Sep 28

SS 22 - Some crHEME With Your Coffee? A Winning Blend of Radiation and Systemic Therapy in Hematologic Malignancies

204 - Tislelizumab plus P-GemOx-14 and Radiotherapy for Early-Stage High-Risk Extranodal NK/T-Cell Lymphoma: A Multicenter, Single-Arm, Phase 2 Trial

10:55am - 11:05am ET

Room 259

Presenter(s)

Shunan Qi, MD, MB - Cancer Hospital Chinese Academy of Medical Sciences, Beijing, Beijing

S. Qi¹, and Y. X. Li²; ¹National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, Beijing, China, ²Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 100021, Beijing, China., Beijing, China, Beijing, China

Purpose/Objective(s):

Patients with early-stage extranodal natural killer/T-cell lymphoma (ENKTCL) presenting with high-risk features have suboptimal outcomes with current standard chemoradiotherapy. The CLCG2102 trial aimed to evaluate the activity and safety of adding the PD-1 inhibitor tislelizumab to induction chemotherapy and radiotherapy in this population.

Materials/Methods:

In this investigator-initiated, multicenter, single-arm, phase 2 study, patients aged 18 years or older with stage I/II ENKTCL who had at least one high-risk feature (primary tumor invasion, elevated lactate dehydrogenase level, or regional nodal involvement) were enrolled across five participating centers in China. Patients received induction chemo-immunotherapy (CIT) with tislelizumab-P-GemOx-14 (tislelizumab 200 mg intravenously on day 1, pegaspargase 3000 IU intramuscularly on day 2, gemcitabine 1000 mg/m² intravenously on day 2, and oxaliplatin 85 mg/m² intravenously on day 2) every 14 days for three cycles, followed by involved-site radiotherapy (50 Gy in 25 fractions) with concurrent tislelizumab (200 mg intravenously on day 1, 15, 22 during radiotherapy). The primary end point was the complete response (CR) rate after induction CIT. Secondary end points included the progression-free survival (PFS), overall survival (OS), and toxicities.

Results:

From June 1, 2021, to April 30, 2025, 54 patients were enrolled. The CR rate after induction CIT was 66.7% (36 of 54 patients; 95% confidence interval [CI], 53.7 to 80.1), which increased to 79.6% (43 of 54 patients) after concurrent immuno-radiotherapy (iRT). At a median follow-up of 28.0 months, the 2-year PFS was 78.0% (95% CI, 66.6-91.3), and the 2-year OS was 91.5% (95% CI, 82.8-100.0). Seven patients discontinued induction CIT or concurrent immunotherapy owing to toxic effects, whereas all patients completed radiotherapy. Grade 3 or 4 adverse events occurred in 79.6% of patients; the most common events were lymphopenia (46.3%) and neutropenia (27.8%). Patients with undetectable plasma Epstein–Barr virus (EBV) DNA after induction CIT had significantly better PFS than those with persistent viremia.

Conclusion:

The addition of tislelizumab to induction P-GemOx-14 and radiotherapy showed activity and safety in patients with early-stage high-risk ENKTCL.