Multicenter phase 1/2 Trial of napabucasin and pembrolizumab in patients with metastatic colorectal cancer (EPOC1503/SCOOP Trial)
Mené sur 55 patients atteints d'un cancer colorectal de stade métastatique, cet essai de phase I/II évalue la dose maximale tolérée et l'efficacité, du point de vue du taux de réponse objective, de la napabucasine en combinaison avec le pembrolizumab
Purpose: This is a phase 1/2 trial of napabucasin plus pembrolizumab for metastatic colorectal cancer (mCRC). Experimental Design: Phase 1 was conducted to determine the recommended phase 2 dose (RP2D) in a dose escalation design of napabucasin (240mg to 480 mg twice daily) with 200mg pembrolizumab every 3 weeks. Phase 2 included cohort A (n = 10, microsatellite instability high) and cohort B (n = 40, microsatellite stable). The primary endpoint was immune-related objective response rate (irORR). PD-L1 combined positive score (CPS), genomic profiles and the consensus molecular subtypes (CMS) of colorectal cancer were assessed. Results: A total of 55 patients were enrolled in this study. In phase 1, 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. Conclusions:Napabucasin with pembrolizumab showed anti-tumor activity with acceptable toxicities for MSS mCRC patients as well as MSI-H mCRC, although it did not meet the primary end point.