ITEOS

- 10 ongoing or planned clinical trials throughout 2023 to advance both differentiated clinical programs, anti-TIGIT monoclonal antibody EOS-448/GSK4428859A and adenosine A2A receptor antagonist inupadenant - EOS-984, a first-in-class program targeting a new mechanism of action in the adenosine pathway, expected to enter clinical studies in mid-2023 - Cash and investment balance of $731.4MM as of December 31, 2022, expected to provide runway into 2026 WATERTOWN, Mass. and GOSSELIES, Belgium, March 15, 2023 (GLOBE NEWSWIRE) -- iTeos Therapeutics, Inc. (Nasdaq: ITOS), a clinical-stage biopharmaceutical company pioneering the discovery and development of a new generation of immuno-oncology therapeutics for patients, today reported financial results for the fourth quarter and full year ended December 31, 2022. "Building off a successful year of execution in 2022, we continue to advance our robust portfolio of programs through multiple trials with strong financial resources that are expected to provide cash runway into 2026," said Michel Detheux, Ph.D., president, and chief executive officer of iTeos. "Alongside our valued partner GSK, we aim to make significant progress in 2023 in our broad and differentiated development plan for EOS-448, our anti-TIGIT antibody. This includes executing two Phase 2 studies of the doublet with GSK’s anti-PD-1, Jemperli (dostarlimab) and clinical progress with novel triplets. We also remain on track to launch upcoming pivotal trials of EOS-448 in combination with dostarlimab.” Continued Dr. Detheux, “We are progressing in our efforts to unlock the potential of the adenosine pathway. We believe that through our differentiated inupadenant program and unique and targeted approach, we are positioned for success in this important mechanism of immunosuppression. We continue to assess our proprietary biomarker for indication and patient selection. We are encouraged by the recently disclosed monotherapy response, which we are pleased to see is now a confirmed partial response, in a patient who had the highest level of the biomarker that we have recorded to date. We have decided to prioritize development of inupadenant in our ongoing study in combination with platinum-doublet chemotherapy in patients with chemo-naïve NSCLC as we have determined that the post-PD-1 melanoma setting is not a path to accelerated approval. This is consistent with our disciplined investment approach, and we continue to focus our internal resources and capital on our most promising discovery and development programs.” Clinical Development PlansEOS-448/GSK4428859A: IgG1 anti-TIGIT monoclonal antibody designed to engage the Fc gamma receptor (FcγR) and enhance the anti-tumor response through multifaceted mechanisms. In collaboration with GSK, iTeos is evaluating EOS-448 as a potential next-generation immuno-oncology agent in multiple combination studies. Highlights include: Ongoing randomized Phase 2 trial assessing the doublet of dostarlimab with EOS-448 in previously untreated advanced / metastatic non-small cell lung cancer (NSCLC).Ongoing Phase 2 expansion study assessing the doublet of dostarlimab with EOS-448 in 1L advanced or metastatic head and neck squamous cell carcinoma.Continued exploration of two novel triplets in selected advanced solid tumors both in Phase 1b trials: EOS-448 with dostarlimab and GSK’s investigational anti-CD96 antibody, and EOS-448 with dostarlimab and GSK’s investigational anti-PVRIG antibody. Advancement of the monotherapy dose escalation part of a Phase 1/2 trial evaluating EOS-448 as both a monotherapy and in combination with Bristol Myers Squibb’s iberdomide in multiple myeloma. Adenosine PathwayInupadenant (EOS-850): Designed as an insurmountable and highly selective small molecule antagonist of the adenosine A2A receptor, the only high-affinity adenosine receptor expressed on multiple immune cells found in the tumor microenvironment. Highlights include: Enrolling in the dose ranging part (Part 1) of an ongoing two-part Phase 2 trial in post-IO metastatic non-squamous NSCLC to evaluate the combination of inupadenant with platinum-doublet chemotherapy compared to standard platinum-doublet chemotherapy.Completed enrollment in the biomarker-high cohort evaluating inupadenant as a monotherapy in patients with advanced solid tumors selected for high biomarker expression.Completed enrollment in the Phase 2a trial evaluating inupadenant in combination with pembrolizumab in post-PD-1 melanoma.Confirmed partial response using inupadenant in monotherapy in a patient who had the highest level of the biomarker that we have recorded to date.iTeos will present a poster at the upcoming American Association for Cancer Research (AACR) Annual Meeting taking place from April 14-19, 2023, in Orlando, Florida. The poster presentation will further explore the biomarker findings and highlight a new mechanism of action of inupadenant based on the evaluation of tumor biopsies from treated patients and additional translational work. EOS-984: First-in-class small molecule program targeting a novel mechanism in the adenosine pathway. This clinical development program has the potential to fully reverse the profound immunosuppressive action of adenosine on T and B cells. EOS-984 effects have been shown preclinically to be enhanced by combining with inupadenant and other standards of care.The company completed Investigational New Drug / Clinical Trials Application-enabling activities including toxicity studies and anticipates initiating clinical studies for EOS-984 in mid-2023. Fourth Quarter and Full Year 2022 Financial Results Cash and Investment Position: The Company’s cash, cash equivalents and investments position was $731.4 million as of December 31, 2022, as compared to $848.5 million of cash and cash equivalents as of December 31, 2021. The Company continues to expect its cash and investment position to provide runway into 2026.Research and Development (R&D) Expenses: R&D expenses were $25.4 million for the fourth quarter and $97.4 million for the year ended December 31, 2022, as compared to $17.4 million for the fourth quarter and $59.4 million for the year ended December 31, 2021. The increase was primarily due to an increase in activities related to EOS-448 and inupadenant clinical trials.General and Administrative (G&A) Expenses: G&A expenses were $11.1 million for the fourth quarter and $43.9 million for the year ended December 31, 2022, as compared to $9.6 million for the fourth quarter and $40.5 million for the ended December 31, 2021. The increase was primarily due to an increase in headcount and related costs and an increase in stock-based compensation compared to the prior year. This increase was partially offset by decreases in legal and other professional fees compared to the prior year.Net Income/Loss: Net income attributable to common shareholders was $20.5 million, or a net income of $0.57 per basic share and $0.54 of per diluted share, for the quarter ended December 31, 2022, as compared to a net income of $184.9 million, or a net income of $5.24 per basic share and $4.88 per diluted share, for the quarter ended December 31, 2021. Net income was $96.7 million, or net income of $2.72 per basic share and $2.56 per diluted share, for the year ended December 31, 2022, as compared to a net income of $214.5 million, or a net income of $6.10 per basic share and $5.68 per diluted share, for the year ended December 31, 2021. About iTeos Therapeutics, Inc.iTeos Therapeutics is a clinical-stage biopharmaceutical company pioneering the discovery and development of a new generation of immuno-oncology therapeutics for patients. iTeos Therapeutics leverages its deep understanding of tumor immunology and immunosuppressive pathways to design novel product candidates with the potential to restore the immune response against cancer. The Company’s innovative pipeline includes two clinical-stage programs targeting novel, validated immuno-oncology pathways designed with optimized pharmacologic properties for improved clinical outcomes. The first antibody product candidate, EOS-448, is a high affinity, potent, anti-TIGIT antibody with a functional Fc domain, designed to enhance the anti-tumor response through a multifaceted immune modulatory mechanism, currently progressing in multiple indications in collaboration with GSK. The Company is also advancing inupadenant, a next-generation adenosine A2A receptor antagonist tailored to overcome cancer immunosuppression, into proof-of-concept trials in several indications following encouraging single-agent activity in Phase 1. iTeos Therapeutics is headquartered in Watertown, MA with a research center in Gosselies, Belgium. Internet Posting of InformationiTeos routinely posts information that may be important to investors in the 'Investors' section of its website at www.iteostherapeutics.com. The Company encourages investors and potential investors to consult our website regularly for important information about iTeos. Forward-Looking StatementsThis press release contains forward-looking statements. Any statements that are not solely statements of historical fact are forward-looking statements. Words such as “believe,” “anticipate,” “plan,” “expect,” “will,” “may,” “intend,” “prepare,” “look,” “potential,” “possible” and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements relating to the potential benefits of EOS-448, inupadenant and EOS-984; our expectations regarding the anticipated development of our pipeline of candidates; our goal to make significant progress in 2023 in our broad and differentiated development plan for EOS-448, including two Phase 2 studies of the doublet with GSK’s dostarlimab and clinical progress with novel triplets; iTeos remaining on track to launch upcoming pivotal trials of EOS-448 in combination with dostarlimab; iTeos being positioned for success in its adenosine pathway programs; the expectation that EOS-984 will enter clinical studies in mid-2023; and the expectation to have cash runway into 2026. These forward-looking statements involve risks and uncertainties, many of which are beyond iTeos’ control. Actual results could materially differ from those stated or implied by these forward-looking statements as a result of such risks and uncertainties. Known risk factors include the following: market conditions; the expected benefits and opportunities related to the agreement between iTeos and GSK may not be realized or may take longer to realize than expected due to a variety of reasons, including any inability of the parties to perform their commitments and obligations under the agreement, challenges and uncertainties inherent in product research and development and manufacturing limitations; iTeos may encounter unanticipated costs or may expend cash more rapidly or more slowly than currently anticipated due to challenges and uncertainties inherent in product research and development and biologics manufacturing; success in preclinical testing and early clinical trials does not ensure that later clinical trials will be successful, and early results from a clinical trial do not necessarily predict final results; the data for our product candidates may not be sufficient for obtaining regulatory approval to move into later stage trials or to commercialize products; iTeos may not be able to execute on its business plans, including meeting its expected or planned regulatory milestones and timelines, research and clinical development plans, and bringing its product candidates to market, for various reasons, some of which may be outside of iTeos’ control, including possible limitations of company financial and other resources, manufacturing limitations that may not be anticipated or resolved for in a timely manner, regulatory, court or agency decisions such as decisions by the United States Patent and Trademark Office with respect to patents that cover our product candidates and the impact of the COVID-19 pandemic; and those risks identified under the heading “Risk Factors” in iTeos’ Annual Report on Form 10-K for the year ended December 31, 2022 filed with the Securities and Exchange Commission (SEC) as well as other SEC filings made by the Company which you are encouraged to review. Statements regarding the Company’s cash runway do not indicate when the Company may access the capital markets. Any of the foregoing risks could materially and adversely affect iTeos’ business, results of operations and the trading price of iTeos’ common stock. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release. iTeos does not undertake any obligation to publicly update its forward-looking statements other than as required by law. For further information, please contact: Investor Contact:Ryan BakeriTeos Therapeutics, Inc.Ryan.Baker@iteostherapeutics.com Media Contact:media@iteostherapeutics.com

PHILADELPHIA--( BUSINESS WIRE )--Chimeron Bio, an RNA company developing self-amplifying RNA (saRNA) vaccines and therapeutics designed on its proprietary ChaESAR™ RNA delivery platform, announced today that Kevin Heyeck had been named Chief Executive Officer. Kevin comes to Chimeron with a long and successful track record of executive and entrepreneurial experience in life sciences. Kevin began his career at Harvard University’s Office of Technology Licensing, then went on to lead corporate and business development for multiple venture-backed drug discovery companies, and more recently in venture capital as Managing Director of a venture fund investing in early-stage life science companies. In addition to joining the Chimeron Board, his board memberships include Cru Bio, UAMS Bioventures, and previously, Hibercell, Ultivue, and board observer of Iteos. Kevin’s guidance and leadership are informed by more than 25 years of experience starting and growing venture-backed life sciences companies, both in an executive capacity and as a serial entrepreneur. “Kevin Heyeck possesses a rare blend of vision and operational knowledge that will support Chimeron Bio in achieving its next phase of growth. In addition to his experience in venture capital, executive leadership, and entrepreneurial success founding and building life sciences companies, Kevin has hands on experience heading corporate and business development for innovative life sciences companies including Allocure, Vitae Pharmaceuticals and Pharmacopeia,” said Afshin Safavi, Ph.D., Chairman of the Board at Chimeron Bio. Afshin continued, “Kevin’s business development perspective will prove invaluable to Chimeron Bio as we continue on our own growth journey and advance our mission to bring novel, accessible RNA therapies to patients across indications.” “Chimeron Bio represents a ground-breaking company deploying a next-generation, foundational technology platform that pushes the frontier of RNA delivery and RNA medicines and will allow us to quickly build a high impact pipeline that includes pre-clinical studies in oncology, infection disease, and rare disease. I am looking forward to working with Chimeron’s exceptional team to advance the development of its self-amplifying RNA (saRNA) technology across indications using the ChaESAR™ platform to create and deliver innovative RNA medicines that will have a meaningful and positive impact for patients,” said Kevin Heyeck, new CEO of Chimeron Bio. About Chimeron Bio Chimeron Bio is a biotechnology company focused on the research of self-amplifying RNA (saRNA) towards development of novel RNA drugs and vaccines for various diseases. The company uses its proprietary ChaESAR™ platform to develop a pipeline in oncology, rare genetic disorders, and infectious diseases. It is developing two COVID-19 vaccine candidates each with its unique mechanism of action. The candidates have shown strong promise in early safety assessment and are under further development. For more information, visit www.chimeron.com .

- Began enrolling patients with head and neck squamous cell carcinoma in Phase 2 trial expansion evaluating anti-TIGIT monoclonal antibody, EOS-448/GSK4428859A, and GSK’s anti-PD-1 Jemperli (dostarlimab) - Enrolling patients with non-small cell lung cancer in a randomized Phase 2 trial evaluating the combination of inupadenant, an A2A receptor antagonist, with chemotherapy - Cash balance of $792MM as of June 30, 2022, expected to provide runway into 2026 to support differentiated clinical programs for EOS-448 and inupadenant and advance preclinical programs targeting immunosuppression pathways WATERTOWN, Mass. and GOSSELIES, Belgium, Aug. 10, 2022 (GLOBE NEWSWIRE) -- iTeos Therapeutics, Inc. (Nasdaq: ITOS), a clinical-stage biopharmaceutical company pioneering the discovery and development of a new generation of immuno-oncology therapeutics for patients, today reported financial results for the second quarter ended June 30, 2022 and provided corporate highlights. “In the second quarter of 2022, we have remained focused expanding our late-stage development efforts for both of our differentiated immunotherapy programs, EOS-448, our FcγR-engaging anti-TIGIT antibody, and inupadenant, our adenosine A2A receptor antagonist,” said Michel Detheux, Ph.D., president and chief executive officer of iTeos. “We’re pleased to be enrolling non-small cell lung cancer patients in a Phase 2 trial for inupadenant in combination with chemotherapy, which we described in a trial in progress poster at ASCO in June. We also continue to further advance our immunotherapy combinations with EOS-448, with the initiation of the Phase 2 expansion trial evaluating GSK’s anti-PD-1, Jemperli and EOS-448 in patients with head and neck squamous cell carcinoma. Notably, we have multiple clinical trials underway for EOS-448, which will help provide a comprehensive understanding of the treatment potential of TIGIT as an immunotherapy target.” Program HighlightsEOS-448/GSK4428859A: IgG1 anti-TIGIT monoclonal antibody designed to engage the Fc gamma receptor (FcγR) and to enhance the anti-tumor response through multifaceted mechanisms. In collaboration with GSK, iTeos is evaluating the optimal development pathway to assess EOS-448 as a potential next-generation immune-oncology agent through multiple combination studies and emerging data in the field. Recent highlights include: The companies have begun enrolling patients with 1L advanced or metastatic head and neck squamous cell carcinoma (HNSCC) in the Phase 2 expansion part of a trial assessing the doublet of GSK’s anti-PD-1, Jemperli (dostarlimab), with EOS-448.The companies have initiated the Phase 1b trial evaluating the novel triplet of EOS-448 with Jemperli and GSK’s investigational anti-CD96 antibody. The companies also plan to initiate a Phase 1b trial with EOS-448, Jemperli, and inupadenant in the coming months.Enrollment continues in the monotherapy dose escalation part of the Phase 1/2 trial evaluating EOS-448 as both a monotherapy and in combination with Bristol Myers Squibb’s iberdomide in patients with multiple myeloma. Inupadenant (EOS-850): Designed as an insurmountable and highly selective small molecule antagonist of the adenosine A2A receptor, the only high-affinity adenosine receptor expressed on different immune cells found in the tumor micro-environment. iTeos is enrolling patients in a randomized Phase 2 trial in post-IO metastatic non-squamous NSCLC to evaluate the combination of inupadenant with platinum-doublet chemotherapy compared to standard platinum-doublet chemotherapy. The company presented a description of this trial in a Trial in Progress poster at the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting in June.Enrollment is ongoing for the biomarker-high cohort of IO-001, the ongoing Phase 1b/2a trial, evaluating inupadenant as a monotherapy in patients with solid tumors selected for high biomarker expression in four cohorts: NSCLC, endometrial cancer, head and neck squamous cell carcinoma and other solid tumors. Preclinical programs: iTeos continues to focus its research programs on novel targets that address pathways of immunosuppression. This includes its candidate targeting a first-in-class mechanism in the adenosine pathway which is under evaluation in Investigational New Drug-enabling studies. Second Quarter 2022 Financial Results Cash Position: The company’s cash and cash equivalent position was $791.9 million as of June 30, 2022, as compared to $302.9 million as of June 30, 2021. Cash balance is expected to provide the company runway into 2026. Research and Development (R&D) Expenses: R&D expenses were $26.9 million for the quarter ended June 30, 2022, as compared to $14.2 million for the same quarter of 2021. The increase was primarily due to an increase in activities related to EOS-448 and inupadenant clinical trials along with increased spending related to the company’s preclinical programs. General and Administrative (G&A) Expenses: G&A expenses were $11.5 million for the quarter ended June 30, 2022, as compared to $15.1 million for the same quarter of 2021. The decrease was primarily due to one-time legal and advisory fees incurred by the Company in 2021 associated with the Collaboration and License Agreement with GSK. This decrease was partially offset by additional costs related to increased headcount. Net Income/Loss: Net income attributable to common shareholders was $5.6 million, or net income of $0.16 per basic share and $ 0.15 per diluted share, for the quarter ended June 30, 2022, as compared to a net loss of $ 26.5 million, or a net loss of $ 0.75 per basic and diluted share, for the same quarter of 2021. About iTeos Therapeutics, Inc.iTeos Therapeutics is a clinical-stage biopharmaceutical company pioneering the discovery and development of a new generation of immuno-oncology therapeutics for patients. iTeos Therapeutics leverages its deep understanding of tumor immunology and immunosuppressive pathways to design novel product candidates with the potential to restore the immune response against cancer. The Company’s innovative pipeline includes two clinical-stage programs targeting novel, validated immuno-oncology pathways designed with optimized pharmacologic properties for improved clinical outcomes. The first antibody product candidate, EOS-448, is a high affinity, potent, anti-TIGIT antibody with a functional Fc domain, designed to enhance the anti-tumor response through a multifaceted immune modulatory mechanism, currently progressing in multiple indications in collaboration with GSK. The Company is also advancing inupadenant, a next-generation adenosine A2A receptor antagonist tailored to overcome cancer immunosuppression, into proof-of concept trials in several indications following encouraging single-agent activity in Phase 1. iTeos Therapeutics is headquartered in Watertown, MA with a research center in Gosselies, Belgium. Internet Posting of InformationiTeos routinely posts information that may be important to investors in the 'Investors' section of its website at www.iteostherapeutics.com. The Company encourages investors and potential investors to consult our website regularly for important information about iTeos. Forward-Looking StatementsIn order to provide iTeos’ investors with an understanding of its current results and future prospects, this press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995 and other federal securities laws. Any statements that are not statements of historical fact may be deemed to be forward-looking statements. Words such as “believe,” “anticipate,” “plan,” “expect,” “will,” “may,” “intend,” “prepare,” “look,” “potential,” “possible” and similar expressions are intended to identify forward-looking statements. These forward-looking statements include statements relating to the potential benefits of EOS-448 and inupadenant; the potential of our EOS-448 clinical trials to help provide a comprehensive understanding of the treatment potential of TIGIT as an immunotherapy target; our clinical plans and upcoming milestones, including our plan to initiate a Phase 1b trial with EOS-448, Jemperli, and inupadenant; and having cash runway into 2026 to support differentiated clinical programs for EOS-448 and inupadenant and advance preclinical programs targeting immunosuppression pathways. These forward-looking statements involve risks and uncertainties, many of which are beyond iTeos’ control. Actual results could materially differ from those stated or implied by these forward-looking statements as a result of such risks and uncertainties. Known risk factors include the following: market conditions; the expected benefits and opportunities related to the agreement between iTeos and GSK may not be realized or may take longer to realize than expected due to a variety of reasons, including any inability of the parties to perform their commitments and obligations under the agreement, challenges and uncertainties inherent in product research and development and manufacturing limitations; iTeos may encounter unanticipated costs or may expend cash more rapidly than currently anticipated due to challenges and uncertainties inherent in product research and development and biologics manufacturing; success in preclinical testing and early clinical trials does not ensure that later clinical trials will be successful, and early results from a clinical trial do not necessarily predict final results; the data for our product candidates may not be sufficient for obtaining regulatory approval; iTeos may not be able to execute on its business plans, including meeting its expected or planned regulatory milestones and timelines, research and clinical development plans, and bringing its product candidates to market, for various reasons, some of which may be outside of iTeos’ control, including possible limitations of company financial and other resources, manufacturing limitations that may not be anticipated or resolved for in a timely manner, regulatory, court or agency decisions such as decisions by the United States Patent and Trademark Office with respect to patents that cover our product candidates and the impact of the COVID-19 pandemic; and those risks identified under the heading “Risk Factors” in iTeos’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2022 filed with the Securities and Exchange Commission (SEC) as well as other SEC filings made by the Company which you are encouraged to review. Statements regarding the Company’s cash runway do not indicate when the Company may access the capital markets. Any of the foregoing risks could materially and adversely affect iTeos’ business, results of operations and the trading price of iTeos’ common stock. We caution investors not to place considerable reliance on the forward-looking statements contained in this press release. iTeos does not undertake any obligation to publicly update its forward-looking statements based on events or circumstances after the date hereof. For further information, please contact: Investor Contact:Ryan BakeriTeos Therapeutics, Inc.Ryan.Baker@iteostherapeutics.com Media Contact:media@iteostherapeutics.com