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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

August 12, 2024

Date of Report (Date of earliest event reported)

Aprea Therapeutics, Inc.

(Exact name of registrant as specified in its charter)

Delaware

001-39069

84-2246769

(State or other jurisdiction
of incorporation)

(Commission
File Number)

(IRS Employer
Identification No.)

    

3805 Old Easton Road
Doylestown, PA
(Address of principal executive offices)

18902
(Zip Code)

Registrant’s telephone number, including area code: (617) 463-9385

(Former name or former address, if changed since last report): Not applicable

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

   

Trading Symbol(s)

   

Name of each exchange on
which registered

Common stock, par value $0.001 per share

APRE

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

Item 2.02Results of Operations and Financial Condition.

On August 12, 2024, Aprea Therapeutics, Inc. (the “Company”) issued a press release announcing its financial results for the three months ended June 30, 2024, and provided an update on the Company’s operations for the same period. The Company is furnishing a copy of the press release, which is attached hereto as Exhibit 99.1.

In accordance with General Instruction B.2 of Form 8-K, the information included in this Item 2.02, including Exhibit 99.1 hereto, shall not be deemed "filed" for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference into any filing made by the Company under the Exchange Act or Securities Act of 1933, as amended, except as shall be expressly set forth by specific reference in such a filing.

Item 8.01Other Events.

On August 12, 2024, the Company updated its corporate presentation slide deck. A copy of the corporate presentation slide deck is filed as Exhibit 99.2 hereto and incorporated herein by reference.

Item 9.01Financial Statements and Exhibits.

(d) Exhibits.

Exhibit
Number

    

Description

99.1

Press release issued by Aprea Therapeutics, Inc. dated August 12, 2024.

99.2

Corporate Presentation (August 2024).

104

Cover Page Interactive Data File (embedded within the inline XBRL document).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Aprea Therapeutics, Inc.

Dated: August 12, 2024

By:

/s/ Oren Gilad

Name:

Oren Gilad, Ph.D.

Title:

President and Chief Executive Officer

Exhibit 99.1

Aprea Therapeutics Reports Second Quarter 2024 Financial Results and Provides Business Update

Enrollment commenced in the ACESOT-1051 Phase 1 trial evaluating APR-1051 – no myelosuppression observed in the first of eight planned cohorts at sub-therapeutic dose

$28.7 million in cash and cash equivalents as of June 30, 2024 with cash runway extended into Q4 2025

DOYLESTOWN, PA, August 12, 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 second quarter ended June 30, 2024, and provided a business update.

“Aprea continues to make excellent progress advancing its clinical pipeline of therapeutic candidates,” said Oren Gilad, Ph.D., President and Chief Executive Officer of Aprea. “We initiated enrollment in the ACESOT-1051 trial, advancing a second clinical asset in our pipeline, APR-1051. APR-1051 is a next-generation inhibitor of WEE1 kinase which has been designed to limit toxicity. Based on its unique characteristics, we believe it could be best in class.  We continue to enroll patients in the ABOYA-119 trial evaluating ATRN-119, our ATR inhibitor. We believe that our ongoing progress positions Aprea at the forefront of synthetic lethality drug development. We remain committed to developing new treatments that have a positive impact on the lives of cancer patients while creating value for our shareholders.”

Key Business Updates and Potential Upcoming Key Milestones

ACESOT-1051: A Biomarkers Focused, Phase 1 Trial of Oral WEE1 inhibitor, APR-1051, initiated

APR-1051 is a potent and selective small molecule that has been designed to potentially solve liabilities and may achieve greater clinical activity than other WEE1 programs currently in development. Aprea is advancing APR-1051 as monotherapy in cancers with Cyclin E over expression, as well as other biomarkers that are predicted to be sensitive to WEE1 inhibition. Cancers overexpressing Cyclin E represent a high unmet medical need. Patients with Cyclin E overexpression have poor prognosis and, currently, have no effective therapies.
In June 2024, enrollment commenced in the ACESOT-1051 (A Multi-Center Evaluation of WEE1 Inhibitor in Patients with Advanced Solid Tumors, APR-1051) Phase 1 clinical trial evaluating single-agent APR-1051 in advanced solid tumors harboring cancer-associated gene alterations. The first patient was dosed at NEXT Oncology, San Antonio, Texas, without any dose-limiting toxicities (including myelosuppression) observed to date in the first cohort. A second patient has been enrolled at The University of Texas MD Anderson Cancer Center and has commenced treatment in the second dose cohort.
The primary objectives of the Phase 1 study are to measure safety, dose-limiting toxicities (DLTs), maximum tolerated dose or maximum administered dose (MTD/MAD), and recommended Phase 2 dose (RP2D); secondary objectives are to evaluate pharmacokinetics, preliminary efficacy according to RECIST or PCWG3 criteria; pharmacodynamics is an exploratory objective.


The Company will provide an update on the progress of this clinical study by year end. Open-label safety/efficacy data are expected in the first half of 2025.
In June 2024, Aprea hosted a virtual KOL event to discuss APR-1051. Joseph Vacca, Ph.D., Medicinal Chemistry Expert and Consultant to Aprea, discussed the medicinal chemistry history, strategy-guided selective drug design, and preclinical findings of APR-1051. Eric J. Brown, Ph.D., University of Pennsylvania and Consultant to Aprea, discussed preclinical findings across the WEE1 inhibitor class. A replay of the event (with slides) can be accessed on Aprea’s corporate website here.
APR-1051 was featured in two posters at the American Association of Cancer Research (AACR) annual meeting which took place in April 2024 in San Diego, which summarized the pre-clinical data supporting APR-1051 and the trial design for ACESOT-1051.

ABOYA-119: Ongoing Clinical Trial Evaluating ATR inhibitor, ATRN-119

ATRN-119 is a potent and highly selective first-in-class macrocyclic ATR inhibitor, designed to be used in patients with mutations in DDR-related genes. Cancers with mutations in DDR-related genes represent a high unmet medical need. Patients with DDR-related gene mutations have a poor prognosis and, currently, have no effective therapies.
ATRN-119 is currently being evaluated in the open-label Phase 1/2a clinical trial of ABOYA-119 (study AR-276-01) as monotherapy in patients with advanced solid tumors having at least one mutation in a defined panel of DDR-related genes. The first five dose cohorts (50mg to 550mg once daily) have been completed, and patients continue to enroll in additional cohorts in the dose escalation part of the trial.
The primary endpoint of this Phase 1 trial is the tolerability and pharmacokinetics of ATRN-119 when administered orally on a continuous, once-daily schedule. Aprea is planning to amend the study protocol to add a group of patients who will receive ATRN-119 twice a day and to investigate the effect of food on ATRN-119 absorption and drug exposure in blood. Under the current protocol, the Company anticipates the ABOYA-119 Phase 1 readout to be available in the first half of 2025.
An update on the ongoing trial was featured in a poster at the AACR Annual Meeting this past April. A copy of the AACR poster can be found here.
For more information, please refer to clinicaltrials.gov NCT04905914. 

Corporate

Appointed Nadeem Q. Mirza, M.D., M.P.H. as Chief Medical Officer (CMO), effective May 1, 2024. Dr. Mirza had been a consultant to Aprea since February 2023 and has now assumed a more central role in leading the Company's development of its expanding clinical pipeline.

Select Financial Results for the Second Quarter ended June 30, 2024

As of June 30, 2024, the Company reported cash and cash equivalents of $28.7 million, compared to $21.6 million at December 31, 2023. The Company believes its cash and cash equivalents as of June 30, 2024, will be sufficient to meet its currently projected operating expenses and capital expenditure requirements into the fourth quarter of 2025.


For the quarter ended June 30, 2024, the Company reported an operating loss of $3.8 million, compared to an operating loss of $3.7 million in the comparable period in 2023.
Grant revenue, primarily from the National Cancer Institute of the National Institutes of Health (“NIH”) for the three months ended June 30, 2024, and 2023 was approximately $0.6 million and $0.2 million, respectively.
Research and development expenses were approximately $2.6 million for the quarter ended June 30, 2024, compared to approximately $2.2 million for the comparable period in 2023. The increase was primarily due to an increase in expenses related to the initiation of ACESOT-1051, our Phase 1 dose-escalation study evaluating APR-1051, our small molecule WEE1 inhibitor, in the second quarter of 2024.
General and administrative expenses were approximately $1.9 million for the quarter ended June 30, 2024, compared to approximately $1.7 million for the comparable period in 2023. The increase was primarily related to an increase in personnel costs primarily related to severance expense.
The Company reported a net loss of $3.5 million ($0.58 per basic share) on approximately 5.9 million weighted-average common shares outstanding for the quarter ended June 30, 2024, compared to a net loss of $3.3 million ($0.87 per basic share) on approximately 3.7 million weighted average common shares outstanding for the comparable period in 2023.

About Aprea

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. APR-1051, an oral, small-molecule WEE1 inhibitor, recently entered the clinic. 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.

Investor Contact:

Mike Moyer

LifeSci Advisors

mmoyer@lifesciadvisors.com

Media Contact:

Ignacio Guerrero-Ros, Ph.D., or David Schull
Russo Partners, LLC
Ignacio.guerrero-ros@russopartnersllc.com
David.schull@russopartnersllc.com
(858) 717-2310



Aprea Therapeutics, Inc.

Consolidated Balance Sheets

June 30, 

December 31, 

    

2024

    

2023

Assets

 

  

 

  

Current assets:

 

  

 

  

Cash and cash equivalents

$

28,694,694

$

21,606,820

Prepaid expenses and other current assets

 

865,092

 

914,275

Total current assets

 

29,559,786

 

22,521,095

Property and equipment, net

 

92,379

 

88,362

Restricted cash

 

41,260

 

40,717

Other noncurrent assets

 

271,162

 

Total assets

$

29,964,587

$

22,650,174

Liabilities and Stockholders’ Equity

 

  

 

  

Current liabilities:

 

  

 

  

Accounts payable

$

964,327

$

1,670,369

Accrued expenses

 

2,079,163

 

2,186,262

Deferred revenue

 

50,739

 

528,974

Total current liabilities

 

3,094,229

 

4,385,605

Total liabilities

 

3,094,229

 

4,385,605

Commitments and contingencies

 

  

 

  

Series A convertible preferred stock, $0.001 par value, 40,000,000 shares authorized; 56,227 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively.

 

1,311,063

 

1,311,063

Stockholders’ equity:

 

  

 

  

Common stock, $0.001 par value, 400,000,000 shares authorized, 5,430,215 and 3,736,673 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively.

 

5,430

 

3,736

Additional paid-in capital

 

350,566,533

 

335,644,204

Accumulated other comprehensive loss

 

(10,649,364)

 

(10,611,273)

Accumulated deficit

 

(314,363,304)

 

(308,083,161)

Total stockholders’ equity

 

25,559,295

 

16,953,506

Total liabilities and stockholders' equity

$

29,964,587

$

22,650,174


Aprea Therapeutics, Inc.

Consolidated Statements of Operations and Comprehensive Loss

Three Months Ended June 30, 

Six Months Ended June 30, 

    

2024

    

2023

    

2024

    

2023

(Unaudited)

Grant revenue

 

$

561,574

$

249,688

$

942,143

$

249,688

Operating expenses:

Research and development

2,557,679

2,202,657

4,158,052

3,459,199

General and administrative

 

1,850,819

1,698,712

3,780,685

5,064,673

Total operating expenses

 

4,408,498

 

3,901,369

 

7,938,737

 

8,523,872

Loss from operations

 

(3,846,924)

 

(3,651,681)

 

(6,996,594)

 

(8,274,184)

Other income (expense):

 

 

 

 

Interest income, net

 

382,374

336,221

665,777

592,631

Foreign currency gain (loss)

 

(5,502)

 

56,363

 

50,674

 

42,566

Total other income

 

376,872

 

392,584

 

716,451

 

635,197

Net loss

$

(3,470,052)

$

(3,259,097)

$

(6,280,143)

$

(7,638,987)

Other comprehensive (loss) gain:

 

 

 

 

Foreign currency translation

 

(23,008)

 

(73,420)

 

(38,091)

 

(11,464)

Total comprehensive loss

 

(3,493,060)

 

(3,332,517)

 

(6,318,234)

 

(7,650,451)

Net loss per share attributable to common stockholders, basic and diluted

$

(0.58)

$

(0.87)

$

(1.24)

$

(2.18)

Weighted-average common shares outstanding, basic and diluted

 

5,937,291

 

3,731,571

 

5,067,809

 

3,497,329


Exhibit 99.2

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Precision Oncology Through Synthetic Lethality August 2024

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2 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Forward-Looking Statements Certain information contained in this presentation 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 clinical trials, regulatory submissions and strategic plans. We may, in some cases use terms such as “predicts,” “believes,” “potential,” “continue,” “anticipates,” “estimates,” “expects,” “plans,” “intends,” “may,” “could,” “might,” “likely,” “will,” “should” or other words that convey uncertainty of the future events or outcomes to identify these forward-looking statements. The forward-looking statements are based on current beliefs and expectations of our management team that involve risks, potential changes in circumstances, assumptions, and uncertainties. Any or all of the forward-looking statements may turn out to be wrong or be affected by inaccurate assumptions our management team 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 and timing of our clinical trials or other studies and the other risks set forth in our filings with the U.S. Securities and Exchange Commission, including our Annual Reports on Form 10-K and Quarterly Reports on Form 10-Q. Forward-looking statements regarding our product candidates are also subject to additional risks and uncertainties, including without limitation, with respect to: our dependence on additional financing to fund our operations and complete the development and commercialization of our product candidates, and the risks that raising such additional capital may restrict our operations or require us to relinquish rights to our technologies or product candidates; our limited history and preclinical status of the assets we acquired from Atrin Pharmaceuticals Inc.; our business plan or the likelihood of the successful implementation of such business plan; the timing of initiation of planned clinical trials for our product candidates; the future success of such trials; the successful implementation of our research and development programs and collaborations and the interpretation of the results and findings of such programs and collaborations and whether such results are sufficient to support the future success of our product candidates; the success, timing and cost of our anticipated clinical trials for our current product candidates; the timing of initiation, futility analyses, data presentation, reporting and publication and receipt of interim results (including, without limitation, any preclinical results or data); any statements about our understanding of product candidates mechanisms of action and interpretation of preclinical and early clinical results from its clinical development programs and any collaboration studies; and other factors, including legislative, regulatory, political and economic developments not within our control. 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 presentation. We undertake no obligation to update such forward-looking statements to reflect subsequent events or circumstances, except to the extent required by law or regulation.

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3 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Aprea Therapeutics (NASDAQ: APRE) All programs address significant unmet medical need, are synergistic with other anticancer therapies, and potentially differentiated in safety and tolerability ATR - Ataxia telangiectasia and Rad3‐related DDR – DNA Damage Response Precision Oncology via Novel Synthetic Lethality Therapeutics • First macrocyclic ATR inhibitor • Highly selective with continuous daily dosing • Phase 1/2a – Ongoing Dose Escalation • Readout H1 2025 • Solid tumor with DDR mutation • Pre-clinical proof-of-principle • Anti-tumor activity at nanomolar concentration • Preserved hematologic safety profile • Best in class, next generation • Pre-clinical proof-of-principle • Highly potent and selective anti-tumor activity • Minimal off target effect • Ovarian cancer with Cyclin E over expression (OVCAR-3) • Stable hematologic function • Favorable pharmacokinetics • Second cohort initiated August 2024 • No myelosuppression observed • Study update by year-end 2024 • Lead optimization • Target identified from our RepliBiom discovery platform • Identify lead candidate by year-end 2024 ATR Inhibitor: ATRN-119 WEE1 Inhibitor: APR-1051 DDR Inhibitor: Undisclosed

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4 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Robust DDR Development Pipeline Milestones 2024-2025 Anticipated Clinical Milestones 2024 2025 H1 H2 H1 H2 ATR ATRN-119 Complete Dose Escalation RP2D Enroll First Patient Additional Open-Label Efficacy Data WEE1 APR-1051 ACESOT-1051 : Phase 1 – Monotherapy Dose Escalation Enrolled First Patient Complete Dose Escalation Open label data IND Cleared Study Update ABOYA-119: Phase 1/2a – Monotherapy Dose Expansion ABOYA-119: Phase 1/2a – Monotherapy Dose Escalation Study Update

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5 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Synthetic Lethality • Cancer cell death only upon the loss of function of two codependent pathways • DNA Damage Response (DDR) allows cells to pause and self repair during replication (mitosis) • Inhibition of DDR leads to mitotic catastrophe and cell death • ATR and WEE1 inhibitors are integral to stopping DDR and are emerging targets for cancer cell death • Builds on scientific innovation led by Aprea founder and key personnel1 1 Gilad et al, (2010) Cancer Res. Healthy cell Pathway A Pathway B Active cancer cell Pathway A Pathway B Dead cancer cell Pathway A Pathway B Active cancer cell Pathway A Pathway B

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6 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Leadership with Strong Drug Development and Commercial Expertise Pioneers in Synthetic Lethality Management Board of Directors Richard Peters, M.D., Ph.D. Chairman of the Board Oren Gilad, Ph.D. President and CEO Jean-Pierre Bizzari, M.D. Director Marc Duey Director Michael Grissinger Director Gabriela Gruia, M.D. Director John Henneman Director Rifat Pamukcu, M.D. Director Bernd R. Seizinger, M.D., Ph.D. Director Oren Gilad, Ph.D. President and CEO John P. Hamill Sr. Vice President and CFO Nadeem Q. Mirza, M.D., MPH Chief Medical Officer Ze’ev Weiss, CPA, B.Sc. Chief Business Advisor Mike Carleton, Ph.D. Translational Medicine Advisor Brian Wiley SVP, Corporate Strategy

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7 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATR Inhibitor: ATRN-119 Potentially Differentiated Clinical Stage ATRi

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8 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119: First and Only Macrocyclic ATR Inhibitor1 Macrocycles: A Well-Evolved Approach for PIK-Related Kinase Inhibition (e.g., rapamycin and mTOR)2-4 1 Based on company knowledge 2 Brown, EJ et al, (1994) Nature 3 Brown, EJ et al, (1995) Nature 4 Brown, EJ and SL Schreiber, (1996) Cell Benefits of Unique Cyclic Skeleton Structure vs Competitors’ First-Generation Acyclic Structure • Increased selectivity • Improved tolerability Improved tolerability More efficacious dosing Macrocycles restrict number of conformations formed for increased selectivity Potential advantages for ATRN-119:

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9 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Reported Challenges with Other ATR Inhibitors First Generation Compounds Share Similar Core, Backbone, Toxicity, and Intermittent Dosing Schedule Note: Head-to-head studies with ATRN-119 have not been conducted 1 Phase I study of ATR inhibitor, AZD6738, as monotherapy in advanced solid tumors (PATRIOT part A, B), Dillon et al, Volume 30, October 2019, Pages v165-v166 2 Poster CT084: A Phase I dose-escalation study of ATR inhibitor monotherapy with AZD6738 in advanced solid tumors (PATRIOT Part A), AACR 2017 3 First-in-Human Trial of the Oral Ataxia Telangiectasia and RAD3-Related (ATR) Inhibitor BAY 1895344 in Patients with Advanced Solid Tumors, Yap et al, Cancer Discov 2021;11:80-91 and 2019 ASCO Poster, De-Bono et al. 4 Preliminary Phase 1 Data From Ongoing First-in-Human Phase 1/2 TRESR Study of RP-3500, AACR 2022 Route of administration Oral Oral Oral MTD/RP2 dose schedule 160mg BID, 2-weeks-on, 2-weeks-off, or: Continuous dosing1 40mg BID, 3-days-on/4-days-off 160mg QD, 3-days-on/4-days-off Main Grade ≥3 hematological toxicities Patriot 1, Escalation Phase, 160mg, BID2 : Anemia (1/6, 17%) Patriot 2, Expansion Phase1 : Fatigue, anemia, nausea, and thrombocytopenia (not differentiated) (4/6, 67%) with continuous dosing (3/15, 20%) with 2-week-on, 2-week-off Anemia (2/2, 100%) Neutropenia (1/2, 50%) Anemia (23/95, 24%) Neutrophil count decreased (10/95, 11%) Platelet count decreased (5/95, 5%) AstraZeneca AZD67381,2 Bayer BAY18953443 Repare RP-35004 N N NH N N N N O N N N O S O HN CH3 N NH N N O N N HO O N NH

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10 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119: Potential Best-in-Class Oral ATR Inhibitor Structurally Differentiated Core, Backbone, and Toxicity Profile 1 ATRN-119, Phase 1/2a Clinical Study Protocol 2 Internal pre-clinical head-to-head tolerability study in male beagle dogs. Route of administration Oral Dosing regimen Continuous daily dosing (RP2D TBD in Phase 1)1 Hematological toxicities in preclinical studies • Small magnitude and within normal range hematological changes in 28-day GLP tox dog study • Significantly less toxicity in head-to-head comparative tolerability study vs other clinical stage ATRI2 ATRN-1191 ATRN-119 potentially the preferred ATRi both as a single agent and in combination with standard-of-care therapies

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11 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119 Daily Dosing Supports Potential Continuous Tumor Suppression Intermittent Dosing May Lead to Tumor Resistance Tumor reduction and regrowth Continuous tumor reduction Drug “On” Drug “Off” Drug “On”

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12 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATR Inhibitor: ATRN-119 ABOYA-119: Clinical Proof-of-Concept

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13 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ABOYA-119: Phase 1/2a - Study Overview A Phase 1/2a, Open-Label, Safety, Pharmacokinetic, and Preliminary Efficacy Study of Oral ATRN-119 in Patients with Advanced Solid Tumors Part 1 Up to 30 patients1 Dose escalation (8 dose levels1 ) 3+3 design Objectives: Primary • Safety, MTD, RP2D • Pharmacokinetics Secondary • Antitumor activity (RECIST/PCWG3) Exploratory • Association between identified mutations and clinical outcomes Patient population: Male or female subjects 12 years of age or older with solid tumors harboring specific DDR mutations per NGS Part 2 Up to 30 patients Dose expansion, after MTD / RP2D established Sites: 4 US sites for dose escalation • University of Pennsylvania • Mary Crowley Cancer Research • University Hospitals Cleveland Medical Center • Yale Cancer Center Patient enrollment: Up to 60 patients in total • Escalation phase: up to 30 patients • Expansion phase: up to 30 patients ATRN-119 is an oral ATR kinase inhibitor given daily 1. Planning to amend the study protocol to add a group of patients who will receive ATRN-119 twice a day and to investigate the effect of food on ATRN-119 absorption and drug exposure in the blood.

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14 © 2024 Aprea Therapeutics, Inc. All Rights Reserved 3+3 dose escalation with once-daily dosing (up to 301 patients) Dose expansion (up to 30 patients) Potential indications Colorectal Prostate Gastric Endometrial Mutations Undisclosed RepliBiom biomarkers ABOYA-119: Clinical Study Design MTD/RP2D = cleared Dose level 1 50 mg Dose level 2 100 mg Dose level 3 200 mg Dose level 4 350 mg Dose level 5 550 mg Dose level 6 800 mg Currently Enrolling Dose level 7 1,100 mg Dose level 8 1,300 mg 1. Planning to amend the study protocol to add a group of patients who will receive ATRN-119 twice a day and to investigate the effect of food on ATRN-119 absorption and drug exposure in the blood.

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15 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119 Steady State Plasma Concentrations (Cycle 1 Day 7) ATRN-119 Exhibits Near-dose Proportional Exposure Following Oral Administration Dose Level mg, once daily N AUC 0-24hr (ng*h/mL) Cmax (ng/mL) Half-life (hours) Mean (SD) Mean (SD) Mean (SD) 50 3 180 (143) 94 (119) 1.4 (1.1) 100 3 1771 (920) 305 (171) 4.6 (0.5) 200 3 1024 (162) 179 (23) 4.3 (0.3) 350 3 5252 (4362) 605 (358) 6 (0.7) 550 3 6899 (6058) 797 (522) 4.5 (0.7) 800 1100 1300 • Tmax is approximately 2 hours and the half-life is estimated between 4-6 hours • The duration of systemic exposure substantially increases with each dose level Presented at AACR 2024

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16 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Site Key 001 - University of Pennsylvania 002 - Mary Crowley Cancer Research 003 - University Hospitals Cleveland Medical Center 004 - Yale Cancer Center 30 55 112 55 25 45 57 55 196 57 52 28 0 50 100 150 200 250 001-001 002-002 003-003 003-004 002-005 002-006 003-007 002-008 003-009 003-010 003-011 004-012 003-013 004-014 003-015 003-016 004-017 001-018 800 mg 550 mg 350 mg 200 mg 100 mg 50 mg 53 * * * Dose increased to 350 mg * ABOYA-119: Summary of Duration of Treatment# Update – June 10, 2024 Study patient Days on treatment * * * * * * * * * Stable disease Treatment continues * Progressive Disease ATRN-119 once-daily dose * * Consent withdrawal 57 6 7 14 # Not all data source verified Unrelated death 71

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17 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ABOYA-119: Summary of Related Adverse Events Update - June 10, 2024 * Resulted in treatment interruption Not all data source verified Gastrointestinal General Metabolism Vascular Related AEs Nausea Grade 1 (002-006, 004-012, 004-017) Grade 2 (003-015) Hypotension Grade 2 (001-001*) Diarrhea Grade 1 (001-001*, 003-003, 004-014, 004-017) Grade 2 (003-015) Decreased Appetite Grade 1 (001-001) Vomiting Grade 1 (001-001*) Grade 2 (003-015) Dehydration Grade 2 (001-001*) Hypokalemia Grade 1 (003-015) Non-cardiac chest pain Grade 1 (001-001) Fatigue Grade 1 (002-008, 003-013) Grade 2 (002-005, 003-009) Grade 3 (003-011) Influenza like illness Grade 2 (003-015) No ATRN-119 Related SAE or Grade 4 Adverse Events Reported

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18 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119: Summary First and only macrocyclic ATR inhibitor • Potentially differentiated from other ATR inhibitors in selectivity and toxicity profile, permitting continuous dosing • Strong tumor control observed in vivo, including in challenging genetic backgrounds • Daily oral dosing provides potential continuous tumor suppression ABOYA-119: Ongoing Phase 1/2a Clinical Study (NCT04905914) • Patients with advanced solid tumors harboring specific DDR mutations • Well tolerated with no DLTs to date (550mg/daily) • Near-dose proportional exposure following oral administration • Preliminary signs of clinical benefit already observed at low doses • Potential efficacy data readout in H1 2025

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19 © 2024 Aprea Therapeutics, Inc. All Rights Reserved WEE1 Inhibitor: APR-1051 Potentially Differentiated Clinical Stage WEE1i

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20 © 2024 Aprea Therapeutics, Inc. All Rights Reserved WEE1 – Clinically Validated Target: An Unmet Medical Need Phase 2 Study Indication Evaluable Patients N ORR PFS NCT03668340 2 Recurrent uterine serous carcinoma 34 29.4% 1 CR 9 PR mPFS - 6.1 PFS6 – 16 Pt (47.1%) IGNITE 3 Recurrent high-grade, serous ovarian cancer with CCNE1 overexpression with (Cohort 1) and without (Cohort 2) gene amplification 79 Cohort 1 - 21 Cohort 2 - 58 Cohort 1: 38% 7 PR 1 CA125 Cohort 2: 45% 3 CR 18 PR 5 CA125 No PD for ≥ 18 weeks: Cohort 1: 53% Cohort 2: 48% NCT03253679 4 Refractory solid tumors harboring CCNE1 amplification 30 Ovarian - 14, Breast - 3, Uterine - 3, Other - 10 All Pt: 27% (8 PR) Ovarian Pt: 36% (5 PR) mPFS: All Pt: 4.1 Ovarian Pt: 6.3 Multiple Phase 2 Studies Show Substantial Single-Agent Activity Of A WEE1 Inhibitor (Adavosertib1 ) Examples for Phase 2 Studies with Adavosertib as monotherapy 1 AZD-1775. AstraZeneca announced in July 2022 the discontinuation of development of AZD-1775 due to its tolerability profile 2 Phase II Study of the WEE1 Inhibitor Adavosertib in Recurrent Uterine Serous Carcinoma, Liu et al, J Clin Oncol 2021;39:1531–9. 3 IGNITE: A phase II signal-seeking trial of Adavosertib targeting recurrent high-grade, serous ovarian cancer with cyclin E1 overexpression with and without gene amplification. Au-Yeung et al, Int J Gynecol Cancer 2023;33(Suppl 4):A1–A278 4 Multicenter Phase II Trial of the WEE1 Inhibitor Adavosertib in Refractory Solid Tumors Harboring CCNE1 Amplification, Fu et al, J Clin Oncol. 2023 Mar 20; 41(9): 1725–1734. WEE1 Inhibitors have been associated with significant Grade ≥3 hematological, GI and CV toxicities The Need – a highly efficient WEE1 inhibitor with a good safety and tolerability profile

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21 © 2024 Aprea Therapeutics, Inc. All Rights Reserved WEE1 Inhibitor – APR-1051 Mechanism of Action – Prevent CDK1 Phosphorylation by WEE1 Kinase pCDK1- Phosphorylated Cyclin Dependent Kinase 1 Data on file -10 -9 -8 -7 -6 0 20 40 60 80 100 120 ATRN-1051 Log10 [ATRN1051] (M) Activity (% Displacement) -5 -4 -3 -2 -1 0 1 2 3 4 5 0 1 2 3 4 5 6 Cumulative Cell Doublings Days Post Initial Treatment NT 125nm 250nm 500nm APR-1051 binds to WEE1 …inhibits its biological activity… …and triggers mitotic catastrophe and cancer cell death Mitotic catastrophe Cancer cell death WEE1 inactive APR-1051 Active pCDK1 Active CDK1 Mitotic cycle pause DNA repair WEE1 Cancer cell survival active Phos-CDK1 Control (Tubulin) µM APR-1051

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22 © 2024 Aprea Therapeutics, Inc. All Rights Reserved AstraZeneca Adavosertib (AZD-1775)1,2 Zentalis Azenosetrib (ZN-c3)3 Aprea APR-1051 On-Target IC50 (nM) WEE1 3.9 3.2 1.8 APR-1051 Potentially Best in Class WEE1 Inhibitor APR-1051 Potent and Structurally Differentiated, with High Selectivity to Limit Off-target Toxicity 1Huang et al, (2021) J Med Chem 2AstraZeneca announced in July 2022 the discontinuation of development of AZD-1775 22 3 Data on File AACR-NCI-EORTC Meeting, Poster C147, 2023 Undisclosed -10 -9 -8 -7 -6 -5 -4 0 25 50 75 100 125 PLK1 IC50 Determination Log10 [conc] (M) % Activity ZN-c3 APR-1051 -10 -9 -8 -7 -6 -5 -4 0 25 50 75 100 125 PLK2 IC50 Determination Log10 [conc] (M) % Activity ZN-c3 APR-1051 -10 -9 -8 -7 -6 -5 -4 0 25 50 75 100 125 PLK3 IC50 Determination Log10 [conc] (M) % Activity ZN-c3 APR-1051 ZN-c3 = 92.1 nM APR-1051 = 15,900 nM PLK1 Inhibition IC50 values show >150-fold ZN-c3 = 32.0 nM APR-1051 = 1,800 nM PLK2 Inhibition IC50 values show >50-fold ZN-c3 = 52.2 nM APR-1051 = 31,600 nM PLK3 Inhibition IC50 values show >600-fold

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23 © 2024 Aprea Therapeutics, Inc. All Rights Reserved PLK1 Inhibition Reduces Cytotoxic Effects of WEE1 Inhibitors Minimal PLK1 Co-inhibition Enables Full Therapeutic Potential APR-1051 0 nM NT 675 nM 25 nM 225 nM 75 nM Phos– H2AX Control (MCM3) Phos-CDK1 300 nM APR-1051 + increasing GSK-461364 37 nM 111 nM 333 nM APR-1051 1 µM 37 nM 111 nM 333 nM 1 µM Phos-H2AX Control (MCM3) NT 75 nM GSK-461364 Phos-CDK1 Control (MCM3) 37 nM 111 nM 333 nM 1 µM 37 nM 111 nM 333 nM NT 1 µM 400 nM BI-2536 APR-1051 Phos-H2AX Phos-CDK1 Dose range of PLK inhibitor GSK-461364 in combination with a single dose of APR-1051 in OVCAR-3 cells PLK inhibitor, GSK-461364 interferes with the effects of APR-1051 in OVCAR-3 cells PLK inhibitor, BI-2536, interferes with the effects of APR-1051 in OVCAR-3 cells AACR-NCI-EORTC Meeting, Poster C147, 2023

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24 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051 Preclinical Data Highlight Potentially Favorable PK Properties Note: Head-to-head studies have not been conducted 1 Data from an exploratory formulation of APR-1051 administered to fasted Balb/c mice 2 Data from study in A-427 NSCLC xenograft model as reported in Zentalis Corporate Overview, March 2022 Based on Pre-clinical Studies, APR-1051 Shows Potentially Favorable Drug Exposure APR-10511 Zentalis Azenosertib (ZN-c3)2 AstraZeneca Adavosertib (AZD-1775)2 Dose (mg/kg/d) 10 20 40 80 20 40 80 Cmax ng/ml 1,460 1,167 1,997 5,100 635 2,460 4,703 Tmax hr 3 1 1 1 1 1 1 AUC0-24, ng*hr/ml 16,739 4,863 17,088 39,722 1,494 6,313 13,408 AACR-NCI-EORTC Meeting, Poster C147, 2023

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25 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051 Shows Negligible Inhibition of hERG Channels In vitro kinase assays IC50 Average WEE1 kinase IC50 hERG inhibition IC50 Average hERG IC50 Fold difference between kinase IC50 and hERG IC50 LanthaScreen (Thermo) Hotspot (Reaction Biology) HEK293 cells (Medicilon) CHO cells (WuXi) hERG inhibition over WEE1 kinase inhibition 2.2 nM 41.4 nM 21.8 nM 8,840 nM 660 nM 4,750 nM 218-fold (range 16- to 3,946-fold) QT prolongation AEs were reported with some competitor WEE1 inhibitors No ECG changes related to APR-1051 were observed in IND enabling studies Potential absence of QT prolongation at doses that significantly inhibit WEE1 AACR-NCI-EORTC Meeting, Poster C147, 2023

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26 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Pre-clinical studies with APR-1051 Data on file N=7 mice per group, APR-1051, 30 mg/kg/day APR-1051 Demonstrated Potentially Compelling Anti-tumor Activity Preclinical Tumor Growth Inhibition OVCAR-3

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27 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051 Suppresses Tumor Growth with Little Effect on RBCs and Body Weight Tumor Volume (mm3 ) (Mean±SEM) Body Weight (g) (Mean±SEM) APR-1051 15mg/kg, PO, BID, 5 on/2 off x 28 days Vehicle 10mL/kg, PO, QD x 28 days OVCAR Xenograft Tumor Model in Female Nude Mice Heme Toxicity (Mean±SEM) 28 Days Post Treatment 0 5 10 15 20 25 30 0 200 400 600 800 1000 1200 1400 Days Post Treatment Tumor Volume (mm 3 ) 0 5 10 15 20 25 30 0 5 10 15 20 25 Days Post Treatment Body Weight (g) 0 5 10 15 RBC (1012/L) 0 200 400 600 800 Reticulocyte Count (10 9/L) AACR-NCI-EORTC Meeting, Poster C147, 2023

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28 © 2024 Aprea Therapeutics, Inc. All Rights Reserved WEE1 Inhibitor: APR-1051 ACESOT-1051: Clinical Proof-of-Concept

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29 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Patients aged 18 years or older with advanced solid tumor harboring cancer-associated gene alterations CCNE1 or CCNE2 FBXW7 or PPP2R1A, KRAS-GLY12 & TP531 USC2 regardless biomarker status Part 2 Dose selection optimization further evaluation of the selected 2 dose levels Up to 40 patients Part 1 Dose escalation accelerated titration followed by a BOIN design Up to 39 patients` ACESOT-1051: Clinical Study Overview Multi-center, Open-Label Phase1 Single-Agent Dose Escalation and Dose Selection Optimization First patient dosed in June 2024. Study update expected by year-end 2024. Enrollment up to 79 patients Oral APR-1051 will be administered once-daily for 28-day cycles Primary objectives: Safety, DLT, MTD/MAD, RP2D Secondary objectives: Pharmacokinetics, Antitumor activity (RECIST/PCWG3) Exploratory objectives: Pharmacodynamics Select two RP2D doses 1 Colorectal cancer patients 2 Uterine serous carcinoma patients

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30 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Up to 39 patients with advanced solid tumors harboring cancer-associated gene alterations: ACESOT-1051: Clinical Study Design Part 1 - Single-agent APR-1051 Dose Escalation Study Schema BOIN design 3-12 patients per dose level Accelerated titration 1-6 patients per dose level Dose level 1 Dose level 2 Dose level 3 Dose level 4 Dose level 5 Dose level 6 Dose level 7 Dose level 8 Select two doses Enrollment Ongoing = cleared

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31 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051: Summary Potential best in class WEE1 inhibitor • High potency for WEE1 inhibition in vitro​ • Low off-target inhibition of the PLK family of kinases​ • Suppresses growth of CCNE1-amplified HGSOC xenografted tumors and relatively well-tolerated in mice​ ACESOT-1051: First-In-Human Study (NCT06260514) • First patient dosed June 2024, second cohort now enrolling • No myelosuppression observed to date in the first of 8 planned cohorts at sub-therapeutic doses • Biomarker-driven study in patients with advanced/metastatic solid tumors • Targeted gene alterations include CCNE1, CCNE2, FBXW7, PPP2R1A, or KRAS-G12 with TP53 • Study update expected year-end 2024 • MD Anderson Cancer Center lead study site, with up to 10 sites in U.S

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32 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Aprea Therapeutics (NASDAQ: APRE) Intellectual Property Portfolio Financial Summary & Capitalization Investment Highlights

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33 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Strong Intellectual Property Portfolio Family 1: Ataxia Telengiectasia and Rad3-Related (ATR) Protein Kinase Inhibitors • Macrocyclic inhibitors of ATR & methods of using them to treat various cancers, filed on Oct. 13th, 2015 • Patents granted in AU, CA, CN, EP, IL, JP, MX, HK. National phase examinations ongoing in BR, IN, KR • 1.1: Issued on May 30, 2017 as U.S. Patent 9,663,535 • 1.2: Issued on May 29, 2018 as U.S. Patent 9,981,989 • 1.3: Issued on Feb. 5, 2019 as U.S. Patent 10,196,405 Family 2: ATR Inhibitors and Methods of Use • Carboxylic acid-containing macrocyclic ATR inhibitors, and prodrugs; methods of using these inhibitors to treat various cancers; filed on Apr. 12th, 2017 • Issued on May 28th, 2019 as U.S. Patent 10,301,324 Family 3: ATR Inhibitor Pharmaceutical Composition and Methods • International application filed on Apr. 14th, 2023 • Pharmaceutical formulation and composition of our lead molecule in the clinic Family 4: WEE1 Inhibitor Pharmaceutical Compositions and Methods • International Application filed on Jun. 3rd, 2022 • Composition of our lead WEE1 inhibitor compounds Family 5: Methods of Treating Cancer • U.S. Provisional Application filed on Oct. 20th, 2023 • Clinical methods of treating advanced solid cancer tumors using lead molecule Four issued US patents protecting lead molecule and analogs

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34 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Aprea Therapeutics (NASDAQ: APRE) Financial Summary & Capitalization Cash & Equivalents of $28.7M as of June 30, 2024 Closed approximately $16.0M (before deducing placement agent fees and offering costs of approximately $1.3 million) from our private placement of our common stock in March 2024 with the potential to receive up to an additional $18.0 million upon cash exercise of accompanying warrants at the election of the investors. Securities Common Equivalents as of August 12, 2024 Preferred Stock (as converted) 28,112 Common Stock 5,431,903 Warrants: Pre-Funded Tranche A Tranche B Total 507,076 1,097,394 1,097,394 2,701,864 Options 734,131 Restricted Stock Units 39,442 Fully Diluted Equivalents 8,935,452

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35 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Financed into Q4 2025 • Achieve short term inflection points and catalysts • Evaluate optimal strategic partnerships Near term catalysts • H2 2024 study update ATRN-119; Complete dose escalation H1 2025 • Year-end 2024 study update APR-1051 Phase 1; Open label data H1 2025 Diversified portfolio with best in class, de-risked clinical and preclinical programs • Highly potent and selective ATR (ATRN-119) and WEE1 (APR-1051) inhibitors • Opportunities in ovarian, colorectal, prostate, and breast cancers • Single agent and combination therapies Technology developed by pioneers in synthetic lethality • Management with strong drug development and commercial expertise Investment Highlights