CytomX Therapeutics Presents Data for First-in-Class Jagged Probody™ Program at AACR-NCI-EORTC International Conference

Findings Demonstrate Preclinical Proof of Concept for Jagged Probody

AACR-NCI-EORTC Anticancer Conference 2013

SOUTH SAN FRANCISCO, Calif.--()--CytomX Therapeutics, the Probody™ therapeutics company, today announced the presentation of new data demonstrating preclinical proof of concept of the Company’s Jagged Probody blocking Jagged-dependent Notch signaling for the treatment of cancer. These data were presented for the first time during a poster session today at the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics being held Oct. 19-23, 2013, in Boston.

In studies conducted in multiple preclinical models, the data show that CTX-033, CytomX’s anti-Jagged Probody, demonstrates efficacy in pancreatic cancer models as both a single agent and in combination with gemcitabine, a currently available anti-metabolite drug approved by the U.S. Food and Drug Administration to treat pancreatic and other cancers. Additionally, the data demonstrate that CTX-033 is locally activated in the tumor microenvironment and spares systemic side effects, such as skin toxicity, associated with systemically blocking Notch pathway signaling.

“The Notch pathway is centrally implicated in tumor biology and is involved in the progression of a number of cancers, including pancreatic cancer, triple negative breast cancer and multiple myeloma,” stated Henry Lowman, Ph.D., chief scientific officer of CytomX and senior author of the poster. “Our anti-Jagged Probody represents a novel approach to targeting the Notch signaling pathway, and our data establish preclinical proof-of-concept that selective activation of CTX-033 in the tumor microenvironment results in robust efficacy with an acceptable therapeutic index.”

Probodies are masked antibodies that remain inert in healthy tissue but are activated or “unmasked” in the disease microenvironment. CytomX is developing a novel, first-in-class Probody program that blocks Notch signaling by both the Jagged-1 and Jagged-2 ligands locally in the tumor microenvironment.

“Following our recent publication on the Probody platform in Science Translational Medicine, these data provide further validation of our unique and highly differentiated Probody approach,” said Sean McCarthy, D.Phil., chief executive officer of CytomX. “Our Jagged Probody program showcases the value of the Probody platform in targeting a pathway that has been challenging with traditional antibodies because of healthy tissue toxicities, and we look forward to advancing this novel concept towards clinical testing.”

About CytomX

CytomX Therapeutics, the Probody™ therapeutics company, is dedicated to transforming lives with safer, more effective therapies. CytomX’s Probody Platform represents a disruptive approach to discovering and developing the next generation of antibody therapeutics and is enabling the development of a diversified pipeline in major unmet medical needs including cancer and inflammation. Probodies are masked antibodies that remain inert in healthy tissue but are activated specifically in the disease microenvironment. This breakthrough selectivity allows CytomX to drug previously undruggable antibody targets, unlock new therapeutic targets for antibody-drug conjugates (ADCs), and focus activity in the tumor microenvironment, thereby redefining the landscape for therapeutic antibodies. CytomX is led by a seasoned and proven management team and is financed by leading life science investors including Third Rock Ventures, Canaan Partners and the Roche Venture Fund. For more information, please visit www.cytomx.com.

Contacts

Pure Communications, Inc.
Kathryn Cook, 910-509-3976
Kathryn@purecommunicationsinc.com

Release Summary

CytomX Therapeutics, the Probody™ therapeutics company, today announced the presentation of new data demonstrating preclinical proof of concept of the Company’s Jagged Probody.

Contacts

Pure Communications, Inc.
Kathryn Cook, 910-509-3976
Kathryn@purecommunicationsinc.com