Phase 2a follow-up period data for RAP-219 in focal onset seizures (FOS) demonstrated sustained seizure reduction, including a 90% median reduction in clinical seizures over baseline in weeks 9-12

RAP-219 Phase 2 trial in bipolar mania topline results now expected in the fourth quarter of 2026, ahead of previous 1H 2027 guidance

RAP-219 Phase 3 program in FOS remains on track for initiation in the second quarter of 2026

Pipeline programs, including RAP-219 long-acting injectable formulation, RAP-219 in primary generalized tonic-clonic seizures, and <ALPHA>6<BETA>4 nAChR in chronic pain and migraine, continue to advance

Strategic collaboration and license agreement entered into with Tenacia Biotechnology to develop and commercialize RAP-219 in Greater China across indications

Ended the first quarter of 2026 with $476.8 million in cash, cash equivalents and short-term investments, excluding restricted cash, expected to fund operations into the second half of 2029

BOSTON and SAN DIEGO, May 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 or psychiatric disorders, today reported financial results for the quarter ending March 31, 2026, and provided a business update.

"We entered 2026 with strong momentum across the RAP-219 development program, highlighted by compelling new follow-up Phase 2a data recently presented at AAN that further reinforces RAP-219's treatment effect in focal onset seizures and builds confidence as we enter our Phase 3 trials," said Abraham N. Ceesay, chief executive officer of Rapport. "With multiple important development milestones ahead, including continued advancement of our epilepsy franchise, progress in bipolar mania, and development of our long-acting injectable formulation, we believe we are well positioned to continue building value across our pipeline."

CORPORATE HIGHLIGHTS

RAP-219 in Epilepsy

   -- Positive Phase 2a Follow-up Period Data Reinforces RAP-219's Sustained 
      Activity in Focal Onset Seizures. In April 2026, Rapport presented new 
      8-week follow-up period data from its Phase 2a trial of RAP-219 in 
      patients with drug-resistant FOS at the American Academy of Neurology 
      $(AAN)$ Annual Meeting. 
 
          -- Therapeutic levels of RAP-219 were sustained, resulting in 
             continued biomarker and clinical responses in the 8-week follow-up 
             period (weeks 9-16). 
 
          -- RAP-219 continued to demonstrate clinically meaningful 
             improvements in long episodes (LEs) and clinical seizures during 
             the follow-up period, with an 80% median reduction in LEs and 90% 
             median reduction in clinical seizures compared to baseline in 
             weeks 9-12 and a 68% median reduction in LEs and 59% median 
             reduction in clinical seizures compared to baseline in weeks 
             13-16. 
 
          -- 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. 
 
   -- Phase 3 Program in FOS. Following feedback from an end-of-Phase 2 meeting 
      with the U.S. Food and Drug Administration (FDA) in December 2025, the 
      Company accelerated the initiation of its Phase 3 program in FOS, which 
      is on track to begin in the second quarter of 2026. 
 
   -- Open-label Trial Initiated. The Company is enrolling patients from its 
      Phase 2a FOS trial into an open-label, long-term safety trial. Data from 
      the trial is expected to be released in the second half of 2026. 
 
   -- Expansion into Primary Generalized Tonic-Clonic Seizures (PGTCS). 
      Building on the robust clinical data generated in FOS, Rapport plans to 
      initiate a Phase 3 trial of RAP-219 in PGTCS in the first half of 2027, 
      expanding its epilepsy franchise into the most common type of generalized 
      seizure. 

Additional Pipeline Updates

   -- Bipolar Mania Phase 2 Trial Topline Results Expected Ahead of Plan. 
      Enrollment in the Phase 2 trial is progressing well and topline results 
      are now expected in the fourth quarter of 2026, ahead of the previous 
      guidance of first half of 2027. Additionally, the Company modified the 
      trial's statistical analysis plan and increased target enrollment, 
      enabling the trial to potentially be considered as confirmatory evidence 
      of effectiveness. Following completion of the Phase 2 trial, and subject 
      to the results, the Company plans to engage with the FDA in an 
      End-of-Phase 2 meeting to align on the design of a potential Phase 3 
      program to support a New Drug Application for the treatment of bipolar 
      mania. 
 
   -- Long-Acting Injectable Formulation Development Continues. Development of 
      RAP-219's long-acting injectable formulation continues to advance, with 
      IND-enabling activities underway and initial Phase 1 pharmacokinetic data 
      expected in 2027. 
 
   -- <ALPHA>6<BETA>4 Program Advancing Toward Clinic. Rapport continues 
      IND-enabling activities for its <ALPHA>6<BETA>4 nAChR agonist development 
      candidate, which is being developed as a potential novel non-opioid 
      treatment for chronic pain and migraine. 

Business Updates

   -- Strategic Collaboration with Tenacia Biotechnology. In March 2026, 
      Rapport entered into a strategic collaboration and license agreement with 
      Tenacia Biotechnology (Hong Kong) Co., Ltd. (the Tenacia License 
      Agreement) for the development and commercialization of RAP-219 in 
      Greater China across indications, including FOS and bipolar mania. 

FIRST QUARTER 2026 FINANCIAL RESULTS

   -- Net Loss: Net Loss for the first quarter of 2026 was $19.9 million, as 
      compared to $24.1 million for the prior year period. 
 
   -- Collaboration Revenue: Collaboration revenues were $20.0 million for the 
      first quarter of 2026, as compared to zero for the prior year period due 
      to the execution of the Tenacia License Agreement in the first quarter of 
      2026. 
 
   -- Research and Development (R&D) Expenses: R&D expense was $32.7 million 
      for the first quarter of 2026, as compared to $19.6 million for the prior 
      year period. The increase in R&D expense was primarily driven by 
      operational costs related to clinical development and costs to support 
      the progression of the Company's overall pipeline. 
 
   -- General and Administrative (G&A) Expenses: G&A expense was $11.5 million 
      for the first quarter of 2026, as compared to $7.5 million for the prior 
      year period. The increase in G&A expense was primarily driven by costs 
      associated with the growth of the business. 
 
   -- Cash Position: The Company ended the first quarter of 2026 with $476.8 
      million in cash, cash equivalents and short-term investments, excluding 
      restricted cash, compared to $490.5 million as of December 31, 2025. 
 
   -- Cash Runway: The Company expects that cash, cash equivalents, and 
      short-term investments as of March 31, 2026, will enable it to fund its 
      operating expenses and capital expenditure requirements into the second 
      half of 2029. 

About RAP-219

RAP-219 is an investigational and potential first-in-class, clinical-stage TARP<GAMMA>8-specific AMPA receptor (AMPAR) negative allosteric modulator (NAM). Whereas AMPARs are distributed widely in the central nervous system, the receptor associated protein (RAP) TARP<GAMMA>8 is expressed only in discrete brain regions, including the hippocampus and neocortex, where focal seizures often originate. By contrast, TARP<GAMMA>8 has minimal expression in the hindbrain, where drug effects are often associated with intolerable adverse events. With this precision approach, the Company believes RAP-219 has the potential to provide a differentiated profile as compared to traditional neuroscience medications. Due to the role of AMPA biology in various neurological disorders and the selective targeting of TARP<GAMMA>8, the Company believes RAP-219 has pipeline-in-a-product potential and is evaluating the compound as a potential treatment for patients with focal onset seizures, primary generalized tonic-clonic seizures and bipolar mania. A long-acting injectable formulation of RAP-219 is also in development and could be the first of its kind in epilepsy.

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 includes the Company's lead investigational drug, RAP-219, which is designed to achieve neuroanatomical specificity through selective targeting of a RAP expressed only in discrete regions of the brain. The pipeline is anchored by the Company's epilepsy portfolio, including FOS and primary generalized tonic-clonic seizures, as well as bipolar mania. The Company is also advancing additional discovery and preclinical programs leveraging its platform, including in chronic pain and migraine and in hearing and vestibular disorders.

Availability of Other Information About Rapport Therapeutics

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