Cibisatamab

- Initiation of GLP toxicology study for the first clinical candidate in the collaboration triggers a $5 million milestone payment to CytomX - - Program is one of several ongoing collaboration projects in broad CytomX-Astellas alliance on T-cell engaging bispecifics - - CytomX retains option for US co-commercialization and economic rights for certain programs - SOUTH SAN FRANCISCO, Calif., March 18, 2024 (GLOBE NEWSWIRE) -- CytomX Therapeutics, Inc. (Nasdaq: CTMX), a leader in the field of conditionally activated, localized biologics, today announced that the first clinical candidate in its TCB agreement with Astellas has entered into GLP toxicology studies which triggers a $5 million payment to CytomX. The clinical candidate is the first PROBODY® TCB molecule under this alliance to progress into a GLP toxicology study. CytomX and Astellas are also collaborating on additional conditionally activated TCB programs with CytomX eligible to receive future preclinical, clinical and commercial milestones. CytomX retains a cost share and co-commercialization option on a select number of targets. “We are excited by the continued momentum towards a potential future IND for the first PROBODY® TCB clinical candidate in our collaboration with Astellas, and we continue to partner with Astellas on multiple preclinical programs. The progress with this collaboration highlights the benefits of our strategy to create value through both wholly-owned and partnered programs, as well as the potential of our expanding pipeline of PROBODY T-cell engagers which are designed to localize T-cell activity to the tumor microenvironment,” said Sean McCarthy, D.Phil., chief executive officer and chairman of CytomX Therapeutics. About CytomX Therapeutics CytomX is a clinical-stage, oncology-focused biopharmaceutical company focused on developing novel conditionally activated 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-904, CX-2051 and CX-801. CX-904 is a conditionally activated T-cell-engaging antibody targeting the epidermal growth factor receptor (EGFR) on tumor cells and the CD3 receptor on T cells and partnered with Amgen in a global co-development alliance. CX-2051 is a conditionally activated ADC directed toward epithelial cell adhesion molecule, EpCAM, with potential applicability across multiple EpCAM-expressing epithelial cancers. CX-801 is an 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 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. 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, CX-801, and CX-904, 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-904, and the timing of the commencement of clinical trials or initial and ongoing data availability for CX-801 and CX-2051, 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; 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 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-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 we may incur higher costs than expected for research and development or unexpected costs and expenses. 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 Annual Report on Form 10-K filed with the SEC on March 11, 2024. 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. Investor Contact: Chris Ogden SVP, Finance and Accounting cogden@cytomx.com Investor and Media Contact: Stern Investor Relations Stephanie Ascher stephanie.ascher@sternir.com

Roche removed schizophrenia candidate ralmitaront from its midphase pipeline. Roche’s vision of developing an oral diabetic retinopathy treatment has taken a hit, with the drugmaker stopping development of vicasinabin after completing phase 2. The CB2 agonist was discarded (PDF) as part of a cull that also saw Roche pull back from its CEAxCD3 bispecific candidate cibisatamab. Vicasinabin, also known as RG7774, entered phase 2 in 2020. Roche pitched the candidate as a potential oral alternative to existing invasive treatments, such as injections into the eye, for a condition that leads to vision loss and blindness in some people with diabetes. However, the clinical trial, which finished in July, failed to persuade Roche to keep investing in the candidate. The action eliminates one of the leading oral contenders in diabetic retinopathy. Ocuphire Pharma has an oral candidate, APX3330, that has cleared phase 2. Bayer, InflammX and Rezolute also have oral, clinical-phase assets. Other companies, notably Boehringer Ingelheim, have swung at the indication and missed.  Roche dropped vicasinabin from its pipeline as part of a third quarter cull that also affected cibisatamab, a bispecific designed to bind to CD3 on T cells and CEA on cancer cells. Multiple companies have zeroed in on CEA as an attractive solid tumor drug target. Roche started a phase 1 trial of an older CEAxCD3 bispecific, RO6958688, in 2014 and followed up by taking cibisatamab into the clinic in 2019. The trial evaluated cibisatamab, also known as RG7802, in combination with Roche’s checkpoint inhibitor Tecentriq in colorectal cancer patients. Now, Roche has removed RG7802 in solid tumors from its phase 1 pipeline. The drugmaker continues to assess RG7802 in combination with RO7122290, a bispecific antibody-like fusion protein that simultaneously targets 4-1BB and FAP, in colorectal cancer.     Asked by Fierce Biotech about the pipeline changes on a conference call with the media this morning, Teresa Graham, CEO of Roche Pharmaceuticals, said: “I think these are both very early-stage assets that currently sit in our research and early development organizations.” “We've seen encouraging early data that would lead us to believe that further study is necessary or warranted,” Graham added. “So I would say stay tuned, and hopefully at an upcoming medical conference we'll have more data that we can share.” Roche also removed the schizophrenia candidate ralmitaront from its midphase pipeline. The company terminated a phase 2 trial of the asset earlier this year after an interim analysis found it was unlikely to meet the primary endpoint. Roche terminated another trial of the molecule last year.