APR-1051 - (ACESOT-1051)

July 30, 2026: Aprea Therapeutics, Inc. (NASDAQ: APRE) provided a clinical and development update on its ongoing Phase 1 dose-escalation ACESOT-1051 trial of oral WEE1 inhibitor APR-1051 in advanced solid tumors. The company said the next clinical data update is expected at a medical meeting in Q4 2026 (upcoming catalyst), following its most recent poster update presented at the ASCO 2026 annual meeting.

Aprea reported enrollment is accelerating as dose escalation advances (currently enrolling the 300 mg cohort), with active sites expanding from three to ten and enrollment expected to reach 6–10 patients per month by Q4 2026. The company is expanding enrollment to include at least 50 patients with uterine serous carcinoma (USC) or cyclin E–overexpressing platinum-resistant ovarian cancer (PROC), with completion of dose escalation and backfill expansion anticipated in Q2 2027.

Aprea also plans to add combination-regimen arms within ACESOT-1051: APR-1051 plus immune checkpoint therapy in HPV-positive head and neck squamous cell carcinoma, and APR-1051 plus standard-of-care chemotherapy in colorectal cancer, using dose levels that have cleared safety review and shown single-agent activity.