The UK Divide: Does having a Pembrolizumab-Chemotherapy option in head and neck cancer matter? Real-world experience of first-line palliative pembrolizumab monotherapy and pembrolizumab-chemotherapy combination in Scotland

Abstract

Objectives To provide real-world performance data and identify clinical factors associated with survival outcomes for patients receiving first-line pembrolizumab-containing treatment for head and neck squamous cell carcinoma (HNSCC) in the palliative setting. Materials and Methods We analysed the electronic records of patients who initiated pembrolizumab-containing treatment between 01/03/2020-30/09/2021. Outcomes included overall survival (OS), progression-free survival (PFS), duration of response (DOR), disease control rate (DCR). Data were compared with the KEYNOTE-048 study and clinical factors were evaluated for association with survival. Results Our cohort included 91 patients (median follow-up 10.8 months). For patients receiving monotherapy (n=76), 12-month and 24-month OS was 45% and 27%, respectively, 12-month PFS was 22%, median DOR was 13.3 months, and DCR was 56.6%. For patients receiving pembrolizumab-chemotherapy (n=15), 12-month OS was 60%, 12-month PFS was 20%, median DOR was 7.3 months and DCR was 60.0%. Experiencing ≥1 irAE (versus no irAEs), of any grade, was associated with favourable OS and PFS for patients receiving monotherapy in both univariable log-rank analysis (median OS 17.4 months versus 8.6 months, respectively, P=0.0033; median PFS 10.9 months versus 3.0 months, respectively, P<0.0001) and multivariable analysis (Cox proportional hazards regression: OS HR: 0.31, P=0.0009; PFS HR: 0.17, P<0.0001). Conclusion Our real-world data, first from a European population, support the KEYNOTE-048 study findings. Additionally, our data is first to show irAEs are associated with better outcomes in this patient group, adding to the growing body of evidence showing irAEs are generally a positive marker of PD-L1 inhibitor response.