Weekly paclitaxel (P), carboplatin (CP) plus pembrolizumab (PMB) as first-line treatment of recurrent or metastatic (R/M) or locally very advanced (LVA) head and neck squamous cell carcinoma (HNSCC): A retrospective study in 39 patients (pts).

person Christian Borel Institut de Cancérologie Strasbourg Europe, Strasbourg, France info_outline Christian Borel, Hélène Carinato, Carole Pflumio, Elodie Poprawa, Youssef Brahimi, Marine Oriel, Clara Vacheret, Delphine Ravily, Pierre Coliat, Thierry Petit, Mickael Burgy

Authors person Christian Borel Institut de Cancérologie Strasbourg Europe, Strasbourg, France info_outline Christian Borel, Hélène Carinato, Carole Pflumio, Elodie Poprawa, Youssef Brahimi, Marine Oriel, Clara Vacheret, Delphine Ravily, Pierre Coliat, Thierry Petit, Mickael Burgy Organizations Institut de Cancérologie Strasbourg Europe, Strasbourg, France Abstract Disclosures Research Funding No funding sources reported Background: Since the results of the KN-048 trial, the combination of platinum/5FU plus PMB has become the standard of care (SOC) for R/M HNSCC pts. The KN-B10 study shows that 5FU can be replaced by P with a favorable response rate and toxicity profile. Weekly use of P reduces hematologic toxicity and increases dose-intensity. Methods: We retrospectively reviewed all records of patients with R/M or LVA (T4b and/or N3b) HNSCC, ECOG-PS 0 to 2, PDL1 CPS ≥ 1, treated in first-line with weekly P (80 mg/m2) and CP (AUC 2: maximum total dose of 250 mg and systematic G-CSF at D3 and D4) for up to 12 infusions plus PMB every 3 weeks for up to 35 administrations. Results: From July 2020 to April 2023, 39 pts (median age 63 years, 74% male, 18% PS2) were treated. Primary tumors: oropharynx 44%, larynx 23%, hypopharynx 18% and oral cavity 15%. Disease setting: LVA 20%, local recurrence in irradiated area 54%, local recurrence and distant metastases 10% distant metastases only15%. With a median follow-up of 19 months (m), median Overall Survival (mOS) was 17.2 m (95%CI: 10.8-NR). 31/39 (79%) pts achieved an objective response (OR): 7 CR and 24 PR. For the 8 LVA pts, all achieved an OR, with a median Event Free Survival of 10 m (95%CI: 6.27-NR): the 4 progression-free pts (8.6 m+ to 25 m+) were treated with radiotherapy after neoadjuvant immuno-chemotherapy. For the 31 R/M pts, ECOG-PS was a significant prognostic factor of OS, mOS: 19.3 m (95%CI: 14.4-NR) for ECOG-PS 0-1 pts vs. 10.3 m (95%CI: 5.4-13.9) for ECOG-PS 2 pts (p = 0.02). For R/M pts, median Progression Free survival was 6.9 m (95%CI: 4.4-8.6) and the ORR was 74%, with a median duration of response of 6.5 m (95%CI: 3.13-8.56). Toxicity was manageable, with 20 (51%) pts experiencing at least one grade 3-4 adverse event: hematologic 18% (including one febrile neutropenia), infection 5%, neuropathy 8%, diarrhea 8%, infusion reaction 8%, electrolyte disturbances 8%, renal failure 3% and no toxic deaths. Conclusions: The combination of weekly P and CP plus PMB produces a high ORR and increased OS consistent with the results of the Frail-Immune study (J. Fayette ASCO 2023). This regimen deserves further consideration not only in the R/M setting, but also in the neoadjuvant setting for locally advanced patients.