Dr Andre on Survival Results From the SOLSTICE Trial in mCRC

Thierry Andre, MD, professor of medical oncology, University Pierre et Marie Curie (UMPC), head, Medical Oncology Department, St. Antoine Hospital, Paris, discusses negative overall survival results and updated safety data from the phase 3 SOLSTICE trial (NCT03869892) in metastatic colorectal cancer (mCRC).

The SOLSTICE study investigated the efficacy of trifluridine/tipiracil (TAS-102; Lonsurf) plus bevacizumab (Avastin) vs capecitabine (Xeloda) and bevacizumab for patients with unresectable mCRC who were ineligible for intensive chemotherapy in the first-line setting, Andre says. Previously reported efficacy results from this trial were negative, as the study did not meet its primary end point of improved progression-free survival (PFS) with the experimental regimen. Patients who received the trifluridine/tipiracil regimen had a median PFS of 9.4 months (95% CI, 9.1-10.9) vs 9.3 months (95% CI, 8.9-9.8) with the control (HR, 0.87; 95% CI, 0.75-1.02; P = .0464), Andre reports.

Analysis of the key secondary end point of overall survival (OS), as well as updated safety data, were presented at the 2023 ASCO Annual Meeting, Andre continues. Ultimately, the trifluridine/tipiracil regimen failed to produce a significant improvement in OS vs capecitabine and bevacizumab in this population, he states. Median OS with the experimental regimen was 19.74 months (95% CI, 18.04-22.40) vs 18.59 months (95% CI, 16.82-21.39) with the control regimen (HR, 1.06; 90% CI, 0.90-1.25), he expands. Both regimens also produced a similar likelihood of survival at different time points.

Notably, the study identified several factors correlated with a higher OS, including age 70 years or younger, left-sided primary disease, surgical resection of the primary tumor, 1 to 2 metastatic sites, lack of liver metastasis, a neutrophil-to-lymphocyte ratio lower than 3, Charlson Comorbidity Index score of 0 vs 1 to 2 or 1 to 2 vs 3 or higher, and ECOG performance status of 0 vs 1 and 1 vs 2. However, no significant treatment effect was identified with the experimental regimen vs control after adjusting for these prognostic factors.

Disclosures: Dr Andre reported serving as a consultant or in an advisory role for Amgen, Aptitude Health, Astellas Pharma, AstraZeneca/MedImmune, Bristol-Myers Squibb, GamaMabs Pharma, Gilead Sciences, GlaxoSmithKline, Gritstone Bio, Kaleido Biosciences, MSD Oncology, Nordic Bioscience, Pierre Fabre; Seagen, SERVIER, Tesaro, Transgene; he received honoraria from Amgen, Bristol-Myers Squibb, GlaxoSmithKline, Merck, Merck Serono, Pierre Fabre, Roche/Genentech, Sanofi, Seagen, SERVIER, Ventana Medical Systems; he received funding for travel-related expenses from MSD Oncology; he disclosed uncompensated relationships with the Adjuvant Colon Cancer End Points (ACCENT) Collaborative Group, ARCAD Foundation, and Gercor.