Panitumumab vs Bevacizumab Added to Standard First-line Chemotherapy and Overall Survival Among Patients With RAS Wild-type, Left-Sided Metastatic Colorectal Cancer: A Randomized Clinical Trial
Mené au Japon sur 604 patients atteints d'un cancer colorectal localisé du côté gauche, non résécable, de stade métastatique et sans mutation RAS (âge médian : 66 ans ; durée médiane de suivi : 61 mois), cet essai randomisé compare l'efficacité, du point de vue de la survie globale, et la toxicité du panitumumab et du bévacizumab, en combinaison avec une chimiothérapie standard de première ligne
Importance : For patients with RAS wild-type metastatic colorectal cancer, adding anti–epidermal growth factor receptor (anti-EGFR) or anti–vascular endothelial growth factor (anti-VEGF) monoclonal antibodies to first-line doublet chemotherapy is routine, but the optimal targeted therapy has not been defined. Objective : To evaluate the effect of adding panitumumab (an anti-EGFR monoclonal antibody) vs bevacizumab (an anti-VEGF monoclonal antibody) to standard first-line chemotherapy for treatment of RAS wild-type, left-sided, metastatic colorectal cancer. Design, Setting, and Participants : Randomized, open-label, phase 3 clinical trial at 197 sites in Japan in May 2015–January 2022 among 823 patients with chemotherapy-naive RAS wild-type, unresectable metastatic colorectal cancer (final follow-up, January 14, 2022). Interventions :Panitumumab (n = 411) or bevacizumab (n = 412) plus modified fluorouracil, l-leucovorin, and oxaliplatin (mFOLFOX6) every 14 days. Main Outcomes and Measures : The primary end point, overall survival, was tested first in participants with left-sided tumors, then in the overall population. Secondary end points were progression-free survival, response rate, duration of response, and curative (defined as R0 status) resection rate. Results : In the as-treated population (n = 802; median age, 66 years; 282 [35.2%] women), 604 (75.3%) had left-sided tumors. Median follow-up was 61 months. Median overall survival was 37.9 months with panitumumab vs 34.3 months with bevacizumab in participants with left-sided tumors (hazard ratio [HR] for death, 0.82; 95.798% CI, 0.68-0.99; P = .03) and 36.2 vs 31.3 months, respectively, in the overall population (HR, 0.84; 95% CI, 0.72-0.98; P = .03). Median progression-free survival for panitumumab vs bevacizumab was 13.1 vs 11.9 months, respectively, for those with left-sided tumors (HR, 1.00; 95% CI, 0.83-1.20) and 12.2 vs 11.4 months overall (HR, 1.05; 95% CI, 0.90-1.24). Response rates with panitumumab vs bevacizumab were 80.2% vs 68.6%, respectively, for left-sided tumors (difference, 11.2%; 95% CI, 4.4%-17.9%) and 74.9% vs 67.3% overall (difference, 7.7%; 95% CI, 1.5%-13.8%). Median duration of response with panitumumab vs bevacizumab was 13.1 vs 11.2 months for left-sided tumors (HR, 0.86; 95% CI, 0.70-1.10) and 11.9 vs 10.7 months overall (HR, 0.89; 95% CI, 0.74-1.06). Curative resection rates with panitumumab vs bevacizumab were 18.3% vs 11.6% for left-sided tumors; (difference, 6.6%; 95% CI, 1.0%-12.3%) and 16.5% vs 10.9% overall (difference, 5.6%; 95% CI, 1.0%-10.3%). Common treatment-emergent adverse events were acneiform rash (panitumumab: 74.8%; bevacizumab: 3.2%), peripheral sensory neuropathy (panitumumab: 70.8%; bevacizumab: 73.7%), and stomatitis (panitumumab: 61.6%; bevacizumab: 40.5%). Conclusions and Relevance: Among patients with RAS wild-type metastatic colorectal cancer, adding panitumumab, compared with bevacizumab, to standard first-line chemotherapy significantly improved overall survival in those with left-sided tumors and in the overall population.
JAMA 2022