By the end of day Friday shares of Human Genome Sciences ($HGSI) had been trimmed 11 percent as investors fretted over the implications of an FDA staff analysis of its lupus drug Benlysta, which goes in front of an expert panel tomorrow.
The nut of the issue boils down to balancing Benlysta's modest benefit for lupus patients-particularly in the second Phase III study--against some serious risks like death, infection and a potential for suicidal behavior. And the panelists will also have to weigh evidence of a difference in risks and benefits when patients were broken down by race and geography, with lower efficacy rates for the U.S. and Canada as well as among African-Americans.
BioWorld notes this morning that the key safety issue that seemed to spook investors was the risk of suicide. Three patients taking Benlysta committed suicide during the trial process. But the panel won't be specifically voting on the issue and analysts noted that suicide isn't all that uncommon among patients with the disease.
Analysts didn't seem too worried by the staff review, which followed a common template in highlighting the most serious questions to be considered when reviewing a new therapy. "We saw no new data that [Human Genome] has not previously released that looked less positive than what has previously been presented, and continue to expect a positive panel vote," noted analyst Joseph Schwartz.
The review will be crucial for HGS's future. Benlysta promises to be the first new lupus drug in about a half century, and its shares have been pushed sky high in anticipation of its approval. Any countervailing winds would batter the stock price.