FDA orders Karyopharm to halt enrollment for all selinexor trials, citing incomplete safety warning

Late Friday night Karyopharm Therapeutics $KPT alerted investors that the FDA has slapped a partial hold on all studies involving its lead cancer drug selinexor, halting enrollment for work on a drug that was recently tapped for a 2018 filing with the FDA.

Regulators ordered the partial hold after citing, in writing, incomplete information in a brochure on the drug which included an incomplete list of the adverse events associated with the drug. The statement does not say when the agency first informed the company of the partial hold, but Karyopharm says that as of Friday the company has supplied the information requested to get the hold lifted.

Saying you’ve responded to the FDA at the same time you’re announcing a partial hold raises some questions on timing. How long did the company know about the hold before the alert late Friday?

“Karyopharm Therapeutics received the letter notifying the company of the partial clinical hold within the past week,” a company spokesperson said in response to a query from me. The spokesperson did not answer my query on how many days ago the notice arrived or whether regulators had told them verbally earlier, which is routine.

The suspensions were flagged on Twitter Friday, well ahead of the news, after the biotech’s shares slid 10% ahead of the close.

The Newton, MA-based biotech added that it believes the halt won’t affect the development timelines already offered. Karyopharm, led by CEO Michael Kauffman, lists 8 different clinical programs for selinexor on its web site.

Brian Abrahams at Jefferies was happy to write it off as “just an administrative blunder.”

After speaking with management, our understanding is that this is due to an AE (adverse event) table that had inadvertently been removed from the investigator’s brochure and informed consent forms used in the trials in a recent version. FDA requested that the table be updated and re-inserted, and KPTI has provided that updated information. Our understanding is that this is purely an administrative blunder, and that there have been no new safety issues or deaths from the drug. While this is not favorable for their credibility regarding trial conduct, we believe the company has taken action to improve their processes such that going forward human error should not cause another minor setback in their development program.

Karyopharm touted data from a single-arm study last fall demonstrating a partial response in roughly 1 in 5 patients out of 78 evaluable patients suffering from drug-resistant multiple myeloma. And they gained a spike in the stock price by comparing that favorably to historical data. The biotech planned to add another 120 patients to that study and take the data to the FDA in search of an accelerated approval.

Just a few days ago, though, the biotech also conceded that the drug failed a mid-stage study for acute myeloid leukemia. Selinexor works by inhibiting the nuclear export protein XPO1 (also called CRM1), triggering cell apoptosis.

The best place to read Endpoints News? In your inbox.

Comprehensive daily news report for those who discover, develop, and market drugs. Join 44,100+ biopharma pros who read Endpoints News by email every day.

Free Subscription

Sr. Manager, Regulatory Affairs, CMC
CytomX Therapeutics San Francisco, CA
Marketing Associate - Demand Generation
Catalytic Data Science Charleston, SC
Associate Principal, Life Sciences Partnerships
Flatiron Health New York City or San Francisco

Visit Endpoints Careers ->