Global Blood Therapeutics surprised some observers this morning with their plan to take the first round of positive late-stage data for the sickle cell disease drug voxelotor straight to the FDA in search of an accelerated approval.
The regulatory strategy is based on their data for the primary outcome of the study, with 58% of the patients in the high dose of the arm demonstrating a 1 g/dL-plus increase in hemoglobin at 12 weeks compared to only 9% of patients taking a placebo. In the lower-dose arm there was a 38% response rate, passing the bar set by the FDA.
Elliott Vichinsky, the director of the Comprehensive Center for Sickle Cell Disease, UCSF Benioff Children’s Hospital Oakland, said that “increasing hemoglobin levels by reducing hemolysis in SCD patients is likely to decrease morbidity and mortality.”
“Based upon voxelotor’s robust impact on hemolytic anemia, we believe it meets the standard for accelerated approval,” said CEO Ted Love, “and we look forward to providing further updates on our regulatory discussions as soon as possible, but no later than year-end.”
But some investors were clearly not ready to go so fast, moving past the triumphalism in the biotech’s remarks to some discordant notes in the presentation this morning.
Researchers failed to see a statistically significant reduction in rates for vaso-occlusive crisis (VOC), which they attributed to “limited patient follow-up.” And their attempt to gain a big thumbs-up from patients by tracking patient reported outcomes proved a complete bust, forcing execs to try and put some distance between themselves and the PRO results by dropping it as a key secondary.
Those distinctions caused some hedging on the stock reaction, with a brief surge followed by a dip into the red as the share price waffled. But by mid-afternoon, the optimists appeared to have won out, with the share price surging 20%.
The biotech’s move to win a quick OK on the Part A data fits in with the current flexible approach that the FDA under Scott Gottlieb has promised as regulators hustle to bring more drugs to the market. GBT now has to see just how flexible regulators are.
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