Latebreakers: Warnings issued for Avastin

The risk of forming a tracheoesophageal (TE) fistulamay be increased in patients receiving bevacizumab(Avastin, Genentech), according to a new FDA safetyalert. In a phase II trial of limited-stage small cell lungcancer, for which the biologic is not approved, two confirmedcases (one fatal) of TE fistula occurred in the first29 patients enrolled in the study. Beyond that, there hasbeen a third fatality in which a TE fistula was suspectedbut not confirmed.

The three events occurred during thebevacizumab maintenance phase of the study. Genentechsaid that six other cases of TE fistula have beenreported in other studies involving treatment of lungand esophageal cancer. Currently, the prescribing informationincludes mention of GI tract fistulas that haveoccurred in patients with colorectal cancer; however,Genentech plans revisions to include the incidence of allthe reported cases of fistula. Bevacizumab is approvedto treat metastatic colorectal cancer and as a first-linetherapy of unresectable, locally advanced, recurrent ormetastatic non-squamous, non-small cell lung cancer.