Cetuximab maintenance therapy for wild-type metastatic colorectal cancer is associated with clinically significant overall and progression-free survival. However, cetuximab therapy following FOLFIRI plus cetuximab is not appropriate for patients with mutated mitogen-activated protein kinase, warranting refined treatment strategies.
There continues to be a lack of consensus regarding the best option among de-escalation modalities for managing metastatic colorectal cancer (mCRC). The current European guidelines recommend targeted therapy with anti-epidermal growth factor receptor (anti-EGFR). Leucovorin (folinic acid), fluorouracil, and irinotecan (FOLFIRI) is the first-line therapy administered until disease progression.
This phase-2 clinical trial assessed the safety and efficacy of maintenance therapy with cetuximab following combined FOLFIRI–cetuximab administration in wild-type mCRC patients. The study findings are published in JAMA Network Open.
Out of the 214 patients enrolled in this trial, 139 patients were randomized to the cetuximab and observed groups. The median age of the patients was 64 years (range, 34–85 years) in the cetuximab group and 68 years (range, 23–85 years) in the observed group.
Efficacy of Cetuximab Maintenance Therapy in Metastatic Colorectal Cancer Patients
When assessed at 6 months following randomization, four (5.6%) observation group patients and 26 (38.8%) cetuximab group patients did not have disease progression. The progression-free survival (PFS) from randomization in the observation and cetuximab groups was 2.0 and 5.3 months, respectively. The objective response during maintenance was 17.5% and 4.8% in the cetuximab and observation groups, respectively.
Mitogen-Activated Protein Kinase Pathway Mutation
Mitogen-activated protein kinase (MAPK) pathway mutations were more prevalent among non-randomized patients. In the randomized population, activating MAPK mutations was associated with a significantly reduced median PFS from the randomization period.
Safety of Cetuximab Maintenance Therapy in Metastatic Colorectal Cancer Patients
Approximately 64.4% of the safety group patients experienced a minimum of one grade 3 or higher adverse event either related to or unrelated to cetuximab during induction chemotherapy. A total of seven patients died during induction therapy. Adverse events during the first maintenance therapy were observed in approximately 4.5% of the patients. However, during the maintenance phase, 44.8% of the cetuximab group patients reported a minimum of one grade 3 or higher adverse event either related to or unrelated to cetuximab.
Boige, V., Blons, H., François, E., Ben Abdelghani, M., Phelip, J.-M., Le Brun-Ly, V., Mineur, L., Galais, M. P., Villing, A.-L., Hautefeuille, V., Miglianico, L., De La Fouchardière, C., Genet, D., Levasseur, N., Levaché, C.-B., Penel, N., Mitry, E., Jacquot, S., Aparicio, T., & Brument, E. (2023). Maintenance Therapy With Cetuximab After FOLFIRI Plus Cetuximab for RAS Wild-Type Metastatic Colorectal Cancer: A Phase 2 Randomized Clinical Trial. JAMA Network Open, 6(9), e2333533. https://doi.org/10.1001/jamanetworkopen.2023.33533