CytomX Therapeutics Presents Preclinical Data for mRNA Encoded Masked IL-12 Molecule in Collaboration with Moderna at AACR Annual Meeting

SOUTH SAN FRANCISCO, Calif., April 28, 2025 (GLOBE NEWSWIRE) -- CytomX Therapeutics, Inc. (NASDAQ:CTMX), a leader in the field of masked, conditionally activated biologics, today announced new preclinical data in collaboration with Moderna on an mRNA encoded masked IL-12 molecule. The data will be presented at the American Association for Cancer Research (AACR) Annual Meeting, being held in Chicago, IL on April 25-30, 2025.

"We are excited to share new preclinical data at AACR, establishing proof of concept for an mRNA encoded masked molecule in the treatment of cancer," said Marcia Belvin, Ph.D. SVP, Chief Scientific Officer of CytomX Therapeutics. "IL-12 has shown promising anti-tumor activity, but its clinical use has been limited due to its inflammatory toxicity and narrow therapeutic window. By combining CytomX's proprietary PROBODY^® masking technology and Moderna's mRNA technology, we have created an mRNA therapeutic encoding a masked IL-12, designed to be selectively activated within the tumor microenvironment (TME), with limited systemic activity. The data presented at AACR show proof of concept for this unique technology combination, a key initial goal of the CytomX-Moderna collaboration."

Details for the poster presentation are as follows:

Presentation Title: An mRNA-encoded masked IL-12 improves systemic tolerability while maintaining anti-tumor efficacy in preclinical studies

Poster Number: 3127/12

Section 24

Session Date and Time: April 28, 2025, 2:00 pm – 5:00 pm CT

About CytomX Therapeutics, Inc.

CytomX is a clinical-stage, oncology-focused biopharmaceutical company focused on developing novel conditionally activated, masked biologics designed to be localized to the tumor microenvironment. By pioneering a novel pipeline of localized biologics, powered by its PROBODY^® therapeutic platform, CytomX's vision is to create safer, more effective therapies for the treatment of cancer. CytomX's robust and differentiated pipeline comprises therapeutic candidates across multiple treatment modalities including antibody-drug conjugates ("ADCs"), T-cell engagers, and immune modulators such as cytokines. CytomX's clinical-stage pipeline includes CX-2051 and CX-801. CX-2051 is a masked, conditionally activated ADC directed toward epithelial cell adhesion molecule (EpCAM), armed with a topoisomerase-1 inhibitor payload. CX-2051 has potential applicability across multiple EpCAM-expressing epithelial cancers, including CRC, and was discovered in collaboration with ImmunoGen, now part of AbbVie. CX-801 is a masked interferon alpha-2b PROBODY^® cytokine with broad potential applicability in traditionally immuno-oncology sensitive as well as insensitive (cold) tumors. CytomX has established strategic collaborations with multiple leaders in oncology, including Amgen, Astellas, Bristol Myers Squibb, Regeneron and Moderna. 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 X (formerly 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, including those related to the future potential of partnerships or collaboration agreements and projected cash runway. 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 CX-2051 and CX-801, the potential benefits or applications of CytomX's PROBODY^® therapeutic platform, CytomX's or its collaborative partners' ability to develop and advance product candidates into and successfully complete clinical trials, including the ongoing and planned clinical trials of CX-2051 and CX-801 and the timing of initial and ongoing data availability for our clinical trials, including CX-2051 and CX-801, 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^® therapeutic technology; uncertainties around the Company's ability to raise sufficient funds to carry out its planned research and development; 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 preclinical research and early clinical trials, including initial CX-2051 and CX-801 results, 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 CX-2051 and CX-801; 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 we may incur higher costs than expected for research and development or unexpected costs and expenses or may not obtain expected savings from our announced restructuring. 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-K filed with the SEC on March 6, 2025. 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. All other trademarks are the properties of their respective owners.

Company Contact:

Chris Ogden

SVP, Chief Financial Officer

[email protected]

Investor Contact:

Precision AQ (formerly Stern Investor Relations)

Stephanie Ascher

[email protected]

Media Contact:

Redhouse Communications

Teri Dahlman

[email protected]