Zentalis Announces Presentation of Positive Phase 1b Data Demonstrating Durable Responses and Favorable Safety Profile of Azenosertib in Combination with Chemotherapy at the 2023 ASCO Annual Meeting

Strong anti-tumor activity shown in a platinum-resistant ovarian cancer population, with a confirmed ORR of 50.0% and mPFS of 7.4 months in combination with paclitaxel, and a confirmed ORR of 35.7% and mPFS of 10.4 months in combination with carboplatin  

Patients with Cyclin E1+ tumors benefited most in chemotherapy combination arms, illustrating potential synergy between azenosertib and chemotherapy in this patient population

Intermittent dosing of azenosertib in combination with either paclitaxel or carboplatin compares favorably to historic tolerability data from chemotherapy doublets or other WEE1 inhibitor-chemotherapy combinations

Company plans to initiate Phase 3 trial of azenosertib using intermittent dosing in combination with chemotherapy in Cyclin E1+ platinum-sensitive ovarian cancer in the first quarter 2024

Live webcast to be held on Tuesday, June 6^th at 8:00 a.m. ET

NEW YORK and SAN DIEGO, May 25, 2023 (GLOBE NEWSWIRE) -- Zentalis Pharmaceuticals, Inc. (Nasdaq: ZNTL), a clinical-stage biopharmaceutical company discovering and developing clinically differentiated small molecule therapeutics targeting fundamental biological pathways of cancers, today announced positive data from the Phase 1b trial of azenosertib, the Company’s potentially first-in-class WEE1 inhibitor, in combination with chemotherapy in patients with platinum-resistant ovarian cancer. Azenosertib was well tolerated in combination with multiple types of chemotherapy and demonstrated encouraging clinical activity, with noteworthy improvements in objective response rates (ORRs) and median progression free survival (mPFS) in all patients, especially those with Cyclin E1+ tumors, a subgroup recognized to have a poor prognosis and be refractory to chemotherapy. Results will be presented in a poster discussion session at the 2023 ASCO Annual Meeting on June 5^th (Abstract #5513).

“Azenosertib is emerging as a very promising clinical candidate, with demonstrated anti-tumor activity in difficult-to-treat tumor types when used in combination with standard chemotherapy regimens,” said Kimberly Blackwell, M.D., Chief Executive Officer of Zentalis. “The addition of azenosertib increased ORRs and mPFS over those observed historically with chemotherapy alone, or compared to adavosertib in combination with chemotherapy. We are very encouraged by our robust chemotherapy combination data, particularly the strong efficacy and tolerability results when dosing azenosertib intermittently. These data provide a compelling rationale to advance azenosertib into a registrational study in combination with either carboplatin or paclitaxel in Cyclin E1+ ovarian cancer. We look forward to providing additional insights into our azenosertib clinical programs and the franchise potential we see for this product candidate during our June 6 investor webcast.”