DOYLESTOWN, PA, USA I January 11, 2023 I Aprea Therapeutics, Inc. (Nasdaq: APRE), a biopharmaceutical company focused on developing novel synthetic lethality-based cancer therapeutics targeting DNA damage response (DDR) pathways, today announced that the first patient was dosed in its Phase 1/2a monotherapy clinical trial of ATRN-119, the Company’s lead ATR inhibitor for the treatment of cancers with DDR mutations.

The Phase 1/2a clinical trial is a multi-center, open-label, dose-escalation and expansion study designed to test ATRN-119 monotherapy in patients with advanced solid tumors harboring defined mutations in DDR pathways. The Phase 1 part of the study will assess tolerability, pharmacokinetics, recommended Phase 2 dose and analysis of patient biomarkers. The Phase 2a expansion portion of the trial is designed to further evaluate tolerability and efficacy of ATRN-119 monotherapy. ATRN-119 is structurally differentiated from other ATR inhibitors. In preclinical studies, ATRN-119 has demonstrated potent anti-proliferative activity against a variety of cancer cell lines, inhibited tumor growth in genetically defined ovarian, colon, pancreatic and prostate cancer xenograft models and has shown potential to have lower hematological toxicity than other ATR inhibitors.

“Initiating clinical evaluation of ATRN-119 marks a significant milestone in our efforts to advance the development of our growing pipeline of DDR inhibitors,” said Oren Gilad, Ph.D., President and Chief Executive Officer of Aprea Therapeutics. “We are committed to developing and advancing next-generation, synthetic lethality-based therapies to address the unmet medical needs of patients with genetically defined cancers. We look forward to sharing the preliminary data from this study throughout 2023.”

Principal Investigator for the trial, Dr. Fiona Simpkins, M.D. Assistant Professor of Obstetrics and Gynecology, Perelman School of Medicine at the University of Pennsylvania, added: “Mutations in DDR pathways are a hallmark of many aggressive cancers and inhibition of ATR is a promising therapeutic approach to selectively target and exploit the genetic vulnerabilities of tumors with these mutations. The initiation of this Phase 1 trial represents an important step in the clinical evaluation of ATR as a target for cancer therapy.”

About Aprea Therapeutics, Inc.

Aprea Therapeutics, Inc. is a biopharmaceutical company headquartered in Doylestown, Pennsylvania, focused on developing and commercializing novel synthetic lethality-based cancer therapeutics targeting a critical pathway and some of the most central targets in DDR and cancer progression. The Company’s lead program is ATRN-119, a clinical-stage small molecule ATR inhibitor being developed for solid tumor indications. Our WEE1inhibitor is being advanced to IND submission. 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