Bispecific antibodies in the treatment of follicular lymphoma

Follicular lymphoma (FL) is the most common indolent non-Hodgkin lymphoma. The course of the disease is recurrent with varying periods of remission among individual patients. Treatment in the second and subsequent lines poses a therapeutic challenge, especially in patients with early disease recurrence. Using standard rituximab-based therapy, the progression-free survival (PFS) after the second line of treatment averages 10 months. Currently, new therapeutic options are being sought in this indication. One of the strategies under investigation in the FL treatment is chimeric antigen receptor T-cell therapy and bispecific antibodies. The second ones, by simultaneously binding to the CD3 antigen present on T-lymphocytes and CD20 on B lymphocytes, create an immunological synapse leading to neoplastic cell death. So far, after promising results of the clinical trials, the most extensively studied FL bispecific antibody, mosunetuzumab, has been registered for use in the third and further lines in relapsed and refractory FL. In the phase 2 study, the overall response rate was 80% and the median PFS was 17 months, despite the inclusion of patients with poor prognosis factors. Studies regarding the application of this drug in the first-line treatment are ongoing. Clinical trials have been also conducted with the use of antibodies such as epcoritamab and odronextamab. The aim of this work is an attempt to summarize the current knowledge regarding the effectiveness and safety of the investigated bispecific antibodies.