We had already reported that pre-emptive skin treatment could reduce the severity of panitumumab (Pmab)-associated skin toxicities in Japanese metastatic colorectal cancer patients (Kobayashi Y, et al. Future Oncol, 2015). Therefore, we performed analysis to investigate whether pre-emptive skin treatment affected anti-tumor efficacy.
Patients receiving third-line Pmab-containing regimens for mCRC were randomly assigned 1:1 to pre-emptive (skin moisturizers, sunscreen, topical steroid, and minocycline) or reactive (only skin moisturizers) skin treatment. The primary endpoint was the cumulative incidence of ≥grade 2 skin toxicities during the 6-week treatment period. In this analysis, we compared the two groups for anti-tumor efficacy on the final survival data.
Of 95 enrolled patients, 47 were assigned to pre-emptive, and 48 to reactive treatment. The incidence of ≥grade 2 skin toxicities during the 6-week treatment period (investigators' assessment) was 21.3% and 62.5% (risk ratio [RR], 0.34; 95% CI, 0.19 to 0.62; P < 0.001) for the pre-emptive and reactive treatment groups, respectively. A similar trend was observed in central review (18.6% and 50.0%, respectively [RR, 0.37; 95% CI, 0.19 to 0.74; P = 0.002]). On the final survival analysis, there were no statistical differences in overall response rate (13.3% vs 18.2%; P = 0.530), progression free survival (3.6 vs 4.0 months; hazard ratio [HR], 1.270; 95% CI, 0.833 to 1.938; P = 0.267), overall survival (8.2 vs 12.1 months, [HR, 1.150; 95% CI, 0.754 to 1.755; P = 0.515]) between pre-emptive and reactive treatment groups.
Pre-emptive skin treatment could reduce the severity of skin toxicities during Pmab treatment. On the final survival analysis, pre-emptive skin treatment did not affect the anti-tumor efficacy of Pmab. Our data clearly validate that pre-emptive treatment can also be recommended in Japanese patients. This analysis had been presented at the European Cancer Congress 2015 (Kobayashi Y, et al. Abstract number was 2 094).
Clinical trial identification
Y. Komatsu: Honoraria: Yakult Honsha Co., Ltd., Takeda Pharmaceutical Co., Ltd. Research fund: Yakult Honsha Co., Ltd., Daiichi Sankyo Co., Ltd., Takeda Pharmaceutical Co., Ltd. Y. Sakata: Honoraria Daiichi Sankyo Co., Ltd. Yakult Honsha Co., Ltd. All other authors have declared no conflicts of interest.