Clinical Trial Updates - First patient dosed in Part 2a of the DENALI clinical trial for azenosertib in Cyclin E1+ platinum-resistant ovarian cancer (PROC) with a target enrollment of approximately 30 patients at two dose levels [4] - Topline data from DENALI Part 2 is anticipated by year-end 2026, which could support accelerated approval pending FDA feedback [2] - The objective response rate (ORR) for azenosertib in patients with Cyclin E1+ PROC was reported at 34.9% with a median duration of response of 6.3 months as of January 13, 2025 [4] Financial Performance - Cash, cash equivalents, and marketable securities as of March 31, 2025, totaled $332.5 million, sufficient to fund operations into late 2027 [8] - Research and development expenses decreased to $27.2 million for Q1 2025 from $49.6 million in Q1 2024, a reduction of $22.4 million [8] - General and administrative expenses for Q1 2025 were $10.6 million, down from $15.7 million in Q1 2024, reflecting a decrease of $5.1 million [8] - Total operating expenses for Q1 2025 were $45.6 million, compared to $65.3 million in Q1 2024, including $7.8 million in non-recurring restructuring expenses [8] - Net loss attributable to Zentalis for Q1 2025 was $48.3 million, compared to a net income of $10.1 million in Q1 2024 [15] - Total assets as of March 31, 2025, were $384.0 million, down from $430.3 million as of December 31, 2024 [17] - Total liabilities decreased to $88.6 million as of March 31, 2025, from $93.2 million as of December 31, 2024 [17]

Core Insights - Zentalis Pharmaceuticals has initiated the DENALI Part 2a clinical trial for azenosertib in patients with Cyclin E1+ platinum-resistant ovarian cancer (PROC), with topline data expected by the end of 2026, potentially supporting accelerated approval from the FDA [1][6][9] - The company reported a cash position of $332.5 million as of March 31, 2025, which is projected to fund operations into late 2027 [5][7][19] Company Developments - The first patient has been dosed in Part 2a of the DENALI clinical trial, which aims to confirm the primary dose of azenosertib with a target enrollment of approximately 30 patients at two dose levels [6][9] - Azenosertib has shown clinically meaningful response rates in previous studies, with an objective response rate (ORR) of 34.9% and a median duration of response (mDOR) of 6.3 months in patients with Cyclin E1+ PROC [6][12] Financial Performance - Research and development expenses for Q1 2025 were $27.2 million, a decrease from $49.6 million in Q1 2024, primarily due to reductions in clinical expenses and other operational costs [12][16] - General and administrative expenses also decreased to $10.6 million in Q1 2025 from $15.7 million in Q1 2024, mainly due to lower non-cash stock-based compensation [12][16] Upcoming Events - Zentalis plans to participate in several upcoming scientific and investor conferences, including the ASCO Annual Meeting and the Jefferies Healthcare Conference [4][6]

Core Insights - Zentalis Pharmaceuticals has initiated dosing for the first patient in Part 2 of the Phase 2 DENALI clinical trial for azenosertib, targeting Cyclin E1+ platinum-resistant ovarian cancer [1][3] - The company anticipates topline data from DENALI Part 2 by the end of 2026, which could support accelerated approval from the FDA [2][3] - Azenosertib is a novel WEE1 inhibitor being evaluated as a monotherapy and in combination therapies across multiple tumor types [5][6] Clinical Trial Details - The DENALI trial is designed in two parts, with seamless enrollment; Part 2a aims to confirm the primary dose of azenosertib with approximately 30 patients at two dose levels: 400mg QD 5:2 and 300mg QD 5:2 [7] - Part 2b will enroll around 70 additional patients based on the results from Part 2a, pending FDA feedback [7] Clinical Data and Biomarkers - Previous data from Part 1b of the DENALI study indicated an objective response rate (ORR) of 34.9% among 43 response-evaluable patients, with a median duration of response (mDOR) of 6.3 months [3][4] - Cyclin E1 protein overexpression has been identified as a predictive biomarker for patient selection, with an estimated 50% of PROC patients overexpressing this protein [4] Company Overview - Zentalis Pharmaceuticals is focused on developing azenosertib as a potentially first-in-class and best-in-class treatment for Cyclin E1+ PROC, with ongoing research into additional applications [6] - The company has demonstrated that azenosertib is well tolerated and shows anti-tumor activity across various tumor types [6]

Core Viewpoint - Zentalis Pharmaceuticals is advancing its clinical-stage biopharmaceutical development of azenosertib, a WEE1 inhibitor, with a poster presentation scheduled at the 2025 ASCO Annual Meeting, showcasing its potential in treating metastatic colorectal cancer and other tumor types [1][2][4]. Company Overview - Zentalis Pharmaceuticals, Inc. is focused on developing azenosertib (ZN-c3), a potentially first-in-class and best-in-class WEE1 inhibitor targeting Cyclin E1+ platinum-resistant ovarian cancer and other tumor types [4]. - The company is conducting clinical trials to evaluate azenosertib both as a monotherapy and in combination therapies, demonstrating anti-tumor activity and good tolerability across various cancer types [4]. Clinical Trial Details - An abstract has been accepted for a poster presentation at the 2025 ASCO Annual Meeting, detailing the Phase 1/2 clinical trial results of azenosertib in combination with encorafenib and cetuximab for patients with metastatic BRAF V600E mutant colorectal cancer [2]. - The poster presentation is scheduled for May 31, 2025, and will include clinical data up to an April 4, 2025 cutoff [2]. Mechanism of Action - Azenosertib functions as a selective and orally bioavailable WEE1 inhibitor, which regulates the G1-S and G2-M cell cycle checkpoints, allowing for cell cycle progression despite DNA damage, ultimately leading to cancer cell death [3].

Exhibit 99.1 Zentalis Pharmaceuticals Reports Full Year 2024 Financial Results and Operational Updates Positive azenosertib clinical data demonstrated clinically meaningful results in patients with Cyclin E1+ platinum-resistant ovarian cancer (PROC) Topline data from registration-intent DENALI Part 2 anticipated by year end 2026 Strengthened management team to support execution of highly focused strategy $371.1 million cash, cash equivalents and marketable securities balance as of December 31, 2024, with pr ...

Clinical Development and Trials - Azenosertib (ZN-c3) is a clinical-stage WEE1 inhibitor showing an objective response rate (ORR) of over 30% in Cyclin E1+ platinum-resistant ovarian cancer (PROC) patients[26]. - The DENALI Part 1b trial included 102 PROC patients, revealing an ORR of 34.9% in response-evaluable patients and 31.3% in the intent-to-treat population[32]. - The median duration of response (mDOR) for the intent-to-treat population was approximately 5.5 months, with ongoing maturation of data[32]. - The company plans to initiate enrollment for the DENALI Part 2 trial in the first half of 2025, aiming to disclose topline data by the end of 2026[26]. - Azenosertib is also being evaluated in other solid tumor types, including uterine serous carcinoma (USC), with data expected in the first half of 2026[29]. - In the monotherapy arm of the MAMMOTH study, patients treated with azenosertib at 400 mg QD 5:2 showed an overall response rate (ORR) of 31.3% and a median duration of response (mDOR) of 4.2 months[37]. - Among Cyclin E1+ patients treated at the 300 mg QD 5:2 dose level, the ORR was 21.4% with an mDOR of 4.9 months[37]. - In the ZN-c3-001 study, 23 patients with Cyclin E1+ PROC on intermittent schedules had an ORR of 34.8% and an mDOR of 5.2 months[40]. - For 11 patients with Cyclin E1+ USC on intermittent schedules, the ORR was 36.4% with an mDOR of 5.5 months[41]. - Across all tumor types in the ZN-c3-001 study, azenosertib was well-tolerated with a low treatment-related adverse event discontinuation rate of 5.2%[42]. - The company is developing a companion diagnostic test to identify PROC patients with Cyclin E1 overexpression, with a prototype ready for use in DENALI Part 2[27]. - Patient enrollment in clinical trials is critical, and difficulties in recruitment could lead to significant delays or abandonment of trials, impacting development timelines and costs[191]. - Initial, topline, or preliminary data from clinical trials may change as more data becomes available, necessitating caution in interpreting early results[184]. Market and Financial Overview - Approximately 50% of PROC patients are estimated to overexpress Cyclin E1, translating to about 21,500 patients annually in the U.S. and EU4[28]. - The global ovarian cancer market was valued at approximately $3 billion in 2022, with significant growth expected in the coming years[28]. - Zentalis incurred net losses of $165.9 million and $292.3 million for the years ended December 31, 2024 and December 31, 2023, respectively, with an accumulated deficit of $1.1 billion as of December 31, 2024[137]. - The company has not generated any revenue from product sales to date and does not anticipate generating revenue for the next several years[139]. - The company anticipates incurring significant commercialization expenses related to drug sales, marketing, manufacturing, and distribution if azenosertib is approved for commercial sale[142]. - The company estimates the addressable patient population for azenosertib, but inaccuracies in these estimates could adversely affect revenue projections and business operations[201]. - Coverage and reimbursement for pharmaceutical products are uncertain and vary by third-party payors, impacting sales and physician utilization[111][113]. - The company may face challenges in obtaining adequate reimbursement for its products, impacting their market adoption and revenue generation[216]. Regulatory Environment - Azenosertib has received Fast Track Designation from the FDA for the treatment of PROC patients who are Cyclin E1 positive[30]. - The FDA requires a New Drug Application (NDA) or Biologics License Application (BLA) for a new drug to be legally marketed in the U.S., which involves substantial time and financial resources[60][61]. - The FDA aims to review and act on a standard NDA/BLA for a new molecular entity within ten months from the date of filing[70]. - The FDA conducts a preliminary review of an NDA/BLA within the first 60 days after submission to determine if it is complete enough for substantive review[70]. - The FDA may issue a Complete Response Letter if the NDA/BLA has deficiencies, requiring the sponsor to address these before resubmission[75]. - Regulatory approval may come with limitations on the indicated uses for the product, including the requirement for a Risk Evaluation and Mitigation Strategy (REMS)[76]. - The FDA requires that companion diagnostics be approved simultaneously with the therapeutic product they support, ensuring safety and effectiveness[118][119]. - The approval of product candidates may be contingent on the successful completion of costly post-marketing clinical trials[164]. - Regulatory authorities may impose limitations on product approvals, affecting the commercialization of product candidates[164]. - The company must navigate various ex-U.S. regulatory requirements, which may differ significantly from U.S. regulations and impact approval timelines[222]. Competition and Market Risks - The company faces significant competition from larger pharmaceutical and biotechnology companies with greater resources and expertise[47]. - There are currently no FDA-approved WEE1 inhibitors, but several companies are in various stages of clinical evaluation for their WEE1 inhibitors[49]. - The company faces significant competition in oncology, with numerous products under development that may impact the market opportunity for azenosertib and other product candidates[202]. - Competitors may develop safer, more effective products, potentially leading to reduced market opportunities for the company's candidates[205]. - The company may face significant competition in seeking collaborators for product development, which could impact its ability to capitalize on market potential[153]. Operational and Strategic Considerations - The company currently relies on third-party contract manufacturing organizations (CMOs) for the production of azenosertib and has no plans to establish its own manufacturing facilities[43]. - The company has incurred significant expenses primarily from research and development and management costs, expecting to continue incurring substantial losses in the foreseeable future[138]. - The company is collaborating with Pfizer, GSK, and Dana Farber on the development of azenosertib, which may limit control over the resources dedicated to its development[149]. - The company has no committed external source of funds and may need to seek additional funding through equity offerings or collaborations, which could dilute stockholder value[145]. - The company acknowledges that the success of azenosertib and future product candidates depends on various factors, including clinical trial outcomes and regulatory approvals[148]. - The company is developing azenosertib in combination with other therapies, which introduces additional risks related to supply and regulatory approval of those therapies[198]. - The company may need to conduct additional studies or collect more data independently if third-party collaborators do not perform as expected[168]. - The company is exposed to significant product liability risks, which could adversely affect its business and financial condition if sufficient insurance coverage is not obtained[208]. Corporate Governance and Workforce - Zentalis is committed to enhancing diversity and inclusivity within its workforce and has implemented various employee training programs[133]. - The company prioritizes governance systems that promote fair and transparent business practices, including a Code of Business Conduct and Ethics[131]. - As of December 31, 2024, Zentalis had a total of 166 full-time employees and announced a strategic restructuring to reduce its workforce by approximately 40%[128]. - The company has a defined information security incident response plan to manage cybersecurity incidents and conducts regular employee training on data privacy[133].

Core Insights - Zentalis Pharmaceuticals has reported positive clinical data for azenosertib, a WEE1 inhibitor, showing meaningful results in patients with Cyclin E1+ platinum-resistant ovarian cancer (PROC) [1][2] - The company anticipates topline data from the registration-intent DENALI Part 2 study by the end of 2026 [1][3] - Zentalis has strengthened its management team to support its focused strategy and has a cash position projected to last into late 2027 [1][2] Clinical Development - Updated clinical data from the DENALI Part 1b study showed an objective response rate (ORR) of 34.9% in patients with Cyclin E1+ PROC tumors, with a median duration of response (mDOR) of 6.3 months as of January 13, 2025 [3] - In the MAMMOTH study, Cyclin E1+ patients treated with azenosertib had an ORR of 31.3% and an mDOR of 4.2 months [3] - The ZN-c3-001 Phase 1 study reported an ORR of 34.8% and an mDOR of 5.2 months for patients treated with azenosertib [3] - The company has aligned with the FDA on the study design for DENALI Part 2, which will begin enrollment in the first half of 2025 [3] Financial Performance - As of December 31, 2024, Zentalis had cash, cash equivalents, and marketable securities totaling $371.1 million, sufficient to fund operations into late 2027 [1][5] - Research and development expenses for 2024 were $167.8 million, a decrease from $189.6 million in 2023, primarily due to reduced personnel expenses [5][12] - General and administrative expenses increased to $87.1 million in 2024 from $64.4 million in 2023, largely due to higher personnel costs [5][12] Corporate Updates - The company received Fast Track Designation from the FDA for azenosertib for treating PROC patients who are Cyclin E1 positive [4][6] - A strategic restructuring was announced in January 2025 to enhance efficiency in clinical development, which is expected to be completed by the second quarter of 2025 [4][6] - Zentalis has continued patient enrollment in various clinical trials, including studies for uterine serous carcinoma and in combination with bevacizumab [4][6]

Core Insights - Zentalis Pharmaceuticals is presenting four posters at the 2025 AACR Annual Meeting, focusing on the clinical efficacy and broad therapeutic applications of azenosertib, a WEE1 inhibitor for high-grade serous ovarian cancer [1][2][5] Group 1: Azenosertib Overview - Azenosertib is a novel, selective, and orally bioavailable WEE1 inhibitor currently being evaluated in clinical studies for ovarian cancer and other tumor types [3][5] - The mechanism of action involves inhibiting WEE1, which allows cell cycle progression despite DNA damage, leading to cancer cell death [3] Group 2: Clinical Research and Presentations - The poster titled "Loss of RB1 sensitizes TP53-mutated cancer cells to WEE1 inhibition by azenosertib" will be presented on April 27, 2024 [2] - Another poster, "Cell-free DNA molecular response predicts clinical efficacy in HGSOC patients treated with azenosertib," is scheduled for April 28, 2024 [2] - Azenosertib's potential as a potent and selective WEE1 kinase inhibitor with broad antitumor activity will be highlighted on April 29, 2024 [2] - The final poster presentation will discuss the synergistic anti-tumor activity of azenosertib in combination with encorafenib and cetuximab on April 29, 2024 [2] Group 3: Company Background - Zentalis Pharmaceuticals is a clinical-stage biopharmaceutical company focused on developing azenosertib for patients with Cyclin E1+ platinum-resistant ovarian cancer [5] - The company is leveraging its expertise to explore additional therapeutic opportunities for azenosertib beyond its current indications [5]

Core Insights - Zentalis Pharmaceuticals announced updated clinical data for azenosertib, a WEE1 inhibitor, showing a median duration of response (mDOR) of 6.3 months and an objective response rate (ORR) of approximately 35% in patients with platinum-resistant ovarian cancer (PROC) [1][4] - The company is on track to initiate Part 2 of the DENALI clinical trial in the first half of 2025, with topline data expected by the end of 2026 [1][4] - Preclinical data presented indicates that azenosertib demonstrates synergistic antitumor effects when combined with microtubule inhibitor-based antibody drug conjugates (ADCs) [1][6] Clinical Trial Data - DENALI Part 1b is a Phase 2 single-arm study evaluating azenosertib monotherapy at a dose of 400mg QD 5:2 in 102 patients with PROC [1] - As of January 13, 2025, the ORR for response-evaluable patients with Cyclin E1+ PROC tumors was 34.9%, while the intent-to-treat ORR was 31.3% [1][3] - The mDOR of 6.3 months is subject to change as some patients continue to show ongoing responses [1] Biomarker Insights - Cyclin E1 protein overexpression is identified as a sensitive and specific predictive biomarker for azenosertib efficacy, with an estimated 50% of PROC patients overexpressing Cyclin E1 [2] Safety Profile - The safety and tolerability profile of azenosertib remains consistent with previous reports, with gastrointestinal toxicities and fatigue being the most common treatment-related adverse events [3] Future Development Plans - Zentalis plans to enroll patients in DENALI Part 2 concurrently with a Phase 3 randomized confirmatory study, pending FDA review [4] - The company aims for DENALI Part 2 results to support an accelerated approval pathway [4] Combination Therapy Potential - Preclinical data suggests that azenosertib could serve as a generalizable combination partner with ADCs to enhance treatment responses in advanced solid tumors [6][7]

Core Insights - Zentalis Pharmaceuticals announced updated clinical data for azenosertib, a WEE1 inhibitor, showing a median duration of response (mDOR) of 6.3 months and an objective response rate (ORR) of approximately 35% in patients with platinum-resistant ovarian cancer (PROC) [1][4] - The company is on track to initiate Part 2 of the DENALI clinical trial in the first half of 2025, with topline data expected by the end of 2026 [1][4] - Cyclin E1 overexpression is identified as a predictive biomarker for patient selection, with an estimated 50% of PROC patients overexpressing Cyclin E1 [2] Clinical Trial Data - DENALI Part 1b is a Phase 2 single-arm study evaluating azenosertib monotherapy at a dose of 400mg QD 5:2 in 102 PROC patients [1] - As of January 13, 2025, the ORR for response-evaluable patients with Cyclin E1+ PROC tumors was 34.9%, while the intent-to-treat ORR was 31.3% [1] - The safety profile remains consistent with previous reports, with gastrointestinal toxicities and fatigue being the most common treatment-related adverse events [3] Future Development Plans - Enrollment for DENALI Part 2 is expected to begin in the first half of 2025, with the potential for accelerated approval if successful [4] - The company plans to conduct a Phase 3 randomized confirmatory study concurrently with DENALI Part 2b, subject to FDA review [4] Preclinical Data - Preclinical data presented at the SGO Annual Meeting indicates that azenosertib shows synergistic effects when combined with microtubule inhibitor-based antibody drug conjugates (ADCs), enhancing tumor growth inhibition [5][6] - Azenosertib is being evaluated as a generalizable combination partner with ADCs for advanced solid tumors [6] Company Overview - Zentalis Pharmaceuticals is a clinical-stage biopharmaceutical company focused on developing azenosertib for patients with Cyclin E1+ PROC and other tumor types [8] - Azenosertib is a selective, orally bioavailable WEE1 inhibitor that targets cell cycle regulation to induce cancer cell death [7]