Despite concerns from regulatory staff, advisors to the US Food and Drug Administration have recommended expanding the labels on Pfizer's Sutent and Novartis' Afinitor to cover a rare type of pancreatic cancer.

First up, the FDA's Oncologic Drugs Advisory Committee (ODAC) voted 8-2 that Sutent (sunitinib) provides a favourable benefit-risk profile for the treatment of unresectable pancreatic neuroendocrine tumours (NET). The drug is currently approved across the Atlantic for advanced renal cell carcinoma and Glivec (imatinib)-refractory gastrointestinal stromal tumour, while regulators in Europe gave the thumbs-up in December for pancreatic NET.

Last week staffers at the FDA said they were concerned that as the Pfizer SUN 1111 trial was halted early, there is a risk that Sutent's effectiveness might have been over-estimated, meaning that the magnitude of its effect in pancreatic NET is uncertain. The study was stopped in February 2009, Pfizer notes, "in the interest of patient safety and based on the very strong likelihood that the study would meet its primary endpoint (median progression-free survival) if continued to completion".

Mace Rothenberg, head of clinical development and medical affairs at Pfizer Oncology, said are encouraged by the panel’s favourable review ...we will work closely with the FDA to ensure that it has all of the information that it needs to finalise its review”.

As for Novartis, the ODAC voted unanimously in favour of approval for Afinitor (everolimus) tablets for the treatment of patients with advanced pancreatic NET. The recommendation is based on Phase III results which showed everolimus more than doubled median PFS from 4.6 to 11.0 months when compared with placebo.

FDA staffers had noted in documents released ahead of the ODAC meeting that the data presented by Novartis were "discordant" and that there were discrepancies in the pancreatic NET and a separate trial involving patients with NET in other organs. Last week, Novartis amended its submission to only seek approval for the treatment of patients with advanced pancreatic NET, and not for those with NET of gastrointestinal, lung or pancreatic origin.

Afinitor is presently approved in the USA for advanced kidney cancer in patients who do not benefit from Sutent or Bayer's Nexavar (sorafenib).