Clinical Background and Mechanism of Action of Next-Generation Bispecific Antibody, Epcoritamab

Epcoritamab (brand name 'Epkinly'), a next-generation bispecific antibody, is a key pipeline product co-developed and globally commercialized by Genmab and AbbVie. It simultaneously binds to CD3 on T cells and CD20 on B cells, activating the patient's immune cells and inducing the death of cancer cells. The EPCORE NHL-3 (NCT04542824) Phase 1/2 trial conducted in Japan targeted Japanese patients with relapsed or refractory B-cell non-Hodgkin lymphoma (B-NHL) who had failed prior standard treatments and had limited alternative options. Notably, it was designed as a subcutaneous formulation to reduce toxicity and maximize patient convenience, garnering significant attention from the medical community.

Analysis of Japanese Phase 1/2 Trial Data Demonstrating Excellent Efficacy

According to recently released Japanese clinical data, epcoritamab achieved a strong overall response rate (ORR) of 95.2% and a complete response rate (CR) of 76.2% in the relapsed or refractory follicular lymphoma (FL) cohort. Not only was the complete response rate, where tumors were completely eradicated, high, but the rate of achieving minimal residual disease (MRD)-negative status also reached 88.9%, validating its clinical depth. In the diffuse large B-cell lymphoma (DLBCL) cohort, ORR was 56% and CR was 47%, with 53% of patients who achieved complete response maintaining the effect at the 3-year mark. This significantly improved the possibility of long-term survival, even in patients with advanced disease who were difficult to treat with existing therapies.

Approval by the Japanese Ministry of Health, Labour and Welfare (MHLW) and Regulatory Significance

Based on these clinical results, the Japanese Ministry of Health, Labour and Welfare (MHLW) officially approved epcoritamab on September 25, 2023, for the treatment of relapsed or refractory large B-cell lymphoma (LBCL) with two or more prior lines of systemic therapy. Furthermore, on February 20, 2025, the indication was expanded to include follicular lymphoma (FL) under the same conditions, further broadening its market reach. The rapid approval by the regulatory agency was largely due to the excellent safety and predictable side effects demonstrated throughout the clinical trials. The most common serious adverse reaction, cytokine release syndrome (CRS), was mostly mild (Grade 1-2), and no serious adverse events were reported.

Competitive Landscape in the Growing Bispecific Antibody Market and Commercial Value

The global B-cell non-Hodgkin lymphoma market is currently valued at $8.2 billion in 2024 and is projected to grow into a $22.3 billion market by 2033. Epcoritamab recorded global sales of $281 million in 2024 and demonstrated strong commercial potential with prescription sales of $468 million in 2025, a 67% increase. The market is currently characterized by intense marketing competition among leading companies such as Roche, with products like 'Lunsumio' (mosunetuzumab) and 'Columvi' (glofitamab), to gain market share. However, with its superior complete response rate and convenient subcutaneous administration compared to competing drugs, it is expected to further solidify its market share in the future.