Phase IB Study of Vemurafenib in Combination with Irinotecan and Cetuximab in Patients with Metastatic Colorectal Cancer with BRAFV600E Mutation.

In vitro, EGFR inhibition, combined with the BRAF inhibitor vemurafenib, causes synergistic cytotoxicity for BRAFV600E metastatic colorectal cancer, further augmented by irinotecan. The safety and efficacy of vemurafenib, irinotecan, and cetuximab in BRAF-mutated malignancies are not defined. In this 3+3 phase I study, patients with BRAFV600E-advanced solid cancers received cetuximab and irinotecan with escalating doses of vemurafenib. Nineteen patients (18 with metastatic colorectal cancer and 1 with appendiceal cancer) were enrolled. Three patients experienced dose-limiting toxicities. The MTD of vemurafenib was 960 mg twice daily. Six of 17 evaluable patients (35%) achieved a radiographic response by Response Evaluation Criteria in Solid Tumors 1.1 criteria, consistent with in vivo models demonstrating tumor regressions with the triplet regimen. Median progression-free survival was 7.7 months. BRAFV600E circulating cell-free DNA (cfDNA) trends correlated with radiographic changes, and acquired mutations from cfDNA in genes reactivating MAPK signaling were observed at progression. Vemurafenib, in combination with irinotecan and cetuximab, was well tolerated in patients with refractory, BRAF-mutated metastatic colorectal cancer, and both survival outcomes and response rates exceeded prior reports for vemurafenib and for irinotecan plus cetuximab in BRAFV600E metastatic colorectal cancer. In vivo models demonstrated regressions with the triplet, in contrast with vemurafenib and cetuximab alone. cfDNA predicted radiographic response and identified mutations reactivating the MAPK pathway upon progression. Cancer Discov; 6(12); 1352-65. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1293.

Hong DS ，Morris VK ，El Osta B ，Sorokin AV ，Janku F ，Fu S ，Overman MJ ，Piha-Paul S ，Subbiah V ，Kee B ，Tsimberidou AM ，Fogelman D ，Bellido J ，Shureiqi I ，Huang H ，Atkins J ，Tarcic G ，Sommer N ，Lanman R ，Meric-Bernstam F ，Kopetz S ... -  《-》

Antitumor activity of BRAF inhibitor vemurafenib in preclinical models of BRAF-mutant colorectal cancer.

The protein kinase BRAF is a key component of the RAS-RAF signaling pathway which plays an important role in regulating cell proliferation, differentiation, and survival. Mutations in BRAF at codon 600 promote catalytic activity and are associated with 8% of all human (solid) tumors, including 8% to 10% of colorectal cancers (CRC). Here, we report the preclinical characterization of vemurafenib (RG7204; PLX4032; RO5185426), a first-in-class, specific small molecule inhibitor of BRAF(V600E) in BRAF-mutated CRC cell lines and tumor xenograft models. As a single agent, vemurafenib shows dose-dependent inhibition of ERK and MEK phosphorylation, thereby arresting cell proliferation in BRAF(V600)-expressing cell lines and inhibiting tumor growth in BRAF(V600E) bearing xenograft models. Because vemurafenib has shown limited single-agent clinical activity in BRAF(V600E)-mutant metastatic CRC, we therefore explored a range of combination therapies, with both standard agents and targeted inhibitors in preclinical xenograft models. In a BRAF-mutant CRC xenograft model with de novo resistance to vemurafenib (RKO), tumor growth inhibition by vemurafenib was enhanced by combining with an AKT inhibitor (MK-2206). The addition of vemurafenib to capecitabine and/or bevacizumab, cetuximab and/or irinotecan, or erlotinib resulted in increased antitumor activity and improved survival in xenograft models. Together, our findings suggest that the administration of vemurafenib in combination with standard-of-care or novel targeted therapies may lead to enhanced and sustained clinical antitumor efficacy in CRCs harboring the BRAF(V600E) mutation.

Yang H ，Higgins B ，Kolinsky K ，Packman K ，Bradley WD ，Lee RJ ，Schostack K ，Simcox ME ，Kopetz S ，Heimbrook D ，Lestini B ，Bollag G ，Su F ... -  《-》

Drug Combo Beats Vemurafenib Alone for Colorectal Cancer.

Vemurafenib doesn't shrink BRAF-mutated colorectal tumors, but a regimen that also includes irinotecan and cetuximab improves vemurafenib's effectiveness, more than doubling progression-free survival in patients with metastatic tumors. The drug trio also increases disease-control rates.

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A Phase Ib Dose-Escalation Study of Encorafenib and Cetuximab with or without Alpelisib in Metastatic BRAF-Mutant Colorectal Cancer.

Preclinical evidence suggests that concomitant BRAF and EGFR inhibition leads to sustained suppression of MAPK signaling and suppressed tumor growth in BRAFV600E colorectal cancer models. Patients with refractory BRAFV600-mutant metastatic CRC (mCRC) were treated with a selective RAF kinase inhibitor (encorafenib) plus a monoclonal antibody targeting EGFR (cetuximab), with (n = 28) or without (n = 26) a PI3Kα inhibitor (alpelisib). The primary objective was to determine the maximum tolerated dose (MTD) or a recommended phase II dose. Dose-limiting toxicities were reported in 3 patients receiving dual treatment and 2 patients receiving triple treatment. The MTD was not reached for either group and the phase II doses were selected as 200 mg encorafenib (both groups) and 300 mg alpelisib. Combinations of cetuximab and encorafenib showed promising clinical activity and tolerability in patients with BRAF-mutant mCRC; confirmed overall response rates of 19% and 18% were observed and median progression-free survival was 3.7 and 4.2 months for the dual- and triple-therapy groups, respectively.Significance: Herein, we demonstrate that dual- (encorafenib plus cetuximab) and triple- (encorafenib plus cetuximab and alpelisib) combination treatments are tolerable and provide promising clinical activity in the difficult-to-treat patient population with BRAF-mutant mCRC. Cancer Discov; 7(6); 610-9. ©2017 AACR.See related commentary by Sundar et al., p. 558This article is highlighted in the In This Issue feature, p. 539.

van Geel RMJM ，Tabernero J ，Elez E ，Bendell JC ，Spreafico A ，Schuler M ，Yoshino T ，Delord JP ，Yamada Y ，Lolkema MP ，Faris JE ，Eskens FALM ，Sharma S ，Yaeger R ，Lenz HJ ，Wainberg ZA ，Avsar E ，Chatterjee A ，Jaeger S ，Tan E ，Maharry K ，Demuth T ，Schellens JHM ... -  《-》

Cetuximab and vemurafenib plus FOLFIRI (5-fluorouracil/leucovorin/irinotecan) for BRAF V600E-mutated advanced colorectal cancer (IMPROVEMENT): An open-label, single-arm, phase II trial.

Current therapeutic regimens for patients with v-raf murine sarcoma viral oncogene homolog B1 (BRAF) V600E-mutated colorectal cancer show unsatisfactory efficacy. To improve outcomes in this area, we assessed the safety and efficacy of a new protocol using vemurafenib and cetuximab combined with FOLFIRI (5-fluorouracil/leucovorin/irinotecan) in patients with BRAF V600E-mutated colorectal cancer. This was an investigator-initiated, open-label, single-arm, phase II trial conducted in patients with BRAF V600E-mutated advanced colorectal cancer. Patients were eligible to receive FOLFIRI combined with vemurafenib and cetuximab. The primary end-point was the objective response rate, and the secondary end-points included disease control rate, progression-free survival, overall survival and safety. This trial is registered with ClinicalTrials.gov, NCT03727763. Between 12th January 2018, and 18th June 2021, we screened 27 patients, 21 of which were enrolled in this study. Efficacy analysis showed that objective response rates were 81.0% (17/21; 95% confidence interval [CI] 57.4-93.7) in the intention-to-treat population and 85.0% (17/20, 95%CI 61.0-96.0) in the per-protocol population; two patients achieved complete response, and 15 patients achieved a partial response. In the entire cohort, the median progression-free survival was 9.7 months (95%CI 6.3-10.9), and the median overall survival for all patients was 15.4 months (95%CI 8.5-15.4). The most common adverse events (grade 3 to 4) were neutropenia (8/21), anaemia (3/21) and skin rash (3/21). Vemurafenib and cetuximab can be safely combined with the FOLFIRI regimen, showing promising antitumour activity and tolerable toxicity in patients with BRAF V600E-mutated advanced colorectal cancer. This regimen warrants a further randomised study in phase III clinical trials.

Wang Z ，Qin BD ，Ye CY ，Wang MM ，Yuan LY ，Dai WP ，Sun L ，Liu K ，Qin WX ，Jiao XD ，Li XN ，Zang YS ... -  《-》