1 Summit Therapeutics to Present at Oppenheimer’s 34th Annual Healthcare Life Sciences Conference Miami, Florida, February 07, 2024 – Summit Therapeutics Inc. (NASDAQ: SMMT) (“Summit,” “we,” or the “Company”) today announced that it will participate in and present at Oppenheimer’s 34th Annual Healthcare Life Sciences Conference, which will be held virtually. Summit will present on Wednesday, February 14, 2024, at 2:40PM ET. Dr. Maky Zanganeh, Chief Executive Officer and President, and Robert W. Duggan, Chairman and Chief Executive Officer, will present on behalf of our organization and provide details regarding the development of our innovative investigational bispecific antibody, ivonescimab. The presentation will be available live from our website: www.smmttx.com. An archived version will be available on our website following the presentation. About Ivonescimab Ivonescimab, known as SMT112 in Summit’s license territories, the United States, Canada, Europe, and Japan, and as AK112 in China and Australia, is a novel, potential first-in-class investigational bispecific antibody combining the effects of immunotherapy via a blockade of PD-1 with the anti-angiogenesis effects associated with blocking VEGF into a single molecule. Ivonescimab displays unique cooperative binding to each of its intended targets with higher affinity when in the presence of both PD-1 and VEGF. This could differentiate ivonescimab as there is potentially higher expression (presence) of both PD-1 and VEGF in tumor tissue and the tumor microenvironment (TME) as compared to normal tissue in the body. Ivonescimab’s tetravalent structure (four binding sites) enables higher avidity (accumulated strength of multiple binding interactions) in the tumor microenvironment with over 18-fold increased binding affinity to PD-1 in the presence of VEGF in vitro, and over 4-times increased binding affinity to VEGF in the presence of PD-1 in vitro (Zhong, et al, SITC, 2023). This tetravalent structure, the intentional novel design of the molecule, and bringing these two targets into a single bispecific antibody with cooperative binding qualities have the potential to direct ivonescimab to the tumor tissue versus healthy tissue. The intent of this design is to improve upon previously established efficacy thresholds, in addition to side effects and safety profiles associated with these targets. Ivonescimab was discovered by Akeso Inc. (HKEX Code: 9926.HK) and is currently engaged in multiple Phase III clinical trials. Summit has begun its clinical development of ivonescimab in NSCLC, commencing enrollment in 2023 in its two Phase III clinical trials. Over 1,600 patients have been treated with ivonescimab in clinical studies. About Summit Therapeutics Summit was founded in 2003 and our shares are listed on the Nasdaq Global Market (symbol ‘SMMT’). We are headquartered in Miami, Florida, and we have additional offices in Menlo Park, California, and Oxford, UK. Summit’s mission, in part, is to develop patient, physician, caregiver, and societal-friendly medicinal therapies intended to improve quality of life, increase potential duration of life, and resolve serious unmet medical needs. For more information, please visit https://www.smmttx.com and follow us on X (formerly Twitter) @summitplc. Contact Summit Investor Relations: Dave Gancarz Chief Business & Strategy Officer
2 Nathan LiaBraaten Senior Director, Investor Relations investors@smmttx.com Summit Forward-looking Statements Any statements in this press release about the Company’s future expectations, plans and prospects, including but not limited to, statements about the clinical and preclinical development of the Company’s product candidates, entry into and actions related to the Company’s partnership with Akeso Inc., the therapeutic potential of the Company’s product candidates, the potential commercialization of the Company’s product candidates, the timing of initiation, completion and availability of data from clinical trials, the potential submission of applications for marketing approvals, potential acquisitions and other statements containing the words "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "target," "would," and similar expressions, constitute forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Actual results may differ materially from those indicated by such forward- looking statements as a result of various important factors, including the results of our evaluation of the underlying data in connection with the development and commercialization activities for ivonescimab, the outcome of discussions with regulatory authorities, including the Food and Drug Administration, the uncertainties inherent in the initiation of future clinical trials, availability and timing of data from ongoing and future clinical trials, the results of such trials, and their success, and global public health crises, that may affect timing and status of our clinical trials and operations, whether preliminary results from a clinical trial will be predictive of the final results of that trial or whether results of early clinical trials or preclinical studies will be indicative of the results of later clinical trials, whether business development opportunities to expand the Company’s pipeline of drug candidates, including without limitation, through potential acquisitions of, and/or collaborations with, other entities occur, expectations for regulatory approvals, laws and regulations affecting government contracts and funding awards, availability of funding sufficient for the Company’s foreseeable and unforeseeable operating expenses and capital expenditure requirements and other factors discussed in the "Risk Factors" section of filings that the Company makes with the Securities and Exchange Commission. Any change to our ongoing trials could cause delays, affect our future expenses, and add uncertainty to our commercialization efforts, as well as to affect the likelihood of the successful completion of clinical development of ivonescimab. Accordingly, readers should not place undue reliance on forward-looking statements or information. In addition, any forward-looking statements included in this press release represent the Company’s views only as of the date of this release and should not be relied upon as representing the Company’s views as of any subsequent date. The Company specifically disclaims any obligation to update any forward-looking statements included in this press release.