The targeted therapy Avastin ( Bevacizumab ), alone and in combination with the chemotherapy drug CPT-11, significantly increased response rates, progression-free survival times and survival rates in patients with a deadly form of brain cancer that had recurred.

Patients with recurrent glioblastoma have a grim prognosis, and conventional treatments were typically limited to largely ineffective and highly toxic chemotherapies. Only about 5 percent of patients respond to further treatment – meaning their tumors shrink by 50 percent or more. And only 15 to 20 percent of patients make it to the six month mark before their disease progresses again. Survival is limited to six to seven months.

But a randomized Phase II study of Bevacizumab alone and Bevacizumab given with CPT-11 have improved those statistics, dramatically increasing response rates, progression-free survival times and overall survival. Early results from the study prompted the FDA ( Food and Drug Administration ) to agree to an accelerated approval of Avastin in May 2009 for use in patients with recurrent glioblastomas.

The two-armed study enrolled 167 patients with recurrent glioblastoma. One arm evaluated Bevacizumab used as a single agent, the other Bevacizumab given with CPT-11.

In the Bevacizumab only arm, 28.2 percent of patients responded to the treatment, meaning their tumors shrunk by 50 percent or more, a significant increase from the historic 5 percent response rates. Of the 80 patients, 42.6 percent surpassed the six month mark without their disease progressing, up from the historic 15 to 20 percent of patients. Survival was 9.2 months, a slight increase of the typical six to seven month survival time.

In the arm studying Bevacizumab with CPT-11, 37.8 percent of patients responded to the treatment, while 50.3 percent surpassed the six month progression-free survival mark. Overall survival was 8.7 months, a little less than the Bevacizumab only study.

In addition, Bevacizumab was well tolerated. While some serious side effects were noted – brain hemorrhage, strokes and heart attacks – they were seen in a very small number of patients.
Bevacizumab also appeared to reduce brain swelling, allowing patients to significantly lower the steroid dose they had to take, eliminating a number of debilitating side effects.

About 20,000 patients will be diagnosed with glioblastoma this year, of those 14,000 will die.

The last new systemic therapy for recurrent glioblastoma was approved in 1976. Until Avastin, all other experimental therapies tested in this type of cancer failed to meet the FDA guidelines for approval.

A significant study finding was that Avastin was nearly as effective alone as it was when given with chemotherapy, but was much better tolerated.

Source: University of California - Los Angeles, 2009

XagenaMedicine2009


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