Safety of chidamide plus rituximab in elderly patients with relapsed or refractory B-cell lymphoma in China: a multicenter, single-arm, phase II study.

BACKGROUND

Patients over 65 years old with diffuse large B-cell lymphoma (DLBCL) or follicular lymphoma (FL) relapse or being refractory to rituximab-associated chemotherapy have limited treatment options. Chidamide has the ability to enhance the sensitivity of rituximab-resistant tumors in vivo has been confirmed. We aimed to assess the activity and safety profile of chidamide plus rituximab in elderly Chinese patients with recurrent or refractory B-cell lymphoma.

METHODS

In this prospective, single-arm phase II trial, we enrolled patients from three hospitals in China with histopathological diagnoses of DLBCL and FL who had relapsed or were refractory to previous lines of rituximab-associated chemotherapy. Patients were given chidamide (10 mg on days 1-6 and 8-14) and rituximab (375 mg/m2 on day 7). The treatments were repeated every 21 days. The primary endpoint was the objective response rate (ORR). The secondary endpoints included the disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

Thirteen patients were enrolled and commenced treatment between November 12, 2018, and December 24, 2020. As of March 20, 2021, two patients (15.4%) were still receiving treatment. The median follow-up was 13.4 months. The ORR was 40% for the DLBCL cohort (n=10), and 100% for the FL cohort (n=3). DLBCL patients had a median PFS (mPFS) of 2.6 months (0.9-31.2 months) and a median OS (mOS) of 16.7 months (2.3-13.6 months). Neither mPFS nor mOS was reached in the FL cohort. The most frequent treatment-related adverse events (TRAEs) were leukopenia (38.5%), neutropenia (30.8%), lymphopenia (30.8%), thrombocytopenia (30.8%), fatigue (38.5%), and hyperuricemia (30.8%).

CONCLUSIONS

Chidamide plus rituximab is clinically effective with an acceptable toxicity profile in elderly patients over 65 years old with relapsed or refractory DLBCL and FL. Further investigation is ongoing.