Zogenix (NASDAQ: ZGNX) reported what it called "positive" results from a late-stage clinical trial testing its drug candidate, Fintepla, in patients with a variety of childhood-onset epilepsy called Lennox-Gastaut syndrome. And technically, the company was right: Fintepla reduced the median number of monthly drop seizures by 26.5%, compared to a median reduction of 7.8% in patients taking a placebo.
But shares of Zogenix were down by 37% at 2:25 p.m. Friday because, while Fintepla did beat the placebo, that 26.5% reduction in seizures was fairly small. The highest dose of GW Pharmaceuticals' (NASDAQ: GWPH) Epidiolex, a cannabidiol derived from cannabis, produced reductions of 42% and 44% in the two clinical trials that led the Food and Drug Administration to approve it for treating patients with Lennox-Gastaut syndrome. The placebo effects in the Epidiolex studies were higher, with reductions of 17% and 22%, respectively, but even factoring that in, it appears that Epidiolex (25% and 22% placebo-adjusted) works better than Fintepla (18.7% placebo-adjusted) in Lennox-Gastaut syndrome.
Shares of GW Pharmaceuticals were up almost 7% on news of its rival's positive-but-not-so-much results.