CS1001 Shows High Response Rate in Extranodal Natural Killer T-Cell Lymphoma

According to early phase II trial data, the investigational immunotherapy CS1001 shows anti-tumor activity against relapsed/refractory extranodal natural killer T-cell lymphoma (ENKTL). The results of this small, preliminary study were presented in a poster at the 2019 ASH Annual Meeting.

The safety and efficacy of CS1001, an anti-PDL1 monoclonal antibody, was evaluated in a phase II open-label study conducted in China, which has a high incidence of ENKTL compared with Western countries. The study is enrolling adults with ENKTL who have previously received one or more lines of therapy. At the time of data cut-off in June 2019, 29 patients were enrolled, with a median age of 44 years.

After a median follow-up of 5 months, 9 patients (41%) responded to treatment with CS1001, including 7 (32%) who achieved complete remission. Since the data cut-off in June 2019, 2 more patients reached complete remission, bringing the complete response rate up to 36%.

Adverse events, reported in 86.2% of patients, include fever (20.7%), elevated TSH (13.8%), leukopenia (13.8%), and rash (10.3%).

Currently, there is no effective treatment for patients with ENKTL who respond poorly to chemotherapy. “The preliminary safety and efficacy profile of CS1001 support further exploration and development of CS1001 in [relapsed or refractory] ENKTL,” the researchers said.

Source: Huang H, Tao R, Zou L et al. Preliminary Results from a Multicenter, Single-Arm, Phase 2 Study of CS1001, an Anti-Programmed Death-Ligand 1 (PD-L1) Human Monoclonal Antibody (mAb), in Patients (pts) with Relapsed or Refractory Extranodal Natural Killer/T Cell Lymphoma (rr-ENKTL). Poster #2833. Presented at the 2019 American Society of Hematology Annual Meeting, December 8, 2019; Orlando, FL.