Genentech, a leading biotechnology company, announced that it was discontinuing its Phase II study of Avastin in ovarian cancer patients because a significant number of participants developed ruptures of the bowel.
Although ruptures are a known side effect of the drug, Genentech saw a higher rate in this clinical trial than in previous ones. Forty-four patients were enrolled in the proposed 53-person study, and five, or 11%, developed gastrointestinal perforations. The patients currently enrolled in the study were informed of the findings and, in consultation with their physicians, may choose to either continue or stop the Avastin treatment.
“GI perforations are a known possible adverse event with Avastin; however, we chose to discontinue enrollment in this Phase II study due to the observation of a higher rate seen in this study than in other trials of Avastin in ovarian cancer or other tumor types,” said Hal Barron, M.D., Genentech’s senior vice president, development, and chief medical officer.
Bowel perforations can cause serious infections because bacteria can leak into the abdomen. Such ruptures can be treated with surgery or through a regimen of antibiotics.
The decision to discontinue enrollment was made by Genentech in consultation with the FDA. Genentech spokesman, Neil Cohen, said that Avastin is known to contribute to the development of bowel ruptures in patients who have received chemotherapy or who have undiagnosed bowel obstructions. According to the company, patients enrolled in the Phase II study had more advanced disease, which typically involves the bowel, and had received more chemotherapy than in previous clinical trails of Avastin in ovarian cancer patients. Mr. Cohen said that Genentech will continue testing Avastin on ovarian cancer patients who have not received chemotherapy.
Avastin was approved by the Food and Drug Administration in 2004 for the treatment of colon cancer. It cuts off the blood supply to tumors, and Genentech is testing the drug against other forms of cancer.