Zentalis Pharmaceuticals (ZNTL) 10-K 1 Mar 23 2022 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Feb. 27, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
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 1710
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
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
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,300
Entity Common Stock, Shares Outstanding (in shares)		59,418,460
Documents Incorporated by Reference	Portions of the registrant's definitive Proxy Statement relating to its 2023 Annual Meeting of Stockholders to be filed with the SEC within 120 days after the end of the fiscal year ended December 31, 2022 are incorporated herein by reference in Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0001725160
Amendment Flag	false
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2022

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Auditor Information [Abstract]
Auditor Firm ID	42
Auditor Name	Ernst & Young LLP
Auditor Location	San Diego, California

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets
Cash and cash equivalents	$ 43,069	$ 59,714
Marketable securities, available for sale	394,302	280,173
Prepaid expenses and other current assets	14,562	10,640
Restricted cash	0	243
Total current assets	451,933	350,770
Property and equipment, net	7,705	8,148
Operating lease right-of-use assets	42,373	44,691
Prepaid expenses and other assets	9,723	7,040
Goodwill	3,736	3,736
Investment in Zentera Therapeutics	21,213	37,495
Restricted cash	2,627	2,627
Total assets	539,310	454,507
Current liabilities
Accounts payable	11,247	11,590
Accrued expenses	45,400	32,354
Total current liabilities	56,647	43,944
Deferred tax liability	853	1,622
Long-term lease liability	45,166	44,459
Other long-term liabilities	2,620	0
Total liabilities	105,286	90,025
Commitments and contingencies (see Note 10)
EQUITY
Preferred stock, $0.001 par value; 10,000,000 shares authorized, no shares issued and outstanding at December 31, 2022 and 2021	0	0
Common stock, $0.001 par value; 250,000,000 shares authorized; 59,280,247 and 45,490,764 shares issued and outstanding at December 31, 2022 and 2021, respectively	59	45
Additional paid-in capital	1,031,462	723,593
Accumulated other comprehensive loss	(1,353)	(125)
Accumulated deficit	(596,365)	(359,559)
Total stockholders' equity	433,803	363,954
Noncontrolling interests	221	528
Total equity	434,024	364,482
Total liabilities and stockholders' equity	$ 539,310	$ 454,507

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	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	250,000,000	250,000,000
Common stock issued (in shares)	59,280,247	45,490,764
Common stock outstanding (in shares)	59,280,247	45,490,764

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Expenses
Research and development	$ 172,734	$ 175,601	$ 84,901
General and administrative	54,553	40,941	33,886
Total operating expenses	227,287	216,542	118,787
Loss from operations	(227,287)	(216,542)	(118,787)
Other Income (Expense)
Investment and other income, net	5,987	401	683
Gain on deconsolidation of Zentera	0	51,582	0
Net loss before income taxes, including loss on equity method investment	(221,300)	(164,559)	(118,104)
Income tax expense (benefit)	(469)	(297)	444
Loss on equity method investment	16,282	1,831	0
Net loss	(237,113)	(166,093)	(118,548)
Net loss attributable to noncontrolling interests	(307)	(7,368)	(707)
Net loss attributable to Zentalis	$ (236,806)	$ (158,725)	$ (117,841)
Net loss per common share outstanding, basic	$ (4.48)	$ (3.72)	$ (4.19)
Net loss per common share outstanding, diluted	$ (4.48)	$ (3.72)	$ (4.19)
Common shares used in computing net loss per share, basic	52,857	42,688	28,113
Common shares used in computing net loss per share, diluted	52,857	42,688	28,113

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (237,113)	$ (166,093)	$ (118,548)
Other comprehensive income (loss):
Unrealized gain (loss) on marketable securities, net	(1,228)	(161)	36
Total comprehensive loss	(238,341)	(166,254)	(118,512)
Comprehensive loss attributable to noncontrolling interests	(307)	(7,368)	(707)
Comprehensive loss attributable to Zentalis	$ (238,034)	$ (158,886)	$ (117,805)

Consolidated Statements of Chan

Consolidated Statements of Changes in Convertible Preferred Units and Members’/Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	IPO	Convertible Preferred Units	Preferred Stock Convertible Preferred Units	Common Stock	Common Stock IPO	Common Stock Class A Common Units	Common Stock Class B Common Units	Additional Paid-In Capital	Additional Paid-In Capital IPO	Accumulated Other Comprehensive Income	Accumulated Deficit	Noncontrolling Interests
Temporary equity beginning balance (in shares) at Dec. 31, 2019			9,950,000
Temporary equity, beginning balance at Dec. 31, 2019			$ 141,706
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series C convertible preferred units at $17.50 per unit net of issuance costs (in shares)			867,000
Issuance of Series C convertible preferred units at $17.50 per unit net of issuance costs			$ 14,228
Conversion of convertible preferred units to common stock (in shares)			(10,817,000)		(15,011,000)
Conversion of convertible preferred units to common stock	$ 155,934		$ (155,934)		$ 15				$ 155,919
Temporary equity ending balance (in shares) at Dec. 31, 2020			0
Temporary equity, ending balance at Dec. 31, 2020			$ 0
Beginning balance (in shares) at Dec. 31, 2019				0	0
Beginning balance at Dec. 31, 2019	(73,285)			$ 0	$ 0				0		$ 0	$ (82,993)	$ 6,821
Common units, beginning balance (in shares) at Dec. 31, 2019							5,601,000	2,671,000
Common units, beginning balance at Dec. 31, 2019							$ 709	$ 2,178
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cancellation of profit interest awards, net (in shares)								(64,000)
Issuance of common stock (in shares)					4,744,000	10,589,000
Issuance of common stock, value	155,305	$ 172,365			$ 5	$ 11			155,300	$ 172,354
Contributions from noncontrolling interest owners	18,424												18,424
Share-based compensation expense	23,146							$ 329	22,817
Issuance and withholding of common stock in connection with restricted stock unit vesting, net (in shares)					426,000
Conversion of convertible preferred units to common stock (in shares)			10,817,000		15,011,000
Conversion of convertible preferred units to common stock	155,934		$ (155,934)		$ 15				155,919
Conversion of common and incentive units to common and restricted stock (in shares)					(10,278,000)		(5,601,000)	(2,607,000)
Conversion of common and incentive units to common and restricted stock					$ 10		$ (709)	$ (2,507)	3,206
Cancellation of restricted stock awards (in shares)					(8,000)
Other comprehensive income (loss)	36										36
Net loss attributable to noncontrolling interest	(707)								(257)				(450)
Net loss attributable to Zentalis	(117,841)											(117,841)
Ending balance (in shares) at Dec. 31, 2020				0	41,040,000
Ending balance at Dec. 31, 2020	333,377			$ 0	$ 41				509,339		36	(200,834)	24,795
Common units, ending balance (in shares) at Dec. 31, 2020							0	0
Common units, ending balance at Dec. 31, 2020					$ 41		$ 0	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)					3,691,000
Issuance of common stock, value	171,973				$ 4				171,969
Share-based compensation expense	35,737								35,737
Issuance and withholding of common stock in connection with restricted stock unit vesting, net (in shares)					517,000
Issuance and withholding of common stock in connection with restricted stock unit vesting, net	(1,146)								(1,146)
Deconsolidation event	(16,899)												(16,899)
Issuance of common stock upon exercise of options (in shares)					232,000
Issuance of common stock upon exercise of options	7,149								7,149
Issuance of common stock under employee stock purchase plan (in shares)					15,000
Issuance of common stock under employee stock purchase plan	545								545
Cancellation of restricted stock awards (in shares)					(4,000)
Other comprehensive income (loss)	(161)										(161)
Net loss attributable to noncontrolling interest	(7,368)												(7,368)
Net loss attributable to Zentalis	(158,725)											(158,725)
Ending balance (in shares) at Dec. 31, 2021					45,491,000
Ending balance at Dec. 31, 2021	364,482								723,593		(125)	(359,559)	528
Common units, ending balance at Dec. 31, 2021					$ 45
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock (in shares)					13,495,000
Issuance of common stock, value	257,922				$ 13				257,909
Share-based compensation expense	46,840								46,840
Issuance and withholding of common stock in connection with restricted stock unit vesting, net (in shares)					158,671
Issuance and withholding of common stock in connection with restricted stock unit vesting, net	$ 1				$ 1
Issuance of common stock upon exercise of options (in shares)	122,082				122,000
Issuance of common stock upon exercise of options	$ 2,246								2,246
Issuance of common stock under employee stock purchase plan (in shares)					30,000
Issuance of common stock under employee stock purchase plan	874								874
Cancellation of restricted stock awards (in shares)					(17,000)
Other comprehensive income (loss)	(1,228)										(1,228)
Net loss attributable to noncontrolling interest	(307)												(307)
Net loss attributable to Zentalis	(236,806)											(236,806)
Ending balance (in shares) at Dec. 31, 2022					59,280,000
Ending balance at Dec. 31, 2022	$ 434,024								$ 1,031,462		$ (1,353)	$ (596,365)	$ 221
Common units, ending balance at Dec. 31, 2022					$ 59

Consolidated Statements of Ch_2

Consolidated Statements of Changes in Convertible Preferred Units and Members’/Stockholders' Equity (Deficit) (Parenthetical))	Dec. 31, 2020 $ / shares
Series C Preferred Units
Par value per share (in dollars per share)	$ 17.50

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net loss	$ (237,113)	$ (166,093)	$ (118,548)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,426	544	160
IPR&D impairment	0	8,800	0
Recognized tax gain on IPR&D impairment	0	(2,462)	0
Gain on deconsolidation of Zentera, net of tax	0	(49,930)	0
Share-based compensation	46,840	35,737	23,146
Loss on disposal of equipment	56	15	0
(Accretion of discounts)/amortization of premiums on marketable securities, net	(3,725)	908	556
Loss on equity method investment	16,282	1,831	0
Deferred income taxes	(769)	(48)	17
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(6,605)	1,294	(5,796)
Accounts payable and accrued liabilities	15,527	13,964	14,307
Operating lease right-of-use assets and liabilities, net	4,330	1,347	(667)
Net cash used in operating activities	(163,751)	(154,093)	(86,825)
Investing activities:
Purchases of marketable securities	(533,161)	(363,508)	(400,984)
Proceeds from maturities of marketable securities	421,529	365,820	116,910
Deconsolidation of Zentera cash	0	(14,320)	0
Purchases of property and equipment	(2,548)	(6,107)	(758)
Net cash used in investing activities	(114,180)	(18,115)	(284,832)
Financing activities:
Proceeds from issuance of common stock in initial public offering, net	0	0	172,482
Proceeds from issuance of common stock under equity incentive plans	3,121	7,694	0
Net-settlement of restricted stock unit vesting	0	(1,146)	0
Contributions from noncontrolling interest owners, net	0	0	18,424
Proceeds from issuance of common stock, net	257,922	171,973	155,305
Proceeds from the issuance of Series C convertible preferred units, net	0	0	14,228
Net cash provided by financing activities	261,043	178,521	360,439
Net (decrease) increase in cash, cash equivalents and restricted cash	(16,888)	6,313	(11,218)
Cash, cash equivalents and restricted cash at beginning of year	62,584	56,271	67,489
Cash, cash equivalents and restricted cash at end of year	45,696	62,584	56,271
Supplemental disclosure of cash flow information:
Income taxes paid	12	20	18
Supplemental disclosure of non-cash investing and financing activities:
Right-of-use assets obtained in exchange for operating lease liabilities	0	44,613	300
Accrued capital expenditures	0	(1,510)	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Cash and cash equivalents	43,069	59,714	54,951
Restricted cash, current	0	243	0
Restricted cash, non-current	2,627	2,627	1,320
Total cash, cash equivalents and restricted cash reported in the Consolidated Statement of Cash Flows	$ 45,696	$ 62,584	$ 56,271

Organization and Business

Organization and Business	12 Months Ended
	Dec. 31, 2022
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 focused on discovering and developing small molecule therapeutics targeting fundamental biological pathways of cancer. The Company is developing a focused pipeline of potentially best-in-class oncology candidates. 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) and include our wholly-owned subsidiaries and variable interest entities (“VIEs”) for the periods in which we determined we were 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. Noncontrolling Interests Noncontrolling interests represent interests held by third parties in our consolidated subsidiaries. We reflect noncontrolling interest attributable to the other owners in a separate line in our consolidated statements of operations and a separate line within stockholders' equity in our consolidated balance sheets. 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. Though the impact of the COVID-19 pandemic to our business and operating results presents additional uncertainty, we continue to use the best information available to inform our critical accounting estimates. Cash and Cash Equivalents Cash equivalents are comprised of short-term, highly-liquid investments with maturities of 90 days or less at the date of purchase. As of December 31, 2022 and 2021, our cash equivalents consisted of money market funds and corporate debt securities. Marketable Securities Marketable securities are investments with original maturities of more than ninety days from the date of purchase that we have the ability to liquidate to fund current operations. Accordingly, those investments with contractual maturities greater than one year from the date of purchase are classified as short-term investments on the accompanying consolidated balance sheets. Marketable securities are considered available-for-sale and are carried at fair value with unrealized gains and losses recorded in other comprehensive income (loss) and included as a separate component of stockholders' equity. The cost of marketable securities is adjusted for amortization of premiums or accretion of discounts to maturity, and such amortization or accretion is included in investment and other income, net through an allowance account. We use the specific identification method for calculating realized gains and losses on marketable securities sold. Realized gains and losses on marketable securities, if any, are included in investment and other income, net in the consolidated statements of operations. Restricted Cash Under the terms of our office leases, we are required to maintain a letter of credit as a security deposit during the term of such leases. At December 31, 2022 and 2021, restricted cash of $2.6 million and $2.9 million, respectively, was pledged as collateral for the letters of credit. Fair Value of Financial Instruments The authoritative guidance defines fair value and requires us to establish a framework for measuring fair value and disclosure about fair value measurements using a three-tier approach. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Our financial instruments include cash equivalents, marketable securities, prepaid expenses and other assets, accounts payable and accrued expenses. Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgement and therefore cannot be determined with precision. The fair value of marketable securities is determined using proprietary valuation models and analytical tools, which utilize market pricing or prices for similar instruments that are both objective and publicly available, such as matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities and bids and offers. The carrying amount of cash equivalents, prepaid expenses and other assets, accounts payable and accrued expenses are generally considered to be representative of their respective values because of the short-term nature of those instruments. Concentrations of Credit Risk and Sources of Supply We are subject to credit risk from our portfolios of cash equivalents and marketable securities. We maintain our cash and cash equivalent and marketable securities balances with major commercial banks. Deposits held with the financial institutions exceed the amount of insurance provided on such deposits. We are exposed to credit risk in the event of a default by the financial institutions holding our cash and cash equivalents and marketable securities to the extent recorded on the consolidated balance sheets. We have also established guidelines to limit our exposure to credit risk by diversifying our marketable securities portfolio and placing them in investments with maturities that maintain safety and liquidity. We rely on third-party manufacturers for the supply of active pharmaceutical ingredients. Property and Equipment, Net Property and equipment are recorded at cost, less accumulated depreciation and amortization. Equipment is depreciated using the straight-line method over its estimated useful life ranging from three Leases We have entered into operating leases for real estate. We determine if an arrangement is a lease at inception and evaluate each lease agreement to determine whether the lease is an operating or finance lease. For leases where we are the lessee, right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent an obligation to make lease payments arising from the lease. Liabilities from operating leases are included in accrued expenses Impairment of Long-Lived Assets We account for long-lived assets in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable. Goodwill Our goodwill, which has an indefinite useful life, represents the excess of the cost over the fair value of net assets acquired from its business combination. The determination of the value of goodwill and intangible assets arising from business combinations and asset acquisitions requires extensive use of accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired, including capitalized in-process research and development (“IPR&D”). Goodwill is reviewed for impairment at least annually, or more frequently if an event occurs indicating the potential for impairment. During the impairment review process, we consider qualitative factors to determine whether it is more likely than not that the fair value of the reporting unit is less than the carrying amount, including goodwill. If we determine that it is not more likely than not that the fair value of our reporting unit is less than the carrying amount, then no additional assessment is deemed necessary. Otherwise, we proceed to compare the estimated fair values of the reporting units with the carrying values, including goodwill. If the carrying amounts of the reporting units exceed the fair values, we record an impairment loss based on the difference. We completed our most recent annual evaluation for impairment for goodwill as of December 31, 2022 using the qualitative assessment and determined that no impairment existed, and no charges were recorded. Equity Method Accounting We have significant influence, but not a controlling interest, in our affiliate Zentera. From the deconsolidation of Zentera during July 2021 prospectively, this investment is accounted for using the equity method. Our share of earnings or losses of the investment entity are reported on the consolidated statement of operations, with a corresponding increase or decrease to the equity investment carried on the statement of financial position. This information is generally not received sufficiently timely for us to record our portion of earnings or loss in the current financial statements, and therefore we report our portion of earnings or loss on a one quarter lag. The maximum exposure to loss as a result of our investment in Zentera is directly associated with the carrying amount of the equity method investment on our consolidated balance sheet. Research and Development Expenses Research and development expenses include salaries and benefits, facilities and other overhead expenses, external clinical trial expenses, research-related manufacturing services, contract services and other outside expenses. Research and development expenses are charged to operating expenses as incurred when these expenditures relate to our research and development efforts and have no alternative future uses. Reimbursed research and development costs under government grant arrangements are recorded as a reduction to research and development expenses and are recognized in the period in which the related costs are incurred. We are obligated to make upfront payments upon execution of certain research and development agreements. Advance payments, including nonrefundable amounts, for goods or services that will be used or rendered for future research and development activities are deferred. Such amounts are recognized as expense as the related goods are delivered or the related services are performed, or such time when we do not expect the goods to be delivered or services to be performed. Clinical Trial Expenses We make payments in connection with our clinical trials under contracts with contract research organizations that support conducting and managing clinical trials. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis. A portion of our obligation to make payments under these contracts depends on factors such as the successful enrollment or treatment of patients or the completion of other clinical trial milestones. Expenses related to clinical trials are accrued based on our estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts we are obligated to pay under our clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), we adjust our accruals accordingly. Revisions to our contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain. Share-Based Compensation We record share-based compensation expense associated with equity instruments in accordance with the authoritative guidance for stock-based compensation. The cost of employee services received in exchange for an award of an equity instrument is measured at the grant date based on the estimated fair value of the award and is recognized as expense on a straight-line basis over the requisite service period of the award. Share-based compensation expense for an award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized, and any previously recognized compensation expense is reversed. Forfeitures are recognized as a reduction of share-based compensation expense as they occur. Income Taxes Deferred income taxes are recognized for the tax consequences in future years of differences between the tax basis of assets and liabilities and their financial reporting amounts at each year end based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to affect taxable income. A provision has been made for income taxes due on taxable income and for the deferred taxes on temporary differences. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment. Realization of the deferred income tax asset is dependent on gathering sufficient taxable income in future years. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. Income tax expense is the combination of the tax payable for the period and the change during the period in deferred tax assets and liabilities. We follow the accounting guidance on accounting for uncertainty in income taxes. The guidance prescribes a recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities based on the technical merits of the position. Accumulated Other Comprehensive Income Accumulated other comprehensive income is the result of unrealized gains and losses on marketable securities. Net Loss per Common Share Outstanding Basic net loss per common share outstanding is computed by dividing net loss, after adjusting for dividends, if declared, by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share outstanding is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential common shares. Potential common shares consist of unvested restricted stock awards, unvested restricted stock units and common shares issuable upon the exercise of stock options.

Significant Transactions

Significant Transactions	12 Months Ended
	Dec. 31, 2022
Equity Method Investments and Joint Ventures [Abstract]
Significant Transactions	Significant Transactions Zentera Therapeutics In May 2020, we became a majority common shareholder of Zentera Therapeutics a Shanghai-based clinical-stage biopharmaceutical company focused on developing cancer therapeutics (“Zentera”), concurrent with its Series A convertible preferred stock offering. The financial position and results of operations of Zentera were included in our consolidated financial statements from the date of the initial investment as a result of our control of the entity and our determination that we were the primary beneficiary of Zentera. In July 2021, Zentera completed a Series B convertible preferred stock offering which diluted our investment to a position of less than majority owned. Upon review of the facts and circumstances, together with the authoritative accounting literature, we determined that while Zentera is a variable interest entity ("VIE"), consolidation of Zentera is no longer appropriate. After the July 2021 Series B convertible preferred offering in which we did not participate, our review concluded that we ceased to be the primary beneficiary of Zentera as our equity ownership was reduced to 40.3% and changes were made to the corporate governance of Zentera. As a result, we no longer individually have the ability to direct the activities that most significantly impact Zentera's economic performance. Beginning in July 2021, the financial position and results of operations of Zentera are no longer included in our consolidated financial statements. During the period of deconsolidation we measured the fair value of our retained investment in Zentera using the backsolve method with consideration for a lack of marketability. An equity method investment of $21.2 million is recorded on our balance sheet at December 31, 2022. This amount represents our maximum exposure to loss as a result of our investment in Zentera. A deferred tax liability of $4.5 million representing the tax impact of the unrealized gain on deconsolidation is recorded on our balance sheet at December 31, 2022. A gain of $51.6 million, measured as the difference between the fair value of our retained noncontrolling interest together with the carrying amount of the Zentera noncontrolling interest, and the carrying amount of Zentera’s assets and liabilities was recognized during the year ended December 31, 2021. The difference between the carrying amount of our investment in Zentera and our portion of the Zentera net assets was $5.1 million as of December 31, 2022. This difference is accounted for in our equity method investment analogous to in-process research and development. In May 2020, each of our subsidiaries Zeno Alpha, Inc., K-Group Alpha, Inc. and K-Group Beta, Inc. entered into a collaboration and royalty-bearing license agreement with Zentera, which we refer to as the “Zentera Sublicenses,” pursuant to which we collaborate with Zentera on the development and commercialization of ZN-c5, ZN-d5 and azenosertib, respectively (each a "Collaboration Product"), in the People’s Republic of China, Macau, Hong Kong and Taiwan, which is referred to as the “Zentera Collaboration Territory.” Under each Zentera Sublicense, Zentera will lead development, and upon regulatory approval, the commercialization, of the Collaboration Products in the Zentera Collaboration Territory.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2022
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. During the year ended December 31, 2021, Kalyra determined that they will no longer pursue the development of Kalyra's lead product candidate and ceased the associated clinical trial. The in-process research and development costs ("IPR&D") recorded on Kalyra's balance sheet exclusively relates to this candidate. Management recorded an impairment charge of $8.8 million within the research and development expense line item on the consolidated statement of operations during the year ended December 31, 2021, which resulted in a reduction of the IPR&D asset from $8.8 million to zero. The impairment of IPR&D resulted in a reversal of the associated deferred tax liability of $2.5 million during the year ended December 31, 2021. Total assets and liabilities of Kalyra as of December 31, 2022 and 2021 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 consolidated balance sheets. The following is a reconciliation of equity (net assets) attributable to the noncontrolling interest (in thousands): December 31, 2022 2021 Noncontrolling interest at beginning of period $ 528 $ 24,795 Net loss attributable to noncontrolling interest (307) (7,368) Deconsolidation of Zentera — (16,899) Noncontrolling interest at end of period $ 221 $ 528

Fair Value Measurement

Fair Value Measurement	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement Available-for-sale marketable securities consisted of the following (in thousands): 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 December 31, 2022, fifty-three of our available-for-sale debt securities with a fair market value of $280.1 million were in a gross unrealized loss position of $1.4 million. 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 December 31, 2022, 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): December 31, 2022 Estimated Fair Value Due within one year $ 394,302 After one but within five years — $ 394,302 Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. Fair value should maximize the use of observable inputs and minimize the use of unobservable inputs. The Company determines the fair value of financial assets and liabilities using three levels of inputs as follows: Level 1—Inputs which include quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2—Inputs (other than quoted market prices included in Level 1) that are either directly or indirectly observable, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the instrument’s anticipated life. Level 3—Unobservable inputs for assets or liabilities and include little or no market activity. A financial instrument’s categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. The following table summarizes, by major security type, our cash equivalents and available-for-sale marketable securities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in thousands): December 31, 2022 December 31, 2021 Level 1 Level 2 Total estimated fair value Level 1 Level 2 Total estimated fair value Cash equivalents: Money market funds $ 26,811 $ — $ 26,811 $ 43,653 $ — $ 43,653 Commercial paper 1,998 — 1,998 — — — Total cash equivalents: 28,809 — 28,809 43,653 — 43,653 Available-for-sale marketable securities: Commercial paper — 295,793 295,793 — 199,277 199,277 Corporate debt securities — 7,446 7,446 — 10,078 10,078 US government agencies — 23,788 23,788 — 20,033 20,033 US Treasury securities 67,275 — 67,275 50,785 — 50,785 Total available-for-sale marketable securities: 67,275 327,027 394,302 50,785 229,388 280,173 Total assets measured at fair value $ 96,084 $ 327,027 $ 423,111 $ 94,438 $ 229,388 $ 323,826 There were no transfers between Level 1 and Level 2 of the fair value hierarchy during the year ended December 31, 2022. We had no instruments that were classified within Level 3 as of December 31, 2022 or 2021.

Prepaid Expenses and Other Asse

Prepaid Expenses and Other Assets	12 Months Ended
	Dec. 31, 2022
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): December 31, 2022 2021 Prepaid insurance $ 1,018 $ 990 Prepaid software licenses and maintenance 958 403 Foreign R&D credit refund 659 1,808 Prepaid research and development expenses 15,002 11,204 Interest receivable 508 258 Zentera receivable 5,874 2,373 Other prepaid expenses 266 644 Total prepaid expenses and other current assets 24,285 17,680 Less long-term portion 9,723 7,040 Total prepaid expenses and other assets, current $ 14,562 $ 10,640

Property and Equipment, net

Property and Equipment, net	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net Property and equipment, net consisted of the following (in thousands): December 31, 2022 2021 Lab equipment $ 2,622 $ 2,057 Leasehold improvements 4,891 4,515 Office equipment and furniture 2,065 2,123 Computer equipment 150 211 Construction in process 37 34 Subtotal 9,765 8,940 Accumulated depreciation and amortization (2,060) (792) Property and equipment, net $ 7,705 $ 8,148 Depreciation and amortization expense was approximately $1.4 million and $0.5 million for the years ended December 31, 2022 and 2021, respectively.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consist of the following (in thousands): December 31, 2022 2021 Accrued research and development expenses $ 32,310 $ 18,531 Accrued employee expenses 11,246 9,250 Accrued general and administrative expenses 662 1,480 Lease liability 2,162 1,453 Income taxes payable 384 971 Accrued legal expenses 1,256 669 Total accrued expenses 48,020 32,354 Less long-term portion 2,620 — Total accrued expenses, current $ 45,400 $ 32,354

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Direct Offering of Common Stock On April 29, 2022, pursuant to our Registration Statement on Form S-3 (Registration No. 333-255769), filed with the SEC on May 4, 2021, we completed a direct offering of common stock to Pfizer Inc. (“Pfizer”). We issued and sold 953,834 shares of our common stock at an offering price of $26.21 per share. The total gross proceeds for the offering were approximately $25.0 million, before deducting offering expenses of $0.3 million payable by us. The parties have entered into an agreement to collaborate to advance the clinical development of azenosertib (ZN-c3), a selective Wee1 inhibitor designed to induce synthetic lethality in cancer cells. We did not grant Pfizer any economic ownership or control of azenosertib or the rest of our pipeline. The gross offering proceeds received from Pfizer exceeded the fair value of our common stock on the date of the investment. As of December 31, 2022, $3.8 million has been recorded as accrued research and development expense on the consolidated balance sheet and will be recognized as a reduction of research and development expense over the term of the collaboration agreement. Follow-on Offering of Common Stock On May 18, 2022, pursuant to our Registration Statement on Form S-3 (Registration No. 333-255769), we completed a follow-on offering in which we issued and sold 10,330,000 shares of common stock at a public offering price of $19.38 per share. The total gross proceeds for the offering were approximately $200.2 million, before deducting offering expenses of $11.4 million payable by us. In May 2021, the Company entered into a sales agreement, or the Sales Agreement, with SVB Leerink LLC, or SVB Leerink, as sales agent, pursuant to which the Company may, from time to time, issue and sell common stock with an aggregate value of up to $200.0 million in “at-the-market” offerings, or the ATM, under the Company's Registration Statement on Form S-3 (File No. 333-255769). Sales of common stock, if any, pursuant to the Sales Agreement, may be made in sales deemed to be an “at the market offering” as defined in Rule 415(a) of the Securities Act, including sales made directly through The Nasdaq Global Market or any other existing trading market for the Company's common stock. During the quarter ended December 31, 2022, the Company sold 2,210,500 shares of common stock under the Sales Agreement at a volume weighted-average price of $22.50 per share, raising aggregate gross proceeds of approximately $49.7 million before fees and expenses of approximately $1.1 million. As of December 31, 2022 there was $140.3 million of common stock remaining available for sale under the Sales Agreement. Share-based Compensation In April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved the 2020 Incentive Award Plan (the "2020 Plan"), 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. 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 initially reserved 1,500,000 shares of the Company’s common stock for issuance pursuant to awards granted under the 2022 Inducement Plan. As of December 31, 2022, 7,517,610 shares were subject to outstanding awards under the 2020 Plan and 980,553 shares were available for future grants of share-based awards under the 2020 Plan. As of December 31, 2022, 1,456,750 shares were subject to outstanding awards under the 2022 Inducement Plan and 43,250 shares were available for future grants of share-based awards under the 2022 Inducement Plan. In connection with the corporate conversion, each outstanding profits interest award unit was converted into a number of shares of common stock and restricted common stock based upon the IPO price. The restricted common stock issued in respect of profits interest award units continues to be subject to vesting in accordance with the vesting schedule that was applicable to such profits interest award units. In conjunction with our IPO on April 2, 2020, all unvested profit interest awards were converted into restricted stock awards ("RSAs"). During 2022, we issued an aggregate of 122,082 shares of common stock in connection with the exercises of stock options for cash in the aggregate amount of approximately $2.2 million. We did not issue any shares of common stock in connection with grants of RSA's. We issued 158,671 shares of common stock, upon vesting of RSU's. Total share-based compensation expense related to share-based awards was comprised of the following (in thousands): Year ended December 31, 2022 2021 2020 Research and development expense $ 20,439 $ 14,879 $ 7,296 General and administrative expense 26,401 20,858 15,850 Total share-based compensation expense $ 46,840 $ 35,737 $ 23,146 Share-based compensation expense by type of share-based award (in thousands): Year ended December 31, 2022 2021 2020 Profits interest award units $ — $ — $ 329 Stock options 36,338 20,773 6,925 RSAs and RSUs 10,075 14,643 15,892 Employee Stock Purchase Plan 427 321 — $ 46,840 $ 35,737 $ 23,146 Prior to the deconsolidation of Zentera during the third quarter of 2021, total share-based compensation expense includes $138 thousand of share-based compensation expense for employees, consultants and directors of Zentera, for the twelve months ended December 31, 2021, compared to $187 thousand for the same period in 2020. 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): December 31, 2022 Unrecognized Remaining Stock options $ 95,906 3.1 RSAs 330 0.7 RSUs 18,880 2.5 Stock Options: The following table summarizes option activity for the year ended December 31, 2022. The amounts include stock options granted to both employees and non-employees: Number of Shares Weighted Average Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2021 4,243,482 $ 33.97 Granted 5,329,020 $ 31.16 Exercised (122,082) $ 18.40 Cancelled (1,398,961) $ 47.68 Outstanding at December 31, 2022 8,051,459 $ 29.97 8.2 $3,431 Vested and expected to vest at December 31, 2022 7,524,257 $ 30.38 8.1 $3,431 Exercisable at December 31, 2022 2,037,706 $ 30.94 6.6 $2,307 The weighted average grant date fair value of stock options granted during the years ended December 31, 2022 and 2021 was $20.45 and $33.27, respectively. The total intrinsic value of options exercised during the years ended December 31, 2022 and 2021 was approximately $2.0 million and $8.8 million, respectively. 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 year ended December 31, 2022 was determined with the following assumptions: Year ended December 31, 2022 2021 Expected volatility 73.6% - 80.5% 73.2% - 76.6% Average expected term (in years) 6.0 - 6.5 5.2 - 6.1 Risk-free interest rate 1.5% - 4.2% 0.5% - 1.3% Expected dividend yield —% —% Restricted Stock Awards: RSAs are shares of our common stock subject to forfeiture restrictions that lapse based on the awardee's continued employment or service. The shares covered by a RSA cannot be sold, pledged or otherwise disposed of until the awards vest, and any unvested shares will be forfeited following the awardee's termination of service. The following table summarizes RSA activity for the year ending December 31, 2022. The amounts include RSAs granted to both employees and non-employees: Number of Shares Weighted Average Grant Date Outstanding at December 31, 2021 361,832 $ 3.47 Vested (220,891) $ 4.48 Forfeited (15,435) $ 2.84 Outstanding at December 31, 2022 125,506 $ 5.45 The fair value of RSAs issued upon conversion of the unvested profit interest award units was based on a Black-Scholes pricing model. The estimated fair value of the RSAs for any future grants will be based on the closing market value of our common stock on the date of grant. The total grant date fair value of RSAs vested during the years ended December 31, 2022, 2021 and 2020 was approximately $1.0 million, $1.7 million and $1.1 million, respectively. The fair value of RSAs vested during the years ended December 31, 2022, 2021 and 2020, was approximately $8.3 million, $21.0 million and $14.3 million, respectively. Restricted Stock Units: A RSU is a promise by us to issue a share of our common stock upon vesting of the unit. The following table summarizes RSU activity for the year ending December 31, 2022. The amounts include RSUs granted to both employees and non-employees: Number of Shares Weighted Average Grant Date Outstanding at December 31, 2021 274,195 $ 33.06 Granted 929,083 $ 27.99 Vested (158,671) $ 28.84 Forfeited (121,706) $ 37.13 Outstanding at December 31, 2022 922,901 $ 27.48 The estimated fair value of the RSUs was based on the closing market value of our common stock on the date of grant. The total grant date fair value of RSUs vested during the years ended December 31, 2022, 2021 and 2020 was approximately $4.6 million $12.7 million and $10.1 million, respectively. The fair value of RSUs vested during the years ended December 31, 2022, 2021 and 2020 was approximately $7.3 million, $26.4 million and $21.8 million, respectively. Employee Stock Purchase Plan In April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved the 2020 Employee Stock Purchase Plan (the “2020 ESPP”), which became effective upon the corporate conversion. The number of common shares initially available for issuance under the 2020 ESPP was the sum of (1) 450,000 shares of common stock; plus (2) 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 least of (a) 1% of the shares of common stock outstanding on the final day of the immediately preceding calendar year, (b) 1,500,000 shares and (c) such smaller number of shares as determined by our Board of Directors. The 2020 ESPP was amended and restated effective March 15, 2021 to provide for a share reserve of 2,000,000 shares and the elimination of the evergreen provision. The weighted average assumptions used to estimate the fair value of stock purchase rights under the 2020 ESPP are as follows: Year ended December 31, 2022 2021 ESPP Volatility 74.0 % 48.2 % Expected term (years) 0.5 0.5 Risk free rate 1.6 % 0.1 % Expected dividend yield — % — % Under the terms of the 2020 ESPP, the Company’s employees may elect to have up to 20% of their compensation, up to a maximum of $21,250 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.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
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. Operating Leases In September 2020, we entered into a lease for approximately 117,900 square feet of laboratory and office space in San Diego. This lease was partially terminated and amended during September 2021. This amendment reduced the rentable square feet by approximately 43,200. The lease commenced in December 2021 and continues through September 2032. The lease also included access to a temporary space of 13,200 square feet of laboratory and office space in San Diego. This lease component commenced in November 2020 and continued through January 2022. The lease is subject to approximately 3.0% annual increases throughout the lease term. We also pay for various operating costs, including utilities and real property taxes. The agreement includes two options to extend the lease for a period of five years each. When we determined our lease term for our operating lease right-of-use assets and lease liabilities for these leases, we did not include the extension options for this lease. In March 2021, we entered into a lease for approximately 31,362 square feet of office space in New York, New York. The lease commenced in December 2021 and continues through November 2032. The lease is subject to one increase in per annum rent of approximately 8.1% commencing on the sixth Rent expense recorded by the Company under the leases was approximately $7.0 million and $2.6 million for the years ended December 31, 2022 and 2021, respectively. We paid approximately $2.5 million and $1.3 million of lease payments, respectively, during the years ended December 31, 2022 and 2021. The following table presents the weighted average remaining lease term and weighted average discount rates related to our operating leases as of December 31, 2022: Weighted average remaining lease term (in years) 9.8 Weighted average discount rate 9.0% Approximate annual future minimum operating lease payments as of December 31, 2022 are as follows (in thousands): Year Amount 2023 $ 6,340 2024 6,486 2025 6,799 2026 7,278 2027 7,451 Thereafter 38,778 Total minimum lease payments: 73,132 Less: imputed interest 25,804 Total operating lease liabilities 47,328 Less: current portion 2,162 Lease liability, net of current portion $ 45,166

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Zentalis Pharmaceuticals, Inc. is a corporation for tax purposes and is subject to income taxes which have been included in the consolidated financial statements. The amount of net loss before income taxes and loss on equity method investment for the years ended December 31, 2022, 2021 and 2020 is as follows (in thousands): Year ended December 31, 2022 2021 2020 U.S. net loss before income taxes $ (237,926) $ (171,053) $ (112,827) Foreign net income (loss) before income taxes 344 4,663 (5,277) Net loss before income taxes, including loss on equity method investment $ (237,582) $ (166,390) $ (118,104) The following table presents the current and deferred income tax provision (benefit) for federal, state and foreign income taxes (in thousands): Year ended December 31, 2022 2021 2020 Current tax provision: Federal $ — $ — $ — State 11 11 16 Foreign 298 550 410 Total current tax provision 309 561 426 Deferred tax provision: Federal (683) (120) — State (41) (736) — Foreign (54) (2) 18 Total deferred tax provision (778) (858) 18 Total provision for income taxes: $ (469) $ (297) $ 444 The following table is a reconciliation of the expected tax computed at the U.S. statutory federal income tax rate to the total provision for income taxes (in thousands): Year ended December 31, 2022 2021 2020 Expected tax at 21% $ (49,892) 21.0 % $ (34,941) 21.0 % $ (24,802) 21.0 % State income tax, net of federal tax (4,222) 1.8 % (931) 0.6 % 273 (0.3) % Research credits (12,558) 5.3 % (6,938) 4.2 % (4,025) 3.4 % Share-based compensation 1,245 (0.5) % (3,307) 2.0 % (1,718) 1.5 % Other (2,799) 1.2 % 939 (0.6) % 146 (0.1) % Section 162(m) limitations 3,950 (1.7) % 3,982 (2.4) % 2,956 (2.5) % Change in valuation allowance 63,807 (26.9) % 40,899 (24.6) % 27,614 (23.4) % Provision for income taxes $ (469) 0.2 % $ (297) 0.2 % $ 444 (0.4) % Deferred income taxes as of each of the following periods reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of our net deferred tax asset or liability are as follows (in thousands): December 31, 2022 2021 Deferred tax assets Net operating loss $ 95,392 $ 82,117 Compensation 1,937 1,553 Share-based compensation 7,735 4,123 ASC 842 lease liability 9,967 9,740 Intangibles 1,745 2,004 Capitalized research and experimental expenditures 30,776 — Accrued liabilities 476 675 Research credits 27,024 14,466 Other 62 — Total gross deferred tax assets 175,114 114,678 Valuation allowance (160,967) (97,160) Net deferred tax assets 14,147 17,518 Deferred tax liabilities Depreciable assets (1,609) (1,699) ASC 842 right of use asset (8,924) (9,481) Equity method investment (4,467) (7,954) Other — (6) Deferred tax liabilities (15,000) (19,140) Net deferred tax liabilities $ (853) $ (1,622) Realization of a portion of our deferred tax assets is dependent upon our generating sufficient taxable income in future years to obtain benefit from the reversal of temporary differences. Management considered all available evidence under existing tax law and anticipated expiration of tax statutes and determined that a valuation allowance of $161.0 million and $97.2 million was required as of December 31, 2022 and 2021, for those deferred tax assets that are not expected to provide future tax benefits. The increase in valuation allowance was primarily related to the federal and states losses incurred and tax credits generated during the period ended December 31, 2022. At December 31, 2022, we have federal and state net operating loss ("NOL") carryforwards of approximately $390.3 million and $192.4 million, respectively. The federal NOL carryforwards generated in taxable years beginning prior to January 1, 2018 begin to expire in 2033. The federal NOL carryforwards generated in taxable years beginning after December 31, 2017 of $369.4 million can be carried forward indefinitely but may only be used to offset up to 80% of taxable income in future periods. The state NOL carryforwards begin to expire in 2033. At December 31, 2022, we have federal and state research tax credit carryforwards, net of reserves, of approximately $20.5 million and $8.3 million, respectively. The federal credit carryforwards begin to expire in 2033, and the state credit carryforwards do not expire and can be carried forward indefinitely until utilized. We have not completed a study to determine whether an ownership change per the provisions of Sections 382 or 383 of the Code, as well as similar state provisions, has occurred. Utilization of our NOL and income tax credit carryforwards may be subject to a substantial annual limitation due to ownership changes that may have occurred or that could occur in the future. These ownership changes may limit the amount of the net operating loss and income tax credit carryover that can be utilized annually to offset future taxable income. In general, an “ownership change” as defined by Section 382 of the Code results from a transaction or series of transactions over a rolling three-year period resulting in an ownership change of more than 50 percentage points of the outstanding stock of a company by certain stockholders. Uncertain Tax Positions In accordance with authoritative guidance, the impact of an uncertain income tax position on the income tax return must be recognized at the largest amount that is more-likely-than-not to be sustained upon audit by the relevant taxing authority. An uncertain income tax position will not be recognized if it has less than a 50% likelihood of being sustained. The following table summarized the activity related to our unrecognized tax benefits (in thousands): December 31, 2022 2021 2020 Gross unrecognized tax benefits at the beginning of the year $ 2,835 $ 1,932 $ 1,124 Increase related to current year tax positions 1,112 969 661 Increase related to prior year tax positions 350 — 197 Decrease related to prior year tax positions — (66) (50) Gross unrecognized tax benefits at end of the year $ 4,297 $ 2,835 $ 1,932 Included in the balance of unrecognized tax benefits at December 31, 2022 is $4.0 million that, if recognized, would not impact our income tax benefit or effective tax rate as long as our deferred tax asset remains subject to a valuation allowance. We do not expect any significant increases or decreases to our unrecognized tax benefits within the next 12 months. We recognize interest and penalties related to unrecognized tax positions within the income tax expense line in the accompanying consolidated statements of operations. There were no accrued interest and penalties associated with uncertain tax positions as of December 31, 2022 and 2021. The Company files federal and state income tax returns in the United States and Australia. Due to the Company's unutilized NOLs and credits, all years remain subject to income tax examination by authorities. The Company is not currently under examination by federal, state or foreign jurisdictions.

Net Loss Per Common Share

Net Loss Per Common Share	12 Months Ended
	Dec. 31, 2022
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): Year ended December 31, 2022 2021 2020 Numerator: Net loss attributable to Zentalis $ (236,806) $ (158,725) $ (117,841) Denominator: Weighted average number of common shares outstanding, basic and diluted 52,857 42,688 28,113 Net loss per common share $ (4.48) $ (3.72) $ (4.19) 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 have been excluded from the calculations of diluted net loss per common share because their inclusion would be antidilutive (in thousands). Year ended December 31, 2022 2021 2020 Outstanding stock options 8,051 4,243 3,121 Unvested RSAs 126 361 742 Unvested RSUs 923 274 675 9,100 4,878 4,538

Employee Savings Plan

Employee Savings Plan	12 Months Ended
	Dec. 31, 2022
Retirement Benefits [Abstract]
Employee Savings Plan	Employee Savings PlanWe have an employee savings plan pursuant to Section 401(k) of the Internal Revenue Code. All employees are eligible to participate provided that they meet the requirements of the plan. The Company began making matching contributions under the plan during 2021. The Company has recorded as expense $1.4 million and $991.5 thousand in matching contributions for the years ended December 31, 2022 and 2021, respectively.

Related Party Disclosures

Related Party Disclosures	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Disclosures	Related Party Disclosures Recurium Kevin D. Bunker, Ph.D, our Chief Scientific Officer, and Cam S. Gallagher, our President and a member of our Board of Directors, currently serve as managing members of Recurium IP Holdings, LLC, or Recurium IP. Each of Dr. Bunker and Mr. Gallagher maintains an ownership interest in Recurium IP. Accordingly, the Company identifies Recurium IP as a related party. In December 2014, our wholly owned subsidiary, Zeno Pharmaceuticals, Inc., entered into a license agreement, or the Recurium Agreement, with 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 certain corporate restructuring disclosed elsewhere in this Annual Report on 10-K, 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, ZN-d5 and our BCL-xL product candidate. For the years ended December 31, 2022 and 2021, the amounts incurred under the Recurium Agreement totaled zero and $10.0 million. Kalyra Pharmaceuticals, Inc. On December 21, 2017, we acquired 17,307,692 shares of Series B preferred stock of Kalyra Pharmaceuticals, Inc. for a per share price of twenty-six cents ($0.26) or approximately $4.5 million. The management team and stockholders of Kalyra are also stockholders of the Company. We entered into a Master Services Agreement (“MSA”) with Kalyra in January 2015 which states that Kalyra may provide research and development services to us and that we shall reimburse such expenses on a time and materials basis based on the initial statements of work. For the years ended December 31, 2022 and 2021, we incurred an immaterial amount of expense with Kalyra that was eliminated in consolidation for research and development services provided. As of December 31, 2022, there was an immaterial balance due to Kalyra that eliminated in consolidation. As of December 31, 2021, there was no balance due to Kalyra. We entered into an Intercompany Services Agreement (“ISA”) with Kalyra in January 2018 which states that we may provide research and development services to Kalyra and that Kalyra shall reimburse such expenses on a time and materials basis. For the years ended December 31, 2022 and 2021, we provided an immaterial amount of research and development services to Kalyra that was eliminated in consolidation. As of December 31, 2022 and 2021, an immaterial amount was due from Kalyra that eliminated in consolidation. Tempus Kimberly Blackwell, M.D., our Chief Executive Officer and a member of our Board of Directors, was previously employed by Tempus Labs, Inc., or Tempus, and now serves as an advisor of Tempus. The Company entered into a Master Services Agreement with Tempus in December 2020 to provide data licensing and research services. For the years ended December 31, 2022 and 2021, the fees incurred for services performed by Tempus were $0.2 million and $1.0 million, respectively. Zentera Dr. Bunker serves as a member of the board of directors of Zentera. Accordingly, the Company identifies Zentera as a related party. In May 2020, each of our wholly owned subsidiaries, Zeno Alpha, Inc., K-Group Alpha, Inc. and K-Group Beta, Inc., entered into the Zentera Sublicenses, pursuant to which we collaborate with Zentera on the development and comm ercialization

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”) and include our wholly-owned subsidiaries and variable interest entities (“VIEs”) for the periods in which we determined we were the primary beneficiary. All intercompany transactions and balances have been eliminated in consolidation.
Consolidation	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. Noncontrolling Interests Noncontrolling interests represent interests held by third parties in our consolidated subsidiaries. We reflect noncontrolling interest attributable to the other owners in a separate line in our consolidated statements of operations and a separate line within stockholders' equity in our consolidated balance sheets.
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.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash EquivalentsCash equivalents are comprised of short-term, highly-liquid investments with maturities of 90 days or less at the date of purchase.Restricted CashUnder the terms of our office leases, we are required to maintain a letter of credit as a security deposit during the term of such leases.
Marketable Securities	Marketable Securities Marketable securities are investments with original maturities of more than ninety days from the date of purchase that we have the ability to liquidate to fund current operations. Accordingly, those investments with contractual maturities greater than
Fair Value of Financial Instruments	Fair Value of Financial Instruments The authoritative guidance defines fair value and requires us to establish a framework for measuring fair value and disclosure about fair value measurements using a three-tier approach. These tiers include: Level 1, defined as observable inputs such as quoted prices in active markets; Level 2, defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3, defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Our financial instruments include cash equivalents, marketable securities, prepaid expenses and other assets, accounts payable and accrued expenses. Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. These estimates may be subjective in nature and involve uncertainties and matters of significant judgement and therefore cannot be determined with precision. The fair value of marketable securities is determined using proprietary valuation models and analytical tools, which utilize market pricing or prices for similar instruments that are both objective and publicly available, such as matrix pricing or reported trades, benchmark yields, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities and bids and offers. The carrying amount of cash equivalents, prepaid expenses and other assets, accounts payable and accrued expenses are generally considered to be representative of their respective values because of the short-term nature of those instruments. the measurement date. Fair value should maximize the use of observable inputs and minimize the use of unobservable inputs. The Company determines the fair value of financial assets and liabilities using three levels of inputs as follows: Level 1—Inputs which include quoted prices in active markets for identical assets or liabilities at the measurement date. Level 2—Inputs (other than quoted market prices included in Level 1) that are either directly or indirectly observable, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the instrument’s anticipated life. Level 3—Unobservable inputs for assets or liabilities and include little or no market activity.
Concentrations of Credit Risk and Sources of Supply	Concentrations of Credit Risk and Sources of Supply We are subject to credit risk from our portfolios of cash equivalents and marketable securities. We maintain our cash and cash equivalent and marketable securities balances with major commercial banks. Deposits held with the financial institutions exceed the amount of insurance provided on such deposits. We are exposed to credit risk in the event of a default by the financial institutions holding our cash and cash equivalents and marketable securities to the extent recorded on the consolidated balance sheets. We have also established guidelines to limit our exposure to credit risk by diversifying our marketable securities portfolio and placing them in investments with maturities that maintain safety and liquidity. We rely on third-party manufacturers for the supply of active pharmaceutical ingredients.
Property and Equipment, Net	Property and Equipment, Net Property and equipment are recorded at cost, less accumulated depreciation and amortization. Equipment is depreciated using the straight-line method over its estimated useful life ranging from three
Leases	Leases We have entered into operating leases for real estate. We determine if an arrangement is a lease at inception and evaluate each lease agreement to determine whether the lease is an operating or finance lease. For leases where we are the lessee, right-of-use (“ROU”) assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent accrued expenses
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets We account for long-lived assets in accordance with authoritative guidance for impairment or disposal of long-lived assets. Long-lived assets are reviewed for events or changes in circumstances, which indicate that their carrying value may not be recoverable.
Goodwill	Goodwill Our goodwill, which has an indefinite useful life, represents the excess of the cost over the fair value of net assets acquired from its business combination. The determination of the value of goodwill and intangible assets arising from business combinations and asset acquisitions requires extensive use of accounting estimates and judgments to allocate the purchase price to the fair value of the net tangible and intangible assets acquired, including capitalized in-process research and development (“IPR&D”).
Equity Method Accounting	Equity Method Accounting We have significant influence, but not a controlling interest, in our affiliate Zentera. From the deconsolidation of Zentera during July 2021 prospectively, this investment is accounted for using the equity method. Our share of earnings or losses of the investment entity are reported on the consolidated statement of operations, with a corresponding increase or decrease to the equity investment carried on the statement of financial position. This information is generally not received sufficiently timely for us to record our portion of earnings or loss in the current financial statements, and therefore we report our portion of earnings or loss on a one quarter lag. The maximum exposure to loss as a result of our investment in Zentera is directly associated with the carrying amount of the equity method investment on our consolidated balance sheet.
Research and Development Expenses	Research and Development Expenses Research and development expenses include salaries and benefits, facilities and other overhead expenses, external clinical trial expenses, research-related manufacturing services, contract services and other outside expenses. Research and development expenses are charged to operating expenses as incurred when these expenditures relate to our research and development efforts and have no alternative future uses. Reimbursed research and development costs under government grant arrangements are recorded as a reduction to research and development expenses and are recognized in the period in which the related costs are incurred. We are obligated to make upfront payments upon execution of certain research and development agreements. Advance payments, including nonrefundable amounts, for goods or services that will be used or rendered for future research and development activities are deferred. Such amounts are recognized as expense as the related goods are delivered or the related services are performed, or such time when we do not expect the goods to be delivered or services to be performed.
Clinical Trial Expenses	Clinical Trial Expenses We make payments in connection with our clinical trials under contracts with contract research organizations that support conducting and managing clinical trials. The financial terms of these agreements are subject to negotiation and vary from contract to contract and may result in uneven payment flows. Generally, these agreements set forth the scope of work to be performed at a fixed fee, unit price or on a time and materials basis. A portion of our obligation to make payments under these contracts depends on factors such as the successful enrollment or treatment of patients or the completion of other clinical trial milestones. Expenses related to clinical trials are accrued based on our estimates and/or representations from service providers regarding work performed, including actual level of patient enrollment, completion of patient studies and progress of the clinical trials. Other incidental costs related to patient enrollment or treatment are accrued when reasonably certain. If the amounts we are obligated to pay under our clinical trial agreements are modified (for instance, as a result of changes in the clinical trial protocol or scope of work to be performed), we adjust our accruals accordingly. Revisions to our contractual payment obligations are charged to expense in the period in which the facts that give rise to the revision become reasonably certain.
Share-Based Compensation	Share-Based Compensation We record share-based compensation expense associated with equity instruments in accordance with the authoritative guidance for stock-based compensation. The cost of employee services received in exchange for an award of an equity instrument is measured at the grant date based on the estimated fair value of the award and is recognized as expense on a straight-line basis over the requisite service period of the award. Share-based compensation expense for an award with a performance condition is recognized when the achievement of such performance condition is determined to be probable. If the outcome of such performance condition is not determined to be probable or is not met, no compensation expense is recognized, and any previously recognized compensation expense is reversed. Forfeitures are recognized as a reduction of share-based compensation expense as they occur.
Income Taxes	Income Taxes Deferred income taxes are recognized for the tax consequences in future years of differences between the tax basis of assets and liabilities and their financial reporting amounts at each year end based on enacted tax laws and statutory tax rates applicable to the periods in which the differences are expected to affect taxable income. A provision has been made for income taxes due on taxable income and for the deferred taxes on temporary differences. Deferred tax assets and liabilities are adjusted for the effects of changes in tax laws and rates on the date of enactment. Realization of the deferred income tax asset is dependent on gathering sufficient taxable income in future years. Valuation allowances are established when necessary to reduce deferred tax assets to the amount expected to be realized. Income tax expense is the combination of the tax payable for the period and the change during the period in deferred tax assets and liabilities. We follow the accounting guidance on accounting for uncertainty in income taxes. The guidance prescribes a recognition threshold and measurement attribute criteria for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by taxing authorities based on the technical merits of the position.
Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Accumulated other comprehensive income is the result of unrealized gains and losses on marketable securities.
Net Loss per Common Share Outstanding	Net Loss per Common Share Outstanding Basic net loss per common share outstanding is computed by dividing net loss, after adjusting for dividends, if declared, by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share outstanding is computed using the weighted-average number of common shares outstanding during the period and, if dilutive, the weighted average number of potential common shares. Potential common shares consist of unvested restricted stock awards, unvested restricted stock units and common shares issuable upon the exercise of stock options.

Business Combinations (Tables)

Business Combinations (Tables)	12 Months Ended
	Dec. 31, 2022
Business Combination and Asset Acquisition [Abstract]
Reconciliation of equity (net assets) attributable to noncontrolling interest	The following is a reconciliation of equity (net assets) attributable to the noncontrolling interest (in thousands): December 31, 2022 2021 Noncontrolling interest at beginning of period $ 528 $ 24,795 Net loss attributable to noncontrolling interest (307) (7,368) Deconsolidation of Zentera — (16,899) Noncontrolling interest at end of period $ 221 $ 528

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Components of available-for-sale marketable securities	Available-for-sale marketable securities consisted of the following (in thousands): 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): December 31, 2022 Estimated Fair Value Due within one year $ 394,302 After one but within five years — $ 394,302
Schedule of fair value, assets and liabilities measured on recurring basis	The following table summarizes, by major security type, our cash equivalents and available-for-sale marketable securities that are measured at fair value on a recurring basis and are categorized using the fair value hierarchy (in thousands): December 31, 2022 December 31, 2021 Level 1 Level 2 Total estimated fair value Level 1 Level 2 Total estimated fair value Cash equivalents: Money market funds $ 26,811 $ — $ 26,811 $ 43,653 $ — $ 43,653 Commercial paper 1,998 — 1,998 — — — Total cash equivalents: 28,809 — 28,809 43,653 — 43,653 Available-for-sale marketable securities: Commercial paper — 295,793 295,793 — 199,277 199,277 Corporate debt securities — 7,446 7,446 — 10,078 10,078 US government agencies — 23,788 23,788 — 20,033 20,033 US Treasury securities 67,275 — 67,275 50,785 — 50,785 Total available-for-sale marketable securities: 67,275 327,027 394,302 50,785 229,388 280,173 Total assets measured at fair value $ 96,084 $ 327,027 $ 423,111 $ 94,438 $ 229,388 $ 323,826

Prepaid Expenses and Other As_2

Prepaid Expenses and Other Assets (Tables)	12 Months Ended
	Dec. 31, 2022
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): December 31, 2022 2021 Prepaid insurance $ 1,018 $ 990 Prepaid software licenses and maintenance 958 403 Foreign R&D credit refund 659 1,808 Prepaid research and development expenses 15,002 11,204 Interest receivable 508 258 Zentera receivable 5,874 2,373 Other prepaid expenses 266 644 Total prepaid expenses and other current assets 24,285 17,680 Less long-term portion 9,723 7,040 Total prepaid expenses and other assets, current $ 14,562 $ 10,640

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Summary of property and equipment, net	Property and equipment, net consisted of the following (in thousands): December 31, 2022 2021 Lab equipment $ 2,622 $ 2,057 Leasehold improvements 4,891 4,515 Office equipment and furniture 2,065 2,123 Computer equipment 150 211 Construction in process 37 34 Subtotal 9,765 8,940 Accumulated depreciation and amortization (2,060) (792) Property and equipment, net $ 7,705 $ 8,148

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of accrued expenses	Accrued expenses consist of the following (in thousands): December 31, 2022 2021 Accrued research and development expenses $ 32,310 $ 18,531 Accrued employee expenses 11,246 9,250 Accrued general and administrative expenses 662 1,480 Lease liability 2,162 1,453 Income taxes payable 384 971 Accrued legal expenses 1,256 669 Total accrued expenses 48,020 32,354 Less long-term portion 2,620 — Total accrued expenses, current $ 45,400 $ 32,354

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2022
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): Year ended December 31, 2022 2021 2020 Research and development expense $ 20,439 $ 14,879 $ 7,296 General and administrative expense 26,401 20,858 15,850 Total share-based compensation expense $ 46,840 $ 35,737 $ 23,146 Share-based compensation expense by type of share-based award (in thousands): Year ended December 31, 2022 2021 2020 Profits interest award units $ — $ — $ 329 Stock options 36,338 20,773 6,925 RSAs and RSUs 10,075 14,643 15,892 Employee Stock Purchase Plan 427 321 — $ 46,840 $ 35,737 $ 23,146
Share-based compensation expense by type of share-based award	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): December 31, 2022 Unrecognized Remaining Stock options $ 95,906 3.1 RSAs 330 0.7 RSUs 18,880 2.5
Summary of stock option activity	The following table summarizes option activity for the year ended December 31, 2022. The amounts include stock options granted to both employees and non-employees: Number of Shares Weighted Average Weighted Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (in thousands) Outstanding at December 31, 2021 4,243,482 $ 33.97 Granted 5,329,020 $ 31.16 Exercised (122,082) $ 18.40 Cancelled (1,398,961) $ 47.68 Outstanding at December 31, 2022 8,051,459 $ 29.97 8.2 $3,431 Vested and expected to vest at December 31, 2022 7,524,257 $ 30.38 8.1 $3,431 Exercisable at December 31, 2022 2,037,706 $ 30.94 6.6 $2,307
Schedule of valuation assumptions	The fair value of the stock options granted during the year ended December 31, 2022 was determined with the following assumptions: Year ended December 31, 2022 2021 Expected volatility 73.6% - 80.5% 73.2% - 76.6% Average expected term (in years) 6.0 - 6.5 5.2 - 6.1 Risk-free interest rate 1.5% - 4.2% 0.5% - 1.3% Expected dividend yield —% —%
Summary of RSA activity	The following table summarizes RSA activity for the year ending December 31, 2022. The amounts include RSAs granted to both employees and non-employees: Number of Shares Weighted Average Grant Date Outstanding at December 31, 2021 361,832 $ 3.47 Vested (220,891) $ 4.48 Forfeited (15,435) $ 2.84 Outstanding at December 31, 2022 125,506 $ 5.45
Summary of RSU activity	The following table summarizes RSU activity for the year ending December 31, 2022. The amounts include RSUs granted to both employees and non-employees: Number of Shares Weighted Average Grant Date Outstanding at December 31, 2021 274,195 $ 33.06 Granted 929,083 $ 27.99 Vested (158,671) $ 28.84 Forfeited (121,706) $ 37.13 Outstanding at December 31, 2022 922,901 $ 27.48
Schedule of valuation assumptions, ESPP	The weighted average assumptions used to estimate the fair value of stock purchase rights under the 2020 ESPP are as follows: Year ended December 31, 2022 2021 ESPP Volatility 74.0 % 48.2 % Expected term (years) 0.5 0.5 Risk free rate 1.6 % 0.1 % Expected dividend yield — % — %

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Summary of operating lease terms	The following table presents the weighted average remaining lease term and weighted average discount rates related to our operating leases as of December 31, 2022: Weighted average remaining lease term (in years) 9.8 Weighted average discount rate 9.0%
Schedule of future minimum operating lease payments	Approximate annual future minimum operating lease payments as of December 31, 2022 are as follows (in thousands): Year Amount 2023 $ 6,340 2024 6,486 2025 6,799 2026 7,278 2027 7,451 Thereafter 38,778 Total minimum lease payments: 73,132 Less: imputed interest 25,804 Total operating lease liabilities 47,328 Less: current portion 2,162 Lease liability, net of current portion $ 45,166

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of net losses before income taxes and loss on equity method investment by domestic and foreign operations	The amount of net loss before income taxes and loss on equity method investment for the years ended December 31, 2022, 2021 and 2020 is as follows (in thousands): Year ended December 31, 2022 2021 2020 U.S. net loss before income taxes $ (237,926) $ (171,053) $ (112,827) Foreign net income (loss) before income taxes 344 4,663 (5,277) Net loss before income taxes, including loss on equity method investment $ (237,582) $ (166,390) $ (118,104)
Schedule of components of income tax provision (benefit) for federal and state income taxes	The following table presents the current and deferred income tax provision (benefit) for federal, state and foreign income taxes (in thousands): Year ended December 31, 2022 2021 2020 Current tax provision: Federal $ — $ — $ — State 11 11 16 Foreign 298 550 410 Total current tax provision 309 561 426 Deferred tax provision: Federal (683) (120) — State (41) (736) — Foreign (54) (2) 18 Total deferred tax provision (778) (858) 18 Total provision for income taxes: $ (469) $ (297) $ 444
Schedule of effective income tax rate reconciliation	The following table is a reconciliation of the expected tax computed at the U.S. statutory federal income tax rate to the total provision for income taxes (in thousands): Year ended December 31, 2022 2021 2020 Expected tax at 21% $ (49,892) 21.0 % $ (34,941) 21.0 % $ (24,802) 21.0 % State income tax, net of federal tax (4,222) 1.8 % (931) 0.6 % 273 (0.3) % Research credits (12,558) 5.3 % (6,938) 4.2 % (4,025) 3.4 % Share-based compensation 1,245 (0.5) % (3,307) 2.0 % (1,718) 1.5 % Other (2,799) 1.2 % 939 (0.6) % 146 (0.1) % Section 162(m) limitations 3,950 (1.7) % 3,982 (2.4) % 2,956 (2.5) % Change in valuation allowance 63,807 (26.9) % 40,899 (24.6) % 27,614 (23.4) % Provision for income taxes $ (469) 0.2 % $ (297) 0.2 % $ 444 (0.4) %
Schedule of deferred tax assets and liabilities	Significant components of our net deferred tax asset or liability are as follows (in thousands): December 31, 2022 2021 Deferred tax assets Net operating loss $ 95,392 $ 82,117 Compensation 1,937 1,553 Share-based compensation 7,735 4,123 ASC 842 lease liability 9,967 9,740 Intangibles 1,745 2,004 Capitalized research and experimental expenditures 30,776 — Accrued liabilities 476 675 Research credits 27,024 14,466 Other 62 — Total gross deferred tax assets 175,114 114,678 Valuation allowance (160,967) (97,160) Net deferred tax assets 14,147 17,518 Deferred tax liabilities Depreciable assets (1,609) (1,699) ASC 842 right of use asset (8,924) (9,481) Equity method investment (4,467) (7,954) Other — (6) Deferred tax liabilities (15,000) (19,140) Net deferred tax liabilities $ (853) $ (1,622)
Schedule of unrecognized tax benefits roll forward	The following table summarized the activity related to our unrecognized tax benefits (in thousands): December 31, 2022 2021 2020 Gross unrecognized tax benefits at the beginning of the year $ 2,835 $ 1,932 $ 1,124 Increase related to current year tax positions 1,112 969 661 Increase related to prior year tax positions 350 — 197 Decrease related to prior year tax positions — (66) (50) Gross unrecognized tax benefits at end of the year $ 4,297 $ 2,835 $ 1,932

Net Loss Per Common Share (Tabl

Net Loss Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2022
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): Year ended December 31, 2022 2021 2020 Numerator: Net loss attributable to Zentalis $ (236,806) $ (158,725) $ (117,841) Denominator: Weighted average number of common shares outstanding, basic and diluted 52,857 42,688 28,113 Net loss per common share $ (4.48) $ (3.72) $ (4.19)
Schedule of antidilutive securities excluded from computation of earnings per unit	The following common stock have been excluded from the calculations of diluted net loss per common share because their inclusion would be antidilutive (in thousands). Year ended December 31, 2022 2021 2020 Outstanding stock options 8,051 4,243 3,121 Unvested RSAs 126 361 742 Unvested RSUs 923 274 675 9,100 4,878 4,538

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Restricted cash	$ 2.6	$ 2.9
Operating lease, liability, current, balance sheet location	Accrued expenses	Accrued expenses
Minimum | Equipment
Variable Interest Entity [Line Items]
Property, plant and equipment, useful life (years)	3 years
Maximum | Equipment
Variable Interest Entity [Line Items]
Property, plant and equipment, useful life (years)	5 years

Significant Transactions (Detai

Significant Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jul. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investment in Zentera Therapeutics	$ 21,213	$ 37,495
Deferred tax liability upon deconsolidation of Zentera	4,467	7,954
Gain on deconsolidation of Zentera	0	51,582	$ 0
Zentera Sublicenses
Schedule of Equity Method Investments [Line Items]
Equity ownership				40.30%
Deferred tax liability upon deconsolidation of Zentera	4,500
Gain on deconsolidation of Zentera	51,600
In-process research and development	5,100
Contra-research and development expense	$ 11,000	$ 5,300

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($)		12 Months Ended
	Dec. 21, 2017	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
IPR&D impairment		$ 0	$ 8,800,000	$ 0
Reversal of deferred tax liability due to IPR&D impairment			2,500,000
In Process Research and Development
Variable Interest Entity [Line Items]
IPR&D impairment		8,800,000
In-process research and development		$ 0	$ 8,800,000
Kalyra Pharmaceuticals, Inc.
Variable Interest Entity [Line Items]
Cash payments to acquire interest	$ 4,500,000
Ownership percentage	25%

Business Combinations - Reconci

Business Combinations - Reconciliation of Equity (Net Assets) Attributable to Noncontrolling Interest (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Net loss attributable to noncontrolling interest	$ (307)	$ (7,368)	$ (707)
Deconsolidation of Zentera		(16,899)
VIE, Primary Beneficiary
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interest at beginning of period	528	24,795
Net loss attributable to noncontrolling interest	(307)	(7,368)
Deconsolidation of Zentera	0	(16,899)
Noncontrolling interest at end of period	$ 221	$ 528	$ 24,795

Fair Value Measurement - Compon

Fair Value Measurement - Components of Available-for-sale Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 395,655
Gross Unrealized Gains	71
Gross Unrealized Losses	(1,424)
Estimated Fair Value	394,302	$ 280,173
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	296,309
Gross Unrealized Gains	71
Gross Unrealized Losses	(587)
Estimated Fair Value	295,793	199,277
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	7,472
Gross Unrealized Gains	0
Gross Unrealized Losses	(26)
Estimated Fair Value	7,446	10,078
US government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	23,970
Gross Unrealized Gains	0
Gross Unrealized Losses	(182)
Estimated Fair Value	23,788	20,033
US Treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	67,904
Gross Unrealized Gains	0
Gross Unrealized Losses	(629)
Estimated Fair Value	$ 67,275	$ 50,785

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) $ in Millions	Dec. 31, 2022 USD ($) security
Fair Value Disclosures [Abstract]
Number of available-for-sale securities in unrealized loss position | security	53
Debt securities fair market value	$ 280.1
Fair value of available-for-sale securities in unrealized loss position	$ 1.4

Fair Value Measurement - Contra

Fair Value Measurement - Contractual Maturities of Available-for-sale Securities (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Fair Value Disclosures [Abstract]
Due within one year	$ 394,302
After one but within five years	0
Estimated Fair Value	$ 394,302

Fair Value Measurement - Fair V

Fair Value Measurement - Fair Value of Assets Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	$ 28,809	$ 43,653
Marketable securities, available for sale	394,302	280,173
Total assets measured at fair value	423,111	323,826
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	28,809	43,653
Marketable securities, available for sale	67,275	50,785
Total assets measured at fair value	96,084	94,438
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	0	0
Marketable securities, available for sale	327,027	229,388
Total assets measured at fair value	327,027	229,388
Commercial paper
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	295,793	199,277
Commercial paper | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	0	0
Commercial paper | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	295,793	199,277
Corporate debt securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	7,446	10,078
Corporate debt securities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	0	0
Corporate debt securities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	7,446	10,078
US government agencies
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	23,788	20,033
US government agencies | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	0	0
US government agencies | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	23,788	20,033
US Treasury securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	67,275	50,785
US Treasury securities | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	67,275	50,785
US Treasury securities | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Marketable securities, available for sale	0	0
Money market funds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	26,811	43,653
Money market funds | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	26,811	43,653
Money market funds | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	0	0
Commercial paper
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	1,998	0
Commercial paper | Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	1,998	0
Commercial paper | Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Cash equivalents	$ 0	$ 0

Prepaid Expenses and Other As_3

Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid insurance	$ 1,018	$ 990
Prepaid software licenses and maintenance	958	403
Foreign R&D credit refund	659	1,808
Prepaid research and development expenses	15,002	11,204
Interest receivable	508	258
Zentera receivable	5,874	2,373
Other prepaid expenses	266	644
Total prepaid expenses and other current assets	24,285	17,680
Less long-term portion	9,723	7,040
Total prepaid expenses and other assets, current	$ 14,562	$ 10,640

Property and Equipment, net - S

Property and Equipment, net - Summary (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Subtotal	$ 9,765	$ 8,940
Accumulated depreciation and amortization	(2,060)	(792)
Property and equipment, net	7,705	8,148
Lab equipment
Property, Plant and Equipment [Line Items]
Subtotal	2,622	2,057
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	4,891	4,515
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Subtotal	2,065	2,123
Computer equipment
Property, Plant and Equipment [Line Items]
Subtotal	150	211
Construction in process
Property, Plant and Equipment [Line Items]
Subtotal	$ 37	$ 34

Property and Equipment, net - N

Property and Equipment, net - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 1,426	$ 544	$ 160

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 32,310	$ 18,531
Accrued employee expenses	11,246	9,250
Accrued general and administrative expenses	662	1,480
Lease liability	2,162	1,453
Income taxes payable	384	971
Accrued legal expenses	1,256	669
Total accrued expenses	48,020	32,354
Less long-term portion	2,620	0
Total accrued expenses, current	$ 45,400	$ 32,354

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details)			1 Months Ended		3 Months Ended	12 Months Ended
	May 18, 2022 USD ($) $ / shares shares	Apr. 29, 2022 USD ($) $ / shares shares	May 31, 2021 USD ($)	Apr. 30, 2020 shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) shares	Jul. 31, 2022 shares	Mar. 15, 2021 shares
Class of Stock [Line Items]
Issuance of common stock upon exercise of options (in shares) | shares						122,082
Proceeds from exercises of stock options						$ 2,200,000
Options, weighted average grant date fair value (dollars per share) | $ / shares						$ 20.45	$ 33.27
Intrinsic value of options exercised						$ 2,000,000	$ 8,800,000
Common Stock
Class of Stock [Line Items]
Issuance of common stock upon exercise of options (in shares) | shares						122,000	232,000
Issuance of common stock in connection with restricted stock unit vesting (in shares) | shares						158,671	517,000	426,000
Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Class of Stock [Line Items]
Gross proceeds from issuance of common stock		$ 3,800,000
Sales Agreement
Class of Stock [Line Items]
Gross proceeds from issuance of common stock					$ 49,700,000
Maximum gross sales proceeds			$ 200,000,000
Expenses and fees from the issuance of common stock					$ 1,100,000
The 2020 Plan
Class of Stock [Line Items]
Outstanding awards (in shares) | shares					7,517,610	7,517,610
Shares available for future grants (in shares) | shares					980,553	980,553
2022 Inducement Plan
Class of Stock [Line Items]
Number of shares reserved for future issuance (in shares) | shares									1,500,000
Outstanding awards (in shares) | shares					1,456,750	1,456,750
Shares available for future grants (in shares) | shares					43,250	43,250
Zentera Stock Plan
Class of Stock [Line Items]
Share-based compensation prior to deconsolidation							$ 138,000	$ 187,000
2020 ESPP
Class of Stock [Line Items]
Employee Stock Purchase Plan (ESPP), number of shares available | shares				450,000
Employee Stock Purchase Plan (ESPP), number of shares outstanding, percentage				0.01
Employee Stock Purchase Plan (ESPP), number of shares available, other term in calculation | shares				1,500,000
Amended 2020 ESPP
Class of Stock [Line Items]
Employee Stock Purchase Plan (ESPP), shares in ESPP reserve | shares										2,000,000
Common Stock | Direct Offering
Class of Stock [Line Items]
Number of shares issued and sold (in shares) | shares		953,834
Share price (in dollars per share) | $ / shares		$ 26.21
Gross proceeds from issuance of common stock		$ 25,000,000
Issuance fees and expenses		$ 300,000
Common Stock | Follow-On Offering
Class of Stock [Line Items]
Number of shares issued and sold (in shares) | shares	10,330,000
Share price (in dollars per share) | $ / shares	$ 19.38
Gross proceeds from issuance of common stock	$ 200,200,000
Issuance fees and expenses	$ 11,400,000
Common Stock | Sales Agreement
Class of Stock [Line Items]
Number of shares issued and sold (in shares) | shares					2,210,500
Remaining amount available					$ 140,300,000	$ 140,300,000
Common Stock | Weighted Average | Sales Agreement
Class of Stock [Line Items]
Share price (in dollars per share) | $ / shares					$ 22.50	$ 22.50
Common Stock | The 2020 Plan
Class of Stock [Line Items]
Shares authorized to be issued under plan (in shares) | shares				5,600,000
Percent of common stock outstanding used as threshold to calculate shares available for issuance				5%
Class B Common Units | The 2020 Plan | Maximum
Class of Stock [Line Items]
Shares authorized to be issued under plan (in shares) | shares				1,250,000
Outstanding stock options
Class of Stock [Line Items]
Generally expected vesting term of the option contract (in years)						10 years
Expected dividend yield						0%	0%
Unvested RSUs
Class of Stock [Line Items]
Grant date fair value of shares vested						$ 4,600,000	$ 12,700,000	10,100,000
Fair value of vested shares						7,300,000	26,400,000	21,800,000
Unvested RSAs
Class of Stock [Line Items]
Grant date fair value of shares vested						1,000,000	1,700,000	1,100,000
Fair value of vested shares						$ 8,300,000	$ 21,000,000	$ 14,300,000
Employee Stock Purchase Plan
Class of Stock [Line Items]
Expected dividend yield						0%	0%
Employee Stock Purchase Plan (ESPP) maximum percent of compensation to contribute					20%	20%
Employee Stock Purchase Plan (ESPP) maximum contribution amount						$ 21,250
Employee Stock Purchase Plan (ESPP), purchase price of common stock, percent of market price						85%
Employee Stock Purchase Plan (ESPP), offering period (in months)						6 months

Stockholders' Equity - Share-ba

Stockholders' Equity - Share-based Compensation Related to Share Based Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 46,840	$ 35,737	$ 23,146
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	20,439	14,879	7,296
General and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 26,401	$ 20,858	$ 15,850

Stockholders' Equity - Share-_2

Stockholders' Equity - Share-based Compensation Expense by Type of Share-based Awards (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 46,840	$ 35,737	$ 23,146
Profits interest award units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	0	0	329
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	36,338	20,773	6,925
RSAs and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	10,075	14,643	15,892
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 427	$ 321	$ 0

Stockholders' Equity - Unrecogn

Stockholders' Equity - Unrecognized Compensation Cost (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Outstanding stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options	$ 95,906
Remaining Weighted-Average Recognition Period (Years)	3 years 1 month 6 days
Unvested RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than options	$ 330
Remaining Weighted-Average Recognition Period (Years)	8 months 12 days
Unvested RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than options	$ 18,880
Remaining Weighted-Average Recognition Period (Years)	2 years 6 months

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Option Activity (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares
Stock Option Activity
Outstanding at the beginning of the period (in shares) | shares	4,243,482
Options granted (in shares) | shares	5,329,020
Options exercised (in shares) | shares	(122,082)
Options cancelled (in shares) | shares	(1,398,961)
Outstanding at the ending of the period (in shares) | shares	8,051,459
Stock Options Weighted Average Exercise Price
Options outstanding, weighted average grant date fair value beginning of the period (in dollars per share) | $ / shares	$ 33.97
Options granted (in dollars per share) | $ / shares	31.16
Options exercised (in dollars per share) | $ / shares	18.40
Options cancelled (in dollars per share) | $ / shares	47.68
Options outstanding, weighted average grant date fair value ending of the period (in dollars per share) | $ / shares	$ 29.97
Stock Option Activity, Additional Disclosures
Options outstanding, weighted average remaining contractual term (years)	8 years 2 months 12 days
Options outstanding, aggregate intrinsic value (in USD) | $	$ 3,431
Options vested and expected to vest, number of options (in shares) | shares	7,524,257
Options vested and expected to vest, weighted average exercise price per share (in dollars per share) | $ / shares	$ 30.38
Options vested and expected to vest, weighted average remaining contractual term (years)	8 years 1 month 6 days
Options vested and expected to vest, aggregate intrinsic value (in USD) | $	$ 3,431
Options exercisable, number of options (in shares) | shares	2,037,706
Options exercisable, weighted average exercise price per share (in dollars per share) | $ / shares	$ 30.94
Options exercisable, weighted average remaining contractual term (years)	6 years 7 months 6 days
Options exercisable, aggregate intrinsic value (in USD) | $	$ 2,307

Stockholders' Equity - Fair Val

Stockholders' Equity - Fair Value Assumptions for Stock Options (Details) - Outstanding stock options	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected dividend yield	0%	0%
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Volatility (as a percent)	73.60%	73.20%
Average expected term (in years)	6 years	5 years 2 months 12 days
Risk free rate (as a percent)	1.50%	0.50%
Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Volatility (as a percent)	80.50%	76.60%
Average expected term (in years)	6 years 6 months	6 years 1 month 6 days
Risk free rate (as a percent)	4.20%	1.30%

Stockholders' Equity - Equity i

Stockholders' Equity - Equity instruments Other than Options (Details)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Restricted Stock Awards (RSAs)
Activity
Outstanding at the beginning of the period (in shares) | shares	361,832
Vested (shares) | shares	(220,891)
Forfeited (in shares) | shares	(15,435)
Outstanding at the end of the period (in shares) | shares	125,506
Weighted Average Grant Date Fair Value
Outstanding, weighted average grant date fair value beginning of the period (in dollars per share) | $ / shares	$ 3.47
Vested (in dollars per share) | $ / shares	4.48
Forfeited (in dollars per share) | $ / shares	2.84
Outstanding, weighted average grant date fair value end of the period (in dollars per share) | $ / shares	$ 5.45
Restricted Stock Units (RSUs)
Activity
Outstanding at the beginning of the period (in shares) | shares	274,195
Granted (in shares) | shares	929,083
Vested (shares) | shares	(158,671)
Forfeited (in shares) | shares	(121,706)
Outstanding at the end of the period (in shares) | shares	922,901
Weighted Average Grant Date Fair Value
Outstanding, weighted average grant date fair value beginning of the period (in dollars per share) | $ / shares	$ 33.06
Granted, (in dollars per share) | $ / shares	27.99
Vested (in dollars per share) | $ / shares	28.84
Forfeited (in dollars per share) | $ / shares	37.13
Outstanding, weighted average grant date fair value end of the period (in dollars per share) | $ / shares	$ 27.48

Stockholders' Equity - Fair V_2

Stockholders' Equity - Fair Value Assumptions for Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Volatility (as a percent)	74%	48.20%
Average expected term (in years)	6 months	6 months
Risk free rate (as a percent)	1.60%	0.10%
Expected dividend yield	0%	0%

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	1 Months Ended				12 Months Ended
	Sep. 30, 2021 ft² option	Mar. 31, 2021 ft² option	Nov. 30, 2020 ft²	Sep. 30, 2020 ft²	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2022
Lessee, Lease, Description [Line Items]
Operating lease, rent expense | $					$ 7	$ 2.6
Operating lease payments | $					$ 2.5	$ 1.3
San Diego | Building
Lessee, Lease, Description [Line Items]
Area of leased space (in square feet)				117,900
Reduction due to amendment (in square feet)	43,200
Potential annual increase to lease rent (percent)	0.030
Number of renewal options | option	2
Operating lease, renewal term (in years)							5 years
San Diego | Temporary Leased Building
Lessee, Lease, Description [Line Items]
Area of leased space (in square feet)			13,200
New York | Building
Lessee, Lease, Description [Line Items]
Area of leased space (in square feet)		31,362
Potential annual increase to lease rent (percent)		0.081
Number of renewal options | option		1
Operating lease, renewal term (in years)		5 years
Anniversary year of potential rent increase post commencement date		6 years

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Operating Lease Terms (Details)	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Weighted average remaining lease term (in years)	9 years 9 months 18 days
Weighted average discount rate	9%

Commitments and Contingencies_3

Commitments and Contingencies - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
2023	$ 6,340
2024	6,486
2025	6,799
2026	7,278
2027	7,451
Thereafter	38,778
Total minimum lease payments:	73,132
Less: imputed interest	25,804
Total operating lease liabilities	47,328
Less: current portion	2,162	$ 1,453
Long-term lease liability	$ 45,166	$ 44,459

Income Taxes - Net Loss Before

Income Taxes - Net Loss Before Taxes And Loss on Equity Method Investment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
U.S. net loss before income taxes	$ (237,926)	$ (171,053)	$ (112,827)
Foreign net income (loss) before income taxes	344	4,663	(5,277)
Net loss before income taxes, including loss on equity method investment	$ (237,582)	$ (166,390)	$ (118,104)

Income Taxes - Provision_Benefi

Income Taxes - Provision/Benefit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current tax provision:
Federal	$ 0	$ 0	$ 0
State	11	11	16
Foreign	298	550	410
Total current tax provision	309	561	426
Deferred tax provision:
Federal	(683)	(120)	0
State	(41)	(736)	0
Foreign	(54)	(2)	18
Total deferred tax provision	(778)	(858)	18
Total provision for income taxes:	$ (469)	$ (297)	$ 444

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Effective Income Tax Rate Reconciliation, Amount
Expected tax at 21%	$ (49,892)	$ (34,941)	$ (24,802)
State income tax, net of federal tax	(4,222)	(931)	273
Research credits	(12,558)	(6,938)	(4,025)
Share-based compensation	1,245	(3,307)	(1,718)
Other	(2,799)	939	146
Section 162(m) limitations	3,950	3,982	2,956
Change in valuation allowance	63,807	40,899	27,614
Total provision for income taxes:	$ (469)	$ (297)	$ 444
Effective Income Tax Rate Reconciliation, Percent
Expected tax at 21%	21%	21%	21%
State income tax, net of federal tax	1.80%	0.60%	(0.30%)
Research credits	5.30%	4.20%	3.40%
Share-based compensation	(0.50%)	2%	1.50%
Other	1.20%	(0.60%)	(0.10%)
Section 162(m) limitations	(0.017)	(0.024)	(0.025)
Change in valuation allowance	(26.90%)	(24.60%)	(23.40%)
Provision for income taxes	0.20%	0.20%	(0.40%)

Income Taxes Net Deferred Tax A

Income Taxes Net Deferred Tax Asset or Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets
Net operating loss	$ 95,392	$ 82,117
Compensation	1,937	1,553
Share-based compensation	7,735	4,123
ASC 842 lease liability	9,967	9,740
Intangibles	1,745	2,004
Capitalized research and experimental expenditures	30,776	0
Accrued liabilities	476	675
Research credits	27,024	14,466
Other	62	0
Total gross deferred tax assets	175,114	114,678
Valuation allowance	(160,967)	(97,160)
Net deferred tax assets	14,147	17,518
Deferred tax liabilities
Depreciable assets	(1,609)	(1,699)
ASC 842 right of use asset	(8,924)	(9,481)
Equity method investment	(4,467)	(7,954)
Other	0	(6)
Deferred tax liabilities	(15,000)	(19,140)
Net deferred tax liabilities	$ (853)	$ (1,622)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Operating Loss Carryforwards [Line Items]
Deferred tax assets, valuation allowance	$ 160,967,000	$ 97,160,000
Unrecognized tax benefits that would not impact effective tax rate	4,000,000
Accrued interest and penalties associated with uncertain tax positions	0	$ 0
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	390,300,000
Net operating loss carryforwards, not subject to expiration	369,400,000
Federal and state research tax credit carryforwards, net of reserves	20,500,000
State and Local Jurisdiction
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	192,400,000
Federal and state research tax credit carryforwards, net of reserves	$ 8,300,000

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits at the beginning of the year	$ 2,835	$ 1,932	$ 1,124
Increase related to current year tax positions	1,112	969	661
Increase related to prior year tax positions	350	0	197
Decrease related to prior year tax positions	0	(66)	(50)
Gross unrecognized tax benefits at end of the year	$ 4,297	$ 2,835	$ 1,932

Net Loss Per Common Share - Cal

Net Loss Per Common Share - Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Numerator:
Net loss attributable to Zentalis	$ (236,806)	$ (158,725)	$ (117,841)
Denominator:
Weighted average number of common shares/Class A common units outstanding, basic (in shares)	52,857	42,688	28,113
Weighted average number of common shares/Class A common units outstanding, diluted (in shares)	52,857	42,688	28,113
Net loss per common share, basic (in dollars per share)	$ (4.48)	$ (3.72)	$ (4.19)
Net loss per common share, diluted (in dollars per share)	$ (4.48)	$ (3.72)	$ (4.19)

Net Loss Per Common Share - Ant

Net Loss Per Common Share - Antidilutive Securities (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	9,100	4,878	4,538
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)	8,051	4,243	3,121
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	126	361	742
Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	923	274	675

Employee Savings Plan (Details)

Employee Savings Plan (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Matching contributions made by employer for savings plan	$ 1,400,000	$ 991,500

Related Party Disclosures (Deta

Related Party Disclosures (Details) - USD ($)		3 Months Ended	12 Months Ended
	Dec. 21, 2017	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Preferred stock, shares issued (in shares)			0	0
VIE, Primary Beneficiary | Kalyra Pharmaceuticals, Inc.
Related Party Transaction [Line Items]
Share price (in dollars per share)	$ 0.26
Cash payments to acquire interest	$ 4,500,000
VIE, Primary Beneficiary | Kalyra Pharmaceuticals, Inc. | Series B Preferred Units
Related Party Transaction [Line Items]
Preferred stock, shares issued (in shares)	17,307,692
Zentera Sublicenses
Related Party Transaction [Line Items]
Contra-research and development expense			$ 11,000,000	$ 5,300,000
Divestiture of early stage asset		$ 200,000
Chief Scientific Officer, President And Director | Recurium Agreement
Related Party Transaction [Line Items]
Due to related parties			0	10,000,000
Affiliated Entity | Master Services Agreement
Related Party Transaction [Line Items]
Due to related parties			0	0
Chief Executive Officer And Director | Master Services Agreement
Related Party Transaction [Line Items]
Due to related parties			$ 200,000	$ 1,000,000