PRAX: Relutrigine Major Amendment Surprising - Fundamentally Manageable, But Highlights Regulatory Risks

Research evidence excerpt

PRAX: Relutrigine Major Amendment Surprising - Fundamentally Manageable, But Highlights Regulatory Risks

EQUITY RESEARCH QUICK TAKE

RBC Capital Markets, LLC

Leonid Timashev, Ph.D. (Analyst)

Joshua Brewer, Ph.D. (Associate)

June 29, 2026

Praxis Precision Medicines, Inc.

Relutrigine Major Amendment Surprising - Fundamentally Manageable, But Highlights

Regulatory Risks

NASDAQ: PRAX | USD 350.56 | Outperform | Speculative Risk | Price Target USD 449.00

Sentiment: Negative

Today PRAX announced a major amendment for relutrigine (a Na+ channel drug for SCN2A and SCN8A DEEs), which now pushes

the PDUFA date to December 27, '26 (from September 27, '26), and delaying a potential launch by ~3 months.

The extension was issued following Praxis’s submission of additional sensitivity analyses of existing clinical data. While the agency

performing sensitivity analyses is routine, given what we saw as reasonably clear-cut data (53% seizure reduction, p <0.0002 in

the registrational cohort) that was unlikely to be due to chance, the fact that additional analyses by the agency warranted a major

amendment is surprising to us. This could be a signal that either the FDA requires more time to look into the detailed data due to

its complexity or due to ongoing staffing issues at the agency (which we have frequently called out as a risk to complex packages),

or that the original dataset might not be convincing for approval (e.g. recall BHVN had received one for SCA and was rejected).

The FDA did not request any new clinical studies, nor did it raise any new safety or manufacturing concerns in relation to the

application, which are more likely signs of a CRL.

That said, this appears to be a second misstep in recent months, following vormatigine's trials being paused after the sodium