Single-Agent and Associated Therapies with Monoclonal Antibodies: What About Follicular Lymphoma?

Monoclonal antibodies (mAbs) have become a cornerstone in the treatment of follicular lymphoma (FL), offering highly specific therapeutic targeting that enhances efficacy while minimizing systemic toxicity. Their mechanisms of action include antibody-dependent cellular cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and direct apoptotic signaling, effectively mediating malignant B-cell depletion. Anti-CD20 mAbs, such as rituximab and obinutuzumab, have significantly improved progression-free survival (PFS) and overall survival (OS), establishing immunochemotherapy as the standard of care for FL. However, the emergence of treatment resistance, often characterized by CD20 antigen downregulation or immune escape, has prompted the development of next-generation mAbs with enhanced effector functions. Bispecific antibodies (BsAbs), which simultaneously engage CD20-expressing tumor cells and CD3-positive cytotoxic T cells, have emerged as a novel immunotherapeutic strategy, redirecting T-cell activity to eliminate malignant B cells independently of major histocompatibility complex (MHC) antigen presentation. Additionally, antibody-drug conjugates (ADCs) offer a targeted cytotoxic approach by delivering potent chemotherapeutic payloads directly to tumor cells while limiting off-target effects. The integration of mAbs with immune checkpoint inhibitors and immunomodulatory agents is further enhancing treatment outcomes by overcoming immunosuppressive mechanisms within the tumor microenvironment. Despite these advancements, challenges remain, including optimizing the treatment sequence, mitigating immune-related toxicities-particularly cytokine release syndrome (CRS)-and identifying predictive biomarkers to guide patient selection. As the role of monoclonal antibodies continues to expand, their integration into therapeutic regimens is transforming the management of FL, paving the way for chemotherapy-free treatment approaches and long-term disease control. This review provides an updated overview of mAbs therapies for FL, emphasizing the advances brought by BsAbs and ADCs toward more tailored and effective treatments.