naphthoquinones and Microsatellite-Instability

This is a phase I/II trial to assess the efficacy and safety of napabucasin plus pembrolizumab for metastatic colorectal cancer (mCRC).. Phase I was conducted to determine the recommended phase 2 dose (RP2D) in a dose escalation design of napabucasin (240 to 480 mg twice daily) with 200 mg pembrolizumab every 3 weeks. Phase II included cohort A (. A total of 55 patients were enrolled in this study. In phase I, no patients experienced dose-limiting toxicities, and napabucasin 480 mg was determined as RP2D. The irORR was 50.0% in cohort A and 10.0% in cohort B. In cohort B, the irORR was 0%, 5.3%, and 42.9% in CPS < 1, 1≤ CPS <10, and CPS ≥ 10, respectively. Patients with objective response tended to have higher tumor mutation burden than those without. Of evaluable 18 patients for CMS classification in cohort B, the irORR was 33.3%, 0%, 33.3%, and 33.3% in CMS1, CMS2, CMS3, and CMS4, respectively. The common grade 3 or higher treatment-related adverse events included fever (10.0%) in cohort A and decreased appetite (7.5%) and diarrhea (5.0%) in cohort B.. Napabucasin with pembrolizumab showed antitumor activity with acceptable toxicities for patients with MSS mCRC as well as MSI-H mCRC, although it did not meet the primary end point. The impact of related biomarkers on the efficacy warrants further investigations in the additional cohort.

Topics: Adult; Aged; Antibodies, Monoclonal, Humanized; Antineoplastic Agents, Immunological; Antineoplastic Combined Chemotherapy Protocols; B7-H1 Antigen; Benzofurans; Colorectal Neoplasms; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Male; Microsatellite Instability; Middle Aged; Naphthoquinones; Neoplasm Metastasis

Most colorectal cancers are microsatellite-stable with no response to anti-PD-1 therapy, necessitating the development of new immunomodulatory treatment strategies. Coinhibition of anti-PD-1 and STAT3 can elicit an effective antitumor response in a small subset of patients with microsatellite-stable colorectal cancer, and biomarkers predictive of response are under investigation.

Topics: Antibodies, Monoclonal, Humanized; Benzofurans; Colorectal Neoplasms; Humans; Microsatellite Instability; Microsatellite Repeats; Naphthoquinones