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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

March 26, 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 March 26, 2024, Aprea Therapeutics, Inc. (the “Company”) issued a press release announcing its financial results for the three and twelve months ended December 31, 2023, 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 March 26, 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 March 26, 2024.

99.2

Corporate Presentation (March 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: March 26, 2024

By:

/s/ Oren Gilad

Name:

Oren Gilad, Ph.D.

Title:

President and Chief Executive Officer

Exhibit 99.1

Aprea Therapeutics Reports Fourth Quarter and Full Year 2023 Financial Results and Provides a Business Update

First-in-class macrocyclic ATR inhibitor, ATRN-119, on track to complete dose escalation and potentially generate human efficacy data in H2 2024

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 H1 2024. 

$21.6 million in cash and cash equivalents as of December 31, 2023

Private placement financing in March 2024 raised upfront gross proceeds of approximately $16 million

DOYLESTOWN, PA, Mar. 26, 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 fourth quarter and full year ended December 31, 2023, and provided a business update.

“Aprea had a very productive 2023 with significant progress across our diversified pipeline of synthetic lethality-based cancer therapeutics. We are pleased to continue this positive momentum in 2024 and focus on the execution on our programs towards successfully delivering potentially safer and more effective therapies for cancer patients,” said Oren Gilad, Ph.D., President and Chief Executive Officer of Aprea. “We continue to enroll and treat patients in the ongoing Phase 1/2a study of our novel macrocyclic ATR inhibitor, ATRN-119. ATRN-119 appears to be well tolerated with a manageable toxicity profile. Dose escalation will proceed throughout 2024 with potential for human efficacy data in the second half of the year. We are preparing to enter the clinic with our next generation inhibitor of WEE1 kinase, APR-1051, having received clearance from the FDA on our IND. Based on the unique characteristics of APR-1051 we believe it will be best in class.”

Dr. Gilad continued “the closing of our recent private placement financing provides us with the capital to fund both of these lead programs through meaningful clinical milestones. I would like to thank our dedicated team, our academic collaborators, as well as existing and new investors who have supported our recent advancements. Our mission is to be a global leader in synthetic lethality and we see a great opportunity to help cancer patients in need and create value for our shareholders.”

Key Business Updates and Potential Upcoming Key Milestones

ATR inhibitor, ATRN-119, on track to complete monotherapy dose escalation end of the year; initial efficacy data expected in second half of 2024

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 mutation in DDR-related genes represent a high unmet medical need. Patients with DDR-related gene mutations have poor prognosis and, currently, have no effective therapies.
In January 2023, enrollment commenced in an open-label Phase 1/2a clinical trial of ATRN-119 (study AR-276-010) as monotherapy in patients with advanced solid tumors having at least one mutation in a defined panel of DDR-related genes. In the ongoing monotherapy dose escalation phase (Part 1) of the trial, the primary endpoint is evaluating the tolerability and pharmacokinetics of continuous daily oral dosing of ATRN-119 using a 3+3 trial design in up to approximately 30 patients. A secondary endpoint is evaluating potential initial efficacy.
An update from Part 1 of the trial was featured in a poster presentation at the AACR-NCI-EORTC International Conference in October 2023. 
As of January 2, 2024, 12 patients were enrolled to the first four cohorts of the Phase 1 escalation stage (50mg/day, 100mg/daily, 200mg/daily and 350mg/daily). ATRN-119 was found to be safe and well tolerated in all four cohorts, with no related adverse effects > grade 2. The most recent efficacy analysis conducted at that date shows that two patients achieved stable disease – one each in the 50 mg and 200 mg cohorts. Both these patients’ tumors have mutations that have been predicted to confer sensitivity to ATR inhibition.
As of March 26, 2024 four clinical sites have been activated in the US. At completion of Part 1 of the study, the company anticipates identification of a recommended Phase 2 dose (RP2D) that will be used in a Phase 2a cohort expansion (Part 2) to test the tolerability and potential efficacy of ATRN-119 monotherapy in approximately 30 additional patients. The Phase 1 dose


escalation is expected to be completed in 4Q 2024, and RP2D is to be determined in 1Q 2025. Enrollment in the Phase 2a cohort is expected to begin in 1Q 2025 with additional efficacy data expected in 3Q 2025.
A more comprehensive dataset from Part 1 of the study has been accepted for presentation at the American Association of Cancer Research (AACR) annual meeting in April 2024.
For more information, please refer to clinicaltrials.gov NCT04905914

Oral WEE1 inhibitor, APR-1051, expected to enter Phase 1 clinical trial in the first half of 2024

APR-1051 is a potent and selective small molecule that has the potential to avoid off target toxicity and achieve greater clinical activity than other WEE1 programs currently in development. Aprea is advancing APR-1051 as monotherapy in ovarian cancer with Cyclin E over expression. Cancers over expressing Cyclin E represent a high unmet medical need. Patients with Cyclin E over expression have poor prognosis and, currently, have no effective therapies.
In March 2024, the U.S. FDA cleared the Investigational New Drug (IND) application (IND 169359) for APR-1051. Clearance of this IND will allow Aprea to initiate the Phase 1 ACESOT-1051 (A Multi-Center Evaluation of WEE1 Inhibitor in Patients with Advanced Solid Tumors, APR-1051) trial. This dose escalation trial will evaluate the safety, tolerability, and preliminary efficacy of APR-1051. Enrollment of the first patient is expected in H1 2024 with an update expected in the Q4 2024.
Preclinical data on APR-1051 were presented in a poster at the AACR-NCI-EORTC International Conference in October 2023. The data highlighted the selectivity of APR-1051 with low off-target activity against PLK1, PLK2 and PLK3, a family of kinases that promote M phase entry, a critical phase in the cell cycle. APR-1051 showed potentially favorable PK properties and appears to cause lower inhibition of hERG, a potential indication of low cardiotoxicity. At doses and scheduling that suppress tumor growth, APR-1051 causes little anemia. The selectivity of APR-1051 may solve a long-standing problem with other WEE1 inhibitors. Recent studies indicate that PLK1 off-targeting partially counters the intracellular effects of WEE1 inhibition and could potentially contribute to the myelosuppression observed with other WEE1 inhibitors.

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

Aprea’s research and development team has identified a new target in synthetic lethality. Our discovery team is developing a series of molecules that are selective and potent against it.
A lead molecule is expected to be declared in 2Q 2024.
This program may provide clinically meaningful differences for cancer patients that currently have limited therapies.

KOL Event

Hosted a Key Opinion Leader (KOL) event on October 31, 2023, highlighting the Company’s portfolio of small molecules focused on Synthetic Lethality (SL) by targeting the DNA Damage Response (DDR) Pathways. The event featured Key Opinion Leaders Dr. Fiona Simpkins, Professor in the Division of Gynecology Oncology and Department of OB-GYN at the University of Pennsylvania, Dr. Timothy Yap, medical oncology physician-scientist and Professor at the University of Texas MD Anderson Cancer Center, Dr. Eric Brown, a consultant to Aprea and a Professor at the University of Pennsylvania and a member of the Abramson Family Cancer Research Institute, and Aprea’s Dr. Nadeem Mirza, Senior Medical Advisor. The speakers, along with the management team, provided an overview of the Company’s lead ATR inhibitor candidate, ATRN-119, and its WEE1 inhibitor candidate, APR-1051, and highlighted the addressable unmet clinical need and potential combination therapies using these programs. A replay of the event can be access on the Aprea corporate website here.

Select Financial Results for the Fourth Quarter ended December 31, 2023

As of December 31, 2023, Aprea reported cash and cash equivalents of $21.6 million.
For the quarter ended December 31, 2023, the Company reported an operating loss of $3.7 million, compared to an operating loss of $2.7 million in the fourth quarter of 2022.
Research and Development (R&D) expenses were $2.0 million for the quarter ended December 31, 2023, compared to $0.5 million for the fourth quarter of 2022. The increase in R&D expense was primarily related to the Phase 1/2a clinical trial evaluating ATRN-119 which enrolled its first subject in Q1 2023 and IND enabling studies for APR-1051, the Company’s small molecule WEE1 inhibitor.
General and Administrative (G&A) expenses were $1.6 million for the quarter ended December 31, 2023, compared to $2.1 million for the comparable period in 2022. The decrease in G&A expenses was primarily due to a decrease in personnel costs and insurance premiums.
The Company reported a net loss of $3.4 million ($0.92 per basic share) on approximately 3.7 million weighted-average common shares outstanding for the quarter ended December 31, 2023, compared to a net loss of $2.4 million ($0.92 per basic share) on approximately 2.6 million weighted average common shares outstanding for the comparable period in 2022.


Select Financial Results for the Year ended December 31, 2023

As of December 31, 2023, the Company reported cash and cash equivalents of $21.6 million compared to $28.8 million as of December 31, 2022. The Company believes its cash and cash equivalents as of December 31, 2023, combined with the upfront gross proceeds of approximately $16.0 million received from the Company’s private placement of common stock and warrants in March 2024, before deducting placement agent fees and offering costs of approximately $1.4 million, will be sufficient to meet its currently projected operating expenses and capital expenditure requirements into the third quarter of 2025.
For the year ended December 31, 2023, the Company reported an operating loss of $15.5 million, compared to an operating loss of $113.4 million, which include $76.0 million for acquired in-process research and development, for the year ended December 31, 2022.
Research and Development (R&D) expenses were $7.6 million for the year ended December 31, 2023, compared to $16.4 million for the year ended December 31, 2022. The decrease in R&D expense was primarily related to the close out of our clinical trials of eprenetapopt and APR-246, non-cash stock-based compensation from the acceleration of vesting of all outstanding stock options and restricted stock units in connection with the acquisition of Atrin Pharmaceuticals Inc. in 2022 and personnel costs primarily related to the close out of our research facility in Sweden during 2022.
General and Administrative (G&A) expenses were $8.4 million for the year ended December 31, 2023, compared to $21.0 million for the year ended December 31, 2022. The decrease in G&A expenses was primarily due to a decrease in non-cash stock-based compensation from the acceleration of vesting of all outstanding stock options and restricted stock units in connection with the acquisition of Atrin Pharmaceuticals Inc. in 2022 and insurance premiums.
The Company reported a net loss of $14.3 million ($3.95 per basic share) on approximately 3.6 million weighted-average common shares outstanding for the year ended December 31, 2023, compared to a net loss of $112.7 million ($67.99 per basic share) on approximately 1.7 million weighted average common shares outstanding for the comparable period in 2022.

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. 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.

Investor Contact:

Mike Moyer

LifeSci Advisors

mmoyer@lifesciadvisors.com


Aprea Therapeutics, Inc.

Consolidated Statements of Operations and Comprehensive Loss

Three Months Ended December 31, 

Year Ended December 31, 

    

2023

    

2022

    

2023

    

2022

(Unaudited)

Grant revenue

 

$

14,075

$

$

583,231

$

Operating expenses:

Research and development

2,045,689

531,406

7,627,491

16,402,273

General and administrative

 

1,643,315

2,120,222

8,427,703

20,969,771

Acquired in-process research and development

 

 

 

 

76,020,184

Total operating expenses

 

3,689,004

 

2,651,628

 

16,055,194

 

113,392,228

Loss from operations

 

(3,674,929)

 

(2,651,628)

 

(15,471,963)

 

(113,392,228)

Other income:

 

 

 

 

Interest income, net

 

310,287

243,082

1,224,133

448,667

Foreign currency gain (loss)

 

(78,612)

 

(33,596)

 

(38,926)

 

281,534

Total other income

 

231,675

 

209,486

 

1,185,207

 

730,201

Net loss

$

(3,443,254)

$

(2,442,142)

$

(14,286,756)

$

(112,662,027)

Other comprehensive gain (loss):

 

 

 

 

Foreign currency translation

 

24,601

 

(382,763)

 

12,135

 

(264,452)

Total comprehensive loss

 

(3,418,653)

 

(2,824,905)

 

(14,274,621)

 

(112,926,479)

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

$

(0.92)

$

(0.92)

$

(3.95)

$

(67.99)

Weighted-average common shares outstanding, basic and diluted

 

3,736,673

 

2,649,349

 

3,617,607

 

1,657,055


Aprea Therapeutics, Inc.

Consolidated Balance Sheets

December 31, 

December 31, 

    

2023

    

2022

Assets

 

  

 

  

Current assets:

 

  

 

  

Cash and cash equivalents

$

21,606,820

$

28,786,647

Prepaid expenses and other current assets

 

914,275

 

1,366,859

Total current assets

 

22,521,095

 

30,153,506

Property and equipment, net

 

88,362

 

2,321

Restricted cash

 

40,717

 

Total assets

$

22,650,174

$

30,155,827

Liabilities and Stockholders’ Equity

 

  

 

  

Current liabilities:

 

  

 

  

Accounts payable

$

1,670,369

$

842,754

Accrued expenses

 

2,186,262

 

2,358,332

Deferred revenue

 

528,974

 

Total current liabilities

 

4,385,605

 

3,201,086

Total liabilities

 

4,385,605

 

3,201,086

Commitments and contingencies

 

  

 

  

Series A convertible preferred stock, $0.001 par value, 40,000,000 shares authorized; 56,227 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively.

 

1,311,063

1,311,063

Stockholders’ equity:

 

  

 

  

Common stock, $0.001 par value, 400,000,000 shares authorized, 3,736,673 and 2,655,269 shares issued and outstanding at December 31, 2023 and December 31, 2022, respectively.

 

3,736

 

2,655

Additional paid-in capital

 

335,644,204

 

330,060,836

Accumulated other comprehensive loss

 

(10,611,273)

 

(10,623,408)

Accumulated deficit

 

(308,083,161)

 

(293,796,405)

Total stockholders’ equity

 

16,953,506

 

25,643,678

Total liabilities and stockholders' equity

$

22,650,174

$

30,155,827


Exhibit 99.2

GRAPHIC

Precision Oncology Through Synthetic Lethality March 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 targeted • Phase 1/2a – Ongoing Dose Escalation • Readout 1Q 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 • Limited off target effect • Ovarian cancer with Cyclin E over expression (OVCAR-3) • Stable hematologic function • Favorable pharmacokinetics • IND cleared March 2024 • Phase 1 planned for 1H 2024 • Lead optimization • Target identified from our RepliBiom discovery platform 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 1. A Multi-Center Evaluation of WEE1 Inhibitor in Patients with Advanced Solid Tumors, APR-1051 2024 2025 1Q 2Q 3Q 4Q 1Q 2Q 3Q 4Q ATR ATRN-119 Complete Dose Escalation RP2D Enroll First Patient Additional Open-Label Efficacy Data WEE1 APR-1051 Phase 1 – Monotherapy Dose Escalation (ACESOT-1051 trial)1 Enroll First Patient Open-Label RP2D Efficacy Data IND Cleared Clinical Update Phase 1/2a – Monotherapy Dose Expansion Phase 1/2a – Monotherapy Dose Escalation Initial Efficacy Results

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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 • Single pathway loss of function is inconsequential • 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 Hamill Sr. Vice President and CFO Nadeem Mirza, M.D., MPH Senior Medical Advisor 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 Clinical Proof-of-Concept

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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 Macrocycles restrict the number of conformations that can be formed, which can: • Increase potency • Increase selectivity These effects can then promote: • Increased tolerability by decreasing off-targeting • Permit more efficacious dosing

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9 © 2024 Aprea Therapeutics, Inc. All Rights Reserved AR-276-01: Aprea 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 patients Dose escalation (8 dose levels*) 3+3 design Primary objectives: • Safety, MTD, RP2D • Pharmacokinetics Secondary objectives: • Antitumor activity (RECIST/PCWG3) Exploratory objectives: • 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: 60 patients in total • Escalation phase: up to 30 patients • Expansion phase: up to 30 patients IMP: ATRN-119 is an oral ATR kinase inhibitor given daily *Planned protocol amendment adding cohorts 7 and 8

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10 © 2024 Aprea Therapeutics, Inc. All Rights Reserved 3+3 dose escalation with once-daily dosing (up to 30* patients) Dose expansion (up to 30 patients) Potential indications Colorectal Prostate Gastric Endometrial Mutations Undisclosed RepliBiom biomarkers Aprea AR-276-01 Study MTD/RP2D *Planned protocol amendment adding cohorts 7 and 8 = 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

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11 © 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 55 175 57 52 28 0 20 40 60 80 100 120 140 160 180 200 001-001 002-002 003-003 003-004 002-005 002-006 003-007 002-008 003-009 003-010 003-011 004-012 003-013 004-014 003-015 003-016 550 mg 350 mg 200 mg 100 mg 50 mg AR-276-01 Summary of Duration of Treatment Update – Feb 28, 2024 Study patient Days on treatment * * * * * * * * * Stable disease Treatment continues * Progressive Disease ATRN-119 once-daily dose * * NE 30 16 7 23 NE = Not Evaluable Not all data source verified Dose increased to 350 mg

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12 © 2024 Aprea Therapeutics, Inc. All Rights Reserved No ATRN-119 Related SAE or Grade 4 Adverse Events Reported As of February 23, 2024: Seven Of Fifteen Patients Experienced AEs# Possibly/probably Related to ATRN-119 # No grade 4 AEs were observed * Resulted in treatment interruption Not all data source verified Diarrhea Grade 1 (001-001*, 003-003, 004-014) Vomiting Grade 1 (001-001*) Non-cardiac chest pain Grade 1 (001-001) Dehydration Grade 2 (001-001*) Decreased Appetite Grade 1 (001-001) Hypotension Grade 2 (001-001*) Nausea Grade 1 (002-006, 004-012) Fatigue Grade 1 (002-008, 003-013) Grade 2 (002-005) Grade 3 (003-011) Gastrointestinal General Metabolism Vascular Related AEs

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13 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119 2024-2025 Anticipated Clinical Milestones Planned protocol amendment adding cohorts 7 and 8 to monotherapy dose escalation 1Q2024 Milestone Timeline Phase 1/2a – Monotherapy Dose Escalation Potential efficacy data 2H 2024 Complete Dose Escalation 4Q 2024 RP2D 1Q 2025 Phase 1/2a – Monotherapy Dose Expansion First Patient Enrolled 1Q 2025 Additional Open-Label Efficacy Data 3Q 2025

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14 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATR Inhibitor: ATRN-119 Preclinical Proof-of-Principal

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15 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATR Inhibitor – ATRN-119 Mechanism of Action – Prevent CHK1 Phosphorylation by ATR Kinase pCHK1 – Phosphorylated Checkpoint kinase 1 Data on file No Treatment ATRN-119 Tumor Samples Pharmacodynamics - ɣH2AX (green) -9 -8 -7 -6 -5 0 20 40 60 80 100 120 ATRN-119 / E v ATR/ATRIP(h) Log10 [ATRN-119] (M) Activity (% Control) ATRN-119 binds to ATR …inhibits its biological activity… …and triggers replication fork collapse and double-strand breaks (ɣH2AX) -9 -8 -7 -6 -5 0 20 40 60 80 100 120 ATRN-119 / E v ATR/ATRIP(h) Log10 [ATRN-119] (M) A c t i v i t y ( % C o n t r o l ) NT NT 125 62 32 16 8 4 2 1 Phos-CHK1 Control (GAPDH) nM 0.5 0.25 + Replication stress Replication fork collapse Double strand breaks Cancer cell death ATR Inactive ATRN-119 Active pCHK1 Inactive CHK1 ATR active Cell cycle pause DNA repair Cancer cell survival

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16 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119 Preclinical Profile Nanomolar potency in vitro across a broad spectrum of cancer cell lines Strong tumor control observed in vivo, including in challenging genetic backgrounds N=4 female mice per group, ATRN-119 - 100 mg/kg/day P.O, ATRN-157 - 20 mg/kg/day SQ. ATRN-157 is an active metabolite identified in dogs receiving ATRN-119 P.O.. In vitro metabolism studies in dog and human hepatocytes and liver microsomes indicated formation of ATRN-157 in both species. Potency and selectivity of ATRN-157 was comparable to ATRN-119. Pre-clinical studies with ATRN-119 and ATRN-157. Tumor Growth Inhibition HCT-116 (KRASG13D, p53 null) Body Weight HCT-116 (KRASG13D, p53 null)

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17 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119 + Olaparib: Regression of BRCA2-Deficient Ovarian (HGSOC) Tumors N=6-8 mice per group, ATRN-119 - 90 mg/kg P.O BID, Olaparib - 50 mg/kg/day P.O, ATRN-119+Olaparib at the same doses and schedules. Pre-clinical studies with ATRN-119. Data on file ATRN-119 + Olaparib Inhibits Ovarian Tumor Growth Over Time ATRN-119 + Olaparib Shows Negligible Weight Loss Over Time Body Weight Human ovarian PDX Tumor Growth Inhibition Human ovarian PDX

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18 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATR Inhibitor: ATRN-119 A Potentially Differentiated ATRi

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19 © 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 Repare announced a worldwide license and collaboration agreement with Roche on June 1, 2022 5 Preliminary Phase 1 Data From Ongoing First-in-Human Phase 1/2 TRESR Study of RP-3500, AACR 2022 Parameter 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 / Roche4 RP-35005 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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20 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Tumor reduction and regrowth Continuous tumor reduction Drug “On” Drug “Off” Drug “On” ATRN-119 Daily Dosing Means Continuous Tumor Reduction Intermittent Dosing May Lead to Tumor Resistance

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21 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Daily Dosing Is Clinically Superior Based on Other ATRi in Development Artios ATR Inhibitor: ART0380 Initial Results From Phase 1 Dose Escalation1 1ART0380-ESMO-Poster-2023 Efficacy Among Measurable Patients • Continuous – ORR 29% (2/7). One of two responders treated at twice the RP2D. • Intermittent – ORR 8% (2/26). One of two responders treated at twice the RP2D. Dose Escalation Phase • 49 patients • Continuous dosing: QD; Range 200-400mg, (n=10) • Intermittent dosing: 3D on/4D off; Range 100 - 1,200mg, (n=39) RP2D • Continuous = 200mg • Intermittent dosing = 600mg Safety • 36% Anemia Grade 3 at doses considered tolerable

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22 © 2024 Aprea Therapeutics, Inc. All Rights Reserved ATRN-119: Potential Best-in-Class Oral ATR Inhibitor with Structurally Differentiated Core, Backbone, and Toxicity Profile Note: ATRN-119 has not yet been tested clinically 1 ATRN-119, Phase 1/2a Clinical Study Protocol 2 Internal pre-clinical head-to-head tolerability study in male beagle dogs. Parameter Route Of Administration Oral Clinical Studies Chosen (MTD/RP2D), Dose Schedule Continuous daily dosing (RP2D TBD in Phase 1)1 Hematological toxicities in preclinical studies Pre-Clinical, Toxicology Studies: • In 28-day GLP tox study in dogs, hematological changes were of small magnitude and within normal ranges • In a head-to-head comparative tolerability study, ATRN-119 demonstrated significantly less toxicity than another oral ATRi that is currently in clinical development2 ATRN-119 potential for reduced toxicity could make it a preferred ATR inhibitor as a single agent, as well as a candidate for combination with standard-of-care therapies. ATRN-119 (1)

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23 © 2024 Aprea Therapeutics, Inc. All Rights Reserved WEE1 Inhibitor: APR-1051 Preclinical Proof-of-Principle

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24 © 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 Inactive CDK1 Mitotic cycle pause DNA repair WEE1 Cancer cell survival active Phos-CDK1 Control (Tubulin) µM APR-1051

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25 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Pre-clinical studies with APR-1051 Data on file Tumor Growth Inhibition OVCAR-3 N=7 mice per group, APR-1051, exploratory formulation - 30 mg/kg/day APR-1051 Demonstrated Potentially Compelling Anti-tumor Activity IND Cleared March 2024 Vehicle APR-1051

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26 © 2024 Aprea Therapeutics, Inc. All Rights Reserved WEE1 Inhibitor: APR-1051 A Potentially Differentiated Wee1i

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27 © 2024 Aprea Therapeutics, Inc. All Rights Reserved AstraZeneca Adavosertib (AZD-1775)1,2 Zentalis Azenosetrib (ZN-c3)1 Aprea APR-1051 On-Target IC50 (nM) WEE1 3.8 3.8 2.2 Off-Target Inhibition at 1 µM (%) PLK1 70 79 17 PLK2 101 96 33 PLK3 91 92 12 APR-1051 Potentially Differentiated from Other WEE1 Inhibitors APR-1051 Potent and Structurally Differentiated, with High Selectivity to Limit Off-target Toxicity Note: Head-to-head studies have not been conducted 1 Huang et al, (2021) J Med Chem 2AstraZeneca announced in July 2022 the discontinuation of development of AZD-1775 27 AACR-NCI-EORTC Meeting, Poster C147, 2023 Undisclosed

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28 © 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 AACR-NCI-EORTC Meeting, Poster C147, 2023 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

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29 © 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 AACR-NCI-EORTC Meeting, Poster C147, 2023 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

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30 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051 Shows Negligible Inhibition of hERG Channels AACR-NCI-EORTC Meeting, Poster C147, 2023 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

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31 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051 Suppresses Tumor Growth While Causing Little Effect on RBCs and Body Weight Vehicle ATRN-1051, 15mg/kg PO, BID, 5 on/ 2 of 0 5 10 15 RBC (10 12 /L) Vehicle ATRN-1051, 15mg/kg PO, BID, 5 on/ 2 of 0 200 400 600 800 Retiuclocyte Count (10 9 /L) AACR-NCI-EORTC Meeting, Poster C147, 2023 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) Days Post Treatment 28 Days Post Treatment Days Post Treatment

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32 © 2024 Aprea Therapeutics, Inc. All Rights Reserved APR-1051 2024-2025 Anticipated Clinical Milestones Milestone Timeline Phase 1 – Monotherapy Dose Escalation Enroll first patient 1H 2024 Clinical Update 4Q 2024 Open-Label Efficacy Data 2Q 2025 RP2D 2H 2025

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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 $21.6M as of December 31, 2023 Closed approximately $16.0M (before deducing placement agent fees and offering costs of approximately $1.4 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 March 26, 2024 Preferred Stock (as converted) 28,112 Common Stock 5,430,215 Warrants: Pre-Funded Tranche A Tranche B Total 507,076 1,097,394 1,097,394 2,701,864 Options 596,466 Restricted Stock Units 18,040 Fully Diluted Equivalents 8,774,697

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35 © 2024 Aprea Therapeutics, Inc. All Rights Reserved Financed into 3Q 2025 • Reach short term inflection points and catalysts • Evaluate optimal strategic partnerships Near term catalysts • Phase 1/2a ATRN-119 potential efficacy 2H 2024; complete dose escalation 4Q 2024 • Initiate Phase 1 for APR-1051 1H 2024 Diversified portfolio with best in class, de-risked clinical and preclinical programs • Highly potent and selective ATR and WEE1 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