Bevacizumab/Sunitinib Clinical Trials Halted Due to Anemia Cases

Yael Waknine

July 14, 2008

July 14, 2008 — Several studies of bevacizumab (Avastin, Genentech, Inc) plus sunitinib malate (Sutent, Pfizer, Inc) have been halted due to reports of microangiopathic hemolytic anemia (MAHA), the US Food and Drug Administration (FDA) informed healthcare professionals today.

The warning was based in part on data from an investigator-sponsored, phase 1, dose-escalation study of 25 patients with solid tumors who received a fixed dose of bevacizumab (10 mg/kg intravenously every 2 weeks) and increasing doses of oral sunitinib (25, 37.5, and 50 mg) on a 4-week-on, 2-week-off schedule.

Five of 12 patients receiving the highest sunitinib dose (50 mg) exhibited laboratory findings consistent with MAHA, according to an alert sent today by MedWatch, the FDA’s safety information and adverse event reporting program. Two of the cases were considered severe, but they resolved within 3 weeks of treatment discontinuation with no additional interventions.

In a letter to healthcare professionals, Genentech said that the anemia cases led to the discontinuation of a similar Genentech-sponsored phase 2 study in which patients were randomized to receive sunitinib 50 mg with or without bevacizumab. Two of 7 study enrollees were found to have MAHA, the company noted.

Two additional phase 2 studies of bevacizumab with sunitinib and chemotherapy were closed by the company due to myelosuppression, fatigue, and gastrointestinal complications; no MAHA cases were reported.

Bevacizumab is indicated for the treatment of colon, breast, and non–small cell lung cancer. Sunitinib is indicated for the treatment of gastrointestinal stromal tumor and renal cell carcinoma. Bevacizumab plus sunitinib combination therapy is neither approved nor recommended by the FDA for any indication.

Adverse events related to use of bevacizumab or sunitinib should be reported to the FDA's MedWatch reporting program by telephone at 1-800-FDA-1088, by fax at 1-800-FDA-0178, online at, or by mail to 5600 Fishers Lane, Rockville, MD 20852-9787.


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