Zentalis Pharmaceuticals, Inc.

Previous wording

We are a clinical-stage biopharmaceutical company developing azenosertib (ZN-c3), an investigational, potentially first-in-class and best-in-class WEE1 inhibitor, for patients with ovarian cancer and other tumor types. In clinical trials, azenosertib has been well tolerated and has demonstrated anti-tumor activity as a single agent across multiple tumor types. We are currently focused on advancing the clinical development of azenosertib in Cyclin E1-positive platinum-resistant ovarian cancer, or PROC. We believe that our DENALI (ZN-c3-005) Part 2 clinical trial of azenosertib in patients with Cyclin E1-positive PROC, if successful, has the potential to support an accelerated approval, subject to U.S. Food and Drug Administration, or FDA, review. Our Phase 3 ASPENOVA clinical trial is designed as a confirmatory trial to support conversion to potential full approval, subject to data outcomes. We also believe that azenosertib has broad franchise potential beyond Cyclin E1-positive PROC. We exclusively in-license or solely own worldwide development and commercialization rights to azenosertib.

Current wording

We are a clinical-stage biopharmaceutical company developing azenosertib (ZN-c3), an investigational, potentially first-in-class and best-in-class WEE1 inhibitor, for patients with ovarian cancer and other tumor types. In clinical trials, azenosertib has been well tolerated and has demonstrated anti-tumor activity as a single agent across multiple tumor types. We are currently focused on advancing the clinical development of azenosertib in Cyclin E1-positive platinum-resistant ovarian cancer, or PROC. We believe that our DENALI (ZN-c3-005) Part 2 clinical trial of azenosertib in patients with Cyclin E1-positive PROC, if successful, has the potential to support an accelerated approval, subject to U.S. Food and Drug Administration, or FDA, review. Our Phase 3 ASPENOVA (ZN-c3-020) clinical trial is designed as a confirmatory trial to support conversion to potential full approval, subject to data outcomes. We also believe that azenosertib has broad franchise potential beyond Cyclin E1-positive PROC. We exclusively in-license or solely own worldwide development and commercialization rights to azenosertib.

Previous wording

In 2022, the global ovarian cancer market was approximately $3 billion, with significant growth expected over the next several years. PROC is a subset of the ovarian cancer market. Based on our retrospective, historical analysis utilizing our IHC cutoff, we estimate that approximately 50% of PROC patients overexpress Cyclin E1 protein, which accounts for approximately 21,500 patients on an annual basis in the United States, EU4 (France, Germany, Italy, Spain) and the United Kingdom, based on 2024 estimates. As a result, we believe there is a significant opportunity for azenosertib in Cyclin E1-positive PROC patients. Moreover, the successful launch of mirvetuximab in PROC patients with high folate receptor alpha, or FRα-high, expression underscores the demand for biomarker-directed therapies for PROC patients. The limited overlap between FRα-high PROC patients and those that have Cyclin E1 overexpression is estimated to be less than 20% of all PROC patients, which highlights the significant unmet need in patients with Cyclin E1-positive PROC.

Current wording

In 2022, the global ovarian cancer market was approximately $3 billion, with significant growth expected over the next several years. PROC is a subset of the ovarian cancer market. Based on our retrospective, historical analysis utilizing our IHC cutoff, we estimate that approximately 50% of PROC patients overexpress Cyclin E1 protein, which accounts for approximately 20,000 patients on an annual basis in the United States, EU4 (France, Germany, Italy, Spain), the United Kingdom and Japan, based on 2025 estimates. As a result, we believe there is a significant opportunity for azenosertib in Cyclin E1-positive PROC patients. Moreover, the successful launch of mirvetuximab in PROC patients with high folate receptor alpha, or FRα-high, expression underscores the demand for biomarker-directed therapies for PROC patients. The overlap between FRα-high PROC patients and those that have Cyclin E1 overexpression is estimated to be less than 20% of all PROC patients, which highlights the significant unmet need in patients with Cyclin E1-positive PROC.

Previous wording

◦DENALI Part 1b is a single-arm study that evaluated azenosertib monotherapy at 400 mg QD 5:2 (single daily dose on an intermittent schedule of five days on and two days off), in 102 patients with PROC. Tissue collection for biomarker assessment was mandated in the study and upon a retrospective analysis, approximately 50% of the patients were Cyclin E1-positive per our IHC cutoff. In 2025, we announced clinical data from this study.

Current wording

◦DENALI Part 1b is a fully enrolled single-arm study that evaluated azenosertib monotherapy at 400 mg QD 5:2 (single daily dose on an intermittent schedule of five days on and two days off), in 102 patients with PROC. Tissue collection for biomarker assessment was mandated in the study and upon a retrospective analysis, approximately 50% of the patients were Cyclin E1-positive per our IHC cutoff. In 2025, we announced clinical data from this study.

Previous wording

▪Part 2b: Enrollment expansion in the same patient population as Part 2a at the selected 400mg QD 5:2 dose up to approximately 100 patients, including patients at that dose in Part 2a. This cohort is currently enrolling.

Current wording

◦Part 2b: Enrollment expansion in the same patient population as Part 2a at the selected 400mg QD 5:2 dose up to approximately 100 patients, including patients at that dose in Part 2a. Enrollment in this cohort is complete.

Previous wording

◦Part 1: Enrolled patients with PROC treated with azenosertib in combination with one of four chemotherapy regimens: carboplatin, gemcitabine, pegylated liposomal doxorubicin, or paclitaxel. Primary objectives were 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. In April 2026, we announced that data from MUIR Part 1 focusing on azenosertib in combination with paclitaxel in PROC have been accepted for presentation at the 2026 American Society for Clinical Oncology (ASCO) Annual Meeting in June 2026.

Current wording

▪Part 1: Enrolled patients with PROC treated with azenosertib in combination with one of four chemotherapy regimens: carboplatin, gemcitabine, pegylated liposomal doxorubicin, or paclitaxel. Primary objectives were 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. In May 2026, we announced data from MUIR Part 1 focusing on azenosertib in combination with paclitaxel in PROC as paclitaxel is commonly used across multiple tumor types, including ovarian cancer. These data are described in the next section below titled “Recent Data and Presentations.” Data from the other combination arms will be presented at a later date.

Previous wording

◦Part 2: Evaluating azenosertib in combination with bevacizumab as a maintenance regimen (in the first line, or 1L, or second line, or 2L, of treatment) in patients with advanced ovarian, peritoneal, or fallopian tube cancer following platinum-based chemotherapy. The dose escalation portion will determine the recommended dose for azenosertib orally once daily 5 days on, 2 days off in 21-day cycles in combination with bevacizumab 15mg/kg intravenously on Day 1 of each 21-day cycle. The dose expansion portion will evaluate azenosertib at the recommended dose determined from the dose escalation portion in combination with bevacizumab. The dose expansion portion is expected to enroll approximately 40 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.

Current wording

▪Part 2: Evaluating azenosertib in combination with bevacizumab as a maintenance regimen (in the first line, or 1L, or second line, or 2L, of treatment) in patients with advanced ovarian, peritoneal, or fallopian tube cancer following platinum-based chemotherapy. The dose escalation portion will determine the recommended dose for azenosertib orally once daily 5 days on, 2 days off in 21-day cycles in combination with bevacizumab 15mg/kg intravenously on Day 1 of each 21-day cycle. The dose expansion portion will evaluate azenosertib at the recommended dose determined from the dose escalation portion in combination with bevacizumab. The dose expansion portion is expected to enroll approximately 40 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 enrolling.

Previous wording

Since inception, we have incurred significant operating losses. Our net losses were $137.1 million for the year ended December 31, 2025. We had net losses of $35.4 million and $48.3 million for the three months ended March 31, 2026 and March 31, 2025, respectively. We had an accumulated deficit of $1.2 billion as of March 31, 2026. We expect to continue to incur significant expenses and operating losses for the foreseeable future. We had cash, cash equivalents and marketable securities of $211.8 million as of March 31, 2026. We believe that our existing cash, cash equivalents and marketable securities as of March 31, 2026 will be sufficient to fund our operating expenses and capital expenditure requirements into late 2027. We have based these estimates on assumptions that may prove to be imprecise, and we could utilize our available capital resources sooner than we expect.

Current wording

Since inception, we have incurred significant operating losses. Our net losses were $137.1 million for the year ended December 31, 2025. We had net losses of $77.6 million and $75.2 million for the six months ended June 30, 2026 and June 30, 2025, respectively. We had an accumulated deficit of $1.3 billion as of June 30, 2026. We expect to continue to incur significant expenses and operating losses for the foreseeable future. We had cash, cash equivalents and marketable securities of $174.6 million as of June 30, 2026. We believe that our existing cash, cash equivalents and marketable securities as of June 30, 2026 will be sufficient to fund our operating expenses and capital expenditure requirements into late 2027. We have based these estimates on assumptions that may prove to be imprecise, and we could utilize our available capital resources sooner than we expect.

Previous wording

In December 2014, our wholly owned subsidiary, Zeno Pharmaceuticals, Inc., entered into the Recurium Agreement, with Recurium IP Holdings, LLC, or Recurium IP, which was subsequently amended, under which Zeno Pharmaceuticals, Inc. was granted an exclusive worldwide license to certain intellectual property rights owned or controlled by Recurium IP to develop and commercialize pharmaceutical products for the treatment or prevention of disease, other than for providing pain relief. Following a corporate restructuring, our wholly owned subsidiary, ZMI, became the Zentalis contracting party to the Recurium Agreement. The intellectual property rights exclusively licensed by ZMI under the Recurium Agreement include certain intellectual property covering azenosertib. ZMI has the right to sublicense its rights under the Recurium Agreement, subject to certain conditions. ZMI is required to use commercially reasonable efforts to develop and commercialize at least one product that comprises or contains a compound modulating one of ten specific biological targets and to execute certain development activities.

Current wording

In December 2014, our wholly owned subsidiary, Zeno Pharmaceuticals, Inc., entered into the Recurium Agreement, with Recurium IP Holdings, LLC, or Recurium IP, which was subsequently amended, under which Zeno Pharmaceuticals, Inc. was granted an exclusive worldwide license to certain intellectual property rights owned or controlled by Recurium IP to develop and commercialize pharmaceutical products for the treatment or prevention of disease, other than for providing pain relief. Following a corporate restructuring, our wholly owned subsidiary, Zeno Management, Inc., or ZMI, became the Zentalis contracting party to the Recurium Agreement. The intellectual property rights exclusively licensed by ZMI under the Recurium Agreement include certain intellectual property covering azenosertib. ZMI has the right to sublicense its rights under the Recurium Agreement, subject to certain conditions. ZMI is required to use commercially reasonable efforts to develop and commercialize at least one product that comprises or contains a compound modulating one of ten specific biological targets and to execute certain development activities.

Previous wording

Under the terms of the Recurium Agreement, ZMI is obligated to make development and regulatory milestone payments, pay royalties on net sales, and make certain sublicensing payments with respect to products that comprise or contain a compound modulating one of ten specific biological targets, including azenosertib. ZMI is obligated to make development and regulatory milestone payments for each such licensed product of up to $44.5 million, which covers the first two indications for which such licensed product receives regulatory approval and includes a $7.0 million milestone payment payable as a result of the commencement of our Phase 3 ASPENOVA clinical trial. In the event that a licensed product receives regulatory approval in any additional indications beyond the first two, ZMI would be obligated to pay an additional one-time milestone payment for each such approval. In addition, ZMI is obligated to make milestone payments of up to $150,000 for certain licensed products used in animals. ZMI is also obligated to pay royalties on sales of such licensed products at a mid- to high-single digit percentage. In addition, if ZMI chooses to sublicense or assign to any third parties its rights under certain patents exclusively in-licensed under the Recurium Agreement, ZMI must pay to Recurium IP 20% of certain sublicensing income received in connection with such transaction.

Current wording

Under the terms of the Recurium Agreement, ZMI is obligated to make development and regulatory milestone payments, pay royalties on net sales, and make certain sublicensing payments with respect to products that comprise or contain a compound modulating one of ten specific biological targets, including azenosertib. ZMI is obligated to make development and regulatory milestone payments for each such licensed product of up to $44.5 million, which covers the first two indications for which such licensed product receives regulatory approval and includes a $7.0 million milestone payment incurred as a result of the commencement of our Phase 3 ASPENOVA clinical trial and paid during the three months ended June 30, 2026. In the event that a licensed product receives regulatory approval in any additional indications beyond the first two, ZMI would be obligated to pay an additional one-time milestone payment for each such approval. In addition, ZMI is obligated to make milestone payments of up to $150,000 for certain licensed products used in animals. ZMI is also obligated to pay royalties on sales of such licensed products at a mid- to high-single digit percentage. In addition, if ZMI chooses to sublicense or assign to any third parties its rights under certain patents exclusively in-licensed under the Recurium Agreement, ZMI must pay to Recurium IP 20% of certain sublicensing income received in connection with such transaction.

Previous wording

Research and development 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 during the quarter ended March 31, 2025, and a decrease of $0.2 million for allocated overhead.

Current wording

Research and development expenses for the three months ended June 30, 2026 were $35.2 million, compared to $27.6 million for the three months ended June 30, 2025. The increase of $7.6 million was primarily due to a $7.0 million milestone payment to Recurium IP Holdings, LLC required as a result of the commencement of our Phase 3 ASPENOVA clinical trial and an increase of $5.2 million related to clinical expenses and drug manufacturing, including costs associated with advancing the DENALI and ASPENOVA trials. This increase was partially offset by a decrease of $4.5 million for personnel expense, of which $2.1 million was non-cash stock-based compensation, and a decrease of $0.1 million related to allocated overhead.

Previous wording

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.

Current wording

General and administrative expenses for the six months ended June 30, 2026 were$18.4 million, compared to$19.0 million during the six months ended June 30, 2025. This decrease of $0.6 million was attributable to a decrease of $2.8 million of personnel expense of which $2.2 million was non-cash stock-based compensation. This decrease was partially offset by an increase of $2.2 million related primarily to consulting and outside services.

Previous wording

On January 22, 2025, our Board of Directors approved a strategic restructuring of the Company to support execution of late-stage development for azenosertib, and extend its cash runway beyond a potentially registration-enabling azenosertib data readout from the Company’s DENALI Part 2 study, anticipated by the end of 2026. In connection with this strategic restructuring, the Company reduced its workforce by approximately 40%.

Current wording

On January 22, 2025, our Board of Directors approved a strategic restructuring of the Company to support execution of late-stage development for azenosertib, and extend its cash runway beyond a potentially registration-enabling azenosertib data readout from the Company’s DENALI Part 2 study, anticipated in the first half of 2027. In connection with this strategic restructuring, the Company reduced its workforce by approximately 40%.

Previous wording

Restructuring expenses for the three months ended March 31, 2026 were zero, compared to $7.8 million during the three months ended March 31, 2025.

Current wording

Restructuring expenses for the six months ended June 30, 2026 were zero, compared to $7.8 million during the six months ended June 30, 2025.

Previous wording

Investment and other income (expense), net was $2.6 million for the three months ended March 31, 2026, compared to $(2.7) million for the three months ended March 31, 2025. The increase of$5.3 million was primarily driven by a non-cash recognized loss of $7.0 million on the mark to market adjustment for equity securities during the three months ended March 31, 2025 partially offset by a decrease of $1.7 million in returns on invested cash and marketable debt securities.

Current wording

Investment and other income (expense), net was$4.9 million for the six months ended June 30, 2026, compared to$6.5 million for the six months ended June 30, 2025. The decrease of $1.6 million was primarily driven by a decrease of $3.5 million in returns on invested cash and marketable debt securities partially offset by a non-cash recognized loss of $2.4 million on the mark to market adjustment for equity securities during the six months ended June 30, 2025. A gain of $0.5 million on fixed assets sold during the six months ended June 30, 2025 also contributed to the overall decrease.

Previous wording

We do not currently have any approved products and have never generated any revenue from product sales. To date, we have financed our operations primarily through the sale of equity securities. From inception through March 31, 2026, we raised a total of $1.2 billion in gross proceeds from the sale of shares of our common stock and convertible preferred units. As of March 31, 2026, we had $31.9 million in cash and cash equivalents, $179.8 million in marketable debt securities, and an accumulated deficit of $1.2 billion. We maintain the majority of our cash and cash equivalents in accounts with major financial institutions, and our deposits at these institutions exceed insured limits. Market conditions can impact the viability of these institutions. In the event of failure of any of the financial institutions where we maintain our cash and cash equivalents, there can be no assurance that we would be able to access uninsured funds in a timely manner or at all. Any inability to access or delay in accessing these funds could adversely affect our business and financial position. We had no indebtedness as of March 31, 2026.

Current wording

We do not currently have any approved products and have never generated any revenue from product sales. To date, we have financed our operations primarily through the sale of equity securities. From inception through June 30, 2026, we raised a total of $1.2 billion in gross proceeds from the sale of shares of our common stock and convertible preferred units. As of June 30, 2026, we had $24.8 million in cash and cash equivalents, $149.8 million in marketable debt securities, and an accumulated deficit of $1.3 billion. We maintain the majority of our cash and cash equivalents in accounts with major financial institutions, and our deposits at these institutions exceed insured limits. Market conditions can impact the viability of these institutions. In the event of failure of any of the financial institutions where we maintain our cash and cash equivalents, there can be no assurance that we would be able to access uninsured funds in a timely manner or at all. Any inability to access or delay in accessing these funds could adversely affect our business and financial position. We had no indebtedness as of June 30, 2026.

Previous wording

Net cash used in operating activities for the three months ended March 31, 2026 was $33.0 million, consisting primarily of our net loss of $35.4 million as we incurred expenses associated with research and development activities for our product candidate and general and administrative activities, and changes in operating assets and liabilities of $0.7 million, partially offset by non-cash adjustments of $3.1 million.

Current wording

Net cash used in operating activities for the six months ended June 30, 2026 was $70.2 million, consisting primarily of our net loss of $77.6 million as we incurred expenses associated with research and development activities for our product candidate and general and administrative activities, partially offset by changes in operating assets and liabilities of $1.0 million and non-cash adjustments of $6.4 million.

Previous wording

Net cash used in operating activities for the three months ended March 31, 2025 was $32.6 million, consisting primarily of our net loss of $48.3 million as we incurred expenses associated with the restructuring event, research and development activities for our product candidates and incurred general and administrative expenses, as well as changes in operating assets and liabilities of $1.8 million and non-cash adjustments of $13.9 million.

Current wording

Net cash used in operating activities for the six months ended June 30, 2025 was $67.3 million, consisting primarily of our net loss of $75.2 million as we incurred expenses associated with the restructuring event, research and development activities for our product candidates and incurred general and administrative expenses, as well as changes in operating assets and liabilities of $6.6 million and non-cash adjustments of $14.4 million.

Previous wording

Net cash provided by investing activities for the three months ended March 31, 2026 of $30.0 million was primarily attributable to proceeds from maturities of marketable securities of $60.0 million, offset by net investment of excess cash of $30.0 million.

Current wording

Net cash provided by investing activities for the six months ended June 30, 2026 of $60.0 million was primarily attributable to proceeds from maturities of marketable securities of $120.0 million, offset by net investment of excess cash of $59.9 million.

Previous wording

Net cash provided by investing activities for the three months ended March 31, 2025 of $40.5 million was attributable to proceeds from maturities of marketable securities of $60.0 million, offset by net investment of excess cash of $19.5 million.

Current wording

Net cash provided by investing activities for the six months ended June 30, 2025 of $70.9 million was attributable to proceeds from maturities of marketable securities of $130.0 million and proceeds from sale of property and equipment of $0.6 million, offset by net investment of excess cash of $59.7 million.

Previous wording

Net cash used in financing activities for the three months ended March 31, 2026 of $1.1 million resulted from cash used for the net-settlement of restricted stock unit vesting of $1.4 million partially offset by proceeds of $0.3 million from the issuance of common stock under equity incentive plans .

Current wording

Net cash used in financing activities for the six months ended June 30, 2026 of $1.1 million resulted from cash used for the net-settlement of restricted stock unit vesting of $1.5 million partially offset by proceeds of $0.4 million from the issuance of common stock under equity incentive plans .

Previous wording

Net cash provided by financing activities for the three months ended March 31, 2025 of $189 thousand was provided from the issuance of common stock under equity incentive plans.

Current wording

Net cash provided by financing activities for the six months ended June 30, 2025 of $189 thousand was provided from the issuance of common stock under equity incentive plans.

Previous wording

As of March 31, 2026, we have $4.0 million and $34.7 million in current and long-term lease liabilities, respectively. We believe that our existing cash, cash equivalents and marketable securities as of March 31, 2026 will be sufficient to fund our operating expenses and capital expenditure requirements into late 2027. We have based these estimates on assumptions that may prove to be imprecise, and we could utilize our available capital resources sooner than we expect.

Current wording

As of June 30, 2026, we have $4.1 million and $33.6 million in current and long-term lease liabilities, respectively. We believe that our existing cash, cash equivalents and marketable securities as of June 30, 2026 will be sufficient to fund our operating expenses and capital expenditure requirements into late 2027. We have based these estimates on assumptions that may prove to be imprecise, and we could utilize our available capital resources sooner than we expect.

Previous wording

•the progress, costs and results of our clinical trials for azenosertib for patients with Cyclin E1-positive PROC and, resources allowing, any additional indications, and any future product candidates;

Current wording

•the progress, costs and results of our clinical trials and seeking regulatory and marketing authorizations for azenosertib as a treatment for patients with Cyclin E1-positive PROC and, resources allowing, any additional indications, and any future product candidates;

Previous wording

•the progress, costs and results to develop a companion diagnostic to identify patients with Cyclin E1-positive PROC;

Current wording

•the progress, costs and results to develop and commercialize a companion diagnostic to identify patients with Cyclin E1-positive PROC;