Observational, prospective, phase 4 study in patients with first-line recurrent and/or metastatic squamous cell carcinoma of the head and neck treated with cetuximab and platinum-based therapy: DIRECT.

BACKGROUND Cetuximab plus platinum-based therapy (PBT) followed by cetuximab maintenance until progression (EXTREME) is a guideline-recommended first-line treatment option in recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). DIRECT (Dose Intensity RElative to CeTuximab) was the first phase 4 observational study evaluating EXTREME administration in the real-world setting. AIMS The primary aim of this study was to assess the relative dose intensity of cetuximab in patients with R/M SCCHN treated with first-line cetuximab according to the EXTREME regimen. METHODS AND RESULTS Patients were ≥18 years old and eligible to receive cetuximab/PBT. Primary endpoint was cetuximab relative dose intensity (RDI). Of prospectively enrolled patients (n = 157), 119 received ≥1 cycle of EXTREME. Practices differing from the EXTREME trial were 5-fluorouracil omission (14%), maintenance cetuximab given every other week (54%), prior cetuximab, disease-free interval <6 months. 64% of patients reached cetuximab RDI ≥80%; mean cetuximab RDI was 88%. 46% of patients received maintenance cetuximab (mean RDI, 91%). Median progression-free survival and overall survival were 4.5 and 9.4 months. No new/unexpected safety findings were observed. CONCLUSIONS The DIRECT study showed that first-line cetuximab plus PBT was a feasible, beneficial first-line treatment regimen in patients with R/M SCCHN in the real-world setting.