Genentech and OSI Pharmaceuticals’ anticancer drug Tarceva (erlotinib) in combination with Eli Lilly’s Gemzar (gemcitabine) will come before a US Food and Drug Administration advisory panel today as it seeks to determine whether to recommend the drug for treating pancreatic cancer. But the firms look to be in for a rocky day as briefing papers state the compound’s survival benefit not to be clinically meaningful.

“Although some analyses showed statistically significant differences between” Tarceva/Gemzar versus Gemzar alone, “no clinically meaningful differences in response rate, duration of response, [progression free survival] or overall survival were observed,” the FDA says. In one Phase III study, the Tarceva combination demonstrated an approximately 12-day survival advantage over Gemzar alone (6.37 vs. 5.95 months). In addition, the FDA has also observed some gender differences between the two arms, which it says “may explain, at least in part, the differences in overall survival and [progression free survival]” amongst Tarceva receivers.

Again, safety is also an issue. Alongside expected increases in low-grade adverse events, the FDA briefing paper also notes a greater frequency of “stroke, cardiac ischemia/infarction, stent occlusion, infections, [interstitial lung disease]-like events and GI bleeding.” Furthermore, there were five deaths attributed to Tarceva compared to zero in the control arm. “The numbers are small but suggest an increase in the drug-toxicity associated with death in the” Tarceva group, the FDA adds.

The company has previously said that it hopes to win approval of Tarceva – which is already marketed for use in non-small cell lung cancer [[22/11/04d]] - by November [[09/08/05d]], but this is looking uncertain now as the FDA briefing papers call for additional studies to be conducted prior to granting the compound marketing clearance. The firms are seeking an indication for Tarceva, in combination with Gemzar, for first-line treatment of patients with locally advanced, unresectable and/or advanced pancreatic cancer.