Two Studies Challenge Avastin's Effectiveness Against a Rare Brain Cancer CHICAGO - Two new studies have found that the widely used cancer drug Avastin does not prolong the lives of patients with a deadly form of brain cancer, raising questions about the role of the drug in treating that disease. The results, presented at a conference here this weekend, could lead the Food and Drug Administration to revoke Avastin's approval for the treatment of the brain cancer, called glioblastoma, much as it did with the drug's approval for breast cancer. Avastin, which is sold by Genentech, received a sort of conditional approval, subject to further study, in 2009 for the treatment of brain cancer and in 2008 for breast cancer. In 2011, after subsequent studies showed that Avastin did not help women with breast cancer live longer, the agency revoked the drug's approval for that disease, provoking an outcry from some patients and doctors who said that the drug had helped them. Revocation seems less likely for brain cancer treatment because fewer options are available than for breast cancer. "The vast majority of patients with glioblastoma in the United States get Avastin at some point in their illness," said Dr. Mark R. Gilbert of the University of Texas M.D. Anderson Cancer Center, the lead investigator in one of the studies, which were presented at the annual meeting of the American Society of Clinical Oncology. Dr. Howard A. Fine of the New York University Langone Medical Center, who was chosen to comment on the studies at the meeting, said removal of the approval would be "a travesty." He said that while the two new studies show that Avastin should not be used as an initial therapy for glioblastoma, the drug was still very effective when used to treat recurrences, which is what it is approved for. "It's just so dramatic in that population, for which we have no other treatments," he said. Dr. Richard Pazdur, who runs the cancer drug division at the F.D.A., said that he could not comment on specific drugs, but that the agency considers "the totality of the evidence." He added, "We have approved a lot of drugs without a survival advantage." The brain cancer study is only one of those being presented here that could influence the sales of Avastin, which is one of the best-selling cancer drugs in the world, with annual sales last year of $6 billion for Roche, Genentech's parent company. Glioblastoma is rare, and sales of Avastin for that use are only about $170 million a year in the United States, said Daniel P. O'Day, who leads Roche's pharmaceutical business. A possibly bigger blow could come from a study showing that patients with colorectal cancer, major users of Avastin, lived nearly four months longer if they received the rival drug Erbitux than if they received Avastin. Some colon cancer specialists, however, were skeptical about the study's conclusions. But the use of Avastin prolonged the lives of women with advanced cervical cancer, a disease for which virtually no good treatments exist. That could lead to an approval for that disease. Cervical cancer is rare in the United States because of screening with the Pap test. Still, 4,000 American women a year die of the disease. The toll is much greater in developing countries with inadequate screening programs, though those countries would probably have trouble affording Avastin, which costs tens of thousands of dollars a year. In the study of 452 women, sponsored by the National Cancer Institute, those who received Avastin and conventional chemotherapy lived a median of 17 months compared with 13.3 months for those who received only the chemotherapy. The brain cancer study led by Dr. Gilbert, which was also sponsored by the National Cancer Institute, involved 637 patients with newly diagnosed glioblastoma. Those who also received Avastin lived a median of 15.7 months compared with 16.1 months for those who received a placebo. Use of Avastin delayed the time before tumors worsened by about three months, but that difference was not statistically significant. A separate study, sponsored by Genentech, also showed virtually identical median survival for Avastin and the control group. But the drug delayed tumor worsening by more than four months, a statistically significant difference. Genentech's study found that Avastin improved patients" quality of life, which could be important to retaining that approval. But Dr. Gilbert's study, using a different analysis method, found that Avastin increased the burden of symptoms and led to a greater decline in cognition. In the colorectal cancer trial, those who received Erbitux in addition to chemotherapy as an initial treatment for advanced disease lived a median of 28.7 months compared with 25 months for those who got Avastin and chemotherapy. The trial involved 592 patients in Germany and Austria who did not have a mutation in their tumor that renders Erbitux ineffective. The study was paid for by Merck of Germany, which markets Erbitux in Europe. In the United States it is sold by Eli Lilly and Bristol-Myers Squibb. Erbitux and Avastin were approved to treat colorectal cancer in 2004. But only now are they being compared to each other.