs leveraging its platform, including in chronic pain and migraine and in hearing/vestibular disorders.

Availability of Other Information About Rapport Therapeutics
Rapport Therapeutics uses and intends to continue to use its Investor Relations website and LinkedIn (Rapport Therapeutics) as a means of disclosing material nonpublic information and for complying with its disclosure obligations under Regulation FD. Accordingly, investors should monitor the Company’s Investor Relations website and LinkedIn, in addition to following the Company’s press releases, filings with the Securities and Exchange Commission, public conference calls, presentations, and webcasts. The contents of the Company’s website or social media shall not be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended.

Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, each as amended. The words “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These forward-looking statements include, but are not limited to, express or implied statements regarding: the clinical development of RAP-219 for the treatment of focal onset seizures, primary generalized tonic-clonic seizures, and bipolar mania, including the initiation, timing, progress and results of the ongoing and planned clinical trials; expectations for the efficacy, tolerability, and commercial potential of RAP-219; the potential multi-billion dollar market opportunity for RAP-219 in focal onset seizures, if approved; expectations for the development of a long-acting injectable formulation of RAP-219; the prioritization of the Company’s α6β4 program, including the development candidate’s potential in chronic pain and migraine and the Company’s IND-enabling activities; the deferral of further investment in the RAP-219 diabetic peripheral neuropathic pain program; the potential of Rapport’s RAP technology platform; and expectations for Rapport’s uses of capital, including its cash runway into the second half of 2029.

Forward looking statements are based on management’s current expectations and are subject to risks and uncertainties that could negatively affect Rapport’s business, operating results, financial condition and stock value. Factors that could cause actual results to differ materially from those currently anticipated include: risks relating to the Company’s research and development activities; Rapport’s ability to execute on its strategy including obtaining the requisite regulatory approvals on the expected timeline, if at all; uncertainties relating to preclinical and clinical development activities; the Company’s dependence on third parties to conduct clinical trials, manufacture its product candidates and develop and commercialize its product candidates, if approved; Rapport’s ability to attract, integrate and retain key personnel; risks related to the Company’s financial condition and need for substantial additional funds in order to complete development activities and commercialize a product candidate, if approved; risks related to regulatory developments and approval processes of the U.S. Food and Drug Administration and comparable foreign regulatory authorities; risks related to establishing and maintaining Rapport’s intellectual property protections; and risks related to the competitive landscape for Rapport’s product candidates; as well as other risks described in “Risk Factors,” in the Company’s Annual Report on Form 10-K and most recent Quarterly Report on Form 10-Q, as well as discussions of potential risks, uncertainties, and other important factors in Rapport’s subsequent filings with the Securities and Exchange Commission. Any forward-looking statements represent Rapport’s views only as of today and should not be relied upon as representing its views as of any subsequent date. Rapport expressly disclaims any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in its expectations or any changes in events, conditions or circumstances on which any such statement is based, except as required by law, and claims the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995.

Contact
Julie DiCarlo
Head of Communications & IR
Rapport Therapeutics
jdicarlo@rapportrx.com

FAQ

What did Rapport Therapeutics (RAPP) announce about RAP-219 Phase 3 timing?

Rapport said the RAP-219 Phase 3 focal onset seizures program is accelerating to start in Q2 2026.

When does RAPP expect initial data from the RAP-219 open-label safety trial?

The company expects initial open-label safety trial data in H2 2026.

What is Rapport's plan for RAP-219 in primary generalized tonic-clonic seizures (PGTCS)?

Rapport plans to initiate a Phase 3 trial in PGTCS in H1 2027.

Has the FDA lifted any holds related to Rapport's programs (RAPP)?

Yes; the FDA removed the clinical hold on the RAP-219 DPNP IND, though the company is deferring further DPNP investment.

What is Rapport's reported cash runway and amount (RAPP)?

Rapport reported $513.0M in cash, cash equivalents and short-term investments, expected to fund operations into H2 2029.

When will IND-enabling work for RAP-219 long-acting injectable start and when are PK results expected?

IND-enabling activities are expected to start in Q1 2026, with initial PK results anticipated in 2027.