FDA clears Aprea Therapeutic’s Investigational New Drug (IND) application (IND 169359) for oral WEE1 Inhibitor, APR-1051
Aprea to initiate the Phase 1 ACESOT-1051 trial. Learn more

We’re on a Mission to Increase the Specificity and Reduce the Toxicity of DDR Inhibitors


Our therapeutic assets—and the proprietary technologies we use to validate them—reflect our commitment to giving cancer patients more choices.

MOLECULETARGETINDICATIONBIOMARKERPreclinicalIND-EnablingPhase 1Anticipated Milestones
ATRN-119ATRAdvanced Solid TumorsRepliBiom1 Profiling
Complete P 1/2a dose escalation | 4Q 2024
Recommended P 2 dose | 1Q 2025
Initiate dose expansion | 1Q 2025
Additional open-label efficacy data | 3Q 2025
APR-1051WEE1Ovarian Cancer, Others CCNE Amplification, Others
First patient enrolled | 1H 2024
Open-label efficacy data | 2Q 2025
Recommended P 2 dose | 2H 2025
APR-DDRiDDR TargetAdvanced Solid TumorsUndisclosed
Identify lead candidate | Q3 2024
1 RepliBiom – a synthetic lethality discovery platform

Our Lead Programs: ATR inhibitor, ATRN-119, and WEE1 inhibitor, APR-1051

Our novel macrocyclic ATR inhibitor, ATRN-119, and our next-generation inhibitor of the WEE1 kinase, APR-1051, are the cornerstones of our pipeline of synthetic lethality-based cancer therapeutics. These Aprea drugs were internally discovered, developed, and evaluated by our dedicated team of chemists, scientists, and clinicians.

ATR Program: ATRN-119

The ataxia telangiectasia and Rad3-related (ATR) kinase is a master regulator of the DNA damage response, with key roles in cell cycle control and DNA repair following replication stress. Aprea Therapeutics has developed ATRN-119, the first macrocyclic ATR inhibitor to enter clinical trials (NCT04905914).

We observed preliminary signs of clinical benefit in the early stages of development, and based on the interim data from our ongoing first-in-human phase study, ATRN-119 has demonstrated the ability to be safe and well tolerated, with no dose-limiting toxicities and no signs of significant hematological toxicity reported. Currently, four clinical sites are active in the US. Upon completing Part 1 of the study, we anticipate identifying a recommended Phase 2 dose (RP2D).

WEE1 Program: APR-1051

WEE1 is a protein kinase that inhibits premature cell cycle progression. Specifically, WEE1 prevents the premature entry of cells into both the DNA synthetic phase of the cell cycle and the phase in which cells divide after the DNA is duplicated. Through these roles, WEE1 prevents loss of genome stability, particularly in CCNE1-overexpressing cancer cells.

APR-1051 is an orally bioavailable, highly potent, and selective small molecule inhibitor of WEE1. APR-1051 has demonstrated in vivo anti-proliferative activity in multiple cancer cell lines. Importantly, the pharmacodynamic properties of APR-1051 include lower off-target inhibition of three members of the PLK family of kinases (PLK1, PLK2, and PLK3), which may improve its therapeutic value.