A randomized, phase 2 study of cetuximab plus cisplatin with or without paclitaxel for the first-line treatment of patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck

Background: B490 (EudraCT# 2011-002564-24) is a randomized, phase 2b, noninferiority study investigating the efficacy and safety of first-line cetuximab plus cisplatin with/without paclitaxel (CetCis versus CetCisPac) in patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). Patients and methods: Eligible patients had confirmed R/M SCCHN (oral cavity/oropharynx/larynx/hypopharynx/paranasal sinus) and no prior therapy for R/M disease. Cetuximab was administered on day 1 (2-h infusion, 400 mg/m2), then weekly (1-h infusions, 250 mg/m2). Cisplatin was given as a 1-h infusion (CetCis arm: 100 mg/m2; CetCisPac arm: 75 mg/m2) on day 1 of each cycle for a maximum of six cycles. Paclitaxel was administered as a 3-h infusion (175 mg/m2) on day 1 of each cycle. After six cycles, maintenance cetuximab was administered until disease progression or unacceptable toxicity. The primary end point was progression-free survival (PFS). We assumed a noninferiority margin of 1.40 as compatible with efficacy. Results: A total of 201 patients were randomized 1: 1 to each regimen; 191 were assessable. PFS with CetCis (median, 6 months) was noninferior to PFS with CetCisPac (median, 7 months) [HR for CetCis versus CetCisPac 0.99; 95% CI: 0.72-1.36, P=0.906; margin of noninferiority (90% CI of 1.4) not reached]. Median overall survival was 13 versus 11 months (HR=0.77; 95% CI: 0.53=1.11, P=0.117). The overall response rates were 41.8% versus 51.7%, respectively (OR=0.69; 95% CI: 0.38-1.20, P=0.181). Grade≥3 adverse event rates were 76% and 73% for CetCis versus CetCisPac, respectively, while grade 4 toxicities were lower in the two-drug versus three-drug arm (14% versus 33%, P=0.015). No toxic death or sepsis were reported and cardiac events were negligible (1%). Conclusion: The two-drug CetCis regimen proved to be noninferior in PFS to a three-drug combination with CetCisPac. The median OS of both regimens is comparable with that observed in EXTREME, while the life-threatening toxicity rate appeared reduced.