Rapport Therapeutics (RAPP) investor relations material

Key clinical data and trial design

• Phase 2 trial for RAP-219 in drug-resistant focal epilepsy showed statistically significant reductions in both electrographic and clinical seizures, with a 78% median reduction and 24% seizure freedom rate.

• The trial used a novel design enrolling patients with implantable RNS neurostimulation devices, enabling objective electrographic biomarkers to corroborate clinical outcomes.

• Patient population was highly refractory, with most on three or more anti-seizure medications, supporting translatability to broader Phase 3 studies.

• Efficacy and biomarker data were consistent across patients, including those with leads outside the mesial temporal lobe, reinforcing confidence in the drug’s mechanism.

• The drug’s once-daily dosing, long half-life, and low risk of drug-drug interactions support broad clinical use.

Safety and tolerability profile

• RAP-219 demonstrated a highly differentiated tolerability profile, with no adverse events greater than grade two and a low discontinuation rate of 10%.

• No cases of aggression or rage were observed, and rates of sedation, somnolence, and motor impairment were lower than with comparator drugs like Fycompa.

• Discontinuations were due to baseline conditions (memory impairment, anxiety, panic attack), not drug-related neuropsychiatric effects.

• The safety profile is considered suitable for use by general neurologists and internists, not just epileptologists.

Commercial and market opportunity

• The addressable U.S. market includes 560,000 treatment-resistant patients, with potential to expand as the drug moves up the treatment algorithm.

• Market research and community feedback suggest the drug could exceed initial peak sales estimates of $1.5 billion, potentially reaching levetiracetam-like adoption.

• RAP-219’s profile supports rational polypharmacy and broad adoption due to minimal drug-drug interactions.

• Plans are underway for a long-acting injectable formulation, which could be transformative for patient management and further expand the market.