New collaboration to research Probody-enabled CAR-NK cell therapies

Posted: 6 November 2015 | Victoria White

ProCAR-NK cell therapies will be created against targets for which safety and toxicity have traditionally been limiting factors for CAR cell therapies…

CytomX Therapeutics has entered into a collaboration with The University of Texas MD Anderson Cancer Centre to research Probody-enabled chimeric antigen receptor natural killer (ProCAR-NK) cell therapies.

MD Anderson will leverage its expertise in developing allogeneic umbilical cord blood and peripheral blood derived NK-cell therapies and combine it with CytomX’s Probody technology to address new targets for this novel modality in cancer immunotherapy. Designed for more precise binding to tumours and reduced binding to healthy tissue, ProCAR-NK cell therapies will be created against targets for which safety and toxicity have traditionally been limiting factors for CAR cell therapies. Under the collaboration, CytomX and MD Anderson will develop ProCAR-NK cell therapies against multiple targets, and CytomX will have the option to license therapeutics that demonstrate preclinical proof of concept for clinical and commercial development.

“Our researchers see distinct promise in NK cells, as their role in the innate immune system enables immediate tumour killing effect compared to T-cells. In addition, CAR-NK cells have the opportunity to be off the shelf therapies as opposed to autologous CAR-T cell therapies,” said Katy Rezvani, M.D., Ph.D., professor, department of Stem Cell Transplantation and Cellular Therapy, MD Anderson. “By combining these advantages of CAR-NK cell therapies with the added targeting of this novel technology, we believe that we can create therapies that realize the full potential of the therapeutic class.”

CytomX’s Probody derived therapeutics have a mask

Therapeutics developed with CytomX’s Probody platform have a mask linked to the antibody’s antigen-binding site designed to avoid the binding of antigens on healthy tissue. The mask is cleaved by proteases found in the tumour microenvironment, allowing Probody therapeutic to selectively bind to tumour cells. This binding selectivity allows CytomX to potentially expand the therapeutic window for both existing and new antigen targets. CytomX’s pipeline of wholly owned and partnered programs includes development-stage Probody cancer immunotherapies, Probody drug conjugates and Probody bispecifics.

“The progress we continue to make within our pipeline has shown that Probody therapies offer important advantages over traditional antibodies, with the potential for creating safe and effective cancer immunotherapies and antibody drug conjugates,” said Sean McCarthy, D.Phil., chief executive officer of CytomX. “This collaboration will allow us to draw on world-class research from MD Anderson in the field of CAR-NK cell therapies and extend our platform to this exciting modality.”

NK cells are cytotoxic lymphocytes that comprise a central component of the innate immune system. When these cells are engineered to express CARs that target proteins found on cancer cells, they demonstrate powerful anti-tumour responses. The resulting therapeutic class has potential advantages over CAR-T cells, including simpler manufacturing.