Biweekly administration of cetuximab in Japanese patients with recurrent or metastatic head and neck cancer

Background: Cetuximab (Cmab) plays an important role in the treatment for recurrent or metastatic head and neck cancer (R/M HNC). To date, however, no safety data on biweekly administration of cetuximab at a dose of 500 mg/m² (biweekly Cmab) for Japanese HNC patients have been available. Methods: We retrospectively reviewed the clinical records of five R/M HNC patients who received biweekly Cmab in our institute between January 2016 and September 2021 and compared the safety profile between two phases of weekly 250 mg/m² and biweekly 500 mg/m² Cmab in the identical patients. Results: All patients initially received Cmab in combination with chemotherapy. Chemotherapy consisted of paclitaxel plus carboplatin in two patients, cisplatin + 5-FU in one patient, and paclitaxel in two patients. Three patients switched treatment schedule from weekly Cmab to biweekly Cmab, while two patients received biweekly Cmab after completion of chemotherapy. The main reason for switching to biweekly Cmab was an unacceptably long commuting time to the hospital. The median duration of Cmab was 217 days (49–321) during weekly Cmab with or without chemotherapy and 42 days (28–175) during biweekly Cmab. Median dose of biweekly Cmab was 4 (3–12). During biweekly Cmab, worsened (Grade ≥ 2) toxicities were observed in two patients: one with grade 2 dry skin and the second with grade 2 skin infection. None developed grade ≥ 3 adverse events or discontinued treatment due to Cmab-related adverse events. Conclusion: Biweekly Cmab was well tolerated and did not demonstrate severe toxicities related to Cmab for R/M HNC.