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Zentalis Pharmaceuticals, Inc. SEC filings document clinical oncology disclosures, financial results, governance matters and capital actions for the ZNTL public company. Recent Form 8-K filings cover azenosertib program updates, Regulation FD corporate presentations, clinical-trial and scientific-presentation exhibits, and results of operations furnished with business updates.
The company’s proxy materials describe board composition, executive compensation, equity awards and shareholder voting matters. Other event filings also record corporate governance changes and completed common stock repurchase activity, alongside cautionary risk language related to clinical development, regulatory pathways and forward-looking statements.
Zentalis Pharmaceuticals reported updated Phase 1b MUIR trial results for its investigational WEE1 inhibitor azenosertib combined with paclitaxel in platinum-resistant ovarian cancer (PROC). In 46 all-comer PROC patients across four dose cohorts, the regimen achieved a 39.1% overall response rate and 58.7% clinical benefit rate, with median duration of response of 5.6 months and median progression-free survival of 7.3 months as of the December 1, 2025 cutoff. These outcomes are described as encouraging versus historical paclitaxel monotherapy data of roughly 30% response and 4-month median progression-free survival.
At the 250 mg intermittent 5:2 azenosertib dose (12 patients), overall response rate was 50.0%, clinical benefit rate 66.7%, and median duration of response 9.2 months, supporting this as a potential optimal combination dose. Activity appeared similar in Cyclin E1‑positive and Cyclin E1‑negative tumors. The safety profile was characterized as manageable: common treatment-related adverse events included fatigue, anemia, nausea, and neutropenia, with Grade ≥3 neutropenia in 30.4% and anemia in 19.6% of patients, and one Grade 5 sepsis event considered related to azenosertib.
Zentalis Pharmaceuticals reported a narrower quarterly loss while advancing its lead cancer drug azenosertib. For the three months ended March 31, 2026, net loss was $35.4 million (or $0.50 per share), compared with $48.3 million (or $0.67 per share) a year earlier, helped by lower restructuring and stock-based compensation expenses.
Research and development spending was $28.7 million, reflecting higher clinical and manufacturing costs as the DENALI and ASPENOVA trials progress, while general and administrative expenses declined to $9.1 million. Operating cash use was $33.0 million in the quarter.
Cash, cash equivalents and marketable debt securities totaled $211.8 million as of March 31, 2026, and management believes this will fund operations into late 2027. The company began Phase 3 ASPENOVA in Cyclin E1-positive platinum-resistant ovarian cancer, triggering a subsequent $7.0 million milestone payment under its Recurium license, and expects topline DENALI Part 2 data by year-end 2026.
Zentalis Pharmaceuticals reported a first-quarter 2026 net loss of $35.4 million, improving from $48.3 million a year earlier, with net loss per share narrowing to $0.50 from $0.67. Total operating expenses fell to $37.9 million from $45.6 million, reflecting the absence of a prior-year restructuring charge and lower general and administrative costs, partly offset by higher clinical spending.
The company ended March 31, 2026 with $211.8 million in cash, cash equivalents and marketable securities, which it believes will fund operations into late 2027. Zentalis advanced its lead WEE1 inhibitor azenosertib, selecting a 400mg once-daily 5:2 dosing schedule as the pivotal monotherapy dose in platinum-resistant ovarian cancer and expanding the Phase 2 DENALI trial, with topline data expected by year-end 2026. The Phase 3 ASPENOVA confirmatory trial has dosed its first patient, aiming to support full approval and ex-US registrations in Cyclin E1-positive platinum-resistant ovarian cancer.
Zentalis Pharmaceuticals has dosed the first patient in ASPENOVA, its global Phase 3 trial of investigational WEE1 inhibitor azenosertib for Cyclin E1-positive platinum-resistant ovarian cancer. The randomized study plans to enroll about 420 patients, comparing oral azenosertib 400mg once daily on a 5-days-on, 2-days-off schedule to standard single-agent chemotherapy.
ASPENOVA is designed as a confirmatory trial to support potential full approval, alongside the Phase 2 DENALI study, which is intended to underpin an accelerated approval application with a topline readout targeted by year-end 2026. Azenosertib, which has U.S. FDA Fast Track Designation for this setting, is being developed with a biomarker-driven strategy in collaboration with major gynecologic oncology trial groups.
Zentalis Pharmaceuticals, Inc. is asking stockholders to vote at its fully virtual 2026 Annual Meeting on June 16, 2026 at 10:00 a.m. ET. Holders of 71,186,348 shares of common stock as of April 20, 2026 may vote online, by phone, mail or during the webcast.
Stockholders will elect two Class III directors (David Johnson and Jan Skvarka) to terms ending in 2029, ratify Ernst & Young LLP as auditor for 2026, and cast an advisory say‑on‑pay vote on named executive officer compensation. In 2025, the board determined corporate goals were achieved at 105%, and annual bonuses for eligible executives were paid at 105% of target.
Zentalis Pharmaceuticals furnished an update on its WEE1 inhibitor azenosertib, highlighting new preclinical and real‑world data presented at the AACR 2026 meeting in San Diego. In triple‑negative breast cancer models, azenosertib showed 42–99% tumor growth inhibition as monotherapy and drove stronger responses when combined with antibody‑drug conjugates or paclitaxel, including complete responses in 7 of 8 mice in an ADC‑resistant model.
Real‑world analyses in high‑grade serous ovarian cancer showed Cyclin E1‑positive patients had shorter time to next treatment after first‑line therapy, at 13.2 and 14.9 months in two groups versus 19.5 months for Cyclin E1‑negative patients, underscoring a poor‑prognosis population Zentalis is targeting with late‑stage azenosertib studies.
Zentalis Pharmaceuticals is advancing its WEE1 inhibitor azenosertib in platinum-resistant ovarian cancer by selecting 400mg once daily on a 5-days-on, 2-days-off schedule as the pivotal monotherapy dose for Cyclin E1-positive patients. This choice is based on a prespecified interim analysis from the DENALI Phase 2 Part 2a trial, which showed a clearly differentiated response rate versus 300mg with broadly comparable safety.
The 400mg QD 5:2 dose will be used across the registration-intended DENALI Phase 2 study and the confirmatory ASPENOVA Phase 3 trial, expected to initiate in Q2 2026 and enroll about 420 patients against investigator’s-choice chemotherapy. Zentalis plans a DENALI Part 2 topline readout by year-end 2026 and continues to target an accelerated approval pathway. In integrated datasets, azenosertib at 400mg QD 5:2 in Cyclin E1-positive PROC has shown objective response rates above 30% with median duration of response around five to six months, alongside a manageable safety profile. The company estimates roughly 21,500 Cyclin E1-positive PROC patients, about half of the PROC population, and reports $245 cash, cash equivalents and marketable securities as of December 31, 2025, which it believes can fund operations into late 2027.
Zentalis Pharmaceuticals is a clinical-stage biopharma company focused on developing azenosertib (ZN‑c3), an oral WEE1 inhibitor, primarily for Cyclin E1‑positive platinum‑resistant ovarian cancer (PROC). The company has no approved products and relies on external manufacturers and collaborators.
Azenosertib has shown single‑agent anti-tumor activity with objective response rates around one‑third in Cyclin E1‑positive PROC across multiple studies, using an intermittent 400 mg once‑daily 5:2 schedule. Zentalis believes the Phase 2 DENALI Part 2 study, if successful, could support accelerated U.S. approval, with the Phase 3 ASPENOVA trial planned as a confirmatory study.
The company highlights a sizable biomarker‑defined market opportunity in PROC and potential expansion into earlier ovarian cancer lines and other solid tumors. Key risks include continued losses, substantial capital needs, dependence on a single lead asset, complex regulatory pathways, competition from other WEE1 and oncology approaches, and reliance on third‑party manufacturers and CROs.
Zentalis Pharmaceuticals reported full-year 2025 results showing continued investment in its lead WEE1 inhibitor azenosertib while narrowing losses. The company ended 2025 with $245.9 million in cash, cash equivalents and marketable securities and expects this to fund operations into late 2027, beyond the planned DENALI Part 2 topline readout.
Revenue from licensing and intellectual property dropped to $0 in 2025 from $67.4 million in 2024, while net loss attributable to Zentalis improved to $137.1 million from $165.8 million. Research and development expenses declined to $107.3 million and general and administrative expenses to $37.7 million, reflecting sizable cost reductions and a restructuring charge of $7.8 million.
Clinically, Zentalis completed enrollment in DENALI Part 2a, aligned with the FDA on the Phase 3 ASPENOVA trial design, and is advancing the MUIR study of azenosertib plus bevacizumab in ovarian cancer. Key 2026 milestones include DENALI dose confirmation and Phase 3 ASPENOVA initiation in the first half of 2026, and DENALI Part 2 topline data by year-end, which could potentially support accelerated approval subject to FDA feedback.