Background: Scientific data provide the evidence that secondary K-RAS mutations do not occur during anti-epidermal growth factor receptor therapy in colorectal cancer patients. This multicenter phase II prospective study aims to investigate the activity of a retreatment with a cetuximab-based therapy. Patients and methods: We enrolled 39 irinotecan-refractory patients who had a clinical benefit after a line of cetuximab- plus irinotecan-based therapy and then a progression of disease for which underwent a new line chemotherapy and finally, after a clear new progression of disease, were retreated with the same cetuximab- plus irinotecan-based therapy. Results: Median number of therapeutic lines before accrual was 4. Median interval time between last cycle of first cetuximab-based therapy and first cycle of the retreatment was 6 months. Overall response rate was 53.8% with 19 partial responses (48.7%) and 2 complete responses (5.1%). Disease stabilization was obtained in 35.9% of patients and progression in four patients (10.2%). Median progression-free survival was 6.6 months. The correlation between skin toxicity during first cetuximab therapy and during cetuximab rechallenge was significant (P = 0.01). Conclusion: Rechallenge with the same cetuximab-based therapy may achieve a new important clinical benefit further delaying the progression of disease and improving the therapeutic options.

Cetuximab, Clinical trial, Colorectal neoplasms, Phase II, Retreatment,
Annals of Oncology
Erasmus School of Economics

Santini, D, Vincenzi, B, Addeo, R, Garufi, C, Masi, G, Scartozzi, M, … Tonini, G. (2012). Cetuximab rechallenge in metastatic colorectal cancer patients: How to come away from acquired resistance?. Annals of Oncology, 23(9), 2313–2318. doi:10.1093/annonc/mdr623