Aprea Therapeutics Reports First quarter 2024 Financial Results and Provides a Business Update U.S. FDA cleared IND for APR-1051, a highly selective and potentially best-in-class oral WEE1 inhibitor; Company plans to ini

Aprea Therapeutics Reports First quarter 2024 Financial Results and Provides a Business Update

U.S. FDA cleared IND for APR-1051, a highly selective and potentially best-in-class oral WEE1 inhibitor; Company plans to initiate Phase 1 ACESOT-1051 clinical trial in June 2024

First-in-class macrocyclic ATR inhibitor, ATRN-119, on track to complete dose escalation in ABOYA-119 clinical trial and potentially generate initial human efficacy data in 2H 2024

Company had four poster presentations at the AACR Annual Meeting, including updates on APR-1051 and ATRN-119

$32.4 million in cash and cash equivalents as of March 31, 2024

DOYLESTOWN, PA, May 14, 2024 (GLOBE NEWSWIRE) - Aprea Therapeutics, Inc. (Nasdaq: APRE) ("Aprea", or the "Company"), a clinical-stage biopharmaceutical company focused on precision oncology through synthetic lethality, today reported financial results for the first quarter ended March 31, 2024, and provided a business update.

"During the first quarter of 2024, Aprea had a number of noteworthy achievements across clinical, regulatory and corporate fronts," said Oren Gilad, Ph.D., President and Chief Executive Officer of Aprea. "FDA clearance of the IND for APR-1051, our next-generation inhibitor of WEE1 kinase, was an important milestone and allows us to commence clinical trials with this exciting, differentiated and potentially best in class molecule. We look forward to evaluating its therapeutic activity in patients, focusing on Cyclin E overexpressing cancers, including ovarian and breast cancers amongst others. Enrollment continues in the dose escalation portion of our ABOYA-119 clinical trial evaluating ATRN-119 in patients with advanced solid tumors having mutations in defined DDR-related genes. We are encouraged by correlations of the preliminary signs of clinical benefit and genetic mutations. Importantly, Aprea has a strong balance sheet, and the closing of our successful private placement in March of this year provides us with the capital to fund both our lead programs through meaningful clinical milestones. As we progress, we are committed to leveraging our expertise in synthetic lethality in order to provide hope and new treatment options to cancer patients who urgently need them. We believe that our strategic initiatives and pipeline expansion have the potential to drive substantial value for shareholders."

Key Business Updates and Potential Upcoming Key Milestones

ABOYA-119: ATR inhibitor, ATRN-119, on track to complete monotherapy dose escalation end of the year

ACESOT-1051: Oral WEE1 inhibitor, APR-1051, expected to enter Phase 1 clinical trial in June, 2024

Pipeline - lead candidate for a third synthetic lethality program to be selected in 2024

Select Financial Results for the First Quarter ended March 31, 2024

Aprea Therapeutics, Inc. is a clinical-stage biopharmaceutical company headquartered in Doylestown, Pennsylvania, focused on precision oncology through synthetic lethality. The Company's lead program is ATRN-119, a clinical-stage

small molecule ATR inhibitor in development for solid tumor indications. Aprea has completed all IND enabling studies for its oral, small molecule WEE1 inhibitor, APR-1051, and recently received FDA clearance of its IND. For more information, please visit the company website at www.aprea.com.

The Company may use, and intends to use, its investor relations website at https://ir.aprea.com/ as a means of disclosing material nonpublic information and for complying with its disclosure obligations under Regulation FD.

Forward-Looking Statement

Certain information contained in this press release includes "forward-looking statements", within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended related to our study analyses, clinical trials, regulatory submissions, and projected cash position. We may, in some cases use terms such as "future," "predicts," "believes," "potential," "continue," "anticipates," "estimates," "expects," "plans," "intends," "targeting," "confidence," "may," "could," "might," "likely," "will," "should" or other words that convey uncertainty of the future events or outcomes to identify these forward-looking statements. Our forward-looking statements are based on current beliefs and expectations of our management team and on information currently available to management that involve risks, potential changes in circumstances, assumptions, and uncertainties. All statements contained in this press release other than statements of historical fact are forward-looking statements, including statements regarding our ability to develop, commercialize, and achieve market acceptance of our current and planned products and services, our research and development efforts, including timing considerations and other matters regarding our business strategies, use of capital, results of operations and financial position, and plans and objectives for future operations. Any or all of the forward-looking statements may turn out to be wrong or be affected by inaccurate assumptions we might make or by known or unknown risks and uncertainties. These forward-looking statements are subject to risks and uncertainties including, without limitation, risks related to the success, timing, and cost of our ongoing clinical trials and anticipated clinical trials for our current product candidates, including statements regarding the timing of initiation, pace of enrollment and completion of the trials (including our ability to fully fund our disclosed clinical trials, which assumes no material changes to our currently projected expenses), futility analyses, presentations at conferences and data reported in an abstract, and receipt of interim or preliminary results (including, without limitation, any preclinical results or data), which are not necessarily indicative of the final results of our ongoing clinical trials, our understanding of product candidates mechanisms of action and interpretation of preclinical and early clinical results from its clinical development programs, and the other risks, uncertainties, and other factors described under "Risk Factors," "Management's Discussion and Analysis of Financial Condition and Results of Operations" and elsewhere in the documents we file with the U.S. Securities and Exchange Commission. For all these reasons, actual results and developments could be materially different from those expressed in or implied by our forward-looking statements. You are cautioned not to place undue reliance on these forward-looking statements, which are made only as of the date of this press release. We undertake no obligation to update such forward-looking statements for any reason, except as required by law.