Genentech and FDA notified healthcare professionals of important new safety information regarding tracheoesophageal (TE) fistula formation in a recent clinical study in patients with limited-stage small cell lung cancer (SCLC). This multicenter, non-randomized, single-arm phase II clinical trial study combined chemotherapy and radiation plus Avastin. There have been two confirmed serious adverse events of TE fistula (one fatal) reported in the first 29 patients enrolled in this study.
A third, fatal event (upper aerodigestive tract hemorrhage and death of unknown cause), was also reported, in which TE fistula was suspected but not confirmed. All three events occurred during the Avastin maintenance phase of the study in the context of persistent esophagitis. Additionally, six other cases of TE fistula have also been reported in other lung and esophageal cancer studies using Avastin and chemotherapy alone or with concurrent radiation treatment.
Avastin is not approved for the treatment of SCLC. The current prescribing information includes a description of gastrointestinal tract fistula formation in patients with colorectal cancer and other types of cancer treated with Avastin. Genentech intends to revise the Avastin package insert to include more detailed information regarding the incidence of all cases of fistula in patients treated with Avastin.