We will be hosting a SCN2A families only Town Hall this Thursday, 9/5/2024 at 12:00PM EST where we will be discussing these updates and data.
Data Implication to our SCN2A Community
The initial phase 2 data for Relutrigine (Prax-562) looks promising for our community, and the update that the trial is expanding to a registrational trial (instead of starting a new study) is good news because it could mean a shorter time to potential approval. Although it's still early days with only seven SCN2A patients dosed, the initial data suggest that Relutrigine could have a material benefit for our early-seizure onset (more gain-of-function) SCN2A community. The trial showed improvements in seizures, communication, disruptive behaviors, and alertness—areas our community has highlighted as major unmet needs.
Topline Results of Phase 2 Relutrigine Study EMBOLD
Praxis Precision Medicines released initial results from the phase 2 EMBOLD study, which tested Relutrigine (PRAX-562) for the treatment of early-onset SCN2A and SCN8A developmental and epileptic encephalopathies (DEE). The trial demonstrated a 46% reduction in seizures compared to placebo, with a safety profile consistent with other drugs in this class. Patients and clinicians also noted early signs of benefit across various domains, including 1) disruptive behavior, 2) communication, 3) seizure severity and intensity, and 4) alertness. Furthermore, patients enrolled in the study's long-term extension reported a 75% median reduction in seizures. Also reported that five patients experienced seizure-free periods longer than 28 days, with one patient exceeding 200 days without seizures.
About the EMBOLD Study
EMBOLD (cohort 1) was a randomized, placebo-controlled phase 2 study testing Relutrigine (Prax-562) in 16 patients (7-SCN2A and 9-SCN8A). Patients were treated for 4 months with daily relutrigine or a regimen of relutrigine daily for 3 months and matching placebo for 1 month, with the timing of placebo administration blinded to both participants and investigators. Key inclusion criteria included: documentation of severe DEE with mutation in SCN2A or SCN8A, ages 2-18 years of age, ≥ 8 countable motor seizures in 4 weeks preceding and during 28-day baseline observation, on stable anti-seizure medication doses for ≥1 month prior to screening.
About Relutrigine
Relutrigine (Prax-562) is an oral next-generation sodium channel blocker that is designed to be more selective to persistent sodium currents and thus have more selectivity to hyperexcitable sodium channels. It has an oral pediatric formulation and is dosed once daily in clinical studies.
Next Steps for the Program
Praxis is expanding the EMBOLD study into a registrational trial (a trial that may support approval by regulators like the FDA). Praxis plans to enroll 80 patients globally (combination of SCN2A and SCN8A patients) into this study.
Find out more
Press Release
Corporate Presentation
Webcast
Data Slides from Praxis’ Corporate Presentation
Reference: PowerPoint Presentation (praxismedicines.com)
Frequently Asked Questions
Drugs typically have to clear multiple clinical trial hurdles in order to support approval. The typical trial phases are 1, 2, and 3 with lower number being earlier trials and larger numbers being more advanced trials.
Phase 1 trials are typically in healthy volunteers and are evaluating initial safety, and dosing in humans. These trials help ensure that the drug is safe enough to be evaluated in patients and also are used to identify an appropriate dosing range for subsequent trials.
Phase 2 trials are typically used to provide proof of concept (that the drug has an efficacy signal, is providing a benefit to patients) and also tests safety in the patient population. These trials often are used to help design and power registrational phase 3 trials.
Phase 3 trials are often the trials used to support the approval of the agent and may be the final clinical hurdle a drug needs to pass in order to be approved by the FDA.
This is a designation granted by the FDA when a drug is being developed to treat a pediatric condition that is serious and life-threatening and occurs in under 200k people in the US.
This is a program used by the US government to incentivize drug development for pediatric rare diseases. If a drug is approved that has been granted the rare pediatric disease designation, then the developing company receives a voucher that grants priority review of a future drug (which can accelerate the developmental time of a drug by ~4 months; for example: if drug#1 is approved and had been granted the rare pediatric disease designation then said company would receive a priority review voucher that they could use on drug#2 ).
This is a designation granted by the FDA when a drug is being developed to treat a rare disease (occurs in under 200k people in the US).
This is a program used by the US government to incentivize drug development for rare diseases. Drugs awarded this designation received a number of incentives by the FDA including: 1. Market exclusivity for 7 years post approval, 2. A waiver of application of user-fees, and 3. A 50% tax credit for clinical testing expenses