Abstract 979TiP
Background
Patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) often present with loco-regional disease; approximately 14% of patients present with metastatic disease. Despite aggressive primary therapy over 50% of newly diagnosed patients treated radically with either surgery and/or radiotherapy with/without chemotherapy will develop recurrent disease, with the majority of recurrences occurring locally. Standard therapy for these patients is a platinum-containing regime (PCCC) or PD-1 inhibitor. Median survival for fit patients treated for R/M HNSCC is 10-13 months. However, peak age of HNSCC diagnosis is around 70 years; many patients have multiple co-morbidities and are not fit enough to receive PCCC. There is no accepted standard of care for patients unfit for PCCC and little quality data on these patients, who have a median survival of 3-6 months with best supportive care alone. Pembrolizumab, a PD-1 inhibitor, has demonstrated clinical activity in fitter patients with R/M HNSCC, but there is no clinical data on the benefits or toxicities of pembrolizumab in patients with WHO performance status (PS) of 2. This represents a significant proportion of R/M HNSCC patients, and an area of unmet clinical need.
Trial design
POPPY (NCT03813836) is a single-arm, multi-centre phase II trial. Eligible patients have histologically or cytologically confirmed measurable R/M HNSCC, considered incurable by local therapies, and a WHO PS of 2. Patients will receive pembrolizumab 200 mg intravenously every 3 weeks, for up to 24 months. The primary endpoint is disease control rate (DCR) at 24 weeks, using iRECIST. Required sample size is 59 patients, with a planned sample size of 65 (allowing 10% dropout); this gives 85% power to detect a DCR ≥20%, relative to a null DCR ≤10%, with 15% one-sided type I error control. Secondary endpoints include toxicity, duration of response and overall survival. Blood and fresh tissue will be collected for exploratory translational studies to identify potential novel predictive biomarkers for response. The POPPY trial opened in August 2019 and recruitment is ongoing.
Clinical trial identification
NCT03813836; 23, 2019; UCL ID: UCL/17/0396.
Editorial acknowledgement
Legal entity responsible for the study
University College London.
Funding
MSD.
Disclosure
All authors have declared no conflicts of interest.