The KEYNOTE-689 trial evaluated perioperative pembrolizumab + SOC (surgery + adjuvant RT ± cisplatin) in resectable, locally advanced head and neck squamous-cell carcinoma (HNSCC) that is at least 1% PDL1 positive. The addition of pembrolizumab significantly improved 3-year event-free survival (EFS) in all PD-L1 subgroups: CPS≥10 (59.8% vs 45.9%), CPS≥1 (58.2% vs 44.9%), and the total population (57.6% vs 46.4%). Three-year overall survival (OS) also favored pembrolizumab: CPS≥10 (68.2% vs 59.2%), CPS≥1 (69.0% vs 60.2%), and total (68.4% vs 61.1%), though OS was not formally tested at this interim. Toxicities were as expected. Bottom line: perioperative pembro is now a part of the treatment paradigm for locally advanced HNCSCC with PDL1 expression.
The benefit of the addition of perioperative pembrolizumab to standard care with surgery and adjuvant therapy for patients with locally advanced head and neck squamous-cell carcinoma (HNSCC) is unclear.
In this phase 3, open-label trial, we randomly assigned participants with locally advanced HNSCC in a 1:1 ratio to receive 2 cycles of neoadjuvant pembrolizumab and 15 cycles of adjuvant pembrolizumab (both at a dose of 200 mg every 3 weeks) in addition to standard care (pembrolizumab group) or standard care alone (control group). Standard care was surgery and adjuvant radiotherapy with or without concomitant cisplatin. The primary end point was event-free survival, sequentially assessed in participants whose tumors expressed programmed death ligand 1 (PD-L1) with a combined positive score (CPS) of 10 or more (CPS-10 population), participants whose tumors expressed PD-L1 with a CPS of 1 or more (CPS-1 population), and all the participants. A higher CPS indicates a higher proportion of cells that express PD-L1. Research Summary Pembrolizumab in Locally Advanced Head and Neck Cancer
A total of 363 participants (234 with a CPS of ≥10 and 347 with a CPS of ≥1) were assigned to the pembrolizumab group and 351 (231 with a CPS of ≥10 and 335 with a CPS of ≥1) to the control group. Surgery was completed in approximately 88% of the participants in each group. At the first interim analysis, the median follow-up was 38.3 months. Event-free survival at 36 months was 59.8% in the pembrolizumab group and 45.9% in the control group (hazard ratio for progression, recurrence, or death, 0.66; 95% confidence interval [CI], 0.49 to 0.88; two-sided P=0.004) in the CPS-10 population; 58.2% and 44.9%, respectively (hazard ratio, 0.70; 95% CI, 0.55 to 0.89; two-sided P=0.003), in the CPS-1 population; and 57.6% and 46.4%, respectively (hazard ratio, 0.73; 95% CI, 0.58 to 0.92; two-sided P=0.008), in the total population. Grade 3 or higher treatment-related adverse events occurred in 44.6% of the participants in the pembrolizumab group and in 42.9% of those in the control group, including death in 1.1% and 0.3%, respectively. Potentially immune-mediated adverse events of grade 3 or higher occurred in 10.0% of the participants in the pembrolizumab group.
The addition of neoadjuvant and adjuvant pembrolizumab to standard care significantly improved event-free survival among participants with locally advanced HNSCC. Neoadjuvant pembrolizumab did not affect the likelihood of surgical completion. No new safety signals were identified. (Funded by Merck Sharp and Dohme, a subsidiary of Merck [Rahway, NJ]; KEYNOTE-689 ClinicalTrials.gov number, NCT03765918.)
Based on these findings, Carbo/Taxol+Pembro is an active regimen in met-HNC and an option for those patients who are not good candidates for 5FU based therapy.
Although immunotherapy did not beat chemotherapy but was non inferior and with more favorable safety.
Pembro with chemotherapy or alone better then cetuximab combination, also improved responses to subsequent therapy.
Phase II/III study of weekly docetaxel+RT vs. RT alone in cis-ineligible patients. This study was done in India, where oral cancers are an epidemic and possibly biologically unique, as most are related to the use of oral tobacco + betel nut products. >70% of patients were stage IVA / IVB, and HPV was only positive in 4% of patients. Still, the survival benefit was sizeable, and the treatment was tolerable. This is a good option for cis-ineligible HPV-neg patients with bulky disease.
Again, further evidence of continued efficacy and tolerability of IO and IO/chemotherapy in SCCHN as compared to EGFR-blockade/chemotherapy. The PD-L1 negative space remains a more difficult scenario, hence new biomarkers are critically important. The long-term response and CR of a percentage of patients are real and intriguing (patient characteristics leading to such response).