Company plans to initiate Phase 1 ACESOT-1051 (A Multi-Center Evaluation of WEE1 Inhibitor in Patients with Advanced Solid Tumors, APR-1051) clinical trial evaluating, highly selective, oral WEE1 inhibitor, for monotherapy treatment of Cyclin E overexpressing cancers including breast and ovarian cancers

Update from the ACESOT-1051 clinical trial expected in Q4 2024

DOYLESTOWN, PA, USA I March 11, 2024 I Aprea Therapeutics, Inc. (Nasdaq: APRE) (“Aprea”, or the “Company”), a clinical-stage biopharmaceutical company focused on precision oncology through synthetic lethality, today announced that the U.S. Food and Drug Administration (FDA) has cleared its Investigational New Drug (IND) application (IND 169359) for APR-1051.

“APR-1051 is a next-generation inhibitor of WEE1 kinase and, based on its unique characteristics, we believe it will be best in class,” said Dr. Oren Gilad, President and CEO of Aprea. “The FDA’s clearance of our IND is a critical step in the APR-1051 development program. We look forward to evaluating therapeutic activity in patients, focusing on Cyclin E overexpressing cancers, including ovarian and breast cancers.”

Based on preclinical studies, APR-1051 is differentiated from other WEE1 inhibitors in its:

  1. Molecular structure;
  2. Selectivity for WEE1 versus off-target inhibition of the polo-like kinase, or PLK, family of kinases;
  3. Potentially superior pharmacokinetic (PK) properties;
  4. Potential absence of QT prolongation at doses that significantly inhibit WEE1*

APR-1051 was discovered and preclinically evaluated by Aprea’s team of chemists and scientists. Aprea has conducted extensive pre-clinical studies with APR-1051, which have demonstrated that the molecule has potent anti-tumor activity, along with a favorable pharmacokinetic (PK) profile. Additionally, pre-clinical data show that APR-1051 may demonstrate less toxicity than other WEE1 inhibitors.* 

Clearance of the IND application will allow Aprea to initiate the Phase 1 ACESOT-1051 dose escalation trial to evaluate the safety, tolerability, and preliminary efficacy of APR-1051. Enrollment of the first patient in this study is expected in the first half of 2024 with an update expected in the fourth quarter of the year.

* No head-to-head studies have been conducted with APR-1051

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 received FDA clearance on an IND to begin clinical studies of APR-1051, its oral, small molecule WEE1 inhibitor. For more information, please visit the company website at

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

SOURCE: Aprea Therapeutics