Abstract 99P
Background
The prognosis of patients with platinum-refractory head and neck squamous cell carcinoma (HNSCC) was poor. Sintilimab is an immune checkpoint inhibitor. Nab-paclitaxel is a nanoparticle taxane that showed activity in platin-resistant HNSCC. This study aimed to evaluate the efficacy and safety of sintilimab plus nab-paclitaxel in patients with platinum-refractory HNSCC.
Methods
This study is a single-arm, open-label, single-center phase II clinical study. Patients with R/M HNSCC who have failed platinum-based therapy were enrolled. All patients were treated with sintilimab(200mg iv d1) and nab-paclitaxel(120mg/m2 iv d1 and d8) every 3 weeks up to 6 cycles and then maintained with sintilimab until disease progression, death, or dose-limiting toxicities. The primary endpoint was the objective response rate (ORR). The secondary endpoints included progression-free survival (PFS), overall survival(OS), and safety.
Results
From April 2019 to April 2022, 15 patients were enrolled. The median age was 55 years (range34-67), and 11 patients were male. Primary site included the oropharynx (1, 6.7%), nasopharynx (6, 40.0%), larynx/hypopharynx (5, 33.3%) and oral cavity (3, 20.0%). Presence of distant metastases(11, 73.3%); prior platinum-based chemotherapy(15, 100%), radiation (11, 73.3%), EGFR targeted therapy (6, 40.0%); ECOG PS =1 (15, 100%); PD-L1 CPS≥10 (6, 40.0%), not applicable (7, 46.7%). The ORR was 20.0% (95% CI, 7.1-45.2%), DCR was 80.0% (95%CI 54.8-92.9%). With a median follow-up time of 12.1 months, 8 patients experienced disease progression, and 5 died. The median PFS was 14.4 (95% CI, 4.0-24.7) months. The median OS was not reached. Common treatment-related adverse events (TRAEs) were hypothyroidism(26.7%), leukopenia(20.0%), pneumonia (20.0%), and nausea (13.3%). Most of the TRAEs were grade 1 or 2. Only one patient experienced grade 3 hypothyroidism.
Conclusions
Sintilimab plus nab-paclitaxel is well-tolerated with very encouraging clinical activity in platinum-refractory HNSCC and warrant further exploration in this disease.
Clinical trial identification
NCT03975270, June 5, 2019.
Legal entity responsible for the study
The authors.
Funding
Innovent biologics Inc.
Disclosure
All authors have declared no conflicts of interest.