CytomX Therapeutics Announces Phase 1 Data Update for anti-CTLA-4 Probody® Therapeutic BMS-986249

– Presentation at ESMO 2022 by Collaborator, Bristol Myers Squibb –
– BMS-986249 Phase 2 study ongoing –

SOUTH SAN FRANCISCO, Calif., Sept. 12, 2022 (GLOBE NEWSWIRE) — CytomX Therapeutics, Inc. (Nasdaq: CTMX), a leader in the field of conditionally activated oncology therapeutics, today announced that its collaborator, Bristol Myers Squibb, presented updated Phase 1 results with BMS-986249, a Probody^® therapeutic version of ipilimumab, the anti-CTLA-4 antibody, at the ESMO Congress 2022 in Paris, France.

“BMS-986249 is a conditionally activated CTLA-4-targeting antibody that has shown clinical activity in multiple tumor types, and the safety profile and disease control rate observed in the updated Phase 1 data for BMS-986249 with and without nivolumab is promising. BMS-986249 appears to be tolerated at higher doses than traditional ipilimumab dosing, and we are encouraged by the report of a complete response in melanoma and a case study of a partial response in microsatellite-stable colorectal cancer. This Phase 1 study set the stage for the ongoing randomized Phase 2 trial of BMS-986249 in melanoma evaluating the potential differentiation of the Probody from ipilimumab, and we look forward to results from this study in due course,” said Sean McCarthy, D.Phil., chief executive officer and chairman of CytomX Therapeutics.

About CytomX Therapeutics, Inc.
CytomX is a clinical-stage, oncology-focused biopharmaceutical company dedicated to destroying cancer differently. By pioneering a novel class of conditionally activated biologics, powered by its Probody^® technology platform, CytomX’s goal is to transcend the limits of current cancer treatments. CytomX’s robust and differentiated pipeline comprises seven therapeutic candidates across multiple treatment modalities. Three of these candidates are in Phase 2 studies across multiple cancer types, including CX-2029 and praluzatamab ravtansine. CX-2029 is an investigational conditionally activated antibody-drug conjugate (ADC) directed toward CD71, which has demonstrated encouraging antitumor activity in patients with squamous non-small cell lung cancer and is being developed in collaboration with AbbVie. Praluzatamab ravtansine is an investigational conditionally activated ADC directed toward CD166 and is being studied in patients with advanced breast cancer. CytomX’s clinical pipeline also includes cancer immunotherapeutic candidates against validated targets such as the CTLA-4-targeting Probody therapeutics, BMS-986249 and BMS-986288, partnered with Bristol Myers Squibb, as well as CX-904, a conditionally activated T-cell-engaging bispecific antibody targeting the epidermal growth factor receptor on tumor cells and the CD3 receptor on T cells, which is partnered with Amgen. In addition, CytomX has a diverse preclinical portfolio of wholly-owned assets such as CX-801, an interferon alpha-2b Probody cytokine that has broad potential applicability in traditionally immuno-oncology sensitive as well as insensitive (cold) tumors, and CX-2051, a conditionally activated ADC directed toward EpCAM, with potential applicability across multiple EpCAM-expressing epithelial cancers. CytomX has established strategic collaborations with multiple leaders in oncology, including AbbVie, Amgen, Astellas, and Bristol Myers Squibb. For more information about CytomX and how it is working to make conditionally activated treatments the new standard-of-care in the fight against cancer, visit www.cytomx.com and follow us on LinkedIn and Twitter.

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, including BMS-986249, praluzatamab ravtansine, CX-2029, BMS-986288, pacmilimab, CX-904, CX-801, and CX-2051, the potential benefits or applications of CytomX’s Probody platform technology, CytomX’s ability to develop and advance product candidates into and successfully complete clinical trials, including the ongoing and planned clinical trials of praluzatamab ravtansine, CX-2029, BMS-986249, BMS-986288, pacmilimab, and CX-904, and the timing of the commencement of clinical trials, initial and ongoing data availability, investigational new drug applications and other development milestones. 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 possibility that the results of early clinical trials for any of our product candidates, including BMS986249, may not be predictive of future results; the possibility that CytomX’s clinical trials will not be successful; the possibility that current preclinical research may not result in additional product candidates; CytomX’s dependence on the success of praluzatamab ravtansine, CX-2029, BMS-986249, BMS-986288, pacmilimab, CX-904, CX-801, and CX-2051; CytomX’s reliance on third parties for the manufacture of the Company’s product candidates; possible regulatory developments in the United States and foreign countries; and 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. 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 August 4, 2022. 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.

CytomX Contact:
Chris Ogden
SVP, Finance and Accounting
cogden@cytomx.com
(317) 767-4764

Investor and Media Contact:
Stern Investor Relations
Stephanie Ascher
stephanie.ascher@sternir.com
212-362-1200