Tislelizumab produces long-term benefits in relapsed, refractory classical Hodgkin lymphoma

Treatment with the antiprogrammed cell death protein 1 (anti–PD-1) monoclonal antibody tislelizumab yields high response rates in relapsed or refractory classical Hodgkin's lymphoma (cHL), with a similar toxicity profile as other anti–PD-1 therapies, as shown in the extended results of a phase II trial.

The efficacy and safety data of tislelizumab in this trial have been reported previously, with the drug exhibiting high antitumour activity, as reflected by an overall response rate (ORR) of 87.1 percent and a complete response (CR) rate of 62.9 percent at a median follow-up of 9.8 months. The current analysis evaluated the durability of response and long-term safety of tislelizumab over the extended 3-year follow-up. [Leukemia 2020;34:533-542]

Of the 70 patients (median age 32.5 years, 57 percent male) with relapsed or refractory cHL who failed or were ineligible for autologous stem cell transplantation initially enrolled in the trial, 33 (47.1 percent) were transferred to the long-term extension study.

Among the 37 (52.9 percent) patients who discontinued treatment, the most common causes for discontinuation were disease progression (34.3 percent) and adverse events (AEs; 8.6 percent). The median follow-up was 33.8 months, and the median duration of treatment exposure was 119.93 weeks.

The 3-year progression-free survival (PFS) was 40.8 percent, while the overall survival (OS) rate was 84.8 percent. Treatment-related AEs (TRAEs) of any grade were documented in 97.1 percent of patients. The incidence of grade ≥3 TRAE was low at 31.4 percent, and only 8.6 percent of patients experienced AEs that led to treatment discontinuation.

On correlative biomarker analysis, FcγRΙ-expressing macrophages had no observed effect on the clinical outcomes of tislelizumab, which may be potentially attributed to its engineered Fc region.