Celltrion Biosimilar Shows Efficacy in DLBCL Combination

A rituximab biosimilar (Truxima) in combination with lenalidomide and acalabrutinib (R2A) in patients with relapsed or refractory aggressive B-cell lymphoma was tolerable and effective, according to findings presented at EHA25 Virtual, the annual meeting of the European Hematology Association.

In 13 patients who underwent disease assessment following treatment with the R2A regimen, the overall response rate was 69% and the complete response rate was 31%. The 6-month progression-free survival rate was 83%. Just 1 patient experienced disease progression after an initial objective response.

The rituximab product was developed by Celltrion Healthcare and study participants were enrolled in the Republic of Korea.

The Value of a Biosimilar

The addition of rituximab, a targeted therapy, to chemotherapy agents can improve patient outcomes but adds to the financial burden of treatment. Investigators said that exploring the use of biosimilar rituximab may be an avenue to bring down costs.

“By incorporating biosimilar rituximab into combination therapies alongside new drugs, the overall cost burden can be reduced, enhancing patient access,” said Youngil Koh, PhD, associate professor at Seoul National University Hospital and lead researcher for the trial in a statement.

Diffuse large B-cell lymphoma (DLBCL) is a subtype of non-Hodgkin lymphoma that accounts for about 30% to 40% of adult cases. Although global epidemiological data are limited, DLBCL’s estimated incidence is 7 cases per 100,000 individuals. B-cell lymphoma is aggressive and often diagnosed in late stage.

About 30% to 40% of patients who have had B-cell lymphoma relapse, and 10% have refractory disease. Without treatment, patients with relapsed or refractory disease have a life expectancy of 3 to 4 months.

Investigators said 73% of patients enrolled had non-germinal center B-cell—like (non-GCB) DLBCL. Patients received rituximab 375 mg/m² daily intravenously, lenalidomide 20 mg once daily on day 1 to day 21, and acalabrutinib 100 mg twice daily on day 1 to day 28. Each cycle of treatment was delivered over 4 weeks, and each patient received 6 cycles. Responders received acalabrutinib maintenance for up to one year.

Study Findings

The phase 2 study ran from July 2019 to February 2020, and median follow-up was 3.2 months for 22 patients enrolled. Dosage was reduced in 3 and 1 patients for lenalidomide and acalabrutinib, respectively, due to hematological toxicity. During a total of 61 treatment cycles, 3 patients experienced higher than grade 2 toxicity for neutropenia, thrombocytopenia, and skin toxicity, which was the most common adverse event reported and occurred in 4 (18%) patients.

“The data indicate that the R2A regimen was therefore well tolerated in Korean relapse/refractory B-cell lymphoma patients, with initial analysis in non-GCB DLBCL patients showing a promising response,” investigators wrote.

More on Truxima

Recently, the World Health Organization awarded a prequalification to Truxima, making it the first rituximab biosimilar to be certified for use by the organization.

Truxima is currently marketed in the United States under the name Rituxan and in the European Union as MabThera. It launched on the US market in November 2019.

Truxima is a monoclonal antibody that works by binding to CD20 cells on the surface of B-cells and mediates the destruction of cancer cells.

Reference

Koh Y, Park C, Byun Jm et al. Rituximab, lenalidomide and acalabrutinib (R2A) for relapsed/refractory aggressive B-cell lymphoma: interim analysis reporting good tolerability and potential durable response. Presented at EHA25 Virtual; June 11-21, 2020. Abstract EP1272.