Ramucirumab in combination with pembrolizumab for recurrent or metastatic head and neck squamous cell carcinoma: a single-centre, phase 1/2 trial.

BACKGROUND: VEGF, a key mediator of angiogenesis and resistance to immunotherapy, is overexpressed in head and neck squamous cell carcinoma (HNSCC). We aimed to determine the recommended phase 2 dose of ramucirumab, a selective VEGFR2 inhibitor, given with pembrolizumab and the objective response rate of this combination as first-line treatment for recurrent or metastatic HNSCC. METHODS: In this single-centre, phase 1/2 trial, which was done at Washington University (St Louis, MO, USA), eligible patients were aged 18 years or older with incurable recurrent or metastatic HNSCC and an Eastern Cooperative Oncology Group performance status of 0-2. Patients in phase 2 were required to have had no previous systemic therapy for recurrent or metastatic disease. In a dose de-escalation phase 1 design, patients received ramucirumab (starting dose 10 mg/kg given intravenously) and pembrolizumab (200 mg intravenously) on day 1 of each 21-day cycle. The recommended phase 2 dose of ramucirumab was defined as the highest dose at which one or fewer of three patients had dose-limiting toxicity during cycle one (primary endpoint of phase 1). In a Simon's two-stage phase 2 design, patients received the recommended phase 2 dose of ramucirumab and pembrolizumab. Tumour response (primary endpoint of phase 2) was assessed by Response Evaluation Criteria in Solid Tumours (version 1.1). We hypothesised that there would be an objective response rate of 32% or higher (null ≤13%). Eight or more responses among 33 evaluable patients (those with at least one response assessment) was evidence for activity (80% power; one-sided α=0·05). Analyses were done per protocol. The trial is registered with ClinicalTrials.gov, NCT03650764, and is closed to enrolment. FINDINGS: Between June 18, 2019, and Feb 11, 2021, three patients enrolled and were treated in phase 1 and 37 patients in phase 2. Median age of all patients was 64 years (IQR 59-72). 36 (90%) of 40 patients were men and four (10%) were women, and 36 (90%) patients were White, three (8%) were Black or African American, and one (3%) was Asian. In phase 1, no dose-limiting toxicity event occurred. The recommended phase 2 dose of ramucirumab was 10 mg/kg. Median follow-up for patients on phase 2 was 14·8 months (IQR 4·9-31·0). In phase 2, 18 (55%; 95% CI 38-70) of 33 evaluable patients had an objective response, including confirmed complete response in 11 patients, confirmed partial response in six patients, and unconfirmed partial response in one patient. The most common grade 3 or worse adverse events were dysphagia (14 [38%] of 37 patients), lung infection (11 [30%]), lymphocyte count decrease (ten [27%]), hypophosphataemia (nine [24%]), and hypertension (eight [22%]). No treatment-related deaths were recorded. INTERPRETATION: Ramucirumab and pembrolizumab were safe to administer to patients with recurrent or metastatic HNSCC, and the objective response rate with this combination as first-line treatment for recurrent or metastatic HNSCC was favourable. Further studies of ramucirumab and pembrolizumab in patients with recurrent or metastatic HNSCC are warranted. FUNDING: Lilly and the Joseph Sanchez Foundation.

Palbociclib and cetuximab in cetuximab-resistant human papillomavirus-related oropharynx squamous-cell carcinoma: A multicenter phase 2 trial.

OBJECTIVES: We previously reported that palbociclib, a selective CDK4/6 inhibitor, given with cetuximab, resulted in an objective response rate (ORR) of 19% in cetuximab-resistant human papillomavirus (HPV)-unrelated head and neck squamous-cell carcinoma (HNSCC). In this study, we aimed to determine the proportion of patients with cetuximab-resistant HPV-related oropharynx (OP)SCC who achieved an objective response to palbociclib and cetuximab. MATERIALS AND METHODS: We performed a multicenter phase 2 trial. Key eligibility requirements included measurable HPV-related OPSCC that progressed on a cetuximab-containing regimen. Palbociclib 125 mg po was administered on Days 1-21 of 28 day cycles, with weekly cetuximab. The primary endpoint was objective response (RECIST1.1). The study design had a probability of 0.70 of accepting the alternative hypothesis (ORR ≥ 20%) and rejecting the null hypothesis (ORR ≤ 5%). Two or more tumor responses among 24 patients were needed to accept the alternative hypothesis. RESULTS: Twenty-four patients enrolled. The median interval from prior cetuximab to study enrollment was 0.7 months (IQR 0.2-6.1). Disease progression on a platinum agent occurred in 23 patients (96%). An objective response occurred in one patient (ORR 4%). The duration of response was 4 months. Stable disease with ≥ 10% decrease in target lesions occurred in 2 patients (8%). Median follow-up was 8.9 (IQR 3.7-16.8) months. The median progression-free survival was 1.9 months (95% CI 1.8-2.1) and the median overall survival was 17.1 months (95%CI: 5.8-21.5). CONCLUSION: The trial did not meet its primary endpoint. Further investigation of palbociclib and cetuximab in cetuximab-resistant HPV-related OPSCC is not warranted.

Correlation of Ki-67 Proliferative Antigen Expression and Tumor Response to Induction Chemotherapy Containing Cell Cycle-Specific Agents in Head and Neck Squamous Cell Carcinoma.

Determine if highly proliferative head and neck squamous cell carcinomas, assessed by pretreatment Ki-67 expression, respond more robustly to induction chemotherapy (IC) that is selectively toxic to cycling cells. Retrospective analysis of 59 patients treated with IC and chemoradiation. IC included either nab-paclitaxel, cisplatin, 5-FU and cetuximab (APF-C, n = 27) or docetaxel, cisplatin, 5-FU +/- cetuximab (TPF+/-C, n = 32). Ki-67 expression was assessed by immunohistochemistry. Tumor response (complete/partial/stable/progressive) at the primary site after two IC cycles was evaluated by visual examination in all patients. In the APF-C sub-group, tumor response (primary site and neck nodes) after two IC cycles was evaluated by computed tomography (CT) and fluorodeoxyglucose-positron emission tomography (FDG-PET)/CT. Ki-67 expression (median 66%, range: 16-97) did not differ across the tumor response categories assessed by visual examination (p = 0.95), CT (p = 0.30), or FDG-PET/CT (p = 0.65). Median decrease in summed SUVmax of measured lesions was 71.6% (range: 8.3-100%). The Pearson correlation coefficient between Ki-67 expression and the percent decrease in summed SUVmax was 0.48 (p = 0.02). Ki-67 expression was not different between those with or without a relapse (median: 60 and 71%, p = 0.10). In multivariate regression analysis (MVA) controlling for p16 positive oropharyngeal SCC status and smoking status, Ki-67 expression was not significantly associated with tumor response by visual examination (coefficient estimate -0.002, standard error 0.010, p = 0.84), CT (coefficient estimate -0.007, standard error 0.011, p = 0.54), FDG-PET/CT (coefficient estimate 0.006, standard error 0.008, p = 0.51), the percent decrease in summed SUVmax (coefficient estimate 0.389, standard error 0.222, p = 0.09), or relapse events (OR = 1.02(95%CI:0.99-1.05), p = 0.28). No significant relationships were found in MVA between pretreatment Ki-67 expression and tumor response to IC or to relapse.