Safety and Efficacy of Pembrolizumab With Chemoradiotherapy in Locally Advanced Head and Neck Squamous Cell Carcinoma: A Phase IB Study

J Clin Oncol. 2020 Jul 20;38(21):2427-2437. doi: 10.1200/JCO.19.03156. Epub 2020 Jun 1.


Purpose: Pembrolizumab is a humanized monoclonal antibody that blocks interaction between programmed death receptor-1 (PD-1) and its ligands (PD-L1, PD-L2). Although pembrolizumab is approved for recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), its role in the management of locally advanced (LA) disease is not defined. We report a phase IB study evaluating the safety and efficacy of adding pembrolizumab to cisplatin-based chemoradiotherapy in patients with LA HNSCC.

Patients and methods: Eligible patients included those with oral cavity (excluding lip), oropharyngeal, hypopharyngeal, or laryngeal stage III to IVB HNSCC (according to American Joint Committee on Cancer, 7th edition, staging system) eligible for cisplatin-based, standard-dose (70 Gy) chemoradiotherapy. Pembrolizumab was administered concurrently with and after chemoradiotherapy with weekly cisplatin. Safety was the primary end point and was determined by incidence of chemoradiotherapy adverse events (AEs) and immune-related AEs (irAEs). Efficacy was defined as complete response (CR) rate on end-of-treatment (EOT) imaging or with pathologic confirmation at 100 days postradiotherapy completion. Key secondary end points included overall (OS) and progression-free survival (PFS).

Results: The study accrued 59 patients (human papillomavirus [HPV] positive, n = 34; HPV negative, n = 25) from November 2015 to October 2018. Five patients (8.8%) required discontinuation of pembrolizumab because of irAEs, all of which occurred during concurrent chemoradiotherapy; 98.3% of patients completed the full planned treatment dose (70 Gy) of radiotherapy without any delays ≥ 5 days; 88.1% of patients completed the goal cisplatin dose of ≥ 200 mg/m2. EOT CR rates were 85.3% and 78.3% for those with HPV-positive and -negative HNSCC, respectively.

Conclusion: Pembrolizumab in combination with weekly cisplatin-based chemoradiotherapy is safe and does not impair delivery of curative radiotherapy or chemotherapy in HNSCC. Early efficacy data support further investigation of this approach.

Trial registration: NCT02586207.

Publication types

  • Clinical Trial, Phase I
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antibodies, Monoclonal, Humanized / pharmacology
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Antineoplastic Agents, Immunological / pharmacology
  • Antineoplastic Agents, Immunological / therapeutic use*
  • Chemoradiotherapy / methods*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Retrospective Studies
  • Squamous Cell Carcinoma of Head and Neck / drug therapy*
  • Squamous Cell Carcinoma of Head and Neck / radiotherapy*


  • Antibodies, Monoclonal, Humanized
  • Antineoplastic Agents, Immunological
  • pembrolizumab

Associated data