Why A Patient Death Doesn't Necessarily Scuttle Stemline's Chances For SL-401 Approval

Following Stemline Therapeutics Inc STML's announcement of the third confirmed capillary leak syndrome related death in the company’s ongoing Phase 2 Blastic Plasmacytoid Dendritic Cell Neoplasm study, Wedbush’s David M. Nierengarten expressed concern regarding a possible FDA hold and viability of the SL-401 program.

The analyst reiterated an Outperform rating on the company, while lowering the price target from $19 to $11.

Patient Death

Nierengarten believes the drug is still approvable, although possibly only for use in the BPDCN setting.

Two other CLS-related deaths were previously reported by the company during the dose-escalation stage of the study.

However, until this recent death, “no additional cases of severe CLS had been observed in study at up to 12 µg/kg dose following implementation of safety precautions, which included monitoring of albumin and transaminase levels and body weight,” Nierengarten stated.

Timelines Maintained

Stemline Therapeutics said that it would provide additional data on the completion of cohort dosing, while maintaining the previous timelines of enrollment completion in the current quarter and Biologics Licensing Application filing in the second half of 2017.

“No FDA action has been reported yet, and all studies of SL-401 remain open; given that two weeks have passed, we suspect that if FDA was going to put program on hold it would have done so by now,” the analyst noted.