Zentalis Pharmaceuticals (ZNTL) 10-Q 6 Nov 23 2023 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2023	Nov. 02, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	001-39263
Entity Registrant Name	Zentalis Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3607803
Entity Address, Address Line One	1359 Broadway
Entity Address, Address Line Two	Suite 801
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10018
City Area Code	212
Local Phone Number	433-3791
Title of 12(b) Security	Common Stock,$0.001 par value per share
Trading Symbol	ZNTL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		70,765,771
Entity Central Index Key	0001725160
Amendment Flag	false
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 110,751	$ 43,069
Marketable securities, available-for-sale	405,886	394,302
Prepaid expenses and other current assets	11,627	14,562
Total current assets	528,264	451,933
Property and equipment, net	6,393	7,705
Operating lease right-of-use assets	36,184	42,373
Prepaid expenses and other assets	8,511	9,723
Goodwill	3,736	3,736
Investment in Zentera Therapeutics	0	21,213
Restricted cash	2,627	2,627
Total assets	585,715	539,310
Current liabilities
Accounts payable	14,264	11,247
Accrued expenses	44,654	45,400
Total current liabilities	58,918	56,647
Deferred tax liability	0	853
Long-term lease liability	43,266	45,166
Other long-term liabilities	1,634	2,620
Total liabilities	103,818	105,286
Commitments and contingencies
EQUITY
Preferred stock, $0.001 par value; 10,000,000 shares authorized; no shares issued and outstanding at September 30, 2023 and December 31, 2022	0	0
Common stock, $0.001 par value; 250,000,000 shares authorized; 70,640,684 and 59,280,247 shares issued and outstanding at September 30, 2023 and December 31, 2022, respectively	70	59
Additional paid-in capital	1,309,696	1,031,462
Accumulated other comprehensive loss	(359)	(1,353)
Accumulated deficit	(827,639)	(596,365)
Total stockholders’ equity	481,768	433,803
Noncontrolling interests	129	221
Total equity	481,897	434,024
Total liabilities and stockholders’ equity	$ 585,715	$ 539,310

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Sep. 30, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock issued (in shares)	70,640,684	59,280,247
Common stock outstanding (in shares)	70,640,684	59,280,247

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating Expenses
Research and development	$ 46,765	$ 42,181	$ 138,033	$ 132,118
Zentera in-process research and development	0	0	45,568	0
General and administrative	15,953	12,012	47,986	43,415
Total operating expenses	62,718	54,193	231,587	175,533
Operating loss	(62,718)	(54,193)	(231,587)	(175,533)
Other Income (Expense)
Investment and other income, net	7,209	1,905	15,769	2,755
Net loss before income taxes	(55,509)	(52,288)	(215,818)	(172,778)
Income tax expense (benefit)	31	(159)	(466)	(109)
Loss on equity method investment	0	2,371	16,014	9,460
Net loss	(55,540)	(54,500)	(231,366)	(182,129)
Net loss attributable to noncontrolling interests	(12)	(99)	(92)	(294)
Net loss attributable to Zentalis	$ (55,528)	$ (54,401)	$ (231,274)	$ (181,835)
Net loss per common share outstanding, basic (in dollars per share)	$ (0.79)	$ (0.96)	$ (3.64)	$ (3.56)
Net loss per common share outstanding, diluted (in dollars per share)	$ (0.79)	$ (0.96)	$ (3.64)	$ (3.56)
Common shares used in computing net loss per share, basic (in shares)	70,612	56,807	63,601	51,098
Common shares used in computing net loss per share, diluted (in shares)	70,612	56,807	63,601	51,098

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (55,540)	$ (54,500)	$ (231,366)	$ (182,129)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities	(21)	(491)	994	(2,145)
Total comprehensive loss	(55,561)	(54,991)	(230,372)	(184,274)
Comprehensive loss attributable to noncontrolling interests	(12)	(99)	(92)	(294)
Comprehensive loss attributable to Zentalis	$ (55,549)	$ (54,892)	$ (230,280)	$ (183,980)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Operating Activities:
Consolidated net loss	$ (55,540)	$ (54,500)	$ (231,366)	$ (182,129)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	348	375	1,052	1,067
Operating lease right-of-use asset and fixed asset impairment			4,953	0
Noncash consideration portion of Zentera in-process research and development			15,045	0
Loss on equity method investment	0	2,371	16,014	9,460
Share-based compensation			40,942	37,228
Loss on disposal of equipment			(4)	(68)
(Accretion of discounts)/amortization of premiums on marketable securities, net			(8,602)	(1,249)
Deferred income taxes			(853)	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets			(5,199)	(4,716)
Accounts payable and accrued liabilities			522	10,477
Operating lease right-of-use assets and liabilities, net			273	3,508
Net cash used in operating activities			(167,223)	(126,422)
Investing Activities:
Purchases of marketable securities			(453,195)	(407,177)
Proceeds from maturities of marketable securities			451,207	307,279
Purchases of property and equipment			(410)	(2,388)
Net cash used in investing activities			(2,398)	(102,286)
Financing Activities:
Proceeds from issuance of common stock, net			235,680	209,297
Proceeds from issuance of common stock under equity incentive plans			1,623	2,005
Net cash provided by financing activities			237,303	211,302
Net increase (decrease) in cash, cash equivalents and restricted cash			67,682	(17,406)
Cash, cash equivalents and restricted cash at beginning of period			45,696	62,584
Cash, cash equivalents and restricted cash at end of period	113,378	45,178	113,378	45,178
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	110,751	42,551	110,751	42,551
Restricted cash	2,627	2,627	2,627	2,627
Total cash, cash equivalents and restricted cash reported in the Condensed Consolidated Statement of Cash Flows	$ 113,378	$ 45,178	$ 113,378	$ 45,178

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2021		45,491,000
Beginning balance at Dec. 31, 2021	$ 364,482	$ 45	$ 723,593	$ (125)	$ (359,559)	$ 528
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	37,228		37,228
Other comprehensive loss	(2,145)			(2,145)
Issuance of common stock in connection with an equity offering, net of underwriting discounts, commissions and offering costs (in shares)		11,284,000
Issuance of common stock in connection with an equity offering, net of underwriting discounts, commissions and offering costs	209,297	$ 11	209,286
Issuance of common stock in connection with restricted stock unit vesting (in shares)		154,000
Issuance of common stock in connection with restricted stock unit vesting	1	$ 1
Issuance of common stock upon exercise of options, net (in shares)		60,000
Issuance of common stock upon exercise of options, net	1,130		1,130
Shares issued under employee stock purchase plan (in shares)		30,000
Shares issued under employee stock purchase plan	874		874
Cancellation of restricted stock awards (in shares)		(17,000)
Net loss attributable to non-controlling interest	(294)					(294)
Net loss attributable to Zentalis	(181,835)				(181,835)
Ending balance (in shares) at Sep. 30, 2022		57,002,000
Ending balance at Sep. 30, 2022	428,738	$ 57	972,111	(2,270)	(541,394)	234
Beginning balance (in shares) at Dec. 31, 2021		45,491,000
Beginning balance at Dec. 31, 2021	364,482	$ 45	723,593	(125)	(359,559)	528
Ending balance (in shares) at Dec. 31, 2022		59,280,000
Ending balance at Dec. 31, 2022	434,024	$ 59	1,031,462	(1,353)	(596,365)	221
Beginning balance (in shares) at Jun. 30, 2022		56,967,000
Beginning balance at Jun. 30, 2022	472,823	$ 57	961,205	(1,779)	(486,993)	333
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	10,317		10,317
Other comprehensive loss	(491)			(491)
Issuance of common stock in connection with restricted stock unit vesting (in shares)		5,000
Issuance of common stock upon exercise of options, net (in shares)		18,000
Issuance of common stock upon exercise of options, net	327		327
Shares issued under employee stock purchase plan (in shares)		14,000
Shares issued under employee stock purchase plan	262		262
Cancellation of restricted stock awards (in shares)		(2,000)
Net loss attributable to non-controlling interest	(99)					(99)
Net loss attributable to Zentalis	(54,401)				(54,401)
Ending balance (in shares) at Sep. 30, 2022		57,002,000
Ending balance at Sep. 30, 2022	428,738	$ 57	972,111	(2,270)	(541,394)	234
Beginning balance (in shares) at Dec. 31, 2022		59,280,000
Beginning balance at Dec. 31, 2022	434,024	$ 59	1,031,462	(1,353)	(596,365)	221
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	40,942		40,942
Other comprehensive loss	994			994
Issuance of common stock in connection with an equity offering, net of underwriting discounts, commissions and offering costs (in shares)		11,033,000
Issuance of common stock in connection with an equity offering, net of underwriting discounts, commissions and offering costs	$ 235,680	$ 11	235,669
Issuance of common stock in connection with restricted stock unit vesting (in shares)	116,900	235,000
Issuance of common stock upon exercise of options, net (in shares)	54,300	54,000
Issuance of common stock upon exercise of options, net	$ 995		995
Shares issued under employee stock purchase plan (in shares)		42,000
Shares issued under employee stock purchase plan	628		628
Cancellation of restricted stock awards (in shares)		(3,000)
Net loss attributable to non-controlling interest	(92)					(92)
Net loss attributable to Zentalis	(231,274)				(231,274)
Ending balance (in shares) at Sep. 30, 2023		70,641,000
Ending balance at Sep. 30, 2023	481,897	$ 70	1,309,696	(359)	(827,639)	129
Beginning balance (in shares) at Jun. 30, 2023		70,604,000
Beginning balance at Jun. 30, 2023	523,282	$ 70	1,295,520	(338)	(772,111)	141
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	13,867		13,867
Other comprehensive loss	(21)			(21)
Issuance of common stock in connection with restricted stock unit vesting (in shares)		17,000
Issuance of common stock upon exercise of options, net (in shares)		3,000
Issuance of common stock upon exercise of options, net	54		54
Shares issued under employee stock purchase plan (in shares)		17,000
Shares issued under employee stock purchase plan	255		255
Net loss attributable to non-controlling interest	(12)					(12)
Net loss attributable to Zentalis	(55,528)				(55,528)
Ending balance (in shares) at Sep. 30, 2023		70,641,000
Ending balance at Sep. 30, 2023	$ 481,897	$ 70	$ 1,309,696	$ (359)	$ (827,639)	$ 129

Organization and Business

Organization and Business	9 Months Ended
	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business	Organization and Business Organization Zentalis Pharmaceuticals, Inc. (“Zentalis,” “We” or the “Company”) is a clinical-stage biopharmaceutical company discovering and developing small molecule therapeutics targeting fundamental biological pathways of cancers. The Company’s lead product candidate, azenosertib (ZN-c3), is a potentially first-in-class and best-in-class WEE1 inhibitor for advanced solid tumors and hematologic malignancies. The Company is also developing a BCL-2 inhibitor, ZN-d5, in combination with azenosertib. The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. All of the Company’s tangible assets are held in the United States. Liquidity

Interim Unaudited Financial Sta

Interim Unaudited Financial Statements	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Interim Unaudited Financial Statements	Interim Unaudited Financial Statements Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. The year-end condensed consolidated balance sheet data was derived from the Company’s audited financial statements but do not include all disclosures required by U.S. GAAP. These interim unaudited condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 1, 2023. The unaudited financial information for the interim periods presented herein reflects all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial condition and results of operation for the periods presented, with such adjustments consisting only of normal recurring adjustments. Certain reclassifications have been made to the prior period condensed consolidated balance sheet to conform to the current period presentation. The accompanying interim unaudited condensed consolidated financial statements include our wholly-owned subsidiaries and a variable interest entity (“VIE”), for which we are the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. We evaluate our ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether we are the primary beneficiary of the VIE. In determining whether we are the primary beneficiary of a VIE and therefore required to consolidate the VIE, we apply a qualitative approach that determines whether we have both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE. We will continuously assess whether we are the primary beneficiary of a VIE, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of such VIE. During the periods presented, we have not provided any other material financial or other support to our VIE that we were not contractually required to provide. The equity method is used to account for investments in which we have the ability to exercise significant influence, but not control, over the investee. Such investments are recorded on the balance sheet, and the share of net income or losses of equity investments is recognized on a one quarter lag in investment and other income (expense), net. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in our consolidated financial statements and accompanying notes. On an ongoing basis, we evaluate our estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates. Significant Accounting Policies During the nine months ended September 30, 2023, we adopted the following significant accounting policies not previously reported in the Company’s significant accounting policies as described in its Annual Report on Form 10-K for the fiscal year ended December 31, 2022. Acquisitions and Contingent Consideration The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen test to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in Accounting Standards Update (ASU) 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquired entity and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations, including contingent assets and liabilities, and non-controlling interest in the acquired entity based on the fair value estimates as of the date of acquisition. In accordance with Accounting Standards Codification (ASC) 805, Business Combinations, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired. The consideration for the Company’s business acquisitions may include future payments that are contingent upon the occurrence of a particular event or events. The obligations for such contingent consideration payments are recorded at fair value on the acquisition date. The contingent consideration obligations are then evaluated each reporting period. Changes in the fair value of contingent consideration, other than changes due to payments, are recognized as a gain or loss and recorded within change in the fair value of deferred and contingent consideration liabilities in the consolidated statements of comprehensive loss. Contingent consideration liabilities expected to be

Significant Transactions

Significant Transactions	9 Months Ended
	Sep. 30, 2023
Equity Method Investments and Joint Ventures [Abstract]
Significant Transactions	Significant Transactions Zentera Therapeutics On June 15, 2023, we announced that we and certain of our wholly owned subsidiaries had entered into an agreement to terminate our Collaboration and License Agreements (the “Termination Agreement”) with Zentera Therapeutics, a Shanghai-based clinical-stage biopharmaceutical company focused on developing cancer therapeutics (“Zentera”), pursuant to which such wholly owned subsidiaries had granted to Zentera certain development and commercialization rights to our product candidates, azenosertib, ZN-d5 and ZN-c5 (the “Zentera Collaboration Products”) in the People’s Republic of China, Macau, Hong Kong and Taiwan (collectively, “Greater China”). As a result of the termination of these agreements, we have regained the rights from Zentera for azenosertib, ZN-d5 and ZN-c5 in Greater China, and now hold worldwide development and commercialization rights to these assets. Concurrent with the agreement to terminate the Collaboration and License Agreements, we executed a share purchase agreement (the “Share Purchase Agreement”) with Zentera to return our 40.3% equity stake in Zentera for de minimis consideration. We assessed the Termination Agreement and Share Purchase Agreement together and determined that the transaction to reacquire the licensed intellectual property without an acquired workforce, inputs or any substantive processes capable of contributing to the ability to produce outputs, represents asset acquisitions for accounting purposes. The total consideration transferred of $45.6 million was comprised of the following components: Fixed consideration of $30 million, representing an up-front payment. Fixed consideration of forgiveness of $9.4 million of outstanding receivables under the Collaboration and License Agreements. Fixed consideration of the return of our 40.3% equity stake in Zentera for de minimis cash consideration. Using the adjusted balance sheet method under the cost approach, the difference between the carrying value of the equity method investment at the time of the transaction and the fair value of the equity method investment after the return of the intellectual property was $13.7 million, which was recognized as a loss on the equity method investment line item in the statement of operations during the second quarter of 2023. Variable consideration of a change in control milestone payment as contingent consideration can be either zero or $15.0 million. The value of the contingent consideration of approximately $0.5 million was calculated using estimates of future discounted cash flows, and other significant estimates including estimates for probability of milestone achievement and discount rates. The value of the contingent consideration for this milestone will be remeasured at fair value at each reporting period with gains and losses reported in the statement of operations, as applicable. We also incurred $0.5 million of acquisition-related costs that were included in the total consideration for the acquired assets. Additional consideration to be paid to Zentera includes a low single digit royalty on net sales of azenosertib, ZN-d5 and ZN-c5 in the Greater China region. These additional payments are payable only after regulatory approval and commercials sales in the Greater China region and are excluded from the transaction price. The fair value of in-process research and development assets acquired was based on the market approach, which includes significant estimates. These estimates included calibration adjustments for comparable companies, cost estimates, control and marketability discounts, as well as estimates for the probability of success and applicable discount rates. The excess of the fair value of the consideration given in exchange for the Zentera in-process research and development received was accounted for as a contract termination cost. The Company determined to recognize the full amount of $45.6 million in the condensed consolidated statement of operations and comprehensive loss during the nine months ended September 30, 2023.

Business Combinations

Business Combinations	9 Months Ended
	Sep. 30, 2023
Business Combination and Asset Acquisition [Abstract]
Business Combinations	Business Combinations Kalyra Pharmaceuticals, Inc. On December 21, 2017, we acquired $4.5 million of Kalyra Pharmaceuticals, Inc.’s (“Kalyra”) Series B Preferred Stock representing a 25% equity interest in Kalyra for purposes of entering the analgesics therapeutic research space. The acquisition price was paid entirely in cash. In accordance with the authoritative guidance, we concluded that Kalyra is a business consisting of inputs, employees, intellectual property and processes capable of producing outputs. Additionally, we have concluded that Kalyra is a VIE, we are the primary beneficiary and have the power to direct the activities that most significantly affect Kalyra’s economic performance through common management and our board representation. Prior to December 21, 2017, the Company and Kalyra transacted for the delivery of research and development services and support. The financial position and results of operations of Kalyra have been included in our consolidated financial statements from the date of the initial investment. Pursuant with authoritative guidance, we have recorded the identifiable assets, liabilities and noncontrolling interests in the VIE at their fair value upon initial consolidation. The identified goodwill is comprised of the workforce and expected synergies from combining the entities . T otal assets and liabilities of Kalyra as of September 30, 2023 and December 31, 2022 are immaterial. The liabilities recognized as a result of consolidating Kalyra do not represent additional claims on our general assets. Pursuant to the authoritative guidance, the equity interest in Kalyra not owned by Zentalis is reported as a noncontrolling interest on our condensed consolidated balance sheets. The following is a reconciliation of equity (net assets) attributable to the noncontrolling interest (in thousands): September 30, December 31, 2023 2022 Noncontrolling interest at beginning of period $ 221 $ 528 Net loss attributable to noncontrolling interest (92) (307) Noncontrolling interest at end of period $ 129 $ 221

Fair Value Measurement

Fair Value Measurement	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value MeasurementAvailable-for-sale marketable securities consisted of the following (in thousands): September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 87,492 $ 1 $ (69) $ 87,424 Corporate debt securities 149,539 10 (82) 149,467 US government agencies 105,258 7 (110) 105,155 US treasury securities 63,956 — (116) 63,840 $ 406,245 $ 18 $ (377) $ 405,886 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 296,309 $ 71 $ (587) $ 295,793 Corporate debt securities 7,472 — (26) 7,446 US government agencies 23,970 — (182) 23,788 US treasury securities 67,904 — (629) 67,275 $ 395,655 $ 71 $ (1,424) $ 394,302 As of September 30, 2023, fifty-eight of our available-for-sale debt securities with a fair market value of $347.6 million were in a gross unrealized loss position of $0.4 million. Of those, fifty-eight have been in a gross unrealized loss position of $0.4 million for less than one year and zero have been in a gross unrealized loss position for more than one year. When evaluating an investment for impairment, we review factors such as the severity of the impairment, changes in underlying credit ratings, forecasted recovery, our intent to sell or the likelihood that we would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. Based on our review of these marketable securities, we believe none of the unrealized loss is as a result of a credit loss as of September 30, 2023, because we do not intend to sell these securities, and it is not more-likely-than-not that we will be required to sell these securities before the recovery of their amortized cost basis. Contractual maturities of available-for-sale debt securities are as follows (in thousands): September 30, 2023 December 31, 2022 Estimated Fair Value Due within one year $ 238,972 $ 394,302 After one but within five years 166,914 — $ 405,886 $ 394,302 The Company had $0.5 million in contingent consideration liabilities as of September 30, 2023 related to the agreement to terminate its Collaboration and License Agreements with Zentera. The contingent consideration balance is limited to one potential milestone payment measured at fair value (See Note 3 - Significant Transactions for additional information). The fair value of the contingent consideration is estimated based on the monetary value of the milestone discounted for the probability of achieving the milestone and a present value factor based on the timing of when the milestone is expected to be achieved. The value for the contingent consideration balance is based on significant inputs not observable in the market which represents Level 3 measurement within the fair value hierarchy. This liability did not exist as of December 31, 2022. The following table summarizes the financial assets and liabilities that are measured on a recurring basis at fair value as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 76,333 $ — $ — $ 76,333 Commercial paper 10,483 — — 10,483 US government agencies 14,978 — 14,978 Total cash equivalents: 101,794 — — 101,794 Available-for-sale marketable securities: Commercial paper — 87,424 — 87,424 Corporate debt securities — 149,467 — 149,467 US government agencies — 105,155 — 105,155 US treasury securities 63,840 — — 63,840 Total available-for-sale marketable securities: 63,840 342,046 — 405,886 Total assets measured at fair value $ 165,634 $ 342,046 $ — $ 507,680 Financial liabilities: Contingent consideration $ — $ — $ 500 $ 500 Total financial liabilities $ — $ — $ 500 $ 500 December 31, 2022 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 26,811 $ — $ — $ 26,811 Commercial paper 1,998 — — 1,998 Total cash equivalents: 28,809 — — 28,809 Available-for-sale marketable securities: Commercial paper — 295,793 — 295,793 Corporate debt securities — 7,446 — 7,446 US government agencies — 23,788 — 23,788 US treasury securities 67,275 — — 67,275 Total available-for-sale marketable securities: 67,275 327,027 — 394,302 Total assets measured at fair value $ 96,084 $ 327,027 $ — $ 423,111 Financial liabilities: Contingent consideration $ — $ — $ — $ — Total financial liabilities $ — $ — $ — $ — The following significant unobservable inputs were used in the valuation of the contingent consideration payable to Zentera pursuant to the Termination Agreement at September 30, 2023. Contingent Consideration Liability Fair Value as of September 30, 2023 Valuation Technique Unobservable Input Range (in thousands) Milestone payment $ 500 Discounted cash flow Likelihood of occurrence 1.0% - 2.4% Discount rate 40% Expected term Perpetuity The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (in thousands): Contingent consideration at December 31, 2022 $ — Issuance of contingent consideration to Zentera 500 Changes in the fair value of contingent consideration — Contingent consideration at September 30, 2023 $ 500

Prepaid Expenses and Other Asse

Prepaid Expenses and Other Assets	9 Months Ended
	Sep. 30, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Assets	Prepaid Expenses and Other Assets Prepaid expenses and other assets consisted of the following (in thousands): September 30, December 31, 2023 2022 Prepaid insurance $ 1,011 $ 1,018 Prepaid software licenses and maintenance 435 958 Foreign R&D credit refund 1,024 659 Prepaid research and development expenses 14,188 15,002 Interest receivable 1,931 508 Sublease assets 1,265 — Zentera receivable — 5,874 Other prepaid expenses 284 266 Total prepaid expenses and other assets 20,138 24,285 Less long-term portion 8,511 9,723 Total prepaid expenses and other assets, current $ 11,627 $ 14,562

Property and Equipment, net

Property and Equipment, net	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2023 2022 Lab equipment $ 3,069 $ 2,622 Leasehold improvements 4,432 4,891 Office equipment and furniture 1,854 2,065 Computer equipment 150 150 Construction in progress — 37 Subtotal 9,505 9,765 Accumulated depreciation and amortization (3,112) (2,060) Property and equipment, net $ 6,393 $ 7,705 Depreciation and amortization expense for the three months ended September 30, 2023 and 2022 was approximately $348 thousand and $375 thousand, respectively. Depreciation and amortization expense for the nine months ended September 30, 2023 and

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consist of the following (in thousands): September 30, December 31, 2023 2022 Accrued research and development expenses $ 29,882 $ 32,310 Accrued employee expenses 11,159 11,246 Accrued legal expenses 840 1,256 Accrued general and administrative expenses 828 662 Lease liability 2,425 2,162 Contingent consideration 500 — Taxes payable 654 384 Total accrued expenses 46,288 48,020 Less long-term portion 1,634 2,620 Total accrued expenses $ 44,654 $ 45,400

Stockholders_ Equity

Stockholders’ Equity	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Stockholders’ Equity	Stockholders’ Equity Follow-on Offering of Common Stock On June 15, 2023, we completed a follow-on offering in which we issued and sold 11,032,656 shares of common stock at a public offering price of $22.66 per share. The total gross proceeds for the offering were approximately $250.0 million, before deducting offering expenses of $14.3 million payable by us. Share-based Compensation Effective April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved, the 2020 Incentive Award Plan (the “2020 Plan”), as amended in January 2021, which allows for grants to selected employees, consultants and non-employee members of the Board of Directors. We currently grant stock options and restricted stock units (“RSUs”), under the 2020 Plan. Awards may be made under the 2020 Plan covering up to the sum of (1) 5,600,000 shares of common stock; plus (2) any shares forfeited from the unvested restricted shares of our common stock issued upon conversion of unvested Class B common units (up to 1,250,000 shares); plus (3) an annual increase on the first day of each fiscal year beginning with the fiscal year ending December 31, 2021 and continuing to, and including, the fiscal year ending December 31, 2030, equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year and (b) such smaller number of shares as determined by our Board of Directors. At September 30, 2023, 10,155,201 shares were subject to outstanding awards under the 2020 Plan and 1,021,420 shares were available for future grants of share-based awards under the 2020 Plan. In July 2022, the Company’s Board of Directors approved the Zentalis Pharmaceuticals, Inc. 2022 Employment Inducement Incentive Award Plan (the “2022 Inducement Plan”), which is used exclusively for the grant of equity awards to new employees as an inducement material to the employees’ entering into employment with the Company. The Board of Directors has reserved 2,275,000 shares of the Company’s common stock for issuance pursuant to awards granted under the 2022 Inducement Plan. At September 30, 2023, 1,580,825 shares were subject to outstanding awards under the 2022 Inducement Plan and 694,175 shares were available for future grants of share-based awards under the 2022 Inducement Plan. Total share-based compensation expense related to share based awards was comprised of the following (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Research and development expense $ 5,854 $ 4,526 $ 17,712 $ 14,723 General and administrative expense 8,013 5,791 23,230 22,505 Total share-based compensation expense $ 13,867 $ 10,317 $ 40,942 $ 37,228 Share-based compensation expense by type of share-based award (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Stock Options $ 10,408 $ 8,999 $ 31,222 $ 29,301 Employee Stock Purchase Plan 87 93 303 305 RSAs and RSUs 3,372 1,225 9,417 7,622 $ 13,867 $ 10,317 $ 40,942 $ 37,228 Stock Options and Restricted Stock Units The exercise price of stock options granted is equal to the closing price of the Company’s common stock on the date of grant. The fair value of each option award is estimated on the date of grant using the Black-Scholes model. Due to the Company’s limited operating history and a lack of company specific historical and implied volatility data, the Company estimates expected volatility based on the historical volatility of a group of similar companies that are publicly traded. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. The Company uses the “simplified method” for estimating the expected term of employee options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option (generally 10 years). The risk-free interest rate is based on the U.S. Treasury yield for a period consistent with the expected term of the option in effect at the time of the grant. The Company has not issued any dividends and does not expect to issue dividends over the life of the options. As a result, the Company has estimated the dividend yield to be zero. The fair value of the stock options granted during the nine months ended September 30, 2023 and September 30, 2022 was determined with the following assumptions: September 30, 2023 September 30, 2022 Expected volatility 77.5% - 80.8% 73.6% - 80.5% Average expected term (in years) 5.5 - 6.1 6.0 - 6.5 Risk-free interest rate 3.4% - 4.2% 1.5% - 3.3% Expected dividend yield — % — % Employee Stock Purchase Plan Effective April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved the Zentalis Pharmaceuticals, Inc. 2020 Employee Stock Purchase Plan (the “ESPP”), which was subsequently amended and restated effective March 15, 2021. The maximum aggregate number of shares of the Company’s common stock available for issuance under the ESPP at September 30, 2023 was 1,913,160. Under the terms of the ESPP, the Company’s employees may elect to have up to 20% of their compensation, up to a maximum value of $25,000 per calendar year, withheld to purchase shares of the Company’s common stock for a purchase price equal to 85% of the lower of the fair market value per share (at closing) of the Company’s common stock on (i) the first trading day of a six-month offering period, or (ii) the applicable purchase date, defined as the last trading day of the six-month offering period. The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP during the period ended are as follows: Ended September 30, 2023 ESPP Volatility 94.2 % Expected term (years) 0.5 Risk free rate 4.9 % Expected dividend yield — Compensation Expense Summary Total unrecognized estimated compensation cost by type of award and the weighted average requisite service period over which such expense is expected to be recognized (in thousands, unless otherwise noted): September 30, 2023 Unrecognized Remaining Stock options $ 108,520 2.87 RSAs 16 0.25 RSUs 27,849 2.69 ESPP $ — 0

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies From time to time, we may be involved in various disputes, including lawsuits and claims arising in the ordinary course of business, including actions with respect to intellectual property, employment, and contractual matters. Any of these claims could subject us to costly legal expenses. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in a liability and the amounts of loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss to the extent necessary to make the consolidated financial statements not misleading. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in our consolidated financial statements. While we do generally believe that we have adequate insurance to cover many different types of liabilities, our insurance carriers may deny coverage, or our policy limits may be inadequate to fully satisfy any damage awards or settlement. If this were to happen, the payment of any such awards could have a material adverse effect on our consolidated results of operations and financial position. Additionally, any such claims, whether or not successful, could damage our reputation and business. We are currently not a party to any legal proceedings that require a loss liability to be recorded. Leases Our commitments include payments related to operating leases. Approximate annual future minimum operating lease payments as of September 30, 2023 are as follows (in thousands): Year Operating Leases 2023 (remaining) $ 1,548 2024 6,486 2025 6,799 2026 7,278 2027 7,451 Thereafter 38,778 Total minimum lease payments: 68,340 Less: imputed interest (22,649) Total operating lease liabilities 45,691 Less: current portion (2,425) Lease liability, net of current portion $ 43,266 The weighted-average remaining lease term of our operating leases is approximately 9.0 years.

Net Loss Per Common Share

Net Loss Per Common Share	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Net Loss Per Common Share	Net Loss Per Common Share Basic and diluted net loss per common share were calculated as follows (in thousands except per share amounts): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Numerator: Net loss attributable to Zentalis $ (55,528) $ (54,401) $ (231,274) $ (181,835) Denominator: Weighted average number of common shares outstanding, basic and diluted 70,612 56,807 63,601 51,098 Net loss per common share $ (0.79) $ (0.96) $ (3.64) $ (3.56) Our potential and dilutive securities, which include outstanding stock options, unvested RSAs and unvested RSUs have been excluded from the computation of diluted net loss per common share as the effect would be anti-dilutive. The following common stock equivalents have been excluded from the calculations of diluted net loss per common share because their inclusion would be antidilutive (in thousands). September 30, 2023 2022 Outstanding stock options 10,260 7,671 Unvested RSAs 4 172 Unvested RSUs 1,476 468 11,740 8,311

Related Party Disclosures

Related Party Disclosures	9 Months Ended
	Sep. 30, 2023
Related Party Transactions [Abstract]
Related Party Disclosures	Related Party Disclosures Tempus Kimberly Blackwell, M.D., our Chief Executive Officer and a member of our Board of Directors, was previously employed by Tempus Labs, Inc. ("Tempus") and served as an advisor of Tempus until June 2023, at which time Tempus ceased to be a related party of Zentalis. The Company entered into a Master Services Agreement with Tempus in December 2020 to provide data licensing and research services. There were $0.5 million and immaterial fees incurred for services performed by Tempus for the period in which Tempus was a related party in 2023 and for the nine months ended September 30, 2022, respectively. Zentera Kevin D. Bunker, Ph.D., our Chief Scientific Officer, served as a member of the Board of Directors of Zentera until June 2023, when Dr. Bunker resigned in connection with the termination of our Collaboration and License Agreements with Zentera and the sale of our 40.3% equity stake in Zentera back to Zentera. For additional information, please see Note 3. Accordingly, the Company identified Zentera as a related party up until the date of termination. In May 2020, each of our wholly owned subsidiaries, Zeno Alpha, Inc., K-Group Alpha, Inc. and K-Group Beta, Inc., entered into Collaboration and License Agreements, pursuant to which we collaborated with Zentera on the development and comm ercialization of the Zentera Collaboration Products, in Greater China. Under the terms of the Collaboration and License Agreements with Zentera, Zentera was responsible for the costs of developing the Zentera Collaboration Products in Greater China, and we were responsible for the costs of developing the Zentera Collaboration Products outside Greater China, provided that Zentera was obligated to reimburse us for a portion of its costs for global data management, pharmacovigilance, safety database management, and chemistry, manufacturing and controls activities with respect to each Zentera Collaboration Product. For the periods in which Zentera was a related party in 2023 and for the nine months ended September 30, 2022, the amounts incurred under this arrangement totaled $3.5 million and $8.3 million, respectively, and are presented as contra-research and development expense in the consolidated statement of operations. As disclosed above, these Collaboration and License Agreements were terminated in June 2023 at which time Zentera ceased to be a related party of Zentalis.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Pay vs Performance Disclosure
Net loss attributable to Zentalis	$ (55,528)	$ (54,401)	$ (231,274)	$ (181,835)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
	Sep. 30, 2023 shares	Sep. 30, 2023 shares
Trading Arrangements, by Individual
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Melissa Epperly [Member]
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		On September 22, 2023, Melissa Epperly, the Company’s Chief Financial Officer, adopted a Rule 10b5-1 trading arrangement that is intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of up to 22,065 shares of the Company’s common stock until December 22, 2024.
Name	Melissa Epperly
Title	Chief Financial Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	September 22, 2023
Arrangement Duration	457 days
Aggregate Available	22,065	22,065

Interim Unaudited Financial S_2

Interim Unaudited Financial Statements (Policies)	9 Months Ended
	Sep. 30, 2023
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. The year-end condensed consolidated balance sheet data was derived from the Company’s audited financial statements but do not include all disclosures required by U.S. GAAP. These interim unaudited condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2022, filed with the SEC on March 1, 2023. The unaudited financial information for the interim periods presented herein reflects all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial condition and results of operation for the periods presented, with such adjustments consisting only of normal recurring adjustments. Certain reclassifications have been made to the prior period condensed consolidated balance sheet to conform to the current period presentation.
Consolidation	The accompanying interim unaudited condensed consolidated financial statements include our wholly-owned subsidiaries and a variable interest entity (“VIE”), for which we are the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation. We evaluate our ownership, contractual and other interests in entities that are not wholly-owned to determine if these entities are VIEs, and, if so, whether we are the primary beneficiary of the VIE. In determining whether we are the primary beneficiary of a VIE and therefore required to consolidate the VIE, we apply a qualitative approach that determines whether we have both (1) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (2) the obligation to absorb losses of, or the rights to receive benefits from, the VIE that could potentially be significant to that VIE. We will continuously assess whether we are the primary beneficiary of a VIE, as changes to existing relationships or future transactions may result in the consolidation or deconsolidation of such VIE. During the periods presented, we have not provided any other material financial or other support to our VIE that we were not contractually required to provide. The equity method is used to account for investments in which we have the ability to exercise significant influence, but not control, over the investee. Such investments are recorded on the balance sheet, and the share of net income or losses of equity investments is recognized on a one quarter lag in investment and other income (expense), net.
Use of Estimates	Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in our consolidated financial statements and accompanying notes. On an ongoing basis, we evaluate our estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates.
Acquisitions and Contingent Consideration	Acquisitions and Contingent Consideration The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen test to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in Accounting Standards Update (ASU) 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquired entity and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations, including contingent assets and liabilities, and non-controlling interest in the acquired entity based on the fair value estimates as of the date of acquisition. In accordance with Accounting Standards Codification (ASC) 805, Business Combinations, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired. The consideration for the Company’s business acquisitions may include future payments that are contingent upon the occurrence of a particular event or events. The obligations for such contingent consideration payments are recorded at fair value on the acquisition date. The contingent consideration obligations are then evaluated each reporting period. Changes in the fair value of contingent consideration, other than changes due to payments, are recognized as a gain or loss and recorded within change in the fair value of deferred and contingent consideration liabilities in the consolidated statements of comprehensive loss. Contingent consideration liabilities expected to be
Acquisitions and Contingent Consideration	Acquisitions and Contingent Consideration The Company evaluates acquisitions of assets and other similar transactions to assess whether or not the transaction should be accounted for as a business combination or asset acquisition by first applying a screen test to determine if substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset or group of similar identifiable assets. If the screen is met, the transaction is accounted for as an asset acquisition. If the screen is not met, further determination is required as to whether or not the Company has acquired inputs and processes that have the ability to create outputs, which would meet the requirements of a business. If determined to be a business combination, the Company accounts for the transaction under the acquisition method of accounting as indicated in Accounting Standards Update (ASU) 2017-01, Business Combinations (Topic 805): Clarifying the Definition of a Business, which requires the acquiring entity in a business combination to recognize the fair value of all assets acquired, liabilities assumed, and any non-controlling interest in the acquired entity and establishes the acquisition date as the fair value measurement point. Accordingly, the Company recognizes assets acquired and liabilities assumed in business combinations, including contingent assets and liabilities, and non-controlling interest in the acquired entity based on the fair value estimates as of the date of acquisition. In accordance with Accounting Standards Codification (ASC) 805, Business Combinations, the Company recognizes and measures goodwill as of the acquisition date, as the excess of the fair value of the consideration paid over the fair value of the identified net assets acquired. The consideration for the Company’s business acquisitions may include future payments that are contingent upon the occurrence of a particular event or events. The obligations for such contingent consideration payments are recorded at fair value on the acquisition date. The contingent consideration obligations are then evaluated each reporting period. Changes in the fair value of contingent consideration, other than changes due to payments, are recognized as a gain or loss and recorded within change in the fair value of deferred and contingent consideration liabilities in the consolidated statements of comprehensive loss. Contingent consideration liabilities expected to be

Business Combinations (Tables)

Business Combinations (Tables)	9 Months Ended
	Sep. 30, 2023
Business Combination and Asset Acquisition [Abstract]
Reconciliation of Equity Attributable to Noncontrolling Interest	The following is a reconciliation of equity (net assets) attributable to the noncontrolling interest (in thousands): September 30, December 31, 2023 2022 Noncontrolling interest at beginning of period $ 221 $ 528 Net loss attributable to noncontrolling interest (92) (307) Noncontrolling interest at end of period $ 129 $ 221

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	9 Months Ended
	Sep. 30, 2023
Fair Value Disclosures [Abstract]
Components of Available-for-sale Marketable Securities	Available-for-sale marketable securities consisted of the following (in thousands): September 30, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 87,492 $ 1 $ (69) $ 87,424 Corporate debt securities 149,539 10 (82) 149,467 US government agencies 105,258 7 (110) 105,155 US treasury securities 63,956 — (116) 63,840 $ 406,245 $ 18 $ (377) $ 405,886 December 31, 2022 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 296,309 $ 71 $ (587) $ 295,793 Corporate debt securities 7,472 — (26) 7,446 US government agencies 23,970 — (182) 23,788 US treasury securities 67,904 — (629) 67,275 $ 395,655 $ 71 $ (1,424) $ 394,302
Contractual Maturities of Available-for-sale Debt Securities	Contractual maturities of available-for-sale debt securities are as follows (in thousands): September 30, 2023 December 31, 2022 Estimated Fair Value Due within one year $ 238,972 $ 394,302 After one but within five years 166,914 — $ 405,886 $ 394,302
Fair Value of Assets and Liabilities Measured on a Recurring Basis	The following table summarizes the financial assets and liabilities that are measured on a recurring basis at fair value as of September 30, 2023 and December 31, 2022 (in thousands): September 30, 2023 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 76,333 $ — $ — $ 76,333 Commercial paper 10,483 — — 10,483 US government agencies 14,978 — 14,978 Total cash equivalents: 101,794 — — 101,794 Available-for-sale marketable securities: Commercial paper — 87,424 — 87,424 Corporate debt securities — 149,467 — 149,467 US government agencies — 105,155 — 105,155 US treasury securities 63,840 — — 63,840 Total available-for-sale marketable securities: 63,840 342,046 — 405,886 Total assets measured at fair value $ 165,634 $ 342,046 $ — $ 507,680 Financial liabilities: Contingent consideration $ — $ — $ 500 $ 500 Total financial liabilities $ — $ — $ 500 $ 500 December 31, 2022 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 26,811 $ — $ — $ 26,811 Commercial paper 1,998 — — 1,998 Total cash equivalents: 28,809 — — 28,809 Available-for-sale marketable securities: Commercial paper — 295,793 — 295,793 Corporate debt securities — 7,446 — 7,446 US government agencies — 23,788 — 23,788 US treasury securities 67,275 — — 67,275 Total available-for-sale marketable securities: 67,275 327,027 — 394,302 Total assets measured at fair value $ 96,084 $ 327,027 $ — $ 423,111 Financial liabilities: Contingent consideration $ — $ — $ — $ — Total financial liabilities $ — $ — $ — $ —
Measurement Inputs for Contingent Consideration Liability	The following significant unobservable inputs were used in the valuation of the contingent consideration payable to Zentera pursuant to the Termination Agreement at September 30, 2023. Contingent Consideration Liability Fair Value as of September 30, 2023 Valuation Technique Unobservable Input Range (in thousands) Milestone payment $ 500 Discounted cash flow Likelihood of occurrence 1.0% - 2.4% Discount rate 40% Expected term Perpetuity
Activity for Contingent Consideration	The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (in thousands): Contingent consideration at December 31, 2022 $ — Issuance of contingent consideration to Zentera 500 Changes in the fair value of contingent consideration — Contingent consideration at September 30, 2023 $ 500

Prepaid Expenses and Other As_2

Prepaid Expenses and Other Assets (Tables)	9 Months Ended
	Sep. 30, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Summary of Prepaid Expenses and Other Assets	Prepaid expenses and other assets consisted of the following (in thousands): September 30, December 31, 2023 2022 Prepaid insurance $ 1,011 $ 1,018 Prepaid software licenses and maintenance 435 958 Foreign R&D credit refund 1,024 659 Prepaid research and development expenses 14,188 15,002 Interest receivable 1,931 508 Sublease assets 1,265 — Zentera receivable — 5,874 Other prepaid expenses 284 266 Total prepaid expenses and other assets 20,138 24,285 Less long-term portion 8,511 9,723 Total prepaid expenses and other assets, current $ 11,627 $ 14,562

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	9 Months Ended
	Sep. 30, 2023
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, net	Property and equipment, net consisted of the following (in thousands): September 30, December 31, 2023 2022 Lab equipment $ 3,069 $ 2,622 Leasehold improvements 4,432 4,891 Office equipment and furniture 1,854 2,065 Computer equipment 150 150 Construction in progress — 37 Subtotal 9,505 9,765 Accumulated depreciation and amortization (3,112) (2,060) Property and equipment, net $ 6,393 $ 7,705

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): September 30, December 31, 2023 2022 Accrued research and development expenses $ 29,882 $ 32,310 Accrued employee expenses 11,159 11,246 Accrued legal expenses 840 1,256 Accrued general and administrative expenses 828 662 Lease liability 2,425 2,162 Contingent consideration 500 — Taxes payable 654 384 Total accrued expenses 46,288 48,020 Less long-term portion 1,634 2,620 Total accrued expenses $ 44,654 $ 45,400

Stockholders_ Equity (Tables)

Stockholders’ Equity (Tables)	9 Months Ended
	Sep. 30, 2023
Equity [Abstract]
Schedule of Share-based Compensation Expense	Total share-based compensation expense related to share based awards was comprised of the following (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Research and development expense $ 5,854 $ 4,526 $ 17,712 $ 14,723 General and administrative expense 8,013 5,791 23,230 22,505 Total share-based compensation expense $ 13,867 $ 10,317 $ 40,942 $ 37,228 Share-based compensation expense by type of share-based award (in thousands): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Stock Options $ 10,408 $ 8,999 $ 31,222 $ 29,301 Employee Stock Purchase Plan 87 93 303 305 RSAs and RSUs 3,372 1,225 9,417 7,622 $ 13,867 $ 10,317 $ 40,942 $ 37,228
Schedule of Fair Value Assumptions for Stock Options	The fair value of the stock options granted during the nine months ended September 30, 2023 and September 30, 2022 was determined with the following assumptions: September 30, 2023 September 30, 2022 Expected volatility 77.5% - 80.8% 73.6% - 80.5% Average expected term (in years) 5.5 - 6.1 6.0 - 6.5 Risk-free interest rate 3.4% - 4.2% 1.5% - 3.3% Expected dividend yield — % — %
Schedule of Fair Value Assumptions for ESPP	The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP during the period ended are as follows: Ended September 30, 2023 ESPP Volatility 94.2 % Expected term (years) 0.5 Risk free rate 4.9 % Expected dividend yield —
Unrecognized Compensation Cost	Total unrecognized estimated compensation cost by type of award and the weighted average requisite service period over which such expense is expected to be recognized (in thousands, unless otherwise noted): September 30, 2023 Unrecognized Remaining Stock options $ 108,520 2.87 RSAs 16 0.25 RSUs 27,849 2.69 ESPP $ — 0

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Operating Lease Payments	Approximate annual future minimum operating lease payments as of September 30, 2023 are as follows (in thousands): Year Operating Leases 2023 (remaining) $ 1,548 2024 6,486 2025 6,799 2026 7,278 2027 7,451 Thereafter 38,778 Total minimum lease payments: 68,340 Less: imputed interest (22,649) Total operating lease liabilities 45,691 Less: current portion (2,425) Lease liability, net of current portion $ 43,266

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	9 Months Ended
	Sep. 30, 2023
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Unit	Basic and diluted net loss per common share were calculated as follows (in thousands except per share amounts): Three Months Ended Nine Months Ended 2023 2022 2023 2022 Numerator: Net loss attributable to Zentalis $ (55,528) $ (54,401) $ (231,274) $ (181,835) Denominator: Weighted average number of common shares outstanding, basic and diluted 70,612 56,807 63,601 51,098 Net loss per common share $ (0.79) $ (0.96) $ (3.64) $ (3.56)
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Unit	The following common stock equivalents have been excluded from the calculations of diluted net loss per common share because their inclusion would be antidilutive (in thousands). September 30, 2023 2022 Outstanding stock options 10,260 7,671 Unvested RSAs 4 172 Unvested RSUs 1,476 468 11,740 8,311

Significant Transactions (Detai

Significant Transactions (Details) - USD ($) $ in Thousands		3 Months Ended			9 Months Ended
	Jun. 15, 2023	Sep. 30, 2023	Jun. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Loss on equity method investment		$ 0	$ 13,700	$ 2,371	$ 16,014	$ 9,460
Contingent consideration		500			500		$ 0
In-process research and development		$ 0		$ 0	45,568	$ 0
Zentera
Schedule of Equity Method Investments [Line Items]
Total consideration transferred	$ 45,600
Fixed consideration	30,000
Forgiveness of outstanding receivables	9,400
Acquisition-related costs	500
In-process research and development					$ 45,600
Zentera | Variable consideration of a change in control milestone payment | Minimum
Schedule of Equity Method Investments [Line Items]
Contingent consideration	0
Zentera | Variable consideration of a change in control milestone payment | Maximum
Schedule of Equity Method Investments [Line Items]
Contingent consideration	15,000
Zentera | Discounted cash flow | Milestone payment
Schedule of Equity Method Investments [Line Items]
Contingent consideration	$ 500
Zentera
Schedule of Equity Method Investments [Line Items]
Ownership percentage sold	40.30%

Business Combinations - Narrati

Business Combinations - Narrative (Details) - Kalyra Pharmaceuticals, Inc. $ in Millions	Dec. 21, 2017 USD ($)
Variable Interest Entity [Line Items]
Cash payments to acquire interest	$ 4.5
Ownership percentage	25%

Business Combinations - Reconci

Business Combinations - Reconciliation of Equity (Net Assets) Attributable to Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interest at beginning of period			$ 221
Net loss attributable to noncontrolling interests	$ (12)	$ (99)	(92)	$ (294)
Noncontrolling interest at end of period	129		129		$ 221
VIE, Primary Beneficiary
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interest at beginning of period			221	$ 528	528
Net loss attributable to noncontrolling interests			(92)		(307)
Noncontrolling interest at end of period	$ 129		$ 129		$ 221

Fair Value Measurement - Compon

Fair Value Measurement - Components of Available-for-sale Marketable Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 406,245	$ 395,655
Gross Unrealized Gains	18	71
Gross Unrealized Losses	(377)	(1,424)
Estimated Fair Value	405,886	394,302
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	87,492	296,309
Gross Unrealized Gains	1	71
Gross Unrealized Losses	(69)	(587)
Estimated Fair Value	87,424	295,793
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	149,539	7,472
Gross Unrealized Gains	10	0
Gross Unrealized Losses	(82)	(26)
Estimated Fair Value	149,467	7,446
US government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	105,258	23,970
Gross Unrealized Gains	7	0
Gross Unrealized Losses	(110)	(182)
Estimated Fair Value	105,155	23,788
US treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	63,956	67,904
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(116)	(629)
Estimated Fair Value	$ 63,840	$ 67,275

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) $ in Thousands	Sep. 30, 2023 USD ($) potential_milestone_payment security	Dec. 31, 2022 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of available-for-sale securities in unrealized loss position | security	58
Debt securities fair market value	$ 347,600
Fair market value of available-for-sale securities in unrealized loss position	$ 400
Number of available-for-sale securities in unrealized loss position for less than one year | security	58
Gross unrealized loss position for less than one year	$ 400
Number of available-for-sale securities in unrealized loss position for more than one year | security	0
Contingent consideration	$ 500	$ 0
Zentera | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500
Number of potential milestone payments | potential_milestone_payment	1

Fair Value Measurement - Contra

Fair Value Measurement - Contractual Maturities of Available-for-sale Debt Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Due within one year	$ 238,972	$ 394,302
After one but within five years	166,914	0
Total	$ 405,886	$ 394,302

Fair Value Measurement - Fair V

Fair Value Measurement - Fair Value of Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Financial assets:
Cash equivalents	$ 101,794	$ 28,809
Marketable securities, available-for-sale	405,886	394,302
Total assets measured at fair value	507,680	423,111
Financial liabilities:
Contingent consideration	500	0
Total financial liabilities	500	0
Level 1
Financial assets:
Cash equivalents	101,794	28,809
Marketable securities, available-for-sale	63,840	67,275
Total assets measured at fair value	165,634	96,084
Financial liabilities:
Contingent consideration	0	0
Total financial liabilities	0	0
Level 2
Financial assets:
Cash equivalents	0	0
Marketable securities, available-for-sale	342,046	327,027
Total assets measured at fair value	342,046	327,027
Financial liabilities:
Contingent consideration	0	0
Total financial liabilities	0	0
Level 3
Financial assets:
Cash equivalents	0	0
Marketable securities, available-for-sale	0	0
Total assets measured at fair value	0	0
Financial liabilities:
Contingent consideration	500	0
Total financial liabilities	500	0
Commercial paper
Financial assets:
Marketable securities, available-for-sale	87,424	295,793
Commercial paper | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
Commercial paper | Level 2
Financial assets:
Marketable securities, available-for-sale	87,424	295,793
Commercial paper | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
Corporate debt securities
Financial assets:
Marketable securities, available-for-sale	149,467	7,446
Corporate debt securities | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
Corporate debt securities | Level 2
Financial assets:
Marketable securities, available-for-sale	149,467	7,446
Corporate debt securities | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
US government agencies
Financial assets:
Marketable securities, available-for-sale	105,155	23,788
US government agencies | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
US government agencies | Level 2
Financial assets:
Marketable securities, available-for-sale	105,155	23,788
US government agencies | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
US treasury securities
Financial assets:
Marketable securities, available-for-sale	63,840	67,275
US treasury securities | Level 1
Financial assets:
Marketable securities, available-for-sale	63,840	67,275
US treasury securities | Level 2
Financial assets:
Marketable securities, available-for-sale	0	0
US treasury securities | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
Money market funds
Financial assets:
Cash equivalents	76,333	26,811
Money market funds | Level 1
Financial assets:
Cash equivalents	76,333	26,811
Money market funds | Level 2
Financial assets:
Cash equivalents	0	0
Money market funds | Level 3
Financial assets:
Cash equivalents	0	0
Commercial paper
Financial assets:
Cash equivalents	10,483	1,998
Commercial paper | Level 1
Financial assets:
Cash equivalents	10,483	1,998
Commercial paper | Level 2
Financial assets:
Cash equivalents	0	0
Commercial paper | Level 3
Financial assets:
Cash equivalents	0	$ 0
US government agencies
Financial assets:
Cash equivalents	14,978
US government agencies | Level 1
Financial assets:
Cash equivalents	14,978
US government agencies | Level 2
Financial assets:
Cash equivalents	0
US government agencies | Level 3
Financial assets:
Cash equivalents

Fair Value Measurement - Measur

Fair Value Measurement - Measurement Inputs for Contingent Consideration Liability (Details) $ in Thousands	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500	$ 0
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500	$ 0
Level 3 | Discounted cash flow | Likelihood of occurrence | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.010
Level 3 | Discounted cash flow | Likelihood of occurrence | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.024
Level 3 | Milestone payment | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.40
Level 3 | Milestone payment | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500

Fair Value Measurement - Activi

Fair Value Measurement - Activity for Contingent Consideration (Details) - Contingent Consideration Liability $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Contingent consideration, beginning balance	$ 0
Issuance of contingent consideration to Zentera	500
Changes in the fair value of contingent consideration	0
Contingent consideration, ending balance	$ 500

Prepaid Expenses and Other As_3

Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid insurance	$ 1,011	$ 1,018
Prepaid software licenses and maintenance	435	958
Foreign R&D credit refund	1,024	659
Prepaid research and development expenses	14,188	15,002
Interest receivable	1,931	508
Sublease assets	1,265	0
Zentera receivable	0	5,874
Other prepaid expenses	284	266
Total prepaid expenses and other assets	20,138	24,285
Less long-term portion	8,511	9,723
Total prepaid expenses and other assets, current	$ 11,627	$ 14,562

Property and Equipment, net - S

Property and Equipment, net - Summary (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Subtotal	$ 9,505	$ 9,765
Accumulated depreciation and amortization	(3,112)	(2,060)
Property and equipment, net	6,393	7,705
Lab equipment
Property, Plant and Equipment [Line Items]
Subtotal	3,069	2,622
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	4,432	4,891
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Subtotal	1,854	2,065
Computer equipment
Property, Plant and Equipment [Line Items]
Subtotal	150	150
Construction in progress
Property, Plant and Equipment [Line Items]
Subtotal	$ 0	$ 37

Property and Equipment, net - N

Property and Equipment, net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 348	$ 375	$ 1,052	$ 1,067

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 29,882	$ 32,310
Accrued employee expenses	11,159	11,246
Accrued legal expenses	840	1,256
Accrued general and administrative expenses	828	662
Lease liability	2,425	2,162
Contingent consideration	500	0
Taxes payable	654	384
Total accrued expenses	46,288	48,020
Less long-term portion	1,634	2,620
Total accrued expenses	$ 44,654	$ 45,400

Stockholders_ Equity - Narrativ

Stockholders’ Equity - Narrative (Details) - USD ($)		1 Months Ended	9 Months Ended
	Jun. 15, 2023	Jan. 31, 2021	Sep. 30, 2023	Sep. 30, 2022	Jul. 31, 2022
Class of Stock [Line Items]
Issuance of common stock upon exercise of options, net (in shares)			54,300
Shares issued upon vesting of certain RSAs (in shares)			116,900
Stock Options
Class of Stock [Line Items]
Generally expected vesting term of the option contract (in years)			10 years
Expected dividend yield			0%	0%
Options outstanding (in shares)			10,300,000
Employee Stock Purchase Plan
Class of Stock [Line Items]
Number of shares reserved for future issuance (in shares)			1,913,160
Expected dividend yield			0%
ESPP maximum percent of compensation to contribute			20%
Maximum contribution amount			$ 25,000
ESPP purchase price of common stock, percent of market price			85%
Offering period (in months)			6 months
RSAs
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			4,400
RSUs
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			1,500,000
The 2020 Plan
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			10,155,201
Number of shares available for future grants (in shares)			1,021,420
2022 Inducement Plan
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			1,580,825
Number of shares available for future grants (in shares)			694,175
Number of shares reserved for future issuance (in shares)					2,275,000
Follow On Offering
Class of Stock [Line Items]
Gross proceeds from issuance of common stock	$ 250,000,000
Expenses and fees from the issuance of common stock	$ 14,300,000
Common Stock | The 2020 Plan
Class of Stock [Line Items]
Shares authorized to be issued under plan (in shares)		5,600,000
Percent of common stock outstanding used as threshold to calculate shares available for issuance		5%
Common Stock | Follow On Offering
Class of Stock [Line Items]
Number of shares issued and sold (in shares)	11,032,656
Share price (in dollars per share)	$ 22.66
Common Class B | The 2020 Plan | Maximum
Class of Stock [Line Items]
Shares authorized to be issued under plan (in shares)		1,250,000

Stockholders_ Equity - Share-ba

Stockholders’ Equity - Share-based Compensation Expense by Expense Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 13,867	$ 10,317	$ 40,942	$ 37,228
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	5,854	4,526	17,712	14,723
General and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 8,013	$ 5,791	$ 23,230	$ 22,505

Stockholders_ Equity - Share-_2

Stockholders’ Equity - Share-based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 13,867	$ 10,317	$ 40,942	$ 37,228
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	10,408	8,999	31,222	29,301
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	87	93	303	305
RSAs and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 3,372	$ 1,225	$ 9,417	$ 7,622

Stockholders_ Equity - Fair Val

Stockholders’ Equity - Fair Value Assumptions for Stock Options (Details) - Stock Options	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected volatility, minimum	77.50%	73.60%
Expected volatility, maximum	80.80%	80.50%
Risk-free interest rate, minimum	3.40%	1.50%
Risk-free interest rate, maximum	4.20%	3.30%
Expected dividend yield	0%	0%
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average expected term (in years)	5 years 6 months	6 years
Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average expected term (in years)	6 years 1 month 6 days	6 years 6 months

Stockholders_ Equity - Fair V_2

Stockholders’ Equity - Fair Value Assumptions for ESPP (Details) - Employee Stock Purchase Plan	9 Months Ended
	Sep. 30, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Volatility	94.20%
Expected term (years)	6 months
Risk free rate	4.90%
Expected dividend yield	0%

Stockholders_ Equity - Unrecogn

Stockholders’ Equity - Unrecognized Compensation Cost (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, stock options	$ 108,520
Remaining Weighted-Average Recognition Period (years)	2 years 10 months 13 days
RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than stock options	$ 16
Remaining Weighted-Average Recognition Period (years)	3 months
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than stock options	$ 27,849
Remaining Weighted-Average Recognition Period (years)	2 years 8 months 8 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than stock options	$ 0
Remaining Weighted-Average Recognition Period (years)	0 years

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
2023 (remaining)	$ 1,548
2024	6,486
2025	6,799
2026	7,278
2027	7,451
Thereafter	38,778
Total minimum lease payments:	68,340
Less: imputed interest	(22,649)
Total operating lease liabilities	45,691
Less: current portion	(2,425)	$ (2,162)
Lease liability, net of current portion	$ 43,266	$ 45,166

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Operating lease, weighted-average remaining lease term (in years)	9 years
Operating lease right-of-use asset and fixed asset impairment	$ 4,953	$ 0
Sublease income	$ 600

Net Loss Per Common Share - Cal

Net Loss Per Common Share - Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net loss attributable to Zentalis	$ (55,528)	$ (54,401)	$ (231,274)	$ (181,835)
Denominator:
Weighted average number of common shares outstanding, basic (in shares)	70,612	56,807	63,601	51,098
Weighted average number of common shares outstanding, diluted (in shares)	70,612	56,807	63,601	51,098
Net loss per common share, basic (in dollars per share)	$ (0.79)	$ (0.96)	$ (3.64)	$ (3.56)
Net loss per common share, diluted (in dollars per share)	$ (0.79)	$ (0.96)	$ (3.64)	$ (3.56)

Net Loss Per Common Share - Ant

Net Loss Per Common Share - Antidilutive Securities (Details) - shares shares in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	11,740	8,311
Outstanding stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	10,260	7,671
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	4	172
Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	1,476	468

Related Party Disclosures (Deta

Related Party Disclosures (Details) - USD ($) $ in Millions	6 Months Ended	9 Months Ended
	Jun. 30, 2023	Sep. 30, 2022	Jun. 15, 2023
Zentera
Related Party Transaction [Line Items]
Ownership percentage sold			40.30%
Related Party | Zentera
Related Party Transaction [Line Items]
Ownership percentage sold			40.30%
Contra-research and development expense	$ 3.5	$ 8.3
Related Party | Master Services Agreement
Related Party Transaction [Line Items]
Due to related parties	$ 0.5	$ 0