A prospective phase II study of multimodal prophylactic treatment for afatinib-induced adverse events in advanced non-small cell lung cancer (Niigata Lung Cancer Treatment Group 1401).

Background: Afatinib has shown clinical benefits in patients with non-small cell lung cancer (NSCLC) harboring epidermal growth factor receptor () mutations. Many patients treated with afatinib experience skin or gastrointestinal toxicity. However, an effective management strategy has not been established. This prospective study was conducted to evaluate the efficacy of multimodal prophylactic treatment for afatinib-induced toxicity.

Methods: This single-arm prospective study was conducted to evaluate the efficacy of multimodal prophylactic treatment for afatinib-induced toxicity in patients with mutation positive advanced NSCLC who planned to receive a 40 mg dose of afatinib. Eligible patients were treated with oral loperamide (2 mg twice per day), prophylactic minocycline (100 mg once per day), topical medium-class steroids, and gargling with sodium azulene. The primary endpoint was the ability of prophylactic loperamide to prevent severe or intolerable diarrhea during the 4 weeks after the initial administration of afatinib. The incidence, severity and time to occurrence of diarrhea, rash, oral mucositis and paronychia were evaluated based on a daily patient questionnaire.

Results: Forty-six patients were enrolled. The primary endpoint analysis was performed in 35 patients as the per-protocol (PP) population. The 4-week successful prophylaxis rate for severe or intolerable diarrhea was 82.9% (90% confidence interval: 70.1-91.9%). In the total population, the incidences of grade 3 or higher rash, oral mucositis and paronychia within 4 weeks were 4%, 2% and 4%, respectively.

Conclusions: Prophylactic loperamide administration was not effective in preventing severe or intolerable diarrhea during afatinib treatment. Adequate dose reduction will be a better approach to manage afatinib-induced diarrhea. Multimodal prevention using minocycline, topical steroids and gargling with sodium azulene may be helpful to maintain compliance with afatinib treatment (UMIN000016167).