Pre-emptive oral clarithromycin reduces the skin toxicity of panitumumab treatment for metastatic colorectal cancer.

PURPOSE Chemotherapy with panitumumab is expected to be well tolerated and improve survival in patients with metastatic colorectal cancer (mCRC). However, skin toxicities are its most common adverse events. The aim of this trial was to evaluate the efficacy and safety of pre-emptive antibiotic treatment with clarithromycin (CAM) to prevent panitumumab skin toxicities. METHODS We conducted a phase lll, multicenter, open-label, randomized clinical trial on mCRC patients treated with panitumumab. Eligible patients were randomly assigned 1:1 to pre-emptive antibiotic and control groups. In the pre-emptive group, CAM administration (200 mg twice per day) continued daily through the panitumumab treatment period. The control regimen consisted of skin care only. The primary end point was the incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period. RESULTS Of 156 enrolled patients, 78 received pre-emptive antibiotic treatment, and 78 received reactive treatment. The number and incidence of grade ≥ 2 skin toxicities during the 6-week skin treatment period were 16 (21.3%) and 41 (54.7%) for the pre-emptive and control groups, respectively (HR, 0.32; 95% CI, 0.17-0.56). There was almost no difference in the rate of other adverse events between the two groups, but the incidence of grade ≥ 3 diarrhea in the pre-emptive group was high, at 8% vs. 1.3% in the control group. There were no treatment-related deaths. CONCLUSION Prophylactic oral CAM together with relatively simple skin care was found to be effective in suppressing the development of grade ≥ 2 skin toxicities induced by panitumumab. CLINICAL TRIAL REGISTRATION UMIN000011485 DATE OF REGISTRATION: Sep 1st, 2013.