Journal Article

Sotorasib plus Panitumumab in Refractory Colorectal Cancer with Mutated KRAS G12C

Tran, Qui, Kim, Tae-Won, Cremolini, Chiara, Chan, Emily, Lopez-Bravo, David P., Chao, Joseph, Esaki, Taito, Modest, Dominik P., Meriggi, Fausto, Saportas, Yaneth, Pietrantonio, Filippo, Taieb, Julien, Karamouzis, Michalis V., Yeh, Kun-Huei, Ruiz-Garcia, Erika, Fakih, Marwan G., Kuboki, Yasutoshi, Cunningham, David, Salvatore, Lisa

2023

Overview

G12C is a mutation that occurs in approximately 3 to 4% of patients with metastatic colorectal cancer. Monotherapy with KRAS G12C inhibitors has yielded only modest efficacy. Combining the KRAS G12C inhibitor sotorasib with panitumumab, an epidermal growth factor receptor (EGFR) inhibitor, may be an effective strategy. In this phase 3, multicenter, open-label, randomized trial, we assigned patients with chemorefractory metastatic colorectal cancer with mutated G12C who had not received previous treatment with a KRAS G12C inhibitor to receive sotorasib at a dose of 960 mg once daily plus panitumumab (53 patients), sotorasib at a dose of 240 mg once daily plus panitumumab (53 patients), or the investigator's choice of trifluridine-tipiracil or regorafenib (standard care; 54 patients). The primary end point was progression-free survival as assessed by blinded independent central review according to the Response Evaluation Criteria in Solid Tumors, version 1.1. Key secondary end points were overall survival and objective response. After a median follow-up of 7.8 months (range, 0.1 to 13.9), the median progression-free survival was 5.6 months (95% confidence interval [CI], 4.2 to 6.3) and 3.9 months (95% CI, 3.7 to 5.8) in the 960-mg sotorasib-panitumumab and 240-mg sotorasib-panitumumab groups, respectively, as compared with 2.2 months (95% CI, 1.9 to 3.9) in the standard-care group. The hazard ratio for disease progression or death in the 960-mg sotorasib-panitumumab group as compared with the standard-care group was 0.49 (95% CI, 0.30 to 0.80; P = 0.006), and the hazard ratio in the 240-mg sotorasib-panitumumab group was 0.58 (95% CI, 0.36 to 0.93; P = 0.03). Overall survival data are maturing. The objective response was 26.4% (95% CI, 15.3 to 40.3), 5.7% (95% CI, 1.2 to 15.7), and 0% (95% CI, 0.0 to 6.6) in the 960-mg sotorasib-panitumumab, 240-mg sotorasib-panitumumab, and standard-care groups, respectively. Treatment-related adverse events of grade 3 or higher occurred in 35.8%, 30.2%, and 43.1% of patients, respectively. Skin-related toxic effects and hypomagnesemia were the most common adverse events observed with sotorasib-panitumumab. In this phase 3 trial of a KRAS G12C inhibitor plus an EGFR inhibitor in patients with chemorefractory metastatic colorectal cancer, both doses of sotorasib in combination with panitumumab resulted in longer progression-free survival than standard treatment. Toxic effects were as expected for either agent alone and resulted in few discontinuations of treatment. (Funded by Amgen; CodeBreaK 300 ClinicalTrials.gov number, NCT05198934.).

• Publisher: Massachusetts Medical Society
• Subject: Adverse events / Antibodies, Monoclonal, Humanized - administration & dosage / Antibodies, Monoclonal, Humanized - adverse effects / Antibodies, Monoclonal, Humanized - therapeutic use / Antineoplastic Agents - administration & dosage / Antineoplastic Agents - adverse effects / Antineoplastic Agents - therapeutic use / Antineoplastic Agents, Immunological - administration & dosage / Antineoplastic Agents, Immunological - adverse effects / Antineoplastic Agents, Immunological - therapeutic use / Antineoplastic Combined Chemotherapy Protocols - administration & dosage / Antineoplastic Combined Chemotherapy Protocols - adverse effects / Antineoplastic Combined Chemotherapy Protocols - therapeutic use / Cancer / Cancer therapies / Colorectal cancer / Colorectal carcinoma / Colorectal Neoplasms - drug therapy / Colorectal Neoplasms - genetics / Colorectal Neoplasms - pathology / Consent / Epidermal growth factor receptors / ErbB Receptors - antagonists & inhibitors / ErbB Receptors - genetics / Humans / Hypomagnesemia / Immune Checkpoint Inhibitors - administration & dosage / Immune Checkpoint Inhibitors - adverse effects / Immune Checkpoint Inhibitors - therapeutic use / Inhibitor drugs / K-Ras protein / Medical prognosis / Metastases / Metastasis / Monoclonal antibodies / Mutation / Panitumumab - administration & dosage / Panitumumab - adverse effects / Panitumumab - therapeutic use / Patients / Proto-Oncogene Proteins p21(ras) - antagonists & inhibitors / Proto-Oncogene Proteins p21(ras) - genetics / Solid tumors / Survival / Targeted cancer therapy / Trifluridine - administration & dosage / Trifluridine - adverse effects / Trifluridine - therapeutic use / Tumors