GSK Enters Agreement to Acquire CMG1A46 from Chimagen Biosciences to Expand Immunology Pipeline

• CMG1A46 is an investigational T-cell engager with the potential to deeply deplete out-of-control B cells in autoimmune diseases such as lupus.

• Lupus patients still have unmet medical needs, especially those who do not respond to current standard treatment regimens.

• This collaboration strengthens GSK's portfolio in treatments targeting the underlying drivers of lupus and autoimmune diseases.

October 29, 2024GSK plc (LSE/NYSE: GSK) and Chimagen Biosciences ("Enmu") today announced an agreement under which GSK will acquire CMG1A46 from Enmu for an upfront payment of $300 million. CMG1A46 is a bispecific T-cell engager (TCE) targeting CD19 and CD20. GSK plans to develop and commercialize CMG1A46, with a focus on B-cell-driven autoimmune diseases such as systemic lupus erythematosus (SLE) and lupus nephritis (LN), with the potential to expand into related autoimmune conditions.

Over the past decade, GSK has been at the forefront of lupus treatment. This agreement underscores the importance of developing novel therapeutic approaches to address the heterogeneity of lupus manifestations and the ongoing disease burden, particularly in patients with severe disease who do not respond to current standard treatments.

GSK Chief Scientific Officer Dr. Tony Wood stated, "Through our research in systemic lupus erythematosus and lupus nephritis, we are gaining an increasing understanding of the fundamental drivers of B-cell-driven diseases. As a novel therapeutic option for deep B-cell depletion, CMG1A46 shows exciting potential, and we are pleased to advance this program to address the unmet needs of patients with lupus and related autoimmune diseases."

CD20 is a well-established target in the treatment of autoimmune diseases. An increasing amount of clinical evidence indicates that CD19, due to its expression on a wider variety of B cells, holds promising potential as a differentiated therapeutic approach. In preclinical studies, CMG1A46, which targets both CD19 and CD20, has demonstrated rapid and deep B-cell depletion in both blood and tissues, potentially leading to more durable treatment responses in patients.

Dr. Zhou Zhenhao, CEO of Chimagen Biosciences, stated: "We are excited about the potential of CMG1A46 to improve the lives of patients with autoimmune diseases and are grateful to have GSK to accelerate the realization of this vision. This agreement further validates our proprietary T-cell engager platform, and we look forward to continuing our mission of developing novel multispecific antibody therapeutics."

CMG1A46 is currently in Phase I clinical trials for leukemia and lymphoma in the United States and China. GSK plans to begin Phase I trials for lupus in 2025.

Terms of Agreement

Under this agreement, GSK will pay a $300 million upfront fee to obtain global full rights to CMG1A46. Additionally, Chimagen Biosciences will be eligible to receive development and commercial milestone-based payments related to CMG1A46, totaling up to $550 million.

About CMG1A46

CMG1A46 is a bispecific T-cell engager (TCE) targeting CD19 and CD20, an IgG-like molecule with high affinity for CD19 and CD20 positive B cells and low affinity for CD3, which may reduce the toxicity typically associated with TCEs.

About Chimagen Biosciences）

Chimagen Biosciences is a clinical-stage biotechnology company focused on discovering and developing novel multispecific T cell engagers and NK cell engagers through its proprietary antibody engineering platform. Its mission is to advance breakthrough therapies to improve the lives of patients with cancer and autoimmune diseases. For more information, please visitwww.chimagen.com。

Editor's Note:

Lilly Asia Ventures (LAV) co-led the Series B financing of Chimagen Biosciences.