Benzinga | Sep 20, 2021 04:18PM EDT

Aprea Therapeutics Presents Data From Phase 1/2 Trial Of Eprenetapopt In Advanced Solid Tumors At ESMO Congress 2021

Aprea Therapeutics, Inc. (NASDAQ:APRE), a biopharmaceutical company focused on developing and commercializing novel cancer therapeutics that reactivate the mutant tumor suppressor protein, p53, today presented data at the European Society of Medical Oncology (ESMO) Congress 2021 from its Phase I/II clinical trial in advanced solid tumors. The trial is evaluating the safety and efficacy of eprenetapopt in combination with pembrolizumab.



As of the July 31, 2021 data cutoff, 33 patients were enrolled on study and 31 had initiated treatment. The Phase I safety lead-in part was a dose de-escalation design and no dose-limiting toxicities were reported in the 6 enrolled patients. A Phase II expansion part was initiated and, as of the data cutoff, has enrolled 3 patients in the gastric/GEJ cancer, 3 in the bladder/urothelial cancer and 19 in the non-small cell lung cancer (NSCLC) cohorts. Patients in the NSCLC Phase II cohort were required to have prior exposure to a PD-1 or PD-L1 inhibitor. Across all patients, 25 (76%) had a mutation in the TP53 gene. The trial continues to enroll and treat patients and exploratory studies involving analyses of patient-derived immune cell populations are ongoing.

In the bladder/urothelial cohort, 1 patient with locally advanced TP53 mutant high-grade transitional cell bladder cancer had achieved complete remission (CR) by RECIST criteria at the first response assessment at 9 weeks. In the NSCLC cohort, 2 patients with TP53 mutant squamous NSCLC had reductions in target lesions of 26.7% and 8.2%, respectively, from baseline by RECIST criteria at the first response assessment at 9 weeks. Adverse events, regardless of causality, were mostly grade 1/2. Grade ?3 events occurring in more than 1 patient included anemia (3), dyspnea (3), dizziness (2), pain (2) and malnutrition (2). Dizziness (2 patients) was the only grade ?3 adverse event assessed by an investigator as eprenetapopt-related and occurring in more than 1 patient. One patient experienced a fatal adverse event of disease progression which was assessed by an investigator as not related to study treatment, and one patient experienced adverse events of fatigue, dyspnea and maculo-papular rash leading to discontinuation of eprenetapopt.

"The emerging data for the combination of eprenetapopt and pembrolizumab in these difficult-to-treat patients is very encouraging," said Dr. Haeseong Park of Washington University in St. Louis. "Particularly promising are tumor reductions in lung cancer patients who previously received I/O therapy, and the complete remission in a bladder cancer patient with prior chemotherapy exposure, which is rare. In addition, the clinical experience to-date suggests the combination is well-tolerated with adverse events readily managed with standard of care measures. The other investigators and I look forward to maturation of the data from this clinical trial as we seek to enroll and treat additional patients with this novel combination."