Treatment of relapsed/refractory mature T/NK-cell lymphomas with tislelizumab resulted in modest efficacy, with some patients achieving long-term remission, according to the results of a phase 2 study presented at the 2022 ASCO Annual Meeting.

Building on the prior success of tislelizumab among patients with relapsed/refractory classical Hodgkin lymphoma and solid tumors, the aim of this study was to evaluate the safety and efficacy of tislelizumab among patients with T/NK-cell lymphomas.

The open-label, single-arm, phase 2 study treated 77 patients with tislelizumab in 3 different cohorts: cohort 1 included 22 patients with relapsed/refractory extranodal disease; cohort 2 included 44 patients with mature T-cell lymphomas; and cohort 3 included 11 patients with cutaneous T-cell lymphomas (CTCL). The primary endpoint was investigator-assessed objective response rate (ORR) and secondary endpoints included duration of response (DOR), complete response (CR) rate, and survival.


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At baseline, the majority of patients in the entire study population had advanced disease at 76.6%, refractory disease was present among 51.9%, and 49.4% had at least 3 prior lines of systemic therapy.

Patients in cohort 3 derived the greatest benefit from tislelizumab, with an ORR of 45.5%, including a CR of 9.1%. The median DOR was 11.3 months. The median PFS was 16.8 months and the median OS was not yet reached.

The ORR for cohort 1 was 31.8%, with a CR rate of 18.2% and a median DOR not yet reached. The median PFS and OS were 2.7 and 8.8 months, respectively. The ORR was lowest in cohort 2 at 20.5%, which included a CR rate of 9.1% and a median DOR of 8.2 months. The median PFS and OS were 2.7 and 13.3 months, respectively. 

Within cohort 2, patients with peripheral T-cell lymphoma not otherwise specified (n=21) demonstrated the highest response at 23.8% with a CR rate of 14.3%.

The most common grade 3 or higher adverse events included anemia, pneumonia, and neutropenia. Immune-related adverse events of any grade developed in 28.6% of patients, with the most common being hypothyroidism, hyperglycemia, and rash. There were no treatment-related deaths.

The authors concluded that “tislelizumab was well tolerated, achieving modest efficacy in relapsed/refractory mature T/NK-cell neoplasms, with some long-lasting remissions, particularly in CTCL.” They added that “future studies are warranted to determine the biologic features associated with response.”

Disclosures: This study was supported by BeiGene USA, Inc.

Reference

Bachy E, Savage KJ, Huang H, et al. Tislelizumab, a PD-1 inhibitor for relapsed/refractory mature T/NK-cell neoplasms: results from a phase 2 study. Presented at ASCO 2022; June 3-7, 2022. Abstract 7552.