First-Line Genomic Profiling in Previously Untreated Advanced Solid Tumors: 1-Year Follow-Up of the FIRST-Dx Study

The FIRST-Dx study prospectively evaluated the clinical utility of the comprehensive genomic profiling (CGP) test (FoundationOne CDx) in the first-line setting for patients with chemotherapy-naïve advanced solid tumors (gastrointestinal, biliary, pancreatic, lung, breast, gynecologic, melanoma) in six hospitals in Japan. Here, we report the results of the 1-year interim analysis of the follow-up study about the clinical benefits provided by the upfront CGP test. The primary endpoint was overall survival (OS), and secondary endpoints were the proportion of patients who actually received molecular-based recommended therapy (MBRT) determined by the molecular tumor board, best overall response rate (ORR) in each line of therapy, and progression-free survival (PFS) ratio (PFS on MBRT/PFS on the first-line therapy). Data from 172 patients with a median follow-up of 15.1 months (range: 0.1–21.5 months) were available. The median OS was not reached. Thirty-nine patients (22.7%) received MBRT during this follow-up period. ORR in first-line therapy was 56.3% in the MBRT group (n = 16) vs. 42.3% in the non-MBRT group (n = 137), and in the second-line was 26.3% in the MBRT group (n = 19) vs. 17.1% in the non-MBRT group (n = 82). Regarding the PFS ratio of second-line MBRT (n = 12), the median PFS ratio was 1.1, and four patients (33.3%) had a ratio ≥ 1.3, indicating that MBRT might be effective in changing the clinical outcome. The findings of this study imply that CGP testing before the standard of care for patients with advanced solid tumors could prove to be a clinically beneficial strategy for guiding subsequent precision anticancer treatments. Trial Registration: Japan Registry of Clinical Trials (jRCT) ID: jRCT1050220041.