Surprise FDA Approvals of Rejected Drugs Are No Sign of Mercy
No one expected last week's FDA approval of insomnia drug Silenor (doxepin), but it wasn't the first pleasant surprise the agency has delivered of late. So is the FDA becoming more merciful? Not likely.
Silenor, from biotech Somaxon Pharmaceuticals (SOMX), had been rejected twice, the first time prompting Somaxon to narrow its indication and the second time due to a lack of robustness in the efficacy data. Nearly everyone interpreted that as a dreaded request to go do another expensive trial, and Somaxon, with all of about $5 million to its name, looked dead in the water.
Somaxon resubmitted its application again just using existing data -- an often-tried but not-often-successful strategy. The agency's decision to green-light Silenor sent the biotech's stock up 130 percent.
Then there's the case of CombinatoRx (CRXX), which earlier this month got FDA approval of once-daily pain drug Exalgo (hydromorphone). The drug previously had been rejected and bounced through the hands of at least three other companies.
Last month brought the approval of Auxilium Pharmaceuticals' (AUXL) Xiaflex (collagenase Clostridium histolyticum) for hand contracture, which came as somewhat of a surprise because the FDA was several months late on the decision, leaving the company in regulatory limbo even after a positive advisory panel review last fall.
And who could forget last year's surprise approval of Vanda Pharmaceuticals' (VNDA) schizophrenia drug Fanapt (iloperidone), another former FDA reject that turned into a 600 percent single-day stock gainer.
But it's hard to argue that these pleasant surprises are an indication of FDA mercy; the agency has smacked down plenty of other drug hopefuls of late, like XenoPort (XNPT)'s restless legs drug Horizant. If anything, they might be evidence that persistence pays off. But the tricky thing about persistence is that it toes a fine line with delusion, and it's hard to tell which side of the line you're on until you're looking back with 20/20 hindsight.
Flying pig photo from WikiCommons
