Aprea Therapeutics CEO Issues Letter to Shareholders Highlighting Pipeline Progress in 2025 and Outlook for 2026

Rhea-AI Summary

Aprea Therapeutics (Nasdaq: APRE) issued a shareholder letter dated Dec 18, 2025 summarizing 2025 clinical progress and 2026 plans. Key points: lead WEE1 inhibitor APR-1051 is in the ACESOT-1051 dose-escalation study with enrollment in the 220 mg cohort; through 150 mg there have been no dose-limiting toxicities, the longest on-treatment duration is 222 days, and the best observed tumor reduction is 15%. The protocol was amended to add more HPV-positive patients; further safety and efficacy data are expected in Q1 2026 and dose escalation completion is planned in 2026.

The ATR inhibitor ATRN-119 reached a recommended Phase 2 dose for once-daily dosing; the company paused monotherapy enrollment to preserve cash while evaluating combination strategies. Aprea completed a $3.1 million gross private placement and says cash runway extends into Q1 2027.

Positive

• APR-1051 no DLTs through 150 mg
• Longest on-treatment duration: 222 days
• ATRN-119 reached RP2D for once-daily dosing
• Private placement raised $3.1 million gross

Negative

• Paused monotherapy enrollment in ABOYA-119
• Current financing of $3.1 million implies limited near-term capital cushion

News Market Reaction

-0.01%

1 alert

-0.01% News Effect

On the day this news was published, APRE declined 0.01%, reflecting a mild negative market reaction.

Data tracked by StockTitan Argus on the day of publication.

Key Figures

APR-1051 dose cohort: 220 mg Well-tolerated dose: 150 mg Treatment duration: 222 days +4 more

7 metrics

APR-1051 dose cohort 220 mg Current ACESOT-1051 cohort (Cohort 8) enrollment

Well-tolerated dose 150 mg Doses through 150 mg with no dose-limiting toxicities

Treatment duration 222 days Longest duration of treatment with APR-1051 in ACESOT-1051

Tumor burden change 15% reduction Most notable anti-tumor response observed with APR-1051

Early-response dose 70 mg Dose level where early single-agent activity seen in HPV-positive patient

Private placement size $3.1 million (gross) Recent private placement financing mentioned as extending cash runway

Cash runway Into Q1 2027 Management’s projection after recent private placement

Market Reality Check

Price: $0.6600 Vol: Pre-news volume 26,393 vs...

low vol

$0.6600 Last Close

Volume Pre-news volume 26,393 vs 20-day average 69,941, indicating quieter trading ahead of the letter. low

Technical Shares at $0.9102, trading below 200-day MA of $1.63 and 81.8% under the 52-week high.

Peers on Argus

Biotech peers like AEON and PCSA in the momentum scanner showed declines of -4.1...

2 Down

Biotech peers like AEON and PCSA in the momentum scanner showed declines of -4.12% and -34.84% with no same-day news, pointing to broader risk-off sentiment in the group, but APRE’s own direction before this shareholder letter is not specified.

Historical Context

5 past events · Latest: Dec 09 (Negative)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Dec 09	Private placement	Negative	-10.8%	$3.1M at-the-market private placement extending cash runway into Q1 2027.
Nov 12	Earnings and update	Neutral	-4.5%	Q3 2025 results with cash of $13.7M and extended runway into Q4 2026.
Oct 24	Clinical update	Positive	-7.9%	ACESOT-1051 data showing early APR-1051 activity and disease stabilization signals.
Oct 15	Clinical trial plan	Positive	-1.3%	ATRN-119 RP2D set at 1,100 mg QD and shift toward combination strategies.
Oct 14	Conference posters	Positive	+2.7%	Announcement of poster presentations for APR-1051 and ATRN-119 at EORTC‑NCI‑AACR.

Pattern Detected

Recent history shows several instances where clinically or strategically positive updates were followed by negative price reactions, while financing and conference-related news aligned more with price moves.

Recent Company History

Over the last few months, Aprea has advanced both APR-1051 and ATRN-119 while managing liquidity. In October 2025, it reported early activity signals for APR-1051 in ACESOT-1051 and established an RP2D for ATRN-119, then highlighted both programs at the EORTC‑NCI‑AACR conference. On November 12, 2025, Q3 2025 results and a clinical update emphasized a cash runway into late 2026. A $3.1M private placement on December 9, 2025 extended the runway into Q1 2027. Today’s shareholder letter reiterates these themes, stressing pipeline progress and longer cash visibility.

Market Pulse Summary

This announcement underscores ongoing progress for APR-1051, including a 15% tumor burden reduction ...

Analysis

This announcement underscores ongoing progress for APR-1051, including a 15% tumor burden reduction and treatment durations up to 222 days, and outlines next steps for ATRN-119 in combinations. Management also points to a cash runway into Q1 2027 after a $3.1M private placement. In context of prior updates, investors may track forthcoming Q1 2026 data, dose-escalation completion in 2026, and execution on combination strategies as key validation points.

Key Terms

wee1 inhibitor, dose-limiting toxicities, hpv-positive, anti-pd-1 therapy, +4 more

8 terms

wee1 inhibitor medical

"Our lead program, APR-1051, a next-generation WEE1 inhibitor, continues..."

A Wee1 inhibitor is a drug that blocks the Wee1 protein, which normally acts like a safety brake that pauses damaged cells before they divide. By removing that brake, cancer cells with DNA damage are forced into division and often die, making the approach useful for targeting tumors. Investors track Wee1 inhibitors because their clinical trial success, safety profile and use with other therapies can greatly affect a biotechnology company's value.

dose-limiting toxicities medical

"through the 150mg dose, the treatment has been well tolerated with no dose-limiting toxicities..."

Dose-limiting toxicities are the harmful side effects seen in early clinical trials that are severe enough to stop researchers from raising a drug’s dose. Like a car’s speed limiter marking the safe top speed, DLTs define the maximum tolerable dose, and they matter to investors because they determine whether a medicine can reach effective levels, influence development timelines, costs, and regulatory chances, and thus affect a drug’s commercial prospects.

hpv-positive medical

"encouraging early single-agent activity in a patient with HPV-positive head and neck cancer..."

hpv-positive indicates that human papillomavirus (HPV) genetic material or infection has been detected in a biological sample, often a tumor; it's like finding a fingerprint that points to a specific cause. For investors, that designation matters because HPV-positive status can change expected treatment pathways, clinical trial eligibility, regulatory review, and market demand for diagnostics or therapies, which in turn affects the commercial outlook for related medical products.

anti-pd-1 therapy medical

"synergy between our APR-1051 and anti-PD-1 therapy."

Anti-PD-1 therapy are drugs that block the PD-1 protein on immune cells, effectively releasing the “brakes” that can prevent the body from attacking cancer cells; think of it like removing a safety lock so security guards can better recognize intruders. Investors care because these therapies can transform treatment outcomes, drive significant sales if approved for multiple cancers, and carry regulatory, patent and competitive risks that affect a company’s valuation.

atr inhibitor medical

"ATR Inhibitor Program, ATRN-119 Earlier this year, we announced that the ATRN-119 program..."

An ATR inhibitor is a drug that blocks a protein cells use to spot and repair DNA damage, stopping cancer cells from fixing harm caused by treatments or their own rapid growth. Investors care because these drugs can make chemotherapy, radiation, or other targeted treatments much more effective and may work especially well in tumors with specific repair weaknesses; clinical trial progress and safety results can therefore sharply affect a biotech’s value.

antibody-drug conjugates medical

"well positioned for use alongside DNA-damaging agents, including radiation therapy, antibody-drug conjugates..."

A class of targeted cancer medicines that combine a lab-made antibody (which finds and sticks to specific markers on tumor cells) with a powerful cell-killing drug linked together so the toxic payload is delivered directly to the tumor. Think of it like a guided missile that reduces collateral damage compared with traditional chemotherapy; for investors, success or failure of these drugs drives clinical, regulatory and commercial value and can sharply affect a biotech company’s prospects and stock price.

immune checkpoint inhibitors medical

"including radiation therapy, antibody-drug conjugates, and immune checkpoint inhibitors."

Drugs that release the immune system’s natural “brakes,” allowing immune cells to recognize and attack cancer cells; imagine taking the safety off a guard dog so it can chase intruders. They matter to investors because they can become high-value treatments with large sales potential, but their commercial success depends on clinical trial results, regulatory approval, competition and side-effect management, which all affect a company’s valuation.

private placement financial

"our recently completed $3.1 million (gross) private placement financing extends our cash runway..."

A private placement is a way for companies to raise money by selling securities directly to a small group of investors instead of through a public offering. This process is often quicker and less regulated, making it similar to offering a special, exclusive investment opportunity to select individuals or institutions. For investors, it can provide access to unique investment options that are not available on public markets.

AI-generated analysis. Not financial advice.

DOYLESTOWN, Pa., Dec. 18, 2025 (GLOBE NEWSWIRE) -- Aprea Therapeutics, Inc. (Nasdaq: APRE) (“Aprea”, or the “Company”), a clinical-stage biopharmaceutical company developing innovative treatments that target weaknesses in cancer cells while minimizing damage to healthy cells, today issued the following letter to shareholders from Chief Executive Officer, Oren Gilad. The letter highlights the Company’s ongoing clinical progress, operational execution, and plans for 2026.

Dear Shareholders --

As 2025 comes to a close, I am proud of what Aprea has accomplished over the past 12 months and excited for the year ahead. This year, we achieved meaningful milestones that we believe validate our approach and position us for long-term growth. These accomplishments reflect our team’s hard work and dedication, and we are pleased to share them with you.

WEE1 Inhibitor Program, APR-1051

Our lead program, APR-1051, a next-generation WEE1 inhibitor, continues to demonstrate promising anti-tumor activity in our ongoing ACESOT-1051 dose-escalation study. We are enrolling patients in the 220 mg cohort (Cohort 8), and so far, through the 150mg dose, the treatment has been well tolerated with no dose-limiting toxicities (DLTs) or unexpected safety findings or issues.

We have observed disease stabilization in several patients, with the longest duration of treatment reaching 222 days. The most notable response to date is a 15% reduction in tumor burden. Encouragingly, the number of patients achieving disease stabilization appears to increase with higher doses.¹

After observing encouraging early single-agent activity in a patient with HPV-positive head and neck cancer at the 70 mg dose, we amended our clinical protocol to augment the number of HPV-positive patients. We believe this approach will broaden our clinical experience in HPV-positive tumor types, an area with substantial unmet medical need, and aligns with data from our translational research collaboration with MD Anderson Cancer Center. Their preclinical studies showed strong single-agent activity across a broad panel of human and animal head and neck squamous cell carcinoma models, as well as synergy between our APR-1051 and anti-PD-1 therapy.

Near term catalysts for the ongoing APR-1051 clinical program include the availability of further safety and efficacy data in Q1 2026 and completion of dose escalation in 2026.

ATR Inhibitor Program, ATRN-119

Earlier this year, we announced that the ATRN-119 program had reached its recommended Phase 2 dose (RP2D) for once-daily dosing, and we are now shifting our focus toward evaluating combination therapies with this agent. As part of this strategic direction and to preserve cash in a still difficult fundraising environment, Aprea is pausing further enrollment in both once-daily and twice-daily monotherapy dosing arms of the ABOYA-119 study.

Building on the completion of dose escalation and supported by new preclinical data suggesting synergistic anti-tumor activity, we may consider combination strategies to expand ATRN-119’s therapeutic potential as our balance sheet strengthens. With its favorable safety profile, ATRN-119 is well positioned for use alongside DNA-damaging agents, including radiation therapy, antibody-drug conjugates, and immune checkpoint inhibitors.

As previously disclosed, we are in discussions with leading academic centers to investigate ATRN-119 in combination with radiation and immunotherapy, based on preclinical findings that ATR inhibition may enhance anti-tumor immune responses.

We will continue to share updates on this program throughout the coming year.

Cash Runway Into Q1 2027

We remain committed to maintaining financial discipline and delivering value for our shareholders. We believe our recently completed $3.1 million (gross) private placement financing extends our cash runway into 2027 based on current projections. Our focus is on executing our programs with discipline and continuing to expand our investor relations and visibility efforts so the market better understands the value Aprea is creating.

Our strategy is to advance the science, deliver on clinical and regulatory milestones, broaden awareness of the story, and let the fundamentals drive a valuation that better reflects the opportunity.

In this last round of financing, myself, as well as our CFO, and a Board member participated alongside external investors, which included healthcare focused funds and a long-term existing shareholder, reflecting confidence in our strategy and potential.

Aprea remains committed to advancing the fight against cancer. I want to sincerely thank our dedicated employees, our engaged Board of Directors, our patients and their families, clinical investigators and our valued shareholders. Your commitment and belief in our mission are essential to everything we do.

All my best,

Oren Gilad
President & Chief Executive Officer
Aprea Therapeutics

1. For more detailed clinical results from the ongoing ACESOT-1051 trial, refer to Aprea’s corporate presentation which can be found at https://aprea.com/.
   
   

About Aprea
Aprea is pioneering a new approach to treat cancer by exploiting vulnerabilities associated with cancer cell mutations. This approach was developed to kill tumors but to minimize the effect on normal, healthy cells, decreasing the risk of toxicity that is frequently associated with chemotherapy and other treatments. Aprea’s technology has potential applications across multiple cancer types, enabling it to target a range of tumors, including ovarian, endometrial, colorectal, prostate, and breast cancers.

The company’s lead programs are APR-1051, an oral, small-molecule inhibitor of WEE1 kinase, and ATRN-119, a small molecule ATR inhibitor, both in clinical development for solid tumor indications. For more information, please visit the company website at www.aprea.com.

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, the risk that the proposed private placement and the transactions described herein may not be completed in a timely manner or at all, the failure to realize the anticipated benefits of the private placement and related transactions, market and other conditions, as well as 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

FAQ

What clinical progress did Aprea (APRE) report for APR-1051 on Dec 18, 2025?

Aprea reported APR-1051 is enrolling the 220 mg cohort, with no DLTs through 150 mg, a longest treatment of 222 days and a best tumor reduction of 15%.

When will Aprea (APRE) report more APR-1051 data?

The company expects additional APR-1051 safety and efficacy data in Q1 2026 and plans to complete dose escalation in 2026.

What did Aprea announce about ATRN-119 (APRE) dosing and enrollment?

ATRN-119 reached a recommended Phase 2 dose (RP2D) for once-daily dosing and Aprea paused further monotherapy enrollment to conserve cash while exploring combinations.

How long is Aprea's (APRE) cash runway after the Dec 2025 financing?

Aprea said its recently completed $3.1 million gross private placement extends cash runway into Q1 2027 based on current projections.

Why did Aprea (APRE) amend the APR-1051 protocol to add HPV-positive patients?

The amendment increases enrollment of HPV-positive patients after observing early single-agent activity in an HPV-positive head and neck cancer patient and supportive preclinical data.

What are near-term catalysts for Aprea (APRE) investors in 2026?

Near-term catalysts include Q1 2026 APR-1051 data releases, completion of dose escalation in 2026, and updates on ATRN-119 combination strategies.