Disease	Colorectal cancer
Stage of Disease/Treatment	Metastatic/advanced
Prior Therapy	None
Type of Study	Phase II, single arm
Primary Endpoint	Disease control rate
Secondary Endpoints	Overall response rate, progression‐free survival, overall survival, safety, time to treatment failure
Additional Details of Endpoints or Study Design
The aim of the Osaka Gastrointestinal Cancer Chemotherapy Study Group (OGSG) 1602 phase II study was to assess the efficacy of panitumumab as a first‐line treatment for patients with RAS WT unresectable CRC and who were ineligible for intensive chemotherapy. Therefore, the primary endpoint was set as the DCR, defined as the proportion of the best overall response from either complete response (CR), partial response (PR), or stable disease (SD), according to RECIST 1.1. The DCR was also assessed by an independent review committee. Disease reassessments were performed by means of contrast‐enhanced computed tomography every 8 weeks. Secondary endpoints were as follows: OS, defined as the time from enrollment to death from any cause; PFS, defined as the time from enrollment to disease progression or death from any cause; RR, defined as a proportion of best overall response of CR or PR; TTF, defined as the time from enrollment to discontinuation of treatment for any reason, including disease progression, treatment toxicity, or death; and the incidence of grade 3/4 toxicities according to CTCAE ver. 4.0. The null hypothesis was that DCR was 45%, and the alternative hypothesis was that DCR was >70%; this was assessed using an exact p value of .05 and a power of 0.90 based on the Clopper‐Pearson method. Thus, the sample size was 33. The total sample size was set to 36 to account for deviations. All statistical analyses were conducted at the OGSG Data Center. The Data and Safety Monitoring Committee (DSMC) of the OGSG independently reviewed the efficacy and safety data obtained from the present study. Protocol compliance, safety, and on‐schedule study progress were monitored by the DSMC. The OGSG Protocol Review Committee approved this study protocol on October 18, 2016. Approval was obtained from the Institutional Review Board before starting patient accrual at each institution. This trial was registered at the University hospital Medical Information Network (UMIN) Clinical Trials Registry as UMIN000024528 on December 1, 2016. The study was conducted according to the guidelines of the Declaration of Helsinki and the International Conference on Harmonization E6 Good Clinical Practice. The present study was supported by OGSG and funded by Takeda Pharmaceutical Company Limited. The ethical committee or institutional review committee at each site approved the protocol before the initiation of the study. All patients were required to sign a written informed consent form.
Investigator's Analysis	Active and should be pursued further