Zentalis Pharmaceuticals to Present Two Posters at the American Association for Cancer Research (AACR) Annual Meeting 2026

Preclinical evidence supports azenosertib ADC combinations as potential promising therapeutic strategies for Triple-Negative Breast Cancer

Demonstration of Cyclin E1 protein overexpression as an indicator for poor prognosis in ovarian cancer patients with real world data

SAN DIEGO, March 17, 2026 -- Zentalis

 Pharmaceuticals, Inc. (Nasdaq: ZNTL), a clinical oncology innovator advancing late-stage development of investigational first-in-class WEE1 inhibitor azenosertib as a biomarker-driven treatment approach for ovarian cancer, today announced two poster presentations at the 2026 American Association for Cancer Research (AACR) Annual Meeting, taking place April 17-22, 2026, in San Diego, CA.

“We are excited to highlight the potential to expand the opportunity for azenosertib as a combination therapy with cytotoxic agents, including antibody drug conjugates (ADC) and chemotherapy, for Triple-Negative Breast Cancer, a subtype of breast cancer with elevated Cyclin E1 expression. These data support clinical study of azenosertib in tumor types beyond ovarian cancer,” said Julie Eastland, Chief Executive Officer. “In addition, the Cyclin E1 biomarker findings in ovarian cancer based on real world data reinforce the high unmet need for this biomarker-selected patient population with poor prognosis. Our biomarker-driven strategy for azenosertib monotherapy in Cyclin E1-positive platinum-resistant ovarian cancer has potential to address this unmet need.”

AACR poster presentation details are below:

Title: “WEE1 Inhibition as a Therapeutic Strategy in Triple-Negative Breast Cancer: Evaluating Single Agent and Combination Activity of Azenosertib in Preclinical Models”
Abstract Number: 2012
Date/Time: Monday, April 20, 2026, 2:00 p.m. - 5:00 p.m. PDT
Presenting Author: Alexandra Levy, MS

Title: “Real-World Treatment Patterns and Outcomes Reveal Distinct Clinical Trajectories of Patients with Cyclin E1-Positive Ovarian Cancer”
Abstract Number: 1708
Date/Time: Sunday, April 19, 2026, 2:00 p.m. - 5:00 p.m. PDT
Presenting Author: Jinkil Jeong, PhD

The posters can be accessed on the page of the Zentalis at the time of each presentation’s session.

About Azenosertib
Azenosertib is an investigational, potentially first-in-class, selective, and orally bioavailable inhibitor of WEE1 currently being evaluated in clinical studies in ovarian cancer and additional tumor types. WEE1 acts as a master regulator of the G1-S and G2-M cell cycle checkpoints, through negative regulation of both CDK1 and CDK2, to prevent replication of cells with damaged DNA. By inhibiting WEE1, azenosertib enables cell cycle progression, despite high levels of DNA damage, thereby resulting in the accumulation of DNA damage and leading to mitotic catastrophe and cancer cell death.

Azenosertib is in late-stage development as a potential treatment for Cyclin E1-positive platinum-resistant ovarian cancer (PROC). There is currently no approved treatment option specifically for this biomarker-selected population which comprises approximately 50% of PROC patients. Cyclin E1 protein overexpression has been established as a sensitive and specific predictive biomarker for identifying patients who could potentially derive benefit from azenosertib treatment.

About Zentalis Pharmaceuticals
Zentalis is a clinical oncology innovator developing a treatment approach for ovarian cancer and multiple tumor types. Leveraging therapeutics development and biomarker expertise, Zentalis is advancing monotherapy and combination studies of its first-in-class WEE1 inhibitor, azenosertib. Focused on translating WEE1 science into clinical practice, we aim to equip physicians with a targeted, non-chemo, orally available medicine that enhances treatment experience, choice, and outcomes. Our mission: to unburden cancer patients with more convenience and care.

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Contact:
Aron Feingold
VP, Investor Relations & Corporate Communications