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Key Takeaways Zentalis advanced azenosertib with pivotal studies targeting cyclin E1-positive PROC.ZNTL expects DENALI enrollment completion and topline data by the end of 2026 to support approval efforts.Zentalis is expanding azenosertib into combination studies and additional tumor types, including TNBC. Zentalis Pharmaceuticals'(ZNTL - Free Report) shares have gained 28% over the past three months, fueled by investor optimism surrounding its lead oncology candidate, azenosertib.

Azenosertib Drives ZNTL's Ovarian Cancer PushAzenosertib is Zentalis’ potential first-in-class WEE1 inhibitor being developed as a biomarker-driven oral therapy for ovarian cancer and additional tumor types. Based on interim data from part 2a, which demonstrated a favorable benefit-risk profile, Zentalis selected the 400 mg once-daily, 5-days-on/2-days-off (400 mg QD 5:2) regimen in April as the pivotal dose for azenosertib monotherapy for its registration-intended DENALI phase II clinical program to treat patients with cyclin E1-positive platinum-resistant ovarian cancer (PROC).

Management expects to complete enrollment across all DENALI part 2 cohorts and announce top-line data by the end of 2026, which could support an accelerated approval pathway, subject to positive data and FDA feedback.

Further supporting its regulatory strategy, Zentalis dosed the first patient in the phase III ASPENOVA confirmatory study in May. The study compares azenosertib monotherapy with the investigator's choice of standard-of-care chemotherapy in patients with cyclin E1-positive PROC and is designed to support the full FDA approval and potential global regulatory filings.

The FDA granted previously Fast Track Designation to azenosertib for the treatment of patients with cyclin E1-positive PROC.

Year to date, Zentalis shares have skyrocketed 278.5% compared with the industry’s 3% growth.

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Broadening Pipeline Boosts ZNTL's ProspectsBeyond its pivotal monotherapy program, the ongoing multi-part phase Ib MUIR study is evaluating azenosertib-based combination therapies in ovarian cancer to expand the candidate's potential beyond monotherapy. While part one is assessing azenosertib in combination with multiple chemotherapy regimens in patients with PROC, the currently enrolling part two dose-expansion cohort is evaluating azenosertib plus bevacizumab as a maintenance therapy for patients with second-line platinum-sensitive ovarian cancer whose disease progressed during first-line PARP inhibitor maintenance therapy.

Encouraging preclinical data showed that azenosertib combinations demonstrated activity in ADC-resistant triple-negative breast cancer (TNBC), supporting its expansion beyond ovarian cancer.

ZNTL’s Zacks Rank & Stocks to ConsiderZentalis currently carries a Zacks Rank #3 (Hold).

Some better-ranked stocks in the biotech sector are Neurocrine Biosciences (NBIX - Free Report) , Amarin Corporation (AMRN - Free Report) and Liquidia Corporation (LQDA - Free Report) , each currently sporting a Zacks Rank #1 (Strong Buy). You can see the complete list of today’s Zacks #1 Rank stocks here.

Over the past 60 days, estimates for Neurocrine Biosciences’ 2026 earnings per share have risen from $9.15 to $9.44. Over the same period, EPS estimates for 2027 have increased from $10.23 to $10.79. NBIX shares have gained 20.5% year to date.

Neurocrine Biosciences’ earnings beat estimates in three of the trailing four quarters and missed in the remaining one, the average surprise being 9.08%.

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Amarin’s earnings beat estimates in three of the trailing four quarters and missed in the remaining one, the average surprise being 50.02%.

Over the past 60 days, estimates for Liquidia’s 2026 earnings per share have increased to $3.02 from $2.97. Over the same period, EPS estimates for 2027 have risen to $4.92 from $4.81. LQDA shares have soared 131.8% year to date.

Liquidia’s earnings beat estimates in three of the trailing four quarters and missed in the remaining one, the average surprise being 54.40%.

Almitas Capital LLC trimmed its position in Zentalis Pharmaceuticals, Inc. (NASDAQ: ZNTL) by 71.4% during the third quarter, according to the company in its most recent 13F filing with the Securities and Exchange Commission (SEC). The firm owned 457,322 shares of the company's stock after selling 1,141,944 shares during the quarter. Almitas Capital

On track for DENALI Part 2a dose confirmation in 1H 2026 DENALI Part 2 trial topline readout expected by year end 2026; potential to support accelerated approval On track to initiate the ASPENOVA Phase 3, randomized, confirmatory trial in 1H 2026 Expanding azenosertib potential in ovarian cancer with the ongoing MUIR Part 2 trial evaluating the combination of azenosertib and bevacizumab as maintenance therapy $245.9 million cash, cash equivalents and marketable securities balance as of December 31, 2025, with projected cash runway into late 2027 SAN DIEGO, March 26, 2026 (GLOBE NEWSWIRE) -- 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 financial results for the year ended December 31, 2025, and highlighted recent corporate accomplishments and milestones expected for 2026. “The completion of enrollment for DENALI Part 2a represented a key milestone to enable dose confirmation in the first half of 2026, with topline DENALI Part 2 trial readout anticipated by year-end.

Planned interim analysis from DENALI Part 2a showed a clearly differentiated response rate at 400mg QD 5:2 over 300mg QD 5:2 and comparable safety profiles between the two dose groupsAzenosertib therapeutic profile supports Phase 2 DENALI and Phase 3 ASPENOVA advancement as well as initiation of pre-commercial activitiesDENALI Part 2 topline readout expected by year end 2026 SAN DIEGO, April 09, 2026 (GLOBE NEWSWIRE) -- 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 the selection of 400mg once daily on a 5-days-on, 2-days-off schedule (400mg QD 5:2) as the optimal monotherapy dose of azenosertib in patients with Cyclin E1-positive platinum-resistant ovarian cancer (PROC) based on the prespecified interim data analysis from DENALI Part 2a. This dose will be carried forward in the ongoing potentially pivotal DENALI Phase 2 clinical trial as well as the confirmatory ASPENOVA Phase 3 clinical trial.

"Selecting the pivotal monotherapy dose for azenosertib is a key inflection point that supports our registration-intended path. Beyond executing on DENALI and ASPENOVA, we are initiating launch preparedness by adding commercial capabilities to our organization, scaling manufacturing capacity, and advancing companion diagnostic development," said Julie Eastland, Chief Executive Officer of Zentalis. "Importantly, the therapeutic profile of the selected dose from the DENALI Part 2a interim analysis provides us confidence to further pursue expansion of the clinical pipeline for azenosertib into first-line maintenance, or platinum sensitive, ovarian cancer and explore combinations in new tumor types."

“The emerging DENALI Part 2a data from the planned interim analysis provide a favorable benefit-risk profile at the 400mg QD 5:2 dose over 300mg QD 5:2. A meaningful, differentiated response rate with the selected dose and comparable safety profiles across both dose groups were observed in this interim analysis,” said Ingmar Bruns, M.D., Chief Medical Officer of Zentalis. “While DENALI is an ongoing trial, we are encouraged by the interim Part 2a data and continued momentum of the clinical study. As an oral monotherapy, azenosertib may offer Cyclin E1-positive PROC patients an efficacious, convenient alternative to current standard-of-care intravenous chemotherapy, if approved.”

DENALI Part 2a Interim Analysis

A comprehensive review of the interim data from DENALI Part 2a informed the selection of the 400mg QD 5:2 dose over 300mg QD 5:2. A prespecified interim analysis showed:

A meaningful and clearly differentiated response rate at 400mg QD 5:2 over 300mg QD 5:2 doseComparable safety profiles across the two dose groups and observed improvements in several key measures, such as a discontinuation rate due to adverse events at approximately half of the rate reported in DENALI Part 1b and no treatment-related deaths. Consistent with the seamless design of the registration-intended DENALI Part 2 trial, data from Part 2a will be included in the ongoing, full Part 2 dataset after the trial is completed, rather than reported separately. This approach is intended to preserve the integrity of the overall pivotal dataset and support the potential accelerated approval pathway.

DENALI Part 2 Trial Design Updated to Address Evolving PROC Landscape

The treatment landscape in PROC is evolving. The DENALI Part 2 study has been expanded to maintain alignment between the study population and available approved treatment options.

A new DENALI cohort that broadens inclusion to patients previously treated with a taxane-containing regimen for PROC, called Part 2c, intends to further align the study with the evolving treatment landscape. Enrollment in Part 2c is planned to initiate in Q2 2026.

Together, all three DENALI Part 2 cohorts are designed to support a potential accelerated approval pathway in the Cyclin E1 biomarker selected patient population, subject to regulatory review. Zentalis expects to complete enrollment in all cohorts of DENALI Part 2 and provide a topline readout by year-end 2026.

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, based on retrospective analysis of azenosertib studies in PROC. Validation of the Cyclin E1 companion diagnostic assay is ongoing in the DENALI and ASPENOVA trials.

Azenosertib has been granted Fast Track Designation by the U.S. FDA for the treatment of patients with Cyclin E1-positive platinum-resistant ovarian cancer. Fast Track Designation is intended to facilitate the development and expedite the review of therapies that have the potential to treat serious conditions and address unmet medical needs.

About DENALI Clinical Trial 
DENALI is a multi-part Phase 2 registration-intended clinical trial (NCT05128825) studying azenosertib in PROC patients.

Part 1b enrolled patients with PROC regardless of Cyclin E1 protein expression, all treated at 400mg QD 5:2. Part 2 is prospectively enrolling PROC patients with Cyclin E1 protein overexpression based on Zentalis' proprietary immunohistochemistry cutoff.

Part 2, in total, is designed to support accelerated approval, pending study outcome and discussions with the FDA. The study design consists of the following parts:

Part 2a: Dose confirmation evaluated two doses, 300mg QD 5:2 and 400mg QD 5:2, with approximately 30 patients enrolled per dose group. 400mg QD 5:2 was selected as the optimal monotherapy dose. Recruitment at the 300mg QD 5:2 dose level has been discontinued. All patients enrolled in Part 2a will contribute to the overall safety database submitted to the FDA.Part 2b: Enrollment expansion at the selected dose up to approximately 100 patients, including patients at the 400mg QD 5:2 dose in Part 2a. This cohort is currently enrolling.Part 2c: Broadening study population to include approximately 40 patients previously treated with a taxane-containing regimen for PROC. Enrollment is expected to initiate in this cohort in Q2 2026. For physician and patient information about the DENALI trial, please visit www.denalitrial.com.

About ASPENOVA Clinical Trial
ASPENOVA is a Phase 3 randomized, confirmatory clinical trial designed to support full approval of azenosertib in patients with Cyclin E1-positive platinum-resistant ovarian cancer (PROC). The trial will enroll approximately 420 patients and compare azenosertib monotherapy at 400mg QD 5:2 to investigator's choice of standard-of-care single-agent chemotherapy (paclitaxel, pegylated liposomal doxorubicin [PLD], gemcitabine, or topotecan) in this biomarker-selected population. The trial design was aligned with the U.S. FDA to meet requirements for the accelerated approval pathway and potential conversion to full approval. ASPENOVA is expected to initiate in Q2 2026.

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.​

For more information, please visit www.zentalis.com. Follow Zentalis on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, as amended. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, but not limited to, statements regarding the continued development of azenosertib; the clinical and therapeutic potential of azenosertib; the potential for azenosertib to be first-in-class; the significance of the referenced data on the late-stage development of azenosertib; the potential benefits of azenosertib, including the potential for azenosertib to meaningfully improve outcomes for Cyclin E1-positive PROC patients; the Company’s biomarker-driven strategy for azenosertib; the potential to pursue expansion of the clinical pipeline for azenosertib outside PROC; our anticipated milestones and the timing thereof, including the anticipated timing of the completion of enrollment in all cohorts of, and topline readout from, DENALI Part 2; the initiation, design, conduct and timing of DENALI Part 2c and our confirmatory ASPENOVA Phase 3 trial; our planned regulatory strategy for azenosertib and the timing thereof, including the potential for DENALI Part 2 to support an accelerated approval; and our initiation of pre-commercial activities. The terms “add,” “anticipate,” “advance,” “aim,” “believe,” “continued,” “design,” “develop,” “encouraged,” “expect,” “intent,” “look forward,” “may,” “mission,” “momentum,” “on track,” “pivotal,” “plan,” “position,” “potential,” “pursue,” “scale,” “strategy,” “support,” “target,” and “will” and similar references are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our limited operating history, which may make it difficult to evaluate our current business and predict our future success and viability; we have and expect to continue to incur significant losses; our need for additional funding, which may not be available; our substantial dependence on the success of azenosertib; our plans, including the costs thereof, of development of companion diagnostics; the outcome of early clinical trials may not be predictive of the success of later stage clinical trials; potential unforeseen events during clinical trials could cause delays or other adverse consequences; risks relating to the regulatory approval process or ongoing regulatory obligations; our product candidates may cause serious adverse side effects; the interim and preliminary data from our clinical trials may change as more patient data becomes available, and are subject to audit and verification procedures that could result in material changes in the final data; if our confirmatory trials do not verify clinical benefit, the FDA may seek to withdraw accelerated approval; our ability to establish effective sales or marketing capabilities; our reliance on third parties; effects of significant competition; the possibility of system failures or security breaches; risks relating to intellectual property; our ability to attract, retain and motivate qualified personnel; significant costs as a result of operating as a public company; and the other important factors discussed under the caption “Risk Factors” in our most recently filed periodic report on Form 10-K or 10-Q and subsequent filings with the U.S. Securities and Exchange Commission (SEC) and our other filings with the SEC. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change.

ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release. 

Contact:
Aron Feingold
VP, Investor Relations & Corporate Communications
[email protected]  

April 17, 2026 15:15 ET  | Source: ZENTALIS PHARMACEUTICALS

Preclinical data show encouraging activity of azenosertib combinations in ADC-resistant TNBC, supporting the potential for pipeline expansion beyond ovarian cancer Real-world data demonstrate Cyclin E1-positive ovarian cancer patients have significantly worse outcomes, independent of CCNE1 gene amplification status, reinforcing the potential for azenosertib to address the unmet need for these patients
SAN DIEGO, April 17, 2026 (GLOBE NEWSWIRE) -- 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 data from two posters being presented at the 2026 American Association for Cancer Research (AACR) Annual Meeting, taking place April 17-22, 2026, in San Diego, CA. The data show encouraging preclinical activity of azenosertib in triple-negative breast cancer (TNBC) and highlight the poor prognosis of Cyclin E1-positive ovarian cancer patients with currently available treatments in a real-world data analysis.

Compelling Preclinical Activity in Triple-Negative Breast Cancer with Azenosertib

"The preclinical data in triple-negative breast cancer being presented at AACR showed that azenosertib combinations can induce complete tumor responses in a model resistant to emerging ADC therapies, supporting the potential to broaden the impact of azenosertib beyond ovarian cancer," said Julie Eastland, Chief Executive Officer of Zentalis. "This includes potential development of azenosertib through differentiated combination strategies with antibody-drug conjugates (ADCs) and chemotherapy. As ADCs advance toward first-line use in TNBC, effective post-ADC treatment strategies represent a growing unmet need that azenosertib combinations may be uniquely positioned to fill. Our data suggest azenosertib may achieve this through multiple mechanisms – possibly resensitizing tumors to chemotherapy, enhancing the responses to ADC, and extending the duration of response – which is an exciting potential future direction for our pipeline."

Preclinical evidence supports azenosertib as a therapeutic strategy in TNBC:

TNBC cell lines showed higher Cyclin E1 expression and greater sensitivity to WEE1 inhibition compared to other breast cancer cell lines Azenosertib monotherapy demonstrated meaningful antitumor activity across a diverse panel of 12 TNBC in vivo xenograft models (42-99% tumor growth inhibition) In a patient-derived xenograft model of TNBC with clinical resistance to sacituzumab govitecan, an approved topoisomerase 1 inhibitor (TOPO1i) ADC, azenosertib + enfortumab vedotin (EV): Induced complete responses in 7 of 8 mice (87.5%); 5 mice did not progress after treatment discontinuationPrevented tumor progression in 8 of 8 mice for more than 52 days compared to 100% progression observed within 30 days with EV aloneDrove deep tumor regression in mice models refractory to sacituzumab govitecan or trastuzumab deruxtecan with large tumor volumes (average ~900mm3) Combinations of azenosertib with TOPO1i-payload ADCs (sacituzumab govitecan, datopotamab deruxtecan, or trastuzumab deruxtecan) enhanced both depth and duration of response compared to ADC monotherapy in ADC-naïve modelsAzenosertib + paclitaxel restored substantial sensitivity to paclitaxel in a model resistant to both paclitaxel and TOPO1i ADCs (51% tumor growth inhibition vs. 16% with paclitaxel alone) Cyclin E1 Protein Overexpression Characterizes Ovarian Cancer Patients with Poor Prognosis

"The real-world data being presented at AACR provide important validation that Cyclin E1-positive ovarian cancer patients face a particularly challenging disease trajectory with standard-of-care therapies," said Ingmar Bruns, M.D., Chief Medical Officer of Zentalis. "The consistency of worse outcomes across independent cohorts and multiple treatment settings underscores the significant unmet need in this population. These findings provide important context for Zentalis' registration-intended DENALI and ASPENOVA studies, which are evaluating WEE1 inhibition with azenosertib monotherapy as a targeted approach for the Cyclin E1-positive population that currently has limited effective treatment options."

Real-world data from two independent cohorts (Tempus Lens Ovarian cancer dataset and Zentalis' historical clinical trials) consistently demonstrated that Cyclin E1-positive ovarian cancer patients experience worse clinical outcomes:

After first-line treatment, Cyclin E1-positive patients, with or without CCNE1 gene amplification, had shorter time to next treatment compared to Cyclin E1-negative patients (13.2 months and 14.9 months, respectively, compared to 19.5 months, p=0.002)Cyclin E1-positivity is associated with a trend toward reduced clinical benefit from standard-of-care PROC treatments AACR Poster Details

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 Supporting Publications page of the Zentalis website.

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, based on retrospective analysis of azenosertib studies in PROC. Validation of the Cyclin E1 companion diagnostic assay is ongoing in the DENALI and ASPENOVA trials.

Azenosertib has been granted Fast Track Designation by the U.S. FDA for the treatment of patients with Cyclin E1-positive platinum-resistant ovarian cancer. Fast Track Designation is intended to facilitate the development and expedite the review of therapies that have the potential to treat serious conditions and address unmet medical needs.

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.

For more information, please visit www.zentalis.com. Follow Zentalis on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, as amended. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, but not limited to, statements regarding the continued development of azenosertib; the clinical and therapeutic potential of azenosertib; the potential for azenosertib to be first-in-class; the potential benefits of azenosertib, including the potential for azenosertib to be an important treatment option for patients with ovarian cancer, triple negative breast cancer or other indications, the mechanisms through which azenosertib may fill unmet needs, and the ability of azenosertib combinations to induce complete tumor responses; the unmet need for treatments in ovarian cancer, triple negative breast cancer or other indications; the broad franchise potential of azenosertib; the Company’s biomarker-driven strategy for azenosertib; the future direction of our pipeline, including the potential for pipeline expansion; and our participation in poster presentations. The terms “anticipate,” “advance,” “believe,” “design,” “develop,” “encouraging” “expect,” “future,” “intent,” “look forward,” “may,” “on track,” “plan,” “position,” “potential,” “runway,” “strategy,” “target,” “upcoming,” and “will” and similar references are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our limited operating history, which may make it difficult to evaluate our current business and predict our future success and viability; we have and expect to continue to incur significant losses; our need for additional funding, which may not be available; our substantial dependence on the success of azenosertib; our plans, including the costs thereof, of development of companion diagnostics; the outcome of preclinical testing and early trials may not be predictive of the success of later clinical trials; potential unforeseen events during clinical trials could cause delays or other adverse consequences; risks relating to the regulatory approval process or ongoing regulatory obligations; our product candidates may cause serious adverse side effects; the interim, initial, “topline,” and preliminary data from our clinical trials may change as more patient data becomes available, and are subject to audit and verification procedures that could result in material changes in the final data; our reliance on third parties; effects of significant competition; the possibility of system failures or security breaches; risks relating to intellectual property; our ability to attract, retain and motivate qualified personnel, and risks relating to management transitions; significant costs as a result of operating as a public company; and the other important factors discussed under the caption “Risk Factors” in our most recently filed periodic report on Form 10-K or 10-Q and subsequent filings with the U.S. Securities and Exchange Commission (SEC) and our other filings with the SEC. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change.

ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release. 

Contact: 
Aron Feingold
VP, Investor Relations & Corporate Communications
[email protected]

May 01, 2026 17:30 ET  | Source: ZENTALIS PHARMACEUTICALS

SAN DIEGO, May 01, 2026 (GLOBE NEWSWIRE) -- 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 that on May 1, 2026, the Compensation Committee of Zentalis’ Board of Directors granted non-qualified stock options to purchase an aggregate of 26,000 shares of the Company’s common stock to one (1) newly hired employee. The stock options were granted under the Zentalis Pharmaceuticals, Inc. 2022 Employment Inducement Incentive Award Plan (2022 Inducement Plan) as an inducement material to such individual’s entering into employment with Zentalis in accordance with Nasdaq Listing Rule 5635(c)(4).

The 2022 Inducement Plan is used exclusively for the grant of equity awards to individuals who were not previously employees of Zentalis, or following a bona fide period of non-employment, as an inducement material to each such individual’s entering into employment with Zentalis, pursuant to Nasdaq Listing Rule 5635(c)(4).

The stock options have an exercise price of $4.09 per share, which is equal to the closing price of Zentalis’ common stock on The Nasdaq Global Market on the date of grant. The stock options have a 10-year term and will vest over four years, with 25% of the options vesting on the first anniversary of the vesting commencement date and the remaining 75% of the options vesting in equal monthly installments over the three years thereafter.

Vesting of the stock options is subject to the employee’s continued service to Zentalis on each vesting date.

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.​

For more information, please visit www.zentalis.com. Follow Zentalis on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals.

ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release.

Contact: 
Aron Feingold
VP, Investor Relations & Corporate Communications
[email protected]

400mg QD 5:2 selected as azenosertib monotherapy pivotal study dose based on favorable benefit-risk profile in DENALI Part 2a, supporting advancement in registration-intended trialsDENALI Phase 2 trial topline readout expected by year-end 2026, with potential to support accelerated approval pathway, pending data outcomes and FDA feedbackASPENOVA Phase 3 confirmatory trial in Cyclin E1-positive PROC initiated with first patient dosed; designed to support conversion to PROC full approval and ex-US registrations$211.8 million in cash, cash equivalents and marketable securities as of March 31, 2026, providing runway into late 2027 with funding to support execution of key milestones SAN DIEGO, May 12, 2026 (GLOBE NEWSWIRE) -- 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 financial results for the first quarter ended March 31, 2026, and highlighted recent clinical progress.

"This quarter, we built momentum with achievement of key milestones advancing azenosertib in our registration-intended Phase 2 and Phase 3 trials for patients with Cyclin E1-positive platinum-resistant ovarian cancer (PROC),” said Julie Eastland, Chief Executive Officer of Zentalis. "Our core focus is on bringing a convenient, oral, non-chemotherapy treatment option to approximately 50% of PROC patients who are Cyclin E1-positive and may experience poorer prognosis and limited benefit from standard-of-care therapies. Pivotal dose selection supports our regulatory strategy, positioning us to pursue accelerated approval through the DENALI Part 2 trial while simultaneously advancing ASPENOVA as our confirmatory trial—together charting a pathway to bring a potential first-in-class therapy to market for this underserved patient population. Following dose selection, we initiated pre-commercial launch preparedness activities to add commercial capabilities to the organization, scale manufacturing capacity and advance Cyclin E1 companion diagnostic market development. Beyond the lead indication, we see substantial opportunity for strategic expansion of azenosertib into platinum-sensitive or first-line maintenance settings of ovarian cancer, additional tumor types, and combination approaches."

"With a cash position of $211.8 million as of March 31, 2026, we have runway into late 2027 and the resources to support execution of key milestones, most importantly the DENALI Part 2 topline readout, and ongoing trials,” Ms. Eastland continued.

Clinical Development Progress

Pivotal Dose Selected for Registration-Intended Azenosertib Monotherapy Program in Cyclin E1-Positive PROC: In April 2026, selected 400mg once daily on a 5-days-on, 2-days-off schedule (400mg QD 5:2) as the pivotal study dose for azenosertib monotherapy in patients with Cyclin E1-positive PROC based on a pre-specified interim analysis from DENALI Part 2a that showed a meaningful, clearly differentiated response rate at 400mg QD 5:2 and comparable safety profiles across both dose groups. The analysis revealed observed improvements in several key measures, including a discontinuation rate due to adverse events at approximately half the rate reported in DENALI Part 1b and no treatment-related deaths. Concurrently, the Company expanded DENALI Part 2 to include Part 2c, a new cohort broadening inclusion to approximately 40 patients previously treated with a taxane-containing regimen for PROC, to maintain alignment between the study population and the evolving treatment landscape. DENALI Parts 2b and 2c are currently enrolling. DENALI Part 2 is designed to support a potential accelerated approval pathway in the Cyclin E1 biomarker-selected patient population, subject to regulatory review. The Company expects to complete enrollment in all cohorts of DENALI Part 2 and provide a topline readout by year-end 2026.ASPENOVA Phase 3 First Patient Dosed: In May 2026, announced the first patient was dosed in the Phase 3 ASPENOVA confirmatory trial designed to satisfy FDA requirements for potential conversion to full approval and to support approval in major ex-US markets. ASPENOVA is a randomized, controlled Phase 3 trial that is expected to enroll approximately 420 patients and compare azenosertib monotherapy at 400mg QD 5:2 to investigator's choice of standard-of-care single-agent chemotherapy (paclitaxel, pegylated liposomal doxorubicin, gemcitabine, or topotecan) in patients with Cyclin E1-positive PROC. The trial is currently enrolling.MUIR Part 2 dose expansion evaluating azenosertib in combination with bevacizumab as maintenance therapy in ovarian cancer. MUIR is a multi-part, open-label Phase 1b clinical trial evaluating the safety, efficacy and preliminary clinical activity of azenosertib as a combination therapy in patients with ovarian cancer. The dose expansion cohort of Part 2 is currently open for enrollment of azenosertib in combination with bevacizumab in second-line platinum-sensitive ovarian cancer (PSOC) patients for maintenance treatment, whose disease progressed while on a PARP inhibitor. Medical Meeting Presentations Supporting Pipeline Strategy

AACR 2026: Presented two posters at the American Association for Cancer Research (AACR) Annual Meeting featuring: (1) compelling preclinical data showing azenosertib combinations can induce complete tumor responses in a model resistant to emerging antibody-drug conjugate (ADC) therapies in triple-negative breast cancer (TNBC), supporting the potential for pipeline expansion beyond ovarian cancer; and (2) real-world data from two independent cohorts demonstrating that Cyclin E1-positive ovarian cancer patients experience significantly worse clinical outcomes, independent of CCNE1 gene amplification status, reinforcing the potential for azenosertib to address the unmet need for these patients.ASCO 2026 Abstract Acceptance: Announced that the American Society of Clinical Oncology (ASCO) has accepted an abstract for presentation at the 2026 ASCO Annual Meeting featuring results from Part 1 of the Phase 1b MUIR trial, focusing on an evaluation of azenosertib in combination with paclitaxel in platinum-resistant ovarian cancer (PROC). The data will showcase combinability and activity in an all-comer setting, demonstrating the broad potential for azenosertib in multiple lines of ovarian cancer and other tumor types. First Quarter 2026 Financial Results

Cash Position: Cash, cash equivalents and marketable securities were $211.8 million as of March 31, 2026, compared to $245.9 million as of December 31, 2025. The Company believes that its existing cash, cash equivalents and marketable securities as of March 31, 2026 will be sufficient to fund its operating expenses and capital expenditure requirements into late 2027.Research and Development Expenses: Research and development (R&D) expenses for the three months ended March 31, 2026 were $28.7 million, compared to $27.2 million for the three months ended March 31, 2025. The increase of $1.5 million was primarily due to an increase of $6.8 million related to clinical expenses and drug manufacturing, including costs associated with advancing the DENALI and ASPENOVA trials. This increase was partially offset by decreases of $3.9 million for personnel expense, of which $1.2 million was non-cash stock-based compensation, a decrease of $1.2 million related to a one-time impairment charge recorded in Q1 2025, and a decrease of $0.2 million for allocated overhead.General and Administrative Expenses: General and administrative expenses for the three months ended March 31, 2026 were $9.1 million, compared to $10.6 million during the three months ended March 31, 2025. This decrease of $1.5 million was attributable to a decrease of $2.0 million in personnel expense, of which $1.2 million was non-cash stock-based compensation. The decrease was partially offset by an increase of $0.5 million related to consulting, outside services and other allocated costs.Total Operating Expenses: Total operating expenses were $37.9 million for the three months ended March 31, 2026, compared to $45.6 million for the three months ended March 31, 2025. Total operating expenses for the first quarter of 2025 included a non-recurring $7.8 million expense associated with the strategic restructuring announced in January 2025. 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, based on retrospective analysis of azenosertib studies in PROC. Validation of the Cyclin E1 companion diagnostic assay is ongoing in the DENALI and ASPENOVA trials.

Azenosertib has been granted Fast Track Designation by the U.S. FDA for the treatment of patients with Cyclin E1-positive platinum-resistant ovarian cancer. Fast Track Designation is intended to facilitate the development and expedite the review of therapies that have the potential to treat serious conditions and address unmet medical needs.

About DENALI Clinical Trial 
DENALI is a multi-part Phase 2 registration-intended clinical trial (NCT05128825) studying azenosertib in PROC patients.

Part 1b enrolled patients with PROC regardless of Cyclin E1 protein expression, all treated at 400mg QD 5:2. Part 2 is prospectively enrolling PROC patients with Cyclin E1 protein overexpression based on Zentalis' proprietary immunohistochemistry cutoff.

Part 2, in total, is designed to support accelerated approval, pending positive study outcomes and further discussions with the FDA. The study design consists of the following parts:

Part 2a: Dose confirmation evaluated two doses, 300mg QD 5:2 and 400mg QD 5:2, with approximately 30 patients enrolled per dose group. 400mg QD 5:2 was selected as the optimal monotherapy dose. Recruitment at the 300mg QD 5:2 dose level has been discontinued. All patients enrolled in Part 2a will contribute to the overall safety database submitted to the FDA.Part 2b: Enrollment expansion at the selected 400mg QD 5:2 dose up to approximately 100 patients, including patients at this dose in Part 2a. This cohort is currently enrolling.Part 2c: Broadening study population, which is expected to include approximately 40 patients previously treated with a taxane-containing regimen for PROC. This cohort is currently enrolling. Zentalis expects to complete enrollment in all cohorts of DENALI Part 2 (2a, 2b, 2c) and provide a topline readout by year-end 2026.

For physician and patient information about the DENALI trial, please visit www.denalitrial.com.

About ASPENOVA Clinical Trial
ASPENOVA is a Phase 3 randomized, confirmatory clinical trial designed to support full approval of azenosertib in patients with Cyclin E1-positive PROC. The trial is expected to enroll approximately 420 patients and compare azenosertib monotherapy at 400mg QD 5:2 to investigator's choice of standard-of-care single-agent chemotherapy (paclitaxel, pegylated liposomal doxorubicin [PLD], gemcitabine, or topotecan) in this biomarker-selected population. The primary endpoint is progression-free survival (PFS); key secondary endpoints include overall survival (OS) and overall response rate (ORR). The trial design was based on feedback from the U.S. FDA regarding requirements for seeking approval under the accelerated approval pathway and requirements to support potential conversion to full approval.

About MUIR Clinical Trial
MUIR (NCT04516447) is a multi-part, open-label Phase 1b clinical trial evaluating the safety, efficacy and preliminary clinical activity of azenosertib combinations in patients with ovarian cancer. Part 1 enrolled patients with platinum-resistant ovarian cancer (PROC) treated with azenosertib in combination with one of four chemotherapy regimens: carboplatin, gemcitabine, pegylated liposomal doxorubicin, or paclitaxel. Primary objectives are safety and tolerability, with key secondary objectives including clinical activity assessed by objective response rate, duration of response, and progression-free survival per RECIST v1.1.

Part 2 is evaluating azenosertib plus bevacizumab as maintenance regimen (first [1L] or second line [2L]) in patients with advanced ovarian, peritoneal, or fallopian tube cancer following platinum-based chemotherapy. The dose expansion portion will evaluate azenosertib at the recommended dose in combination with bevacizumab in patients with platinum-sensitive ovarian cancer in 2L who progressed while on a PARP inhibitor for 1L maintenance. The primary objective is safety and tolerability; secondary objectives include preliminary clinical activity of the combination as assessed by progression-free survival for the dose expansion portion. The dose expansion portion is currently open for enrollment.

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 investigational 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.​

For more information, please visit www.zentalis.com. Follow Zentalis on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, as amended. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, but not limited to, statements regarding the potential for azenosertib to be first-in-class; the continued development of azenosertib; the clinical and therapeutic potential of azenosertib, including the potential for azenosertib to be an important treatment option for patients with ovarian cancer or other indications; the Company’s biomarker-driven strategy for azenosertib; the potential to advance research on additional areas of opportunity for azenosertib as maintenance therapy in ovarian cancer and to explore additional tumor types; the Company’s anticipated milestones and the timing thereof, including the anticipated enrollment completion of DENALI Part 2, the topline readout from DENALI Part 2, and the design, conduct and timing of our confirmatory APSENOVA Phase 3 and MUIR Phase 1b trials; the Company’s anticipated cash runway; and the Company’s planned regulatory strategy for azenosertib and the timing thereof, including the potential for DENALI Part 2 to support an accelerated approval and for ASPENOVA to support conversion to a full approval and ex-US approval. The terms “anticipate,” “advance,” “believe,” “continue,” “design,” “develop,” “expect,” “focus,” “intend,” “plan,” “potential,” “runway,” “strategy,” “target,” and “will” and similar references are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our limited operating history, which may make it difficult to evaluate our current business and predict our future success and viability; we have and expect to continue to incur significant losses; our need for additional funding, which may not be available; our substantial dependence on the success of azenosertib; our plans, including the costs thereof, of development of a companion diagnostic; risks relating to the regulatory approval process or ongoing regulatory obligations; the outcome of preclinical testing and early trials may not be predictive of the success of later clinical trials; potential unforeseen events during clinical trials could cause delays or other adverse consequences; our product candidates may cause serious adverse side effects; the interim, initial, “topline,” and preliminary data from our clinical trials may change as more patient data becomes available, and are subject to audit and verification procedures that could result in material changes in the final data;; our reliance on third parties; effects of significant competition; the possibility of system failures or security breaches; risks relating to intellectual property; our ability to attract, retain and motivate qualified personnel, and risks relating to management transitions; significant costs as a result of operating as a public company; and the other important factors discussed under the caption “Risk Factors” in our most recently filed periodic report on Form 10-K or 10-Q and subsequent filings with the U.S. Securities and Exchange Commission (SEC) and our other filings with the SEC. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change.

ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release. 

    Zentalis Pharmaceuticals, Inc.
Condensed Consolidated Statements of Operations
(unaudited)
(In thousands, except per share amounts)Three Months Ended March 31,

      2026   2025 Operating Expenses   Research and development$28,716  $27,247 General and administrative 9,139   10,580 Restructuring —   7,796 Total operating expenses 37,855   45,623 Loss from operations (37,855)  (45,623)Other Income (Expense)   Investment and other income (expense), net 2,623   (2,656)Net loss before income taxes (35,232)  (48,279)Income tax expense 120   — Net loss$(35,352) $(48,279)Net loss per common share outstanding, basic and diluted$(0.50) $(0.67)Common shares used in computing net loss per share, basic and diluted 70,264   71,678          Zentalis Pharmaceuticals, Inc.
Selected Condensed Consolidated Balance Sheets Data
(unaudited)
(In thousands)   March 31, 2026 December 31, 2025Cash, cash equivalents and marketable securities$211,758 $245,893Working capital(1) 182,860  216,632Total assets 253,066  288,967Total liabilities 70,386  72,763Total Zentalis equity$182,680 $216,204    (1)The Company defines working capital as current assets less current liabilities.
  Contact:
Aron Feingold
VP, Investor Relations & Corporate Communications
[email protected]  

May 21, 2026 17:39 ET  | Source: ZENTALIS PHARMACEUTICALS

In an all-comer PROC population, across multiple dose cohorts, manageable safety profile of the combination was observed with low frequency of high-grade adverse eventsActivity of the combined regimen across all dose cohorts achieved 39% ORR and 7.3-month median PFSIn the 250 mg QD 5:2 intermittent dose cohort, 50% ORR, 9.2-month median DOR, and low frequency of high-grade adverse events was observed, suggesting a potential optimal dose combination SAN DIEGO, May 21, 2026 (GLOBE NEWSWIRE) -- 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 that data from Part 1 of the Phase 1b MUIR trial will be presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting, being held May 29 – June 2, 2026, in Chicago, Illinois. The poster, titled "Azenosertib Plus Paclitaxel for Platinum-Resistant Ovarian Cancer: Results From a Phase 1b Study," will be presented in the Gynecologic Cancer Poster Session (Abstract #5529, Poster Board #195) on June 1, 2026, from 9:00am–12:00pm CDT.

"Paclitaxel is one of the most widely used chemotherapy agents across tumor types, including in ovarian cancer, and these Phase 1b data show encouraging clinical activity and tolerability of adding azenosertib to paclitaxel in an all-comer platinum-resistant ovarian cancer (PROC) setting," said Ingmar Bruns, M.D., Chief Medical Officer of Zentalis Pharmaceuticals. "Establishing the safety, combinability, and efficacy signal of azenosertib with paclitaxel is an important proof of concept — one that we believe speaks to the broad potential of azenosertib across multiple lines of ovarian cancer and other tumor types where taxanes are commonly used. With our core strategic focus on advancing azenosertib in registration-intended trials as a monotherapy in the Cyclin E1-positive PROC population, the MUIR trial represents an important and complementary part of our broader indication expansion strategy."

"In a heavily pre-treated, all-comer patient PROC population where all patients had received prior paclitaxel, we observed meaningful tumor reductions and durable responses with this azenosertib paclitaxel combination, with an overall response rate of 39% and a median PFS of 7.3 months" said Joyce F. Liu, M.D., MPH, Associate Professor at Dana-Farber Cancer Institute and a study investigator. "At the 250 mg 5:2 intermittent dose — the dose thought to offer the optimal therapeutic index — half of patients achieved a response with a median duration of response of 9.2 months. Interestingly, the clinical activity appears similar in both Cyclin E1-positive and Cyclin E1-negative tumors, suggesting that Cyclin E1 status may not be as important in the azenosertib combination setting where the combination agent is inducing replication stress. These results support continued evaluation of azenosertib-taxane combinations in broader ovarian cancer settings and other tumor types where taxanes are part of the standard of care."

MUIR is a multi-part, open-label Phase 1b clinical trial evaluating azenosertib in combination with chemotherapy in patients with ovarian cancer. Part 1 evaluated azenosertib in combination with four chemotherapy regimens in patients with PROC, with data from the paclitaxel arm presented at ASCO as paclitaxel is commonly used across multiple tumor types, including ovarian cancer. Data from the other combination arms will be presented separately at a later date. The findings reflect a December 1, 2025 data cutoff and include 46 patients who received azenosertib across four dose cohorts — 200 mg QD continuously or 200 mg, 250 mg, or 300 mg QD intermittently (5 days on, 2 days off) — in combination with paclitaxel 80 mg/m². All patients had received prior paclitaxel.

Encouraging Activity in All-Comer PROC Population with Activity Across 4 Dose Groups (n=46)

Overall Response Rate (ORR): 39.1% (95% CI: 25.1–54.6)Clinical Benefit Rate (CBR): 58.7% (95% CI: 42.2–73.0)Median Duration of Response (DOR): 5.6 months (95% CI: 5.6–9.2)Median Progression-Free Survival (PFS): 7.3 months (95% CI: 3.7–7.5) These results are encouraging in the context of the historical efficacy of paclitaxel monotherapy in PROC, with an ORR of approximately 30% and a median PFS of approximately 4 months.

Clinical activity was broadly comparable in Cyclin E1-positive patients (ORR: 41.4% [95% CI: 23.5-61.1]; median PFS: 7.3 months [95% CI: 3.7-9.1]) and Cyclin E1-negative patients (ORR: 35.7% [95% CI: 12.8-64.9]; median PFS: 5.4 months [95% CI: 1.7-NE]), suggesting that Cyclin E1-positive biomarker status may not be required to derive benefit when azenosertib is combined with a cytotoxic agent.

At the 250 mg intermittent (5:2) dose cohort (n=12), which demonstrated the potential optimal therapeutic index:

ORR: 50.0% (95% CI: 21.1–78.9), including one complete responseCBR: 66.7% (95% CI: 34.9-90.1)Median DOR: 9.2 months (95% CI: 3.8–NE)Median PFS: 5.5 months (95% CI: 1.7–12.9) Manageable Safety Profile with Low Rate of High-Grade Events Across 4 Dose Cohorts (n=46)

Most common all-grade treatment-related adverse events (TRAEs): fatigue (60.9%), anemia (58.7%), nausea (52.2%), and neutropenia (50.0%).Most frequent Grade ≥3 TRAEs: neutropenia (30.4%) and anemia (19.6%); rates of high-grade fatigue and nausea were less than 10%.Serious TRAEs occurred in approximately 20% of patients; the most frequent were fatigue, diarrhea, and neutropenia, each occurred in 2 patients.Of 15 patients (32.6%) who discontinued due to adverse events, approximately half discontinued paclitaxel only and were able to continue on azenosertib monotherapy until disease progressionOne G5 event due to sepsis was assessed as related to azenosertib by the investigator (previously reported in June 2024). While the role of azenosertib cannot be excluded, the event may have been attributable to the patient's advanced disease, given the absence of neutropenia and negative blood cultures at the time of the event. The poster will be available at https://zentalis.com/science/scientific-publications/ after ASCO.

About MUIR Clinical Trial
MUIR (ZN-c3-002) is a multi-part, open-label Phase 1b clinical trial (NCT04516447) evaluating the safety, efficacy, and preliminary clinical activity of azenosertib in combination in patients with ovarian cancer.

Part 1 enrolled patients with platinum-resistant ovarian cancer (PROC) treated with azenosertib in combination with one of four chemotherapy regimens: carboplatin, gemcitabine, pegylated liposomal doxorubicin, or paclitaxel. Primary objectives are safety and tolerability, with key secondary objectives including clinical activity assessed by objective response rate, duration of response, and progression-free survival per RECIST v1.1.

Part 2 is evaluating azenosertib plus bevacizumab as maintenance regimen (first [1L] or second line [2L]) in patients with advanced ovarian, peritoneal, or fallopian tube cancer following platinum-based chemotherapy. The dose expansion portion will evaluate azenosertib at the recommended dose in combination with bevacizumab in patients with platinum-sensitive ovarian cancer in 2L who progressed while on a PARP inhibitor for 1L maintenance. The primary objective is safety and tolerability; secondary objectives include preliminary clinical activity of the combination as assessed by progression-free survival for the dose expansion portion.

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, based on retrospective analysis of azenosertib studies in PROC. Validation of the Cyclin E1 companion diagnostic assay is ongoing in the DENALI and ASPENOVA trials.

Azenosertib has been granted Fast Track Designation by the U.S. FDA for the treatment of patients with Cyclin E1-positive platinum-resistant ovarian cancer. Fast Track Designation is intended to facilitate the development and expedite the review of therapies that have the potential to treat serious conditions and address unmet medical needs.

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 investigational 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.

For more information, please visit www.zentalis.com. Follow Zentalis on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the U.S. Private Securities Litigation Reform Act of 1995, as amended. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including, but not limited to, statements regarding the continued development of azenosertib; the clinical and therapeutic potential of azenosertib as a monotherapy and as a combination agent; the potential for azenosertib to be first-in-class; the potential benefits of azenosertib across multiple lines of ovarian cancer and other tumor types the combinability of azenosertib with other agents, including paclitaxel, and the potential benefits thereof; the significance of the referenced results; the presentation of data from other combination arms; the importance of the MUIR trial to the Company’s broader pipeline strategy; the broad franchise potential of azenosertib; the Company’s biomarker-driven strategy for azenosertib; and the Company’s presentation at ASCO. The terms “anticipate,” “advance,” “believe,” “design,” “develop,” “encouraging,” “expect,” “focus,” “intent,” “look forward,” “may,” “objective,” “on track,” “plan,” “position,” “potential,” “runway,” “strategy,” “suggest,” “target,” “upcoming,” and “will” and similar references are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: our limited operating history, which may make it difficult to evaluate our current business and predict our future success and viability; we have and expect to continue to incur significant losses; our need for additional funding, which may not be available; our substantial dependence on the success of azenosertib; our plans, including the costs thereof, of development of companion diagnostics; the outcome of preclinical testing and early trials may not be predictive of the success of later clinical trials; potential unforeseen events during clinical trials could cause delays or other adverse consequences; risks relating to the regulatory approval process or ongoing regulatory obligations; our product candidates may cause serious adverse side effects; the interim, initial, “topline,” and preliminary data from our clinical trials may change as more patient data becomes available, and are subject to audit and verification procedures that could result in material changes in the final data; our reliance on third parties; effects of significant competition; the possibility of system failures or security breaches; risks relating to intellectual property; our ability to attract, retain and motivate qualified personnel, and risks relating to management transitions; significant costs as a result of operating as a public company; and the other important factors discussed under the caption “Risk Factors” in our most recently filed periodic report on Form 10-K or 10-Q and subsequent filings with the U.S. Securities and Exchange Commission (SEC) and our other filings with the SEC. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change.

ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release. 

Contact: 
Aron Feingold
VP, Investor Relations & Corporate Communications
[email protected]

June 01, 2026 17:00 ET  | Source: ZENTALIS PHARMACEUTICALS

SAN DIEGO, June 01, 2026 (GLOBE NEWSWIRE) -- 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 that on June 1, 2026, the Compensation Committee of Zentalis’ Board of Directors granted non-qualified stock options to purchase an aggregate of 191,000 shares of the Company’s common stock to two (2) newly hired employees. The stock options were granted under the Zentalis Pharmaceuticals, Inc. 2022 Employment Inducement Incentive Award Plan (2022 Inducement Plan) as an inducement material to each such individual’s entering into employment with Zentalis in accordance with Nasdaq Listing Rule 5635(c)(4).

The 2022 Inducement Plan is used exclusively for the grant of equity awards to individuals who were not previously employees of Zentalis, or following a bona fide period of non-employment, as an inducement material to each such individual’s entering into employment with Zentalis, pursuant to Nasdaq Listing Rule 5635(c)(4).

The stock options have an exercise price of $3.98 per share, which is equal to the closing price of Zentalis’ common stock on The Nasdaq Global Market on the date of grant. The stock options have a 10-year term and will vest over four years, with 25% of the options vesting on the first anniversary of the vesting commencement date and the remaining 75% of the options vesting in equal monthly installments over the three years thereafter.

Vesting of the stock options is subject to the employee’s continued service to Zentalis on each vesting date.

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 investigational 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.​

For more information, please visit www.zentalis.com. Follow Zentalis on LinkedIn at www.linkedin.com/company/zentalis-pharmaceuticals.

ZENTALIS® and its associated logo are trademarks of Zentalis and/or its affiliates. All website addresses and other links in this press release are for information only and are not intended to be an active link or to incorporate any website or other information into this press release.

Contact:
Aron Feingold
VP, Investor Relations & Corporate Communications
[email protected]