Kronos Bio’s Investigational CDK9 Inhibitor KB-0742 to be Featured in Four Preclinical Poster Presentations at American Association for Cancer Research Annual Meeting 2022

Data include results from preclinical studies of KB-0742 in MYC-amplified cancers, including small-cell lung, triple-negative breast and ovarian, as well as lymphomaPosters also feature data from preclinical chordoma and sarcoma modelsKB-0742 is being evaluated in an ongoing Phase 1/2 trial SAN MATEO, Calif. and CAMBRIDGE, Mass., March 08, 2022 (GLOBE NEWSWIRE) — Kronos Bio, Inc. (Nasdaq: KRON), a company dedicated to transforming the lives of those affected by cancer and other serious diseases, today announced that it will present preclinical data on its internally discovered, highly selective, oral cyclin dependent kinase 9 (CDK9) inhibitor, KB-0742, in four poster presentations at the American Association for Cancer Research (AACR) Annual Meeting 2022, being held April 8-13 in New Orleans. Kronos Bio is currently evaluating KB-0742 in a Phase 1/2 trial. The company reported preliminary positive data from the study last year and expects to announce the recommended Phase 2 dose and share additional Phase 1 data in Q4 2022. The AACR posters include data from the assessment of KB-0742 in preclinical models of MYC-amplified solid tumors, including small-cell lung cancer, triple-negative breast cancer and ovarian cancer, as well as transcriptionally addicted cancers, including chordoma and sarcoma. The company will also present data related to the use of a liquid biopsy assay, which will be used to evaluate patient response to KB-0742 in the ongoing Phase 1/2 study. The abstracts are now available on the AACR website. Details of the poster presentations are as follows: Poster Title: CDK9 inhibition via KB-0742 is a potential strategy to treat transcriptionally addicted cancersAbstract Number: 2564Date and Time: Tuesday, April 12, 2022, 9 a.m. – 12:30 p.m.Poster Title: CDK9 inhibitor KB-0742 is active in preclinical models of small-cell lung cancerAbstract Number: 2565Date and Time: Tuesday, April 12, 2022, 9 a.m. – 12:30 p.m. Poster Title: KB-0742 is active in preclinical MYC-high models of triple-negative breast cancer, ovarian, and diffuse large B-cell lymphoma Abstract Number: 2639Date and Time: Tuesday, April 12, 2022, 9 a.m. – 12:30 p.m. Poster Title: Development of a liquid biopsy assay to longitudinally monitor changes in mutations’ allelic frequency in response to KB-0742Abstract Number: 535Date and Time: Sunday, April 10, 2022, 1:30 p.m. – 5 p.m. All times are in Central Time. About KB-0742 KB-0742 is a highly selective, orally bioavailable inhibitor of cyclin dependent kinase 9 (CDK9) in development for the treatment of MYC-amplified solid tumors. CDK9 is a global regulator of transcription and plays an essential role in both the expression and function of MYC, a well-characterized transcription factor and a long-recognized driver of cancer that is amplified in approximately 30% of solid tumors, including those affecting the lungs, ovaries, esophagus, breast, stomach, pancreas and liver. KB-0742 was generated and optimized from a compound that was identified using the company’s proprietary small molecule microarray (SMM) screening platform. About Kronos Bio, Inc. Kronos Bio is an integrated discovery through late-stage clinical development biopharmaceutical company, focused on developing therapies that target the dysregulated transcription that causes cancer and other serious diseases. Kronos Bio’s lead investigational compound is entospletinib, an orally administered, selective inhibitor targeting spleen tyrosine kinase (SYK) in clinical development for the frontline treatment of NPM1-mutated acute myeloid leukemia (AML) in combination with intensive chemotherapy. The company is also developing KB-0742, an orally administered inhibitor of cyclin dependent kinase 9 (CDK9), in Phase 1/2 clinical development for the treatment of MYC-amplified or overexpressing solid tumors. Kronos Bio is based in San Mateo, Calif., and has a research facility in Cambridge, Mass. For more information, visit www.kronosbio.com or follow the company on LinkedIn. Forward-Looking Statements Statements in this press release that are not statements of historical fact are forward-looking statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. The press release, in some cases, uses terms such as “will,” “expect,” “potential” or other words that convey uncertainty of future events or outcomes to identify these forward-looking statements. Forward-looking statements include statements regarding Kronos Bio’s intentions, beliefs, projections, outlook, analyses or current expectations concerning, among other things: the anticipated timing for announcing the recommended Phase 2 dose in Kronos Bio’s ongoing Phase 1/2 clinical trial of KB-0742; the anticipated timing for reporting data; the development of a liquid biopsy assay and the use of related data; and other statements that are not historical fact. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, including, without limitation: risks associated with the COVID-19 pandemic and risks inherent in the clinical development of novel therapeutics; risks related to Kronos Bio’s lack of experience as a company in conducting clinical trials; and risks associated with the sufficiency of Kronos Bio’s cash resources and need for additional capital. These and other risks are described in greater detail in Kronos Bio’s filings with the Securities and Exchange Commission (SEC), including under the heading “Risk Factors” in its Annual Report on Form 10-K for the year ended December 31, 2021, which was filed with the SEC on February 24, 2022. Any forward-looking statements that are made in this press release speak only as of the date of this press release and are based on management’s assumptions and estimates as of such date. Except as required by law, Kronos Bio assumes no obligation to update the forward-looking statements whether as a result of new information, future events or otherwise, after the date of this press release. Company Contact:Marni KottleSenior Vice President, Corporate Communications & Investor [email protected] Investors:Claudia StyslingerArgot [email protected] Media:Sheryl SeapyReal [email protected]