Genentech Data Bring Jitters

CHICAGO -- The annual meeting of the American Society of Clinical Oncology has traditionally been the forum where Genentech(DNA Quote) and its blockbuster cancer drug Avastin run away with best-in-show honors.

At this year's confab, however, Avastin is showing a bit of its age. It's still a hugely important drug, but clinical data presented lacked pizzazz:

A phase III lung cancer study of low and high doses of Avastin combined with a chemotherapy regimen popular in Europe showed equal efficacy and lower toxicity at the low dose.

The data are potentially damaging to Genentech's revenue line if doctors both in Europe and the U.S. switch patients to lower doses of Avastin. Currently, doctors treat lung cancer patients with higher doses of Avastin.

In a second study, the addition of Avastin to a standard treatment for kidney cancer doubled progression-free survival and showed a positive trend toward prolonging survival.

This is good news for Avastin, but with a catch: kidney cancer patients are now being treated with several new targeted drugs, including Pfizer's(PFE Quote) Sutent and Onyx Phamaceuticals'(ONXX Quote) Nexavar. A third drug, Torisel from Wyeth, was just approved by the Food and Drug Administration.

In other words, kidney cancer has become a crowded field, so the Avastin regimen, which combines the drug with interferon, is no longer considered a standard treatment.

VEGF-Trap, a potential Avastin competitor under development by Regeneron Pharmaceuticals(REGN Quote), reported disappointing data in a phase II ovarian cancer study. Avastin reported better ovarian cancer data at last year's ASCO meeting, so the VEGF-Trap stumble will likely be seen as an advantage of Genentech.

Let's go through each study in more detail:

Avastin is currently approved for use in the U.S. to treat advanced non-small cell lung cancer when given in combination with carboplatin and paclitaxel, two common chemotherapy drugs.