Efficacy and safety of encorafenib-based regimens in colorectal cancer: A systematic review of clinical trials

e15600 Background: BRAF gene mutation is present in 10% of the world’s 3 rd common cancer, i.e., colorectal cancer (CRC). Constitutive activation of the mitogen-activated protein kinase pathway (MAPKP) results from this mutation, abnormal activation of MAPKP, inhibiting apoptosis and enhancing proliferative activity. In this systematic review, we will assess the efficacy of encorafenib (a BRAF inhibitor) based regimens in CRC. Methods: We followed PRISMA guidelines to conduct this systematic review. A literature search was performed on PubMed, Embase, and Clinicaltrials.gov with mesh terms, ‘’Colorectal Neoplasms’’ and “Proto-Oncogene Proteins B-raf” from the inception of data till 01/05/2023. We screened 4572 articles and included 1 randomized clinical trial (RCT, N = 665), and 4 non-randomized trials (nRCTs, N = 175), measuring the efficacy of encorafenib (E) based regimens in BRAF V600-mutated CRC. Results: In 4 clinical trials (N = 840), 246 patients treated with a double regimen and 373 treated with a triple regimen of E. In 2 clinical trials (N = 319), triple therapy of E + C + Binimetinib showed an overall response rate (ORR) of 47.8% and 26% in the untreated metastatic CRC (mCRC) and phase III randomized trial triple regimen arm, respectively. A recent trial on triple therapy of E + C + nivolumab (N) showed an ORR of 45% with overall survival (OS) and progression-free survival (PFS) of 11.4 and 7.3 months, respectively. In 1 randomized trial (N = 665), ORR improved from 2% in the control arm to 26% and 20% in triple and double regimens, respectively, which was mainly partial response (PR) with complete response (CR) of 4-5% in both groups. The OS was 9 and 8.4 months with a hazard ratio (HR) for death vs. control of 0.52; (95% confidence interval [CI], 0.39 to 0.70; P < 0.001) and 0.60; (95% CI, 0.45 to 0.79; P < 0.001) in the triple and dual regimen, respectively. In 1 trial of dose escalation study, alpelisib (A) was added to E + C and the addition of this third drug showed minimal changes in the ORR from 18 to 19%, and PFS improved from 3.7 to 4.2 months. (Table 1). Conclusions: A combination of BRAF inhibitors with anti-EGFR monoclonal antibodies showed a clinically significant increase in antitumor activity in BRAF-mutated mCRC compared to standard therapy. The addition of MEK/PI3K inhibitor as a third drug to E + C also showed some improvement in ORR and PFS. Triple therapy with E + C + N was also effective and tolerated well by the microsatellite stable (MSS) BRAF mutated mCRC population. Randomized trials are needed. [Table: see text]