A Japanese Post-marketing Surveillance of Cetuximab (Erbitux®) in Patients with Metastatic Colorectal Cancer

OBJECTIVE Cetuximab (Erbitux(®)) was approved for the treatment of metastatic colorectal cancer in Japan in 2008. To verify information on the safety in practical use of cetuximab, we conducted post-marketing surveillance in accordance with the conditions for approval. METHODS All patients to be treated with cetuximab were enrolled by the central enrolment method. Data on treatment status, and incidence and severity of adverse drug reactions were collected. The target number of patients was 1800. RESULTS A total of 2126 patients were enrolled from 637 institutions. Among 2006 patients analysed, 93.2% received cetuximab as third-line or later treatment. The median duration of treatment was 15.3 weeks, and 11.1% of patients received treatment for >48 weeks. The incidence of adverse drug reactions was 89.6%, of which ≥grade 3 was 21.5%. The incidence of infusion reactions was 5.7% (any grade), with 83.3% of them occurring at the first administration. The incidence of skin disorders was 83.7% (any grade), and the time to event varied for each skin disorder. The incidence of interstitial lung diseases was 1.2% (any grade). Diarrhoea and haematotoxicity scarcely occurred with cetuximab alone. CONCLUSIONS In this surveillance, the incidence and categories of adverse drug reactions are not distinct from previous reports. Although most patients received cetuximab as third-line or later treatment, treatment was maintained with a median duration of 15 weeks. Cetuximab treatment in practical use is considered to be well tolerated and clinically useful in Japanese patients with metastatic colorectal cancer.