In July 2010, an advisory panel voted 12-1 to urge the FDA to withdraw the approved use of Avastin in metastatic HER2-negative breast cancer. As a result of this announcement, IntrinsiQ hypothesized that physicians would immediately decrease the use the drug in new patients. We also believed that physicians would continue the course of therapy in existing patients, drawing out the decline we would see in Avastin sales. In fact, within the first three months after the advisory panel’s announcement, the usage of Avastin dropped across all lines of therapy as physicians grew reluctant to prescribe the drug when choosing their next course of therapy.

Prior to the public chatter on the FDA review, Avastin was selling approximately $160-$180MM per quarter in the U.S. breast cancer market. These sales were divided practically evenly by metastatic line of therapy. IntrinsiQ estimated the initial market event was significant enough to adversely affect Avastin sales in this tumor. We publicly reported that around $60MM per quarter would be lost within the next three months, but the decline would lose considerable momentum prior to any official FDA decision. A retrospective analysis looking at Avastin clearly shows that sales dropped as expected. IntrinsiQ’s extensive library of oncology market analogs will often show that commonly-believed benign market events (like FDA reviews for approved drugs) are often important enough to reduce sales up to 60% practically overnight.

Unfortunately for other products in the breast cancer market, this does not necessarily open the door for new therapies. We believe that there is no real replacement for Avastin in breast cancer in today’s market. Avastin is primarily seen as an add-on therapy and didn’t replace anything at launch. We believe that the market will revert back to historical usage patterns, or taxanemonotherapy and combination use without adding Avastin.

In December 2010, the FDA moved to withdraw the approval of Avastin in metastatic HER2-negative breast cancer based on the lack of clinical benefit shown in the trial data. We are not in the right position to provide the clinical insight into the FDA’s evaluation of efficacy significance weighed against the drug’s risks. All we can say is that the breast cancer uptake of Avastin was nowhere near the initial expectations of Financial Analysts, and the continued decline will also be much smaller after the approval’s withdrawal. The majority of the market impact on Avastin occurred immediately after the advisory panel vote. Further declines will be less significant and there will also be some continued use, albeit a fraction of what we saw in early 2010, of Avastin in breast cancer.

The FDA’s move makes it clear that the panel is thinking very much like doctors, seeking the greater survival benefit of drugs tailored to specialized patient populations. In the breast cancer space, this means that blanket approval for a costly drug for all HER2-negative patients is simply too large a market. Clinical trials will increasingly need to test for biomarkers, across all cancer markets.The FDA will likely only become stricter in its reviews.

This is a huge problem for Roche who purchased the treatment as part of its merger with Genentech. The drug firm could see sales drop by $1 billion if FDA agrees with the panel and ceases use of the drug for breast cancer. The drug earned Roche $5.7 billion in 2009.

“We are disappointed by the committee’s recommendation and believe Avastin should continue to be an option for women with this incurable disease,” stated Sandra Horning, Roche’s global head of clinical development hematology/oncology, in a release. “We will continue to discuss the data from the more than 2,400 women who participated in three Phase III studies with the FDA. This recommendation does not impact Avastin’s approved uses for other cancer types.”

Avastin (in combination with chemotherapy) was given fast-track approval in early 2008, because it treated HER2 negative breast cancer, a form of the disease with few treatment options. FDA requested that Genetech release the results of two post-market trials to determine how effective the drug is at improving patient lifespan.

According to the two trials, the treatment only slowed cancer progression by approximately a month and didn’t do anything to boost patient survival. Additionally, patients taking Avastin had more adverse reactions than patients taking chemotherapy alone.

FDA will give a final ruling on Sept. 17.

Score another win for Genentech and its cancer treatment Avastin (bevacizumab). On Monday, the biotech giant, now owned entirely by Roche, announced that FDA has approved the drug for kidney cancer.

Avastin blocks new blood vessels from forming and supplying tumors with the nutrients they need to grow and spread to other parts of the body.

Since it was first approved in 2004, Genentech has expanded Avastin’s uses to colorectal cancer, breast cancer, and non-small cell lung cancer. According to Roche, the treatment is being tested for treatment in more than 30 tumor types.

“We hope that researchers some day find a cure for kidney cancer,” stated William P. Bro, chief executive of the Kidney Cancer Association, in a release.  “Until then, each new medicine, like Avastin, offers patients an opportunity to find the treatment best suited for them.”

FDA approved this indication of Avastin after reviewing data from a study that documented a 67 percent increase in progression-free survival of patients receiving Avastin for previously untreated metastatic renal cell carcinoma. Additionally, 30 percent of patients taking Avastin with interferon alpha saw a drop in tumor size, compared to 12 percent in patients not taking Avastin.

According to Roche, the study was conceived to show an increase in overall survival in patients with this type of cancer. The company didn’t succeed in that regard, stating that there was no improvement in overall survival. However, the endpoints that were reached were more than enough to satisfy FDA’s approval process.

Avastin now enters a very crowded kidney cancer market with competition from Pfizer, Wyeth, and Bayer. However, CNN reports that many physicians have been using the drug off-label for kidney cancer, which could boost market penetration.