Karyopharm bags an upset win at the FDA as regulators OK myeloma drug despite a host of objections
Somebody high up at the FDA must really like Karyopharm $KPTI.
On Wednesday the biotech announced that the agency had stamped an OK on their application to market selinexor for multiple myeloma, cutting ahead of the late-stage results — though in an intriguing note the agency said they had a look at additional results from an ongoing study.
The approval came despite a solid majority of experts on an outside panel who voted against a quick OK, preferring to see the Phase III data first. And it arrives despite an internal review complete with a host of objections to the data delivered to back the pitch.
The drug will be sold as Xpovio at a wholesale price of $22,000 a month.
Presented with the surprise turnaround, investors bid up the shares by 36% as a copy of the label spread on Twitter ahead of the release.
FDA representatives were polite about it, but outlined multiple problems with the data that Karyopharm presented: Missing data due to dropouts, unacceptable real world evidence, an absence of evidence of positive single agent activity (there are negative results), mostly partial responses and much, much more — all information that the biotech failed to spotlight in the lead-up to the NDA. In one study the FDA cited, the overall survival rate was worse in the selinexor arm.
Then there was the toxicity profile, with a high frequency of treatment emergent adverse events among patients taking the drug. The agency cited a 94% rate of grade 3 or grade 4 adverse event. 10 deaths were due to a fatal adverse event in the main single arm study used for the accelerated approval. And 9 in 10 patients required a dose modification, with a majority requiring 2 modifications.
That case persuaded 8 of 13 experts to vote against an early approval. But the 5 votes in favor illustrated the agency’s appetite for new drugs for patients who have run out of options.
Dana Farber’s David Harrington joined the minority in favor of providing an accelerated approval. “The data are not conclusive in either direction,” he said at the time, but…”I think we do patients some potential benefit if this is used constructively.”
They’ll have that now. The drug is reserved for the last line of defense after at least 4 prior drugs.