GPC Biotech was dealt a blow this week as an advisory committee recommended that regulatory bodies should hold off on approval of a novel oral formulation of a platinum-based cancer drug.
Satraplatin, the company's investigational new drug, would be the first and only platinum-based cancer drug that can be taken orally, with all other products in this widely-used group of cancer drugs currently only available as intravenous formulations.
The drug has been submitted to regulatory bodies for the treatment of hormone-refractory prostate cancer in patients for whom prior chemotherapy has failed, with promising trial results from studies evaluating satraplatin with corticosteroid prednisone, versus prednisone with placebo.
Earlier this week, the US Oncologic Drugs Advisory Committee (ODAC) recommended (through a unanimous vote) that the US Food and Drug Administration (FDA) wait for the final survival analysis of the company's SPARC (Satraplatin and Prednisone Against Refractory Cancer) trial before deciding whether the satraplatin application is approvable.
Although the FDA is not bound by the ODAC opinion, the agency will take the recommendation into account when considering GPC's new drug application.
GPC Biotech expressed "great disappointment" regarding the ODAC decision, stating that it continues to firmly believe in the strength of the SPARC trial data.
The company also noted that its most recent analysis had revealed a slowing in the monthly death rates associated with the SPARC trial which, although not unusual, will mean final survival rate results could take longer than initially anticipated.
Bernd Seizinger, CEO of the company, estimated that topline survival data should be available in around six months (a few months later than originally thought), though the timeline could change due to the inherent unpredictability associated with these kind of results.
This would lead to a timescale of around 12 months for full approval of the oral satraplatin formulation.
GPC was granted FDA priority review status for satraplatin back in April this year, which set the target date for FDA action at six months from the date of submission. This pins down the impending FDA decision to 15 August, just over two weeks' time.
In December 2005 GPC signed a co-development and license agreement with Swiss firm Pharmion (a wholly owned subsidiary of Pharmion Corporation), through which the company was granted exclusive commercialisation rights to satraplatin in Europe and certain other territories.
Just last month, Pharmion submitted a marketing authorisation application to the European Medicines Agency (EMEA) for satraplatin in combination with prednisone, triggering milestone payments to GPC and Spectrum Pharmaceuticals, from whom GPC in-licensed the drug in 2002.
If the FDA decides to overrule the ODAC recommendation and approve the oral capsule formulation of satraplatin next month, GPC's original estimates put US market launch as soon as the fourth quarter this year. As such, the company has already been busy establishing a sales and marketing force in the region in anticipation of product approval.
The company has also been investigating additional uses for satraplatin, last year initiating trials with satraplatin in combination with Roche's oral anticancer drug Xeloda (capecitabine), as well as separate combination trials investigating satraplatin with Genentech's Tarceva (erlotinib).