Concurrent Definitive Immunoradiotherapy for Patients with Stage III-IV Head and Neck Cancer and Cisplatin Contraindication

Clin Cancer Res. 2020 Aug 15;26(16):4260-4267. doi: 10.1158/1078-0432.CCR-20-0230. Epub 2020 May 5.

Abstract

Purpose: Although cisplatin plus radiotherapy is a standard treatment of locally advanced head and neck squamous cell carcinoma (LA-HNSCC), cisplatin contraindication is common. Radiation elicits and promotes tumor-directed immune stimulation, which may potentiate anti-PD-1 therapy. We provide the first efficacy report of combined pembrolizumab and definitive radiotherapy in LA-HNSCC.

Patients and methods: This single-arm, multi-institution, phase II study (NCT02609503) enrolled 29 cisplatin-ineligible patients. Patients received radiotherapy concurrently with three cycles of pembrolizumab 200 mg every 3 weeks followed by three adjuvant cycles. The primary endpoint was a progression-free survival (PFS) of ≥16 months. Correlative studies included peripheral blood flow cytometry and Luminex cytokine profiling.

Results: Reasons for cisplatin ineligibility included otopathy (69.0%), nephropathy (20.7%), and neuropathy (6.9%). With median follow-up of 21 months, estimated 24-month PFS and overall survival rates were 71% (95% confidence interval, 49%-84%) and 75% (51%-88%). The primary PFS endpoint has exceeded the hypothesis and its median has not been reached. Toxicities were typical of radiotherapy; however, high rates of grade 3/4 lymphopenia (58.6%) were observed. Flow cytometry revealed a relative decline in CD4 T cells and B cells, but not CD8 T cells. Upon treatment, frequencies of transitional B cells and tissue-like memory B cells increased, while resting memory B cells decreased. Patients with progression had greater percentages of baseline naïve B cells and fewer marginal zone B cells.

Conclusions: Pembrolizumab and radiotherapy is efficacious in LA-HNSCC and should be evaluated in a randomized trial. The observed changes in B-cell markers deserve further study both as potential biomarkers and as therapeutic targets.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal, Humanized / administration & dosage*
  • Antibodies, Monoclonal, Humanized / adverse effects
  • Antineoplastic Combined Chemotherapy Protocols / administration & dosage*
  • Antineoplastic Combined Chemotherapy Protocols / adverse effects
  • Cisplatin / adverse effects
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasm Recurrence, Local / drug therapy*
  • Neoplasm Recurrence, Local / genetics
  • Neoplasm Recurrence, Local / immunology
  • Neoplasm Recurrence, Local / pathology
  • Neoplasm Staging
  • Progression-Free Survival
  • Radioimmunotherapy / adverse effects
  • Squamous Cell Carcinoma of Head and Neck / drug therapy*
  • Squamous Cell Carcinoma of Head and Neck / pathology
  • Squamous Cell Carcinoma of Head and Neck / radiotherapy*

Substances

  • Antibodies, Monoclonal, Humanized
  • pembrolizumab
  • Cisplatin

Associated data

  • ClinicalTrials.gov/NCT02609503