An oncology advisory committee (ODAC) yesterday recommended that FDA delay considering prostate cancer candidate satraplatin for approval until overall survival data from the company’s 950-patient SPARC study is available. This recommendation came despite interim analysis strongly supporting the efficacy and safety of satraplatin, which was granted priority FDA review in April 2007.
Still, it wasn’t a complete surprise, at least since the rather negative FDA briefing documents released last week. These raised five “issues” including questions over the company’s assessment of pain progression, and, more importantly, over the definition and composition of one of GPC’s two key primary end-points used in the trial, progression free survival (PFS).
According to GPC’s “greatly disappointed” CEO Bernd Seizinger, GPC had communicated intensively with FDA throughout the application process and amended various aspects of the trials in accordance with FDA suggestions—including suggestions on what pain score to use. In sum, they’d done everything possible to make this work. (Listen for yourselves here.)
But FDA wasn’t having it. According to one analyst, “GPC walked into a complete stitch-up—FDA primed the advisory committee that they didn’t want this to happen.” Reading the briefing document, we’re inclined to agree.
Now, sources tell IN VIVO Blog that there’s no love lost between GPC and FDA—the ODAC meeting was “hostile and antagonistic,” according to one observer. Combine this with FDA’s overall caution (the last thing they want is to be hauled in front of the Senate for injudicious approvals) and you have a recipe for delay, if only temporary.
Still, GPC isn’t just an innocent victim here. Let’s go back to that issue of end-points. The briefing documents state that FDA had all along warned GPC that a PFS end-point may be problematic. Yet GPC failed to communicate this concern to the investment community.
That’s why analysts are so pissed—many had buy ratings on the stock, even after the review documents were released last Thursday. GPC shares fell 35% back then, and about the same again today. “Trust has been lost,” says one in London. “When it comes to the investment community, GPC are on their own.” (They can sulk in a corner beside Sanofi Aventis, which hasn't won any prizes for transparency among the investment community either, particularly with regard to Zimulti's rocky ride, on which we've reported extensively, including here.)
It’s a worrying time for the German biotech. All of a sudden, the overall survival data for satraplatin—which is the other primary end-point, alongside PFS--has become a make-or-break issue for the company. If it’s positive, the drug will probably still make it, although not in an accelerated fashion. If it’s not, the drug may not get onto the US market at all—which could prove fatal for GPC.
The rest of the sector has cause for concern, too, though (not to mention androgen-independent prostate cancer patients that have failed first-line therapy). This bleak little episode—besides showing up personal clashes between applicants and the agency, which, it seems, do matter—may mean that regulators’ caution is spreading beyond primary-care drugs like Avandia or the Cox-2s, where the main concern is safety.
Today, it seems, the tough hurdles can come from anywhere--including from non-safety-related issues like how pain is measured. Some might call this nit-picking.