Chongqing-based Genrix Biopharma Secures $712M Global Out-Licensing Deal for BCMA×CD3 Bispecific Antibody GR1803 (Velinotamig)

On June 5, GENRIX BIO announced that it had entered into an out-licensing collaboration agreement with Cullinan Therapeutics, Inc., a Nasdaq-listed company. Under the terms of the agreement, Cullinan will obtain the global rights (excluding China) for the development, manufacturing, and commercialization of GR1803 injection (Velinotamig), an anti-BCMA×CD3 bispecific antibody developed by GENRIX BIO. GENRIX BIO will retain the rights to develop, manufacture, and commercialize GR1803 injection in China, and will actively advance the development of existing clinical indications and its market launch in China.

Under the terms, Cullinan will pay GENRIX BIO a $20 million upfront payment, as well as up to $692 million in development, regulatory approval, and sales milestone payments (totaling $712 million, approximately RMB 5.115 billion).In addition, GENRIX BIO will receive tiered royalties reaching up to the high double digits of net sales in the licensed territory. The two parties will engage in deep collaboration by jointly leveraging their respective advantageous resources, with GENRIX BIO conducting research on the GR1803 injection project for autoimmune diseases in mainland China to explore additional therapeutic possibilities.

GR1803 is a recombinant humanized anti-BCMA×CD3 bispecific antibody independently developed by GENRIX BIO for the treatment of relapsed/refractory multiple myeloma (RRMM),Classified as a Class 1 therapeutic biological product, with BCMA and CD3 as its targets. This drug can simultaneously bind to the antigens BCMA and CD3, and its affinity for binding to BCMA (10^-10 M) is two orders of magnitude higher than that for binding to CD3 (10^-8 M). This asymmetric affinity design ensures that this bispecific antibody molecule recruits and activates T cells to kill tumor cells while effectively reducing non-specific T cell activation caused by CD3 antibodies, thereby lowering the toxic side effects of GR1803 in the body.

In January 2022, GR1803 received the Notice of Approval for Drug Clinical Trials from the National Medical Products Administration (NMPA) to conduct clinical trials for the indication of multiple myeloma (MM).

In June 2024, the abstract of the GR1803 clinical study was selected for presentation at the 29th Annual Congress of the European Hematology Association (EHA) in 2024. At the 2024 EHA Annual Congress, GENRIX BIO presented the Phase I clinical study results of GR1803 injection, covering its safety, pharmacokinetics, immunogenicity, and preliminary efficacy following single and multiple dosing in patients with relapsed/refractory multiple myeloma.

The study results showed that the majority of patients achieved a response of partial response (PR) or better at the first efficacy assessment, with a median time to response of 3 weeks. The responses in subjects were durable, and deepened with continued treatment. For patients who had not yet responded (stable disease [SD] or minimal response [MR]), or those who achieved PR but had not yet reached very good partial response (VGPR) or better, all efficacy metrics showed a downward trend. The median progression-free survival (mPFS) and median duration of response (mDOR) were not reached in the 25 patients, and no disease progression occurred among all responding subjects. As of January 31, 2024, the most common treatment-emergent adverse events (TEAEs) included cytokine release syndrome (CRS), neutropenia, infection, and anemia.

The study results indicate that GR1803 injection demonstrates significant antitumor activity in relapsed/refractory multiple myeloma (RRMM). It is effective in patients with multiple myeloma (MM) who have received at least three prior lines of therapy, as well as in patients with extramedullary multiple myeloma (EMM). Compared with existing treatment modalities and other investigational or marketed drugs targeting the same mechanism, GR1803 significantly improves the overall response rate (ORR) and markedly enhances disease prognosis. Furthermore, extended follow-up will provide additional data on efficacy and safety.

Based on robust prior clinical study data, in August 2024, GR1803 injection was officially included in the Breakthrough Therapy Designation list by the Center for Drug Evaluation (CDE) of the National Medical Products Administration. Currently, a Phase II clinical trial of GR1803 injection is underway in China for the indication of relapsed/refractory multiple myeloma.

Multiple myeloma is the second most common hematologic malignancy worldwide (after non-Hodgkin lymphoma), with approximately 188,000 new cases annually. It is characterized by the abnormal proliferation of plasma cells in the bone marrow, where malignant plasma cells replace normal blood cells, potentially leading to anemia, bone marrow failure, and renal impairment. According to epidemiological data on multiple myeloma released by the Global Cancer Observatory, there were approximately 30,300 new cases and 18,700 deaths from multiple myeloma in China in 2022.

Currently, this disease remains incurable; however, with the iterative development of therapeutic agents, patient survival times are steadily extending. Studies from abroad indicate that the median overall survival (the time at which half of the patients remain alive) has currently reached 8 to 10 years. Although the survival of patients with multiple myeloma has been significantly improved under treatment regimens primarily comprising proteasome inhibitors, immunomodulatory drugs, and anti-CD38 monoclonal antibodies, patients still face multi-line relapse and disease progression due to clonal evolution of tumor cells and the immunosuppressive nature of the tumor microenvironment. For patients who have previously received at least three lines of therapy, subsequent treatment options are limited and the prognosis is poor.

In this context, bispecific antibodies, as a novel form of cancer immunotherapy, offer additional treatment options for patients in the last-line setting. Taking BCMA/CD3 bispecific antibodies as an example, their uniquely designed dual specificity enables these agents to simultaneously bind to BCMA on multiple myeloma cells and CD3 on T cells, thereby activating the patient’s own immune system to destroy myeloma cells.

According to data from MSA Pharma, the BCMA/CD3 bispecific antibodies currently approved for marketing include Johnson & Johnson’s Teclistamab (approved in 2022, with domestic approval in China in June 2024) and Pfizer’s Elranatamab (approved in 2023).

Among them, teclistamab was approved by the FDA in 2022 for the treatment of relapsed or refractory multiple myeloma in patients who have received at least four prior lines of therapy, becoming the first globally marketed BCMA×CD3 bispecific antibody. In 2024, teclistamab was approved for marketing in China as a monotherapy for adult patients with relapsed or refractory multiple myeloma who have received at least three prior lines of therapy, marking it as the first BCMA×CD3 bispecific antibody approved in China.

Pfizer’s elranatamab was approved by the FDA in 2023 for the treatment of adult patients with relapsed or refractory multiple myeloma who have received prior therapy. In March 2025, elranatamab was approved for marketing in China for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least three prior lines of therapy.

In addition to the aforementioned GENRIX BIO, Johnson & Johnson, and Pfizer, other domestic and international companies—including Regeneron, Bristol Myers Squibb, BeiGene, Innovent Biologics, Akeso Biopharma, Chia Tai Tianqing Pharmaceutical, Keymed Biosciences, Mabwell Bioscience, Lunan Pharmaceutical Group, and New Times Pharmaceutical—are also accelerating their strategic布局 in the BCMA×CD3 bispecific antibody sector, vying for a share of the multi-billion-dollar multiple myeloma market.

Since its inception, GENRIX BIO has built end-to-end competitiveness in the antibody drug sector, spanning from R&D to commercialization. Over the past three years, the company has invested more than RMB 1.68 billion in R&D. Leveraging six core technology platforms—including a monoclonal antibody discovery platform based on its proprietary novel phage display system and a bispecific antibody discovery platform—GENRIX BIO holds competitive advantages in both antibody drug development and manufacturing. This positions the company to establish differentiated barriers in the multiple myeloma market and secure an early foothold in this blue-ocean segment.

References:

1. “Market Trends in Multiple Myeloma Therapeutics: From Bispecific Antibodies to CAR-T, Pfizer and J&J Take the Lead!”

2. "Facing Refractory Multiple Myeloma: With CAR-T Therapies Already Available, Why Are Companies Still Competing in Bispecific Antibodies?"