Stemline Therapeutics (STML)

[guchu]

Shares of Stemline Therapeutics (NASDAQ:STML) tumbled nearly 37% this morning after investors learned that a patient died in a clinical trial involving its lead drug candidate, SL-401. The news was not reported by the company, but confirmed by the patient's family and first reported by Adam Feuerstein of TheStreet.

Not hearing the news directly from management is bad enough, but the death occurred the day before a Jan. 19 stock offering for $45 million. Worse still, this is the third death to occur in a clinical trial involving SL-401 from a side effect known as capillary leak syndrome, a form of low blood pressure. The company had responded to previous patient deaths by altering dosing regimens, so the recent death hints that the drug may not be safe enough for human use in its current form or dosing.

Safety concerns now seem likely to derail an otherwise effective drug candidate -- an increasingly common theme for next-generation immunotherapy treatments. As Feuerstein writes, in earlier clinical trials "SL-401 has demonstrated robust overall tumor response rates of 84%, including 56% complete or near-complete response in patients enrolled in its clinical trial." The company had previously expected to use phase 2 results to obtain marketing approval for the drug candidate, but that now could be in doubt.

https://www.fool.com/investing/2017/02/02/heres-why-stemline-therapeutics-stock-fell-369-thi.aspx