A phase Ib/II dose-escalation study evaluating triple combination therapy with a BRAF (encorafenib), MEK (binimetinib), and CDK 4/6 (ribociclib) inhibitor in patients (Pts) with BRAF V600-mutant solid tumors and melanoma.

作者：Paolo Antonio, Ascierto; Oliver, Bechter; Pascal, Wolter; Celeste, Lebbe; Elena, Elez; Wilson H., Miller; Georgina V., Long; Aurelius Gabriel, Omlin; Salvatore, Siena; Emiliano, Calvo; Mike, Pickard; Ashwin, Gollerkeri; Lance, Wollenberg; Caroline, Germa; Reinhard, Dummer

来源：Journal of Clinical Oncology, 2017, 35(15_suppl): 9518-9518.

DOI：10.1200/jco.2017.35.15_suppl.9518

<jats:p> 9518 </jats:p><jats:p> Background: The benefits of BRAF + MEK inhibition (dual combo) in pts with BRAF V600-mutant ( BRAF<jats:sup>V600</jats:sup>) melanoma are known. Preclinical data supports inhibiting CDK 4/6 and BRAF + MEK (triple combo) to improve antitumor activity. We report safety and preliminary efficacy from a phase 1b/2 study (NCT01543698) of encorafenib (ENCO; a selective BRAF kinase inhibitor), binimetinib (BINI; a MEK inhibitor), and ribociclib (RIBO; a CDK 4/6 inhibitor). Methods: Phase 1b of this open-label, multicenter study enrolled pts with confirmed BRAF<jats:sup>V600</jats:sup>advanced solid tumors. Escalating doses of RIBO 100 mg-600 mg QD for 3 wk on/1 wk off were administered with ENCO 200 mg QD + BINI 45 mg BID in successive cohorts (6 pts each) until the maximum tolerated or recommended phase 2 dose (RP2D) was reached. Due to potential pharmacokinetic interactions with RIBO, the ENCO dose was lower than the dual combo RP2D (450 mg QD). Dose escalations followed an adaptive Bayesian model. In phase 2, the triple combo was tested in pts with BRAF<jats:sup>V600</jats:sup>melanoma naïve to prior BRAF inhibitor treatment; the primary endpoint was objective response rate (ORR) per RECIST v1.1. Results: In phase 1b (n = 21), no dose-limiting toxicities were reported and the triple combo RP2D was ENCO 200 mg QD + BINI 45 mg BID + RIBO 600 mg QD. ENCO AUC was slightly lower than at the dual combo RP2D. In phase 2 (n = 42), 59.5% pts had an ECOG PS of 0 and 43% of pts had elevated lactate dehydrogenase. The most common (≥5%) grade 3/4 toxicities were neutropenia (26.2%), increased alanine transaminase (14.3%), diarrhea (7.1%), and anemia (7.1%). Ten pts (23.8%) discontinued treatment due to an AE, of which 4 were increased transaminases. The confirmed ORR was 52.4%, including 4 complete responses, 18 partial responses, and 15 pts with stable disease. Median duration of exposure in phase 2 was 9.1 mo (range, 0.0-21.6). Median progression-free survival was 9.0 mo (95% confidence interval, 7.0-11.1). Conclusions: Triple therapy with ENCO + BINI + RIBO in this small trial of pts with high disease burden was associated with responses in over half of pts and some evidence of increased toxicity. Clinical trial information: NCT01543698. </jats:p>

• 出版日期2017-5-20
• 单位The University of Sydney; Mcgill University; the University of Sydney; 常州工学院