CytomX Therapeutics Announces Preclinical Data from Anti-CTLA-4 Probody Therapeutic Programs Presented by Partner Bristol Myers Squibb at AACR Annual Meeting

Preclinical Data Supports Expanded Therapeutic Index and Provides Rationale for Ongoing Clinical Studies


SOUTH SAN FRANCISCO, Calif., June 22, 2020 (GLOBE NEWSWIRE) -- CytomX Therapeutics, Inc. (Nasdaq: CTMX) today announced that its partner Bristol Myers Squibb presented preclinical data from BMS-986249 and BMS-986288, anti-CTLA-4 Probody therapeutics generated with CytomX’s novel Probody® technology platform. The electronic poster #4551 titled “Preclinical characterization of novel anti-CTLA-4 prodrug antibodies with an enhanced therapeutic index” was presented as part of the Therapeutic Antibodies 3 Session at the American Association of Cancer Research’s (AACR) 2020 Virtual Annual Meeting II.

BMS-986249 is a Probody version of the anti-CTLA-4 antibody ipilimumab (Yervoy®). In February 2020, Bristol Myers Squibb treated the first patient in a Part 2a randomized cohort expansion in an ongoing Phase 1/2a trial of BMS-986249 in combination with Opdivo® (nivolumab) in patients with metastatic melanoma. Additional information is available at ClinicalTrials.gov using the Identifier NCT03369223

BMS-986288 is a Probody of a nonfucosylated version of ipilimumab (anti-CTLA-4 NF). In September 2019, Bristol Myers Squibb initiated the dose escalation phase of a Phase 1/2a clinical trial of BMS-986288 administered as monotherapy and in combination with nivolumab in patients with selected advanced solid tumors. Additional information is available at ClinicalTrials.gov using the Identifier NCT03994601

These Probody programs, designed to optimize the therapeutic index of CTLA-4-directed therapy, arose from the companies’ 2014 worldwide oncology license and collaboration agreement.

“This important work within our Bristol Myers Squibb alliance is aimed at broadening the utility of this foundational immunotherapeutic approach to the treatment of cancer,” said Sean McCarthy D.Phil., president, chief executive officer and chairman of CytomX Therapeutics. “We look forward to seeing the full potential of these programs as they continue to advance in the clinic.”

About CytomX Therapeutics

CytomX is a clinical-stage, oncology-focused biopharmaceutical company with a vision of transforming lives with safer, more effective therapies. We are developing a novel class of investigational antibody therapeutics, based on our Probody® technology platform, for the treatment of cancer.

Probody therapeutics are designed to remain inactive until they are activated by proteases in the tumor microenvironment. As a result, Probody therapeutics are intended to bind selectively to tumors and decrease binding to healthy tissue, to minimize toxicity and potentially create safer, more effective therapies. As leaders in the field, our innovative technology is designed to turn previously undruggable targets into druggable targets and to enable more effective combination therapies. CytomX and its partners, comprised of leading biotechnology and pharmaceutical companies, have developed a robust pipeline of potential first-in-class therapeutic candidates against novel, difficult to drug targets and potential best-in-class immunotherapeutic candidates against clinically validated targets. The CytomX clinical stage pipeline includes first-in-class product candidates against previously undruggable targets, including a CD166-targeting Probody drug conjugate wholly owned by CytomX (CX-2009) and a CD71-targeting Probody drug conjugate partnered with AbbVie (CX-2029). CD166 and CD71 are among cancer targets that are considered to be inaccessible to conventional antibody drug conjugates due to their presence on many healthy tissues. The CytomX clinical stage pipeline also includes cancer immunotherapeutic candidates against validated targets such as our wholly owned anti-PD-L1 Probody therapeutic, CX-072, and the CTLA-4-targeting Probody therapeutics, BMS-986249 and BMS-986288, partnered with Bristol Myers Squibb. CytomX has strategic drug discovery and development collaborations with AbbVie, Amgen, Astellas and Bristol Myers Squibb. For additional information about CytomX Therapeutics, visit www.cytomx.com and follow us on LinkedIn and Twitter.

CytomX Therapeutics Forward-Looking Statements

This press release includes forward-looking statements. Such forward-looking statements involve known and unknown risks, uncertainties and other important factors that are difficult to predict, may be beyond our control, and may cause the actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied in such statements. Accordingly, you should not rely on any of these forward-looking statements, including those relating to the potential benefits, safety and efficacy or progress of CytomX’s or any of its collaborative partners’ product candidates, the potential benefits or applications of CytomX’s Probody platform technology, and CytomX’s ability to develop and advance product candidates into and successfully complete clinical trials, including the ongoing and planned clinical trials of CX-2009 and CX-2029. Risks and uncertainties that contribute to the uncertain nature of the forward-looking statements include: the unproven nature of CytomX’s novel Probody Platform technology; CytomX’s clinical trial product candidates are in the initial stages of clinical development and its other product candidates are currently in preclinical development, and the process by which preclinical and clinical development could potentially lead to an approved product is long and subject to significant risks and uncertainties, including the risk that the COVID-19 worldwide pandemic may continue to negatively impact the business, research and clinical operations of CytomX or its partners, including the development of preclinical drug candidates due to delays in and disruption of research activities and the development of clinical drug candidates due to delays  in or disruption of clinical trials, including impacts on the enrollment of patients in clinical trials or other clinical trial disruptions; the possibility that the results of early clinical trials may not be predictive of future results; the possibility that CytomX’s clinical trials will not be successful; the possibility that current pre-clinical research may not result in additional product candidates; CytomX’s dependence on the success of CX-2009, CX-2029, BMS-986249, BMS-986288, and CX-072; CytomX’s reliance on third parties for the manufacture of the company’s product candidates; and possible regulatory developments in the United States and foreign countries.  Additional applicable risks and uncertainties include those relating to our preclinical research and development, clinical development, and other risks identified under the heading "Risk Factors" included in CytomX’s Quarterly Report on Form 10-Q filed with the SEC on May 7, 2020. The forward-looking statements contained in this press release are based on information currently available to CytomX and speak only as of the date on which they are made. CytomX does not undertake and specifically disclaims any obligation to update any forward-looking statements, whether as a result of any new information, future events, changed circumstances or otherwise.

Probody is a U.S. registered trademark of CytomX Therapeutics, Inc.

Yervoy and Opdivo are registered trademarks of Bristol Myers Squibb.                  

Investor and Media Contact:

Christopher Keenan
VP, Investor Relations and Corporate Communications
ckeenan@cytomx.com
650-383-0823