Praxis Precision Medicines has received Breakthrough Therapy Designation from the US Food and Drug Administration for elsunersen, its experimental treatment for seizures linked to SCN2A developmental and epileptic encephalopathy.
The decision was based on results from EMBRAVE Part A, a Phase 1/2 study in children aged two to 12 with early-seizure-onset SCN2A-DEE caused by gain-of-function variants. In the study, elsunersen produced a 77% sham-adjusted reduction in monthly seizures from baseline, with a statistically significant result. Praxis also reported that 71% of treated patients had their seizures cut by more than half, while 57% had at least one 28-day period with no seizures during the six-month treatment period.
The follow-up data also supports the case for continued development. Praxis said the treatment effect was maintained in the open-label extension for up to one year. The company also reported a favourable safety profile so far, with no drug-related serious adverse events, no treatment discontinuations and no signs of neuroinflammation at doses up to 8 mg. Most treatment-emergent adverse events were mild or moderate.
Breakthrough Therapy Designation can give Praxis more frequent interaction with the FDA and may help speed up the development and review process if the data continues to support approval. elsunersen is now moving through a pivotal study called EMBRAVE3, which has been aligned with the FDA as a streamlined, single-arm registrational trial. The study is expected to enrol about 30 patients, all of whom will receive elsunersen for 24 weeks, followed by a further 24-week extension.
Biotech Growth Trust has a portfolio holding in Praxis Precision Medicines. The FDA designation adds a relevant development milestone within the trust’s biotech exposure, with the next key area of focus likely to be execution of EMBRAVE3 and the durability of clinical data as the programme moves closer to a potential regulatory filing.
Biotech Growth Trust plc (LON:BIOG) seeks capital appreciation through investment in the worldwide biotechnology industry. The Company and the Company’s Portfolio Manager believe that there is a high congruence between companies that seek to act responsibly and those that succeed in building long-term shareholder value.
