First-line sintilimab with pegaspargase, gemcitabine, and oxaliplatin in advanced extranodal natural killer/T cell...

Programmed cell death protein 1 (PD-1) inhibitor sintilimab is effective in relapsed and refractory extranodal natural killer/T cell lymphoma (ENKTL), nasal type. We aimed to assess the safety and activity of sintilimab plus P-GEMOX (pegaspargase, gemcitabine, and oxaliplatin) in the first-line setting for advanced ENKTL.

The multicentre, single-arm, phase 2 trial was done at three medical centres in China. Patients aged 18-75 years with treatment-naive pathologically confirmed advanced ENKTL and an with Eastern Cooperative Oncology Group performance status score of 0-2 were eligible. Patients received intravenous sintilimab (200 mg on day 1), intramuscular pegaspargase (2000 U/m² on day 1), intravenous gemcitabine (1 g/m² on days 1 and 8), and intravenous oxaliplatin (130 mg/m² on day 1) every 3 weeks for six cycles, followed by intravenous sintilimab (200 mg) every 3 weeks for up to 2 years or until disease progression or unacceptable toxicities. The primary endpoint was the complete response rate in the intention-to-treat population. The secondary endpoints were overall response rate (ORR), progression-free survival (PFS), disease-free survival (DFS), and overall survival. This trial is registered with ClinicalTrials.gov, NCT04127227. Enrolment has been completed, and follow-up is ongoing.

Between Nov 29, 2019, and Sept 7, 2022, 34 eligible patients were enrolled (median age 39 years [IQR 32-55]; 25 [74%] of 34 patients were male; nine [26%] were female; and all were of Asian ethnicity). At the data cutoff (July 20, 2023), the median follow-up was 21 months (IQR 13-32). The complete response rate was 85% (29 of 34 patients, 95% CI 70-94). Five patients (15%; 95% CI 7-30) attained partial response and the ORR was 100% (34 of 34 patients). 24-month PFS was 64% (95% CI 48-86), 24-month DFS was 72% (54-95), and 36-month overall survival was 76% (52-100). The most common grade 3 or 4 treatment-related adverse events were neutropenia (17 [50%] of 34 patients), anaemia (10 [29%] patients), and hypertriglyceridemia (10 [29%] patients). Hypothyroidism was the most frequent immune-related adverse event (18 [53%]), including grade 3 hypothyroidism in one (3%) patient that caused treatment termination. No severe adverse events occurred. There were three deaths: one due to haemophagocytic syndrome, one due to disease progression, and one due to unknown cause, which were not considered to be treatment related.

Combination of sintilimab with P-GEMOX seems to be an active and safe first-line regimen for patients with advanced ENKTL.

National Key Research and Development Program and National Natural Science Foundation of China, Guangzhou Science and Technology Program and the Clinical Oncology Foundation of Chinese Society of Clinical Oncology.