CytomX Therapeutics has expanded its collaboration and licensing agreement with Regeneron Pharmaceuticals to advance the development of next-generation bispecific cancer therapies, strengthening a partnership aimed at improving the precision and effectiveness of immunotherapy treatments.
The enhanced alliance builds on a collaboration first established in 2022 and combines CytomX’s Probody therapeutic platform with Regeneron’s Veloci-Bi bispecific antibody technology. Together, the companies are working to create conditionally activated bispecific antibodies that remain inactive in healthy tissues and become activated only within the tumor microenvironment.
The approach is designed to address one of the major challenges in cancer immunotherapy: minimizing damage to healthy cells while maximizing anti-tumor activity. By utilizing CytomX’s proprietary biologic masking technology, the investigational therapies are engineered to be activated by proteases that are abundant in tumors. This targeted activation could potentially widen the therapeutic window, reduce off-target side effects, and enable the development of treatments for cancers that have historically been difficult to treat with immunotherapy.
Bispecific antibodies are engineered proteins capable of binding to two different targets simultaneously. In cancer treatment, these therapies often redirect immune cells, particularly T cells, toward tumor cells, enhancing the body’s ability to recognize and destroy cancer. However, unwanted activation outside tumors can lead to significant toxicity. The CytomX-Regeneron strategy seeks to overcome this limitation by ensuring that immune activation occurs primarily within the tumor environment.
John Lin, Senior Vice President of Oncology and Antibody Technology Research at Regeneron, said the expanded partnership reflects the company’s commitment to pursuing innovative treatment approaches in oncology. He noted that the combination of Regeneron’s antibody engineering capabilities and CytomX’s masking technologies creates a strong foundation for developing novel cancer medicines.
Sean McCarthy, Chief Executive Officer and Chairman of CytomX, highlighted the companies’ shared focus on advancing cutting-edge cancer science. He said CytomX’s expertise in masking and protease biology is helping unlock new opportunities for immunotherapy, while Regeneron’s experience in bispecific antibody development makes it an ideal collaborator for broadening the application of the Probody platform.
Under the expanded agreement, the companies will continue joint discovery efforts to identify and validate conditionally active bispecific antibody candidates. Regeneron will assume responsibility for funding preclinical research, clinical development, and future commercialization activities.
As part of the deal, CytomX will receive a $37 million target nomination payment related to two newly selected targets. Regeneron also retains the option to nominate up to six additional future targets. The expanded collaboration carries significant financial potential, with total target nomination fees and development, regulatory, and commercial milestone payments potentially reaching approximately $4 billion. In addition, CytomX remains eligible to receive tiered royalties on global net sales of products developed under the partnership.
The agreement underscores growing industry interest in more selective and safer immunotherapies, as biotechnology companies seek to expand the reach of immune-based cancer treatments to a broader range of patients and tumor types.