DOYLESTOWN, PA — Aprea Therapeutics, Inc. (NASDAQ: APRE) is expanding its Phase 1 trial of experimental cancer drug APR-1051 after reporting early signs of antitumor activity, using proceeds from a $30 million financing to accelerate enrollment and test the treatment across additional biomarker-defined cancers and combination regimens.
The clinical-stage oncology company plans to enroll at least 50 patients with uterine serous carcinoma or Cyclin E-overexpressing platinum-resistant ovarian cancer as part of the expanded ACESOT-1051 trial. Dose escalation and backfill expansion are expected to be completed in the second quarter of 2027.
Aprea is increasing the number of active trial sites to 10 from three and expects enrollment to reach six to 10 patients per month by the fourth quarter. The company plans to present its next clinical update at a medical meeting during that quarter.
APR-1051 is an oral WEE1 inhibitor designed to selectively target an enzyme involved in regulating cell division and the DNA damage response. The Phase 1 study is evaluating safety, dose-limiting toxicity and dosing, with pharmacokinetics and antitumor activity among its secondary objectives.
Updated findings presented at the American Society of Clinical Oncology annual meeting in May showed early single-agent activity, including partial responses and disease stabilization, according to Aprea. The results were based on data available through May 6 and remain from an early-stage study primarily designed to evaluate safety and dosing.
The company also intends to move APR-1051 into combination regimens. Plans include pairing the drug with immune checkpoint therapy in HPV-positive head and neck squamous cell carcinoma and with standard chemotherapy in colorectal cancer, following preclinical studies that Aprea reported showed evidence of treatment synergy.
Chief Executive Officer Oren Gilad characterized the expansion as a response to the early clinical findings and noted that advancing dose escalation is intended to inform dose selection for the broader development program.
The expansion is being supported by a $30 million private placement completed in the first quarter. Aprea ended June with $41.2 million in cash and cash equivalents, up from $14.6 million at the end of 2025, and expects its existing resources to fund projected operations and capital expenditures into the first quarter of 2028.
Aprea is concentrating its internal clinical resources on APR-1051 after closing the ABOYA-119 Phase 1/2a dose-escalation study of ATRN-119 in 2025. That program established a recommended Phase 2 monotherapy dose of 1,100 milligrams once daily before the company redirected resources.
The company is considering further development of ATRN-119 through combination studies rather than its previous monotherapy program. Discussions with academic centers include potential investigator-initiated studies combining the ATR inhibitor with immuno-oncology agents, chemotherapy, antibody-drug conjugates or radiation across solid tumors and hematologic malignancies.
Aprea also has an earlier-stage macrocyclic DYRK1A/B inhibitor program that could enter IND-enabling studies in the fourth quarter, subject to available resources.
Research and development spending increased to $2.5 million in the second quarter from $1.9 million a year earlier, primarily reflecting higher spending on ACESOT-1051, partially offset by reduced costs following the closure of the ATRN-119 trial.
The company’s operating loss widened to $4 million from $3.4 million, while general and administrative expenses were unchanged at $1.6 million.
Aprea reported a quarterly net loss of $3.6 million, or 7 cents per share, compared with a $3.2 million loss, or 53 cents per share, a year earlier. Weighted-average shares outstanding increased to approximately 53.5 million from 6.1 million in the prior-year quarter.
Support the local news that supports Chester County. MyChesCo delivers reliable, fact-based reporting and essential community resources—free for everyone. If you value that, click here to become a patron today.