Praxis Precision Medicines (PRAX) H.C. Wainwright 26th Annual Global Investment Conference 2024 summary

Key program updates

• Two phase III studies for ulixacaltamide are underway, with strong patient interest and interim readouts planned by year-end.

• PRAX-628 advanced after successful PPR study; RADIANT open-label study to enroll 50 patients and read out in H1 2025, with two registrational studies (POWER1, POWER2) starting late 2024 and early 2025.

• Relutrigine (PRAX-562) showed 46% seizure reduction in EMBOLD study; moving to registrational studies for SCN2A/SCN8A and broader DEE populations.

• Elsanorisen demonstrated 43% seizure reduction; advancing to a global registrational study with protocol harmonization across regions.

• Recent capital raises extend financial runway into 2027, supporting the full clinical portfolio.

Clinical strategy and trial design

• Interim analysis for ulixacaltamide is a pre-specified part of the statistical plan, serving as an insurance policy to adjust for unforeseen placebo effects.

• If more patients are needed post-interim, final readout may shift to early 2025.

• Emphasis on robust trial design, statistical powering, and compliance to mitigate risks seen in competitor studies.

• Relutrigine and elsanorisen are viewed as potentially complementary therapies for SCN2A gain-of-function patients, with future sequencing strategies to be determined.

• Broader DEE development for relutrigine will use a phenotypically driven approach, aiming to replace or add to current sodium channel therapies.

Pipeline evolution and future milestones

• Focus remains on executing current late-stage programs, with earlier-stage assets deprioritized but available for future development.

• RADIANT study for PRAX-628 will provide open-label data in H1 2025; POWER1 registrational study data expected in H2 2025.

• Generalized epilepsy may be pursued as a line extension for PRAX-628, likely requiring only one additional study.

• Ongoing efforts to harmonize global protocols for registrational studies, especially for rare disease programs.

• Regular updates planned as additional epilepsy studies progress.