Aprea Therapeutics Announces Preliminary Data From Current Phase 1 ACESOT-1051 Study Of WEE1 Kinase Inhibitor Demonstrates Second Unconfirmed Partial Response

Aprea Therapeutics, Inc. (Nasdaq: APRE) ("Aprea" or the "Company"), a clinical-stage biopharmaceutical company developing innovative therapies that exploit cancer-specific vulnerabilities while minimizing damage to healthy cells, today announced additional preliminary data from the ongoing Phase 1 ACESOT-1051 trial evaluating its investigational WEE1 kinase inhibitor APR-1051.

The Company reported a second unconfirmed partial response at first on-treatment scan in a patient with advanced endometrial cancer being treated at the 220 mg dose level (Cohort 8).

At the first on-treatment imaging assessment of single dose daily APR-1051, the responding patient achieved a 50% reduction from baseline in target lesion measurements, consistent with partial response per RECIST v1.1 criteria. In addition, there was a notable decline in the tumor biomarker CA-125, with levels dropping from 362 U/mL at baseline to 47 U/mL (-87%), further supporting the anti-tumor activity of APR-1051. The patient's tumor harbors a PPP2R1A mutation. To date, the patient had only Grade 1 treatment-emergent adverse effects and continues treatment.