Pembrolizumab plus docetaxel for the treatment of recurrent/metastatic head and neck cancer: A prospective phase I/II study.

Abstract Background Taxane-based checkpoint inhibitor combination therapy might improve the outcome in recurrent/metastatic (R/M) head and neck cancer (HNSCC) patients. Thus, we investigated the efficacy and safety of docetaxel (DTX) plus pembrolizumab (P) in a prospective phase I/II trial. Methods Platinum-resistant R/M HNSCC patients received DTX 75 mg/m^2 plus P 200 mg for up to six cycles followed by P maintenance therapy. The primary endpoint was overall response rate (ORR) and safety. Secondary endpoints comprised disease control rate (DCR), overall survival (OS) and progression free survival (PFS). Results Twenty-two patients were enrolled. Nine patients (40.9%) had a primary tumor in the oropharynx, 8 (36.4%) in the oral cavity, 3 (13.6%) in the hypopharynx and 2 (9.1%) in the larynx. The ORR was 22.7% (95% CI 10.1%-43.4%) and one (4.5%) complete response was achieved. The DCR was 54.6% (95% 34.7%-73.1%). The median PFS was 5.8 months (95% CI 2.7–11.6) and the median OS 21.3 months (95% CI 6.3–31.1). The 1-year PFS and OS rates were 27.3% and 68.2%, respectively. While the most frequent adverse event (AE) was myelosuppression, which was reported in all 22 patients, 3 (13.6%) patients experienced grade 3 febrile neutropenia. The most common immune-related AEs were grade skin rash (40.9%) and hypothyroidism (40.9%). One patient (4.5%) experienced grade 5 immune thrombocytopenia. Conclusion DXT in combination with P shows promising activity accompanied with a manageable side effect profile in pre-treated R/M HNSCC patients.