Zentalis Pharmaceuticals (ZNTL) 10-Q 7 May 24 2024 Q1 Quarterly report Financial data

Cover

Cover - shares	3 Months Ended
	Mar. 31, 2024	May 03, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-39263
Entity Registrant Name	Zentalis Pharmaceuticals, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3607803
Entity Address, Address Line One	1359 Broadway
Entity Address, Address Line Two	Suite 801
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10018
City Area Code	212
Local Phone Number	433-3791
Title of 12(b) Security	Common Stock,$0.001 par value per share
Trading Symbol	ZNTL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		71,013,233
Entity Central Index Key	0001725160
Amendment Flag	false
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets
Cash and cash equivalents	$ 37,616	$ 28,038
Marketable securities, available-for-sale	451,368	454,881
Prepaid expenses and other current assets	14,822	13,799
Total current assets	503,806	496,718
Property and equipment, net	5,679	5,819
Operating lease right-of-use assets	34,726	35,916
Prepaid expenses and other assets	6,851	6,818
Goodwill	3,736	3,736
Restricted cash	2,681	2,681
Total assets	557,479	551,688
Current liabilities
Accounts payable	10,502	14,926
Accrued expenses	44,296	54,441
Total current liabilities	54,798	69,367
Long-term lease liability	42,616	43,150
Other long-term liabilities	1,294	1,780
Total liabilities	98,708	114,297
Commitments and contingencies
EQUITY
Preferred stock, $0.001 par value; 10,000,000 shares authorized; no shares issued and outstanding at March 31, 2024 and December 31, 2023	0	0
Common stock, $0.001 par value; 250,000,000 shares authorized; 71,011,982 and 70,765,554 shares issued and outstanding at March 31, 2024 and December 31, 2023, respectively	70	70
Additional paid-in capital	1,336,416	1,323,576
Accumulated other comprehensive income	773	2,194
Accumulated deficit	(878,488)	(888,556)
Total stockholders’ equity	458,771	437,284
Noncontrolling interests	0	107
Total equity	458,771	437,391
Total liabilities and stockholders’ equity	$ 557,479	$ 551,688

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	250,000,000	250,000,000
Common stock issued (in shares)	71,011,982	70,765,554
Common stock outstanding (in shares)	71,011,982	70,765,554

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement [Abstract]
License Revenue	$ 40,560	$ 0
Operating Expenses
Research and development	49,585	48,584
General and administrative	15,740	16,369
Total operating expenses	65,325	64,953
Loss from operations	(24,765)	(64,953)
Other Income (Expense)
Investment and other income, net	34,948	4,109
Net income (loss) before income taxes	10,183	(60,844)
Income tax expense	143	108
Loss on equity method investment	0	2,310
Net income (loss)	10,040	(63,262)
Net loss attributable to noncontrolling interests	(28)	(43)
Net income (loss) attributable to Zentalis	$ 10,068	$ (63,219)
Earnings per share
Basic (in dollars per share)	$ 0.14	$ (1.07)
Diluted (in dollars per share)	$ 0.14	$ (1.07)
Weighted average common shares outstanding
Basic (in shares)	70,898	59,277
Diluted (in shares)	71,192	59,277

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 10,040	$ (63,262)
Other comprehensive income (loss):
Unrealized income (loss) on marketable securities	(1,421)	797
Total comprehensive income (loss)	8,619	(62,465)
Comprehensive income (loss) attributable to noncontrolling interests	(28)	(43)
Comprehensive income (loss) attributable to Zentalis	$ 8,647	$ (62,422)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Operating Activities:
Consolidated net income (loss)	$ 10,040	$ (63,262)
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Depreciation and amortization	324	360
Operating lease right-of-use asset and fixed asset impairment	772	4,953
Loss on equity method investment	0	2,310
Share-based compensation	12,833	13,733
Loss on disposal of equipment	(66)	0
Non-cash impact of license revenue	(25,560)	0
Non-cash recognized mark-to-market of equity securities	(31,169)	0
(Accretion of discounts)/amortization of premiums on marketable securities, net	(2,764)	(3,261)
Deferred income taxes	0	(97)
Deconsolidation of Kalyra	(79)	0
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,056)	(2,917)
Accounts payable and accrued liabilities	(15,249)	(1,411)
Operating lease right-of-use assets and liabilities, net	0	309
Net cash used in operating activities	(51,974)	(49,283)
Investing Activities:
Purchases of marketable securities	(10,115)	(63,879)
Proceeds from maturities of marketable securities	71,700	106,000
Purchases of property and equipment	(40)	0
Net cash provided by investing activities	61,545	42,121
Financing Activities:
Proceeds from issuance of common stock under equity incentive plans	248	373
Net-settlement of restricted stock unit vesting	(241)	0
Net cash provided by financing activities	7	373
Net increase (decrease) in cash, cash equivalents and restricted cash	9,578	(6,789)
Cash, cash equivalents and restricted cash at beginning of period	30,719	45,696
Cash, cash equivalents and restricted cash at end of period	40,297	38,907
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	37,616	36,280
Restricted cash	2,681	2,627
Total cash, cash equivalents and restricted cash reported in the Condensed Consolidated Statement of Cash Flows	$ 40,297	$ 38,907

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders’ Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2022		59,280,000
Beginning balance at Dec. 31, 2022	$ 434,024	$ 59	$ 1,031,462	$ (1,353)	$ (596,365)	$ 221
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	13,733		13,733
Other comprehensive income (loss)	797			797
Issuance of common stock in connection with restricted stock unit vesting (in shares)		139,000
Shares issued under employee stock purchase plan (in shares)		25,000
Shares issued under employee stock purchase plan	373		373
Cancellation of restricted stock awards (in shares)		(2,000)
Net loss attributable to non-controlling interest	(43)					(43)
Net income (loss) attributable to Zentalis	(63,219)				(63,219)
Ending balance (in shares) at Mar. 31, 2023		59,442,000
Ending balance at Mar. 31, 2023	385,665	$ 59	1,045,568	(556)	(659,584)	178
Beginning balance (in shares) at Dec. 31, 2022		59,280,000
Beginning balance at Dec. 31, 2022	434,024	$ 59	1,031,462	(1,353)	(596,365)	221
Ending balance (in shares) at Dec. 31, 2023		70,767,000
Ending balance at Dec. 31, 2023	437,391	$ 70	1,323,576	2,194	(888,556)	107
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	12,833		12,833
Other comprehensive income (loss)	(1,421)			(1,421)
Issuance and withholding of common stock in connection with restricted stock unit vesting, net (in shares)		228,000
Issuance and withholding of common stock in connection with restricted stock unit vesting, net	$ (241)		(241)
Issuance of common stock in connection with restricted stock unit vesting (in shares)	949
Deconsolidation of Kalyra	$ (79)					(79)
Shares issued under employee stock purchase plan (in shares)		18,000
Shares issued under employee stock purchase plan	248		248
Net loss attributable to non-controlling interest	(28)					(28)
Net income (loss) attributable to Zentalis	10,068				10,068
Ending balance (in shares) at Mar. 31, 2024		71,013,000
Ending balance at Mar. 31, 2024	$ 458,771	$ 70	$ 1,336,416	$ 773	$ (878,488)	$ 0

Organization and Business

Organization and Business	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Business	Organization and Business Organization Zentalis Pharmaceuticals, Inc. (“Zentalis,” “We” or the “Company”) is a clinical-stage biopharmaceutical company discovering and developing small molecule therapeutics targeting fundamental biological pathways of cancers. The Company’s lead product candidate, azenosertib (ZN-c3), is a potentially first-in-class and best-in-class WEE1 inhibitor for advanced solid tumors and hematologic malignancies. The Company is also developing a BCL-2 inhibitor, ZN-d5, in combination with azenosertib. The Company manages its operations as a single segment for the purposes of assessing performance and making operating decisions. All of the Company’s tangible assets are held in the United States. Liquidity

Interim Unaudited Financial Sta

Interim Unaudited Financial Statements	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Interim Unaudited Financial Statements	Interim Unaudited Financial Statements Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. The year-end condensed consolidated balance sheet data was derived from the Company’s audited financial statements but do not include all disclosures required by U.S. GAAP. These interim unaudited condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 27, 2024. The unaudited financial information for the interim periods presented herein reflects all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial condition and results of operation for the periods presented, with such adjustments consisting only of normal recurring adjustments. Certain reclassifications have been made to the prior period condensed consolidated balance sheet to conform to the current period presentation. The accompanying interim unaudited condensed consolidated financial statements include our wholly-owned subsidiaries and Kalyra Pharmaceuticals, Inc. (“Kalyra”), a variable interest entity (“VIE”) for which we were the primary beneficiary until Kalyra was dissolved in January 2024 (See Note 4 - Business Combinations for additional information). All intercompany transactions and balances have been eliminated in consolidation. Following the dissolution of Kalyra, we no longer have an interest in any VIEs. Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in our consolidated financial statements and accompanying notes. On an ongoing basis, we evaluate our estimates and judgments, which are based on historical and anticipated results and trends and on various other assumptions that management believes to be reasonable under the circumstances. By their nature, estimates are subject to an inherent degree of uncertainty and, as such, actual results may differ from management’s estimates. Significant Accounting Policies During the three months ended March 31, 2024 we adopted the following significant accounting policies not previously reported in the Company’s significant accounting policies as described in its Annual Report on Form 10-K for the fiscal year ended December 31, 2023 . Investments in equity securities We carry investments in equity securities at fair value and record the changes in fair values in the Consolidated Statement of Operations as a component of Investment and other income, net.

Significant Transactions

Significant Transactions	3 Months Ended
	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Significant Transactions	Significant Transactions Immunome In January 2024 Immunome, Inc. (“Immunome”) and Zentalis Pharmaceuticals, Inc. entered into an exclusive, worldwide license agreement under which Immunome licensed from Zentalis ZPC-21, a preclinical ROR1 antibody-drug conjugate (“ADC”) and stock issuance agreement (the “Stock Issuance Agreement”). The upfront consideration from Immunome amounted to $15.0 million in cash and $20.0 million in shares of Immunome common stock, with the shares valued at the trailing 30-day volume-weighted average price. On the date of execution of the transaction, the Immunome common stock was valued at $25.6 million. The performance obligation associated with this upfront payment was met as of March 31, 2024, and $40.6 million, comprised of cash and the fair value of the Immunome stock on the date of execution of the transaction, was recognized as license revenue, within the condensed consolidated statement of operations. The stock acquired was recorded at fair value on the date of acquisition, within marketable securities, available for sale on the condensed consolidated balance sheet. Pursuant to the terms of the Stock Issuance Agreement, Zentalis will hold and not sell greater than 50% of the shares until the six-month anniversary of the closing date, subject to certain exceptions. Changes in fair value of the Immunome stock for the three months ended March 31, 2024 amounted to $31.2 million, recorded as a component of investment and other income, net within the condensed consolidated statement of operations. There were no disposals of the acquired stock during the three months ended March 31, 2024.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2024
Business Combination and Asset Acquisition [Abstract]
Business Combinations	Business Combinations Kalyra Pharmaceuticals, Inc. On December 21, 2017, we acquired $4.5 million of Kalyra’s 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. On January 10, 2024, Kalyra was dissolved and we no longer have an ownership interest in Kalyra. The dissolution and deconsolidation of Kalyra had an immaterial impact on our consolidated financial statements. In accordance with the authoritative guidance, we concluded that, prior to its dissolution, Kalyra was a business consisting of inputs, employees, intellectual property and processes capable of producing outputs. Additionally, we concluded that Kalyra was a VIE, we were the primary beneficiary and had the power to direct the activities that most significantly affected 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 were included in our consolidated financial statements from the date of the initial investment up until the dissolution of Kalyra on January 10, 2024. Pursuant with authoritative guidance, we recorded the identifiable assets, liabilities and noncontrolling interests in Kalyra at their fair value upon initial consolidation. The identified goodwill was comprised of the workforce and expected synergies from combining the entities . T otal assets and liabilities of Kalyra as of March 31, 2024 and December 31, 2023 are zero and immaterial, respectively. The liabilities recognized as a result of consolidating Kalyra did not represent additional claims on our general assets. Pursuant to the authoritative guidance, the equity interest in Kalyra not owned by Zentalis was reported as a noncontrolling interest on our condensed consolidated balance sheets. The following is a reconciliation of equity (net assets) attributable to the noncontrolling interest (in thousands): March 31, December 31, 2024 2023 Noncontrolling interest at beginning of period $ 107 $ 221 Net loss attributable to noncontrolling interest (28) (114) Deconsolidation of Kalyra (79) — Noncontrolling interest at end of period $ — $ 107

Fair Value Measurement

Fair Value Measurement	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurement	Fair Value Measurement Available-for-sale marketable debt securities consisted of the following (in thousands): March 31, 2024 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 34,967 $ 13 $ (9) $ 34,971 Corporate debt securities 236,112 792 (15) 236,889 US government agencies 57,672 20 (13) 57,679 US treasury securities 65,115 2 (17) 65,100 $ 393,866 $ 827 $ (54) $ 394,639 December 31, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 75,227 $ 60 $ (15) $ 75,272 Corporate debt securities 229,896 2,036 — 231,932 US government agencies 83,025 100 (78) 83,047 US treasury securities 64,538 103 (11) 64,630 $ 452,686 $ 2,299 $ (104) $ 454,881 As of March 31, 2024, seventeen of our available-for-sale debt securities with a fair market value of $115.0 million were in a gross unrealized loss position of $0.1 million. All seventeen have been in a gross unrealized loss position of $0.1 million for less than one year and none has been in a gross unrealized loss position for more than one year. When evaluating an investment for impairment, we review factors such as the severity of the impairment, changes in underlying credit ratings, forecasted recovery, our intent to sell or the likelihood that we would be required to sell the investment before its anticipated recovery in market value and the probability that the scheduled cash payments will continue to be made. Based on our review of these marketable securities, we believe none of the unrealized loss is as a result of a credit loss as of March 31, 2024, 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): March 31, 2024 December 31, 2023 Estimated Fair Value Due within one year $ 255,964 $ 267,336 After one but within five years 138,675 187,545 $ 394,639 $ 454,881 The Company had $0.5 million in contingent consideration liabilities as of March 31, 2024 related to the agreement to terminate its Collaboration and License Agreements with Zentera. The contingent consideration balance is limited to one potential milestone payment measured at fair value. The fair value of the contingent consideration is estimated based on the monetary value of the milestone discounted for the probability of achieving the milestone and a present value factor based on the timing of when the milestone is expected to be achieved. The value for the contingent consideration balance is based on significant inputs not observable in the market which represents Level 3 measurement within the fair value hierarchy. The following table summarizes the financial assets and liabilities that are measured on a recurring basis at fair value as of March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 25,784 $ — $ — $ 25,784 Total cash equivalents: 25,784 — — 25,784 Available-for-sale marketable securities: Commercial paper — 34,971 — 34,971 Corporate debt securities — 236,889 — 236,889 US government agencies — 57,679 — 57,679 US treasury securities — 65,100 — 65,100 Immunome equity securities 56,729 — — 56,729 Total available-for-sale marketable securities: 56,729 394,639 — 451,368 Total assets measured at fair value $ 82,513 $ 394,639 $ — $ 477,152 Financial liabilities: Contingent consideration 500 500 Total financial liabilities $ — $ — $ 500 $ 500 December 31, 2023 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 4,755 $ — $ — $ 4,755 Total cash equivalents: 4,755 — — 4,755 Available-for-sale marketable securities: Commercial paper — 75,272 — 75,272 Corporate debt securities — 231,932 — 231,932 US government agencies — 83,047 — 83,047 US treasury securities — 64,630 — 64,630 Total available-for-sale marketable securities: — 454,881 — 454,881 Total assets measured at fair value $ 4,755 $ 454,881 $ — $ 459,636 Financial liabilities: Contingent consideration 500 500 Total financial liabilities $ — $ — $ 500 $ 500 The following significant unobservable inputs were used in the valuation of the contingent consideration payable to Zentera pursuant to the Termination Agreement at March 31, 2024: Contingent Consideration Liability Fair Value as of March 31, 2024 Valuation Technique Unobservable Input Range (in thousands) Milestone payment $ 500 Discounted cash flow Likelihood of occurrence 1.0% - 2.4% Discount rate 40% Expected term Perpetuity The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (in thousands): Contingent consideration at December 31, 2023 500 Changes in the fair value of contingent consideration — Contingent consideration at March 31, 2024 $ 500

Prepaid Expenses and Other Asse

Prepaid Expenses and Other Assets	3 Months Ended
	Mar. 31, 2024
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): March 31, December 31, 2024 2023 Prepaid insurance $ 192 $ 747 Prepaid software licenses and maintenance 574 691 Foreign R&D credit refund 765 500 Prepaid research and development expenses 13,098 13,640 Interest receivable 3,155 3,337 Sublease assets 852 1,471 Other prepaid expenses 3,037 231 Total prepaid expenses and other assets 21,673 20,617 Less long-term portion 6,851 6,818 Total prepaid expenses and other assets, current $ 14,822 $ 13,799

Property and Equipment, net

Property and Equipment, net	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property and Equipment, net	Property and Equipment, net Property and equipment, net consisted of the following (in thousands): March 31, December 31, 2024 2023 Lab equipment $ 3,308 $ 3,069 Leasehold improvements 4,168 4,235 Office equipment and furniture 1,340 1,340 Computer equipment 150 150 Construction in progress 118 173 Subtotal 9,084 8,967 Accumulated depreciation and amortization (3,405) (3,148) Property and equipment, net $ 5,679 $ 5,819 Depreciation and amortization expense for the three months ended March 31, 2024 and 2023

Accrued Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Accrued Expenses	Accrued Expenses Accrued expenses consist of the following (in thousands): March 31, December 31, 2024 2023 Accrued research and development expenses $ 33,938 $ 36,261 Accrued employee expenses 6,626 14,477 Accrued general and administrative expenses 688 1,032 Lease liability 2,739 2,623 Contingent consideration 500 500 Income Taxes payable 403 281 Accrued legal expenses 696 1,047 Total accrued expenses 45,590 56,221 Less long-term portion 1,294 1,780 Total accrued expenses $ 44,296 $ 54,441

Stockholders_ Equity

Stockholders’ Equity	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Stockholders’ Equity	Stockholders’ Equity Follow-on Offering of Common Stock On June 15, 2023, we completed a follow-on offering in which we issued and sold 11,032,656 shares of common stock at a public offering price of $22.66 per share. The total gross proceeds for the offering were approximately $250.0 million, before deducting offering expenses of $14.3 million payable by us. Share-based Compensation Effective April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved, the 2020 Incentive Award Plan (the “2020 Plan”), which allows for grants to selected employees, consultants and non-employee members of the Board of Directors. We currently grant stock options and restricted stock units (“RSUs”), under the 2020 Plan. Awards may be made under the 2020 Plan covering up to the sum of (1) 5,600,000 shares of common stock; plus (2) any shares forfeited from the unvested restricted shares of our common stock issued upon conversion of unvested Class B common units (up to 1,250,000 shares); plus (3) an annual increase on the first day of each fiscal year beginning with the fiscal year ending December 31, 2021 and continuing to, and including, the fiscal year ending December 31, 2030, equal to the lesser of (a) 5% of the shares of common stock outstanding on the final day of the immediately preceding calendar year and (b) such smaller number of shares as determined by our Board of Directors. At March 31, 2024, 12,375,531 shares were subject to outstanding awards under the 2020 Plan and 2,011,553 shares were available for future grants of share-based awards under the 2020 Plan. In July 2022, the Company’s Board of Directors approved the Zentalis Pharmaceuticals, Inc. 2022 Employment Inducement Incentive Award Plan (the “2022 Inducement Plan”), which is used exclusively for the grant of equity awards to new employees as an inducement material to the employees’ entering into employment with the Company. The Board of Directors has reserved 3,275,000 shares of the Company’s common stock for issuance pursuant to awards granted under the 2022 Inducement Plan. At March 31, 2024, 2,409,241 shares were subject to outstanding awards under the 2022 Inducement Plan and 840,759 shares were available for future grants of share-based awards under the 2022 Inducement Plan. Total share-based compensation expense related to share based awards was comprised of the following (in thousands): Three Months Ended 2024 2023 Research and development expense $ 4,740 $ 5,873 General and administrative expense 8,093 7,860 Total share-based compensation expense $ 12,833 $ 13,733 Share-based compensation expense by type of share-based award (in thousands): Three Months Ended 2024 2023 Stock Options $ 9,874 $ 10,609 Employee Stock Purchase Plan 53 105 RSAs and RSUs 2,906 3,019 $ 12,833 $ 13,733 Stock Options and Restricted Stock Units The exercise price of stock options granted is equal to the closing price of the Company’s common stock on the date of grant. The fair value of each option award is estimated on the date of grant using the Black-Scholes model. Due to the Company’s limited operating history and a lack of company specific historical and implied volatility data, the Company estimates expected volatility based on the historical volatility of a group of similar companies that are publicly traded. The historical volatility data was computed using the daily closing prices for the selected companies’ shares during the equivalent period of the calculated expected term of the stock-based awards. The Company uses the “simplified method” for estimating the expected term of employee options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option (generally 10 years). The risk-free interest rate is based on the U.S. Treasury yield for a period consistent with the expected term of the option in effect at the time of the grant. The Company has not issued any dividends and does not expect to issue dividends over the life of the options. As a result, the Company has estimated the dividend yield to be zero. The fair value of the stock options granted during the three months ended March 31, 2024 and March 31, 2023 was determined with the following assumptions: March 31, 2024 March 31, 2023 Expected volatility 75.3% - 78.2% 79.0% - 80.8% Average expected term (in years) 6.0 - 6.1 5.5 - 6.1 Risk-free interest rate 3.8% - 4.1% 3.4% - 4.2% Expected dividend yield — % — % Employee Stock Purchase Plan Effective April 2020, the Company’s Board of Directors adopted, and the Company’s stockholders approved the Zentalis Pharmaceuticals, Inc. 2020 Employee Stock Purchase Plan (the “ESPP”), which was subsequently amended and restated effective March 15, 2021. The maximum aggregate number of shares of the Company’s common stock available for issuance under the ESPP at March 31, 2024 was 1,894,676. Under the terms of the ESPP, the Company’s employees may elect to have up to 20% of their compensation, up to a maximum value of $25,000 per calendar year, withheld to purchase shares of the Company’s common stock for a purchase price equal to 85% of the lower of the fair market value per share (at closing) of the Company’s common stock on (i) the first trading day of a six-month offering period, or (ii) the applicable purchase date, defined as the last trading day of the six-month offering period. The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP during the period ended are as follows: Ended March 31, 2024 ESPP Volatility 53.8 % Expected term (years) 0.5 Risk free rate 5.6 % Expected dividend yield — Compensation Expense Summary Total unrecognized estimated compensation cost by type of award and the weighted average requisite service period over which such expense is expected to be recognized (in thousands, unless otherwise noted): March 31, 2024 Unrecognized Remaining Stock options $ 96,655 2.83 RSUs 34,822 3.19 ESPP $ — 0

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies From time to time, we may be involved in various disputes, including lawsuits and claims arising in the ordinary course of business, including actions with respect to intellectual property, employment, and contractual matters. Any of these claims could subject us to costly legal expenses. The Company records a liability in its consolidated financial statements for these matters when a loss is known or considered probable and the amount can be reasonably estimated. The Company reviews these estimates each accounting period as additional information is known and adjusts the loss provision when appropriate. If a matter is both probable to result in a liability and the amounts of loss can be reasonably estimated, the Company estimates and discloses the possible loss or range of loss to the extent necessary to make the consolidated financial statements not misleading. If the loss is not probable or cannot be reasonably estimated, a liability is not recorded in our consolidated financial statements. While we do generally believe that we have adequate insurance to cover many different types of liabilities, our insurance carriers may deny coverage, or our policy limits may be inadequate to fully satisfy any damage awards or settlement. If this were to happen, the payment of any such awards could have a material adverse effect on our consolidated results of operations and financial position. Additionally, any such claims, whether or not successful, could damage our reputation and business. We are currently not a party to any legal proceedings that require a loss liability to be recorded. Leases Our commitments include payments related to operating leases. Approximate annual future minimum operating lease payments as of March 31, 2024 are as follows (in thousands): Year Operating Leases 2024 (remaining) $ 5,197 2025 7,002 2026 7,487 2027 7,606 2028 7,760 Thereafter 31,018 Total minimum lease payments: 66,070 Less: imputed interest (20,715) Total operating lease liabilities 45,355 Less: current portion (2,739) Lease liability, net of current portion $ 42,616 The weighted-average remaining lease term of our operating leases is approximately 8.5 years.

Net Income (Loss) Per Common Sh

Net Income (Loss) Per Common Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Income (Loss) Per Common Share	Net Income (Loss) Per Common Share Basic and diluted net income (loss) per common share were calculated as follows (in thousands except per share amounts): Three Months Ended 2024 2023 Numerator: Net income (loss) attributable to Zentalis $ 10,068 $ (63,219) Denominator: Weighted average number of common shares outstanding for basic 70,898 59,277 Dilutive potential common stock outstanding Restricted Stock Units 294 — Weighted average common shares outstanding for diluted earnings per share 71,192 59,277 Earnings per share Basic $ 0.14 $ (1.07) Diluted $ 0.14 $ (1.07) Our potential and dilutive securities, which include outstanding stock options, unvested RSAs and unvested RSUs have been excluded from the computation of diluted net loss per common share as the effect would be anti-dilutive. The following common stock equivalents have been excluded from the calculations of diluted net income (loss) per common share because their inclusion would be antidilutive (in thousands). March 31, 2024 2023 Outstanding stock options 12,233 9,895 Unvested RSAs — 82 Unvested RSUs 665 1,566 12,898 11,543

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net income (loss) attributable to Zentalis	$ 10,068	$ (63,219)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Interim Unaudited Financial S_2

Interim Unaudited Financial Statements (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and with the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. The year-end condensed consolidated balance sheet data was derived from the Company’s audited financial statements but do not include all disclosures required by U.S. GAAP. These interim unaudited condensed consolidated financial statements and notes thereto should be read in conjunction with the Company’s audited financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 27, 2024. The unaudited financial information for the interim periods presented herein reflects all adjustments which, in the opinion of management, are necessary for a fair presentation of the financial condition and results of operation for the periods presented, with such adjustments consisting only of normal recurring adjustments. Certain reclassifications have been made to the prior period condensed consolidated balance sheet to conform to the current period presentation.
Consolidation	The accompanying interim unaudited condensed consolidated financial statements include our wholly-owned subsidiaries and Kalyra Pharmaceuticals, Inc. (“Kalyra”), a variable interest entity (“VIE”) for which we were the primary beneficiary until Kalyra was dissolved in January 2024 (See Note 4 - Business Combinations for additional information). All intercompany transactions and balances have been eliminated in consolidation. Following the dissolution of Kalyra, we no longer have an interest in any VIEs.
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.
Investments in equity securities	Investments in equity securities We carry investments in equity securities at fair value and record the changes in fair values in the Consolidated Statement of Operations as a component of Investment and other income, net.

Business Combinations (Tables)

Business Combinations (Tables)	3 Months Ended
	Mar. 31, 2024
Business Combination and Asset Acquisition [Abstract]
Reconciliation of Equity Attributable to Noncontrolling Interest	The following is a reconciliation of equity (net assets) attributable to the noncontrolling interest (in thousands): March 31, December 31, 2024 2023 Noncontrolling interest at beginning of period $ 107 $ 221 Net loss attributable to noncontrolling interest (28) (114) Deconsolidation of Kalyra (79) — Noncontrolling interest at end of period $ — $ 107

Fair Value Measurement (Tables)

Fair Value Measurement (Tables)	3 Months Ended
	Mar. 31, 2024
Fair Value Disclosures [Abstract]
Components of Available-for-sale Marketable Securities	Available-for-sale marketable debt securities consisted of the following (in thousands): March 31, 2024 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 34,967 $ 13 $ (9) $ 34,971 Corporate debt securities 236,112 792 (15) 236,889 US government agencies 57,672 20 (13) 57,679 US treasury securities 65,115 2 (17) 65,100 $ 393,866 $ 827 $ (54) $ 394,639 December 31, 2023 Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Commercial paper $ 75,227 $ 60 $ (15) $ 75,272 Corporate debt securities 229,896 2,036 — 231,932 US government agencies 83,025 100 (78) 83,047 US treasury securities 64,538 103 (11) 64,630 $ 452,686 $ 2,299 $ (104) $ 454,881
Contractual Maturities of Available-for-sale Debt Securities	Contractual maturities of available-for-sale debt securities are as follows (in thousands): March 31, 2024 December 31, 2023 Estimated Fair Value Due within one year $ 255,964 $ 267,336 After one but within five years 138,675 187,545 $ 394,639 $ 454,881
Fair Value of Assets and Liabilities Measured on a Recurring Basis	The following table summarizes the financial assets and liabilities that are measured on a recurring basis at fair value as of March 31, 2024 and December 31, 2023 (in thousands): March 31, 2024 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 25,784 $ — $ — $ 25,784 Total cash equivalents: 25,784 — — 25,784 Available-for-sale marketable securities: Commercial paper — 34,971 — 34,971 Corporate debt securities — 236,889 — 236,889 US government agencies — 57,679 — 57,679 US treasury securities — 65,100 — 65,100 Immunome equity securities 56,729 — — 56,729 Total available-for-sale marketable securities: 56,729 394,639 — 451,368 Total assets measured at fair value $ 82,513 $ 394,639 $ — $ 477,152 Financial liabilities: Contingent consideration 500 500 Total financial liabilities $ — $ — $ 500 $ 500 December 31, 2023 Level 1 Level 2 Level 3 Total estimated fair value Financial assets: Cash equivalents: Money market funds $ 4,755 $ — $ — $ 4,755 Total cash equivalents: 4,755 — — 4,755 Available-for-sale marketable securities: Commercial paper — 75,272 — 75,272 Corporate debt securities — 231,932 — 231,932 US government agencies — 83,047 — 83,047 US treasury securities — 64,630 — 64,630 Total available-for-sale marketable securities: — 454,881 — 454,881 Total assets measured at fair value $ 4,755 $ 454,881 $ — $ 459,636 Financial liabilities: Contingent consideration 500 500 Total financial liabilities $ — $ — $ 500 $ 500
Measurement Inputs for Contingent Consideration Liability	The following significant unobservable inputs were used in the valuation of the contingent consideration payable to Zentera pursuant to the Termination Agreement at March 31, 2024: Contingent Consideration Liability Fair Value as of March 31, 2024 Valuation Technique Unobservable Input Range (in thousands) Milestone payment $ 500 Discounted cash flow Likelihood of occurrence 1.0% - 2.4% Discount rate 40% Expected term Perpetuity
Activity for Contingent Consideration	The following table reflects the activity for the Company’s contingent consideration, measured at fair value using Level 3 inputs (in thousands): Contingent consideration at December 31, 2023 500 Changes in the fair value of contingent consideration — Contingent consideration at March 31, 2024 $ 500

Prepaid Expenses and Other As_2

Prepaid Expenses and Other Assets (Tables)	3 Months Ended
	Mar. 31, 2024
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): March 31, December 31, 2024 2023 Prepaid insurance $ 192 $ 747 Prepaid software licenses and maintenance 574 691 Foreign R&D credit refund 765 500 Prepaid research and development expenses 13,098 13,640 Interest receivable 3,155 3,337 Sublease assets 852 1,471 Other prepaid expenses 3,037 231 Total prepaid expenses and other assets 21,673 20,617 Less long-term portion 6,851 6,818 Total prepaid expenses and other assets, current $ 14,822 $ 13,799

Property and Equipment, net (Ta

Property and Equipment, net (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Summary of Property and Equipment, net	Property and equipment, net consisted of the following (in thousands): March 31, December 31, 2024 2023 Lab equipment $ 3,308 $ 3,069 Leasehold improvements 4,168 4,235 Office equipment and furniture 1,340 1,340 Computer equipment 150 150 Construction in progress 118 173 Subtotal 9,084 8,967 Accumulated depreciation and amortization (3,405) (3,148) Property and equipment, net $ 5,679 $ 5,819

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2024
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consist of the following (in thousands): March 31, December 31, 2024 2023 Accrued research and development expenses $ 33,938 $ 36,261 Accrued employee expenses 6,626 14,477 Accrued general and administrative expenses 688 1,032 Lease liability 2,739 2,623 Contingent consideration 500 500 Income Taxes payable 403 281 Accrued legal expenses 696 1,047 Total accrued expenses 45,590 56,221 Less long-term portion 1,294 1,780 Total accrued expenses $ 44,296 $ 54,441

Stockholders_ Equity (Tables)

Stockholders’ Equity (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Schedule of Share-based Compensation Expense	Total share-based compensation expense related to share based awards was comprised of the following (in thousands): Three Months Ended 2024 2023 Research and development expense $ 4,740 $ 5,873 General and administrative expense 8,093 7,860 Total share-based compensation expense $ 12,833 $ 13,733 Share-based compensation expense by type of share-based award (in thousands): Three Months Ended 2024 2023 Stock Options $ 9,874 $ 10,609 Employee Stock Purchase Plan 53 105 RSAs and RSUs 2,906 3,019 $ 12,833 $ 13,733
Schedule of Fair Value Assumptions for Stock Options	The fair value of the stock options granted during the three months ended March 31, 2024 and March 31, 2023 was determined with the following assumptions: March 31, 2024 March 31, 2023 Expected volatility 75.3% - 78.2% 79.0% - 80.8% Average expected term (in years) 6.0 - 6.1 5.5 - 6.1 Risk-free interest rate 3.8% - 4.1% 3.4% - 4.2% Expected dividend yield — % — %
Schedule of Fair Value Assumptions for ESPP	The weighted average assumptions used to estimate the fair value of stock purchase rights under the ESPP during the period ended are as follows: Ended March 31, 2024 ESPP Volatility 53.8 % Expected term (years) 0.5 Risk free rate 5.6 % Expected dividend yield —
Unrecognized Compensation Cost	Total unrecognized estimated compensation cost by type of award and the weighted average requisite service period over which such expense is expected to be recognized (in thousands, unless otherwise noted): March 31, 2024 Unrecognized Remaining Stock options $ 96,655 2.83 RSUs 34,822 3.19 ESPP $ — 0

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Operating Lease Payments	Approximate annual future minimum operating lease payments as of March 31, 2024 are as follows (in thousands): Year Operating Leases 2024 (remaining) $ 5,197 2025 7,002 2026 7,487 2027 7,606 2028 7,760 Thereafter 31,018 Total minimum lease payments: 66,070 Less: imputed interest (20,715) Total operating lease liabilities 45,355 Less: current portion (2,739) Lease liability, net of current portion $ 42,616

Net Income (Loss) Per Common _2

Net Income (Loss) Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Income (Loss) Per Unit	Basic and diluted net income (loss) per common share were calculated as follows (in thousands except per share amounts): Three Months Ended 2024 2023 Numerator: Net income (loss) attributable to Zentalis $ 10,068 $ (63,219) Denominator: Weighted average number of common shares outstanding for basic 70,898 59,277 Dilutive potential common stock outstanding Restricted Stock Units 294 — Weighted average common shares outstanding for diluted earnings per share 71,192 59,277 Earnings per share Basic $ 0.14 $ (1.07) Diluted $ 0.14 $ (1.07)
Schedule of Antidilutive Securities Excluded from Computation of Diluted Net Income (Loss) Per Common Share	The following common stock equivalents have been excluded from the calculations of diluted net income (loss) per common share because their inclusion would be antidilutive (in thousands). March 31, 2024 2023 Outstanding stock options 12,233 9,895 Unvested RSAs — 82 Unvested RSUs 665 1,566 12,898 11,543

Significant Transactions (Detai

Significant Transactions (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2024	Mar. 31, 2024	Mar. 31, 2023
Schedule of Equity Method Investments [Line Items]
License Revenue		$ 40,560	$ 0
Investment and other income, net		34,948	$ 4,109
Immunome, Inc
Schedule of Equity Method Investments [Line Items]
Upfront consideration, cash	$ 15,000
Upfront consideration, value of shares	$ 20,000
Trailing volume-weighted average price period (in days)	30 days
Value of common stock	$ 25,600
License Revenue		$ 40,600
Percent of shares to be hold and not sold		50%
Anniversary term of shares to be held and not sold (in months)		6 months
Investment and other income, net		$ 31,200

Business Combinations - Narrati

Business Combinations - Narrative (Details) - USD ($) $ in Thousands	Dec. 21, 2017	Mar. 31, 2024	Dec. 31, 2023
Variable Interest Entity [Line Items]
Assets		$ 557,479	$ 551,688
Liabilities		98,708	114,297
Kalyra Pharmaceuticals, Inc.
Variable Interest Entity [Line Items]
Cash payments to acquire interest	$ 4,500
Ownership percentage	25%
Kalyra Pharmaceuticals, Inc. | Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Assets		0	0
Liabilities		$ 0	$ 0

Business Combinations - Reconci

Business Combinations - Reconciliation of Equity (Net Assets) Attributable to Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2021
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interest at beginning of period	$ 107
Net loss attributable to noncontrolling interests	(28)	$ (43)
Deconsolidation of Kalyra	(79)
Noncontrolling interest at end of period	0		$ 107
VIE, Primary Beneficiary
Stockholders' Equity Attributable to Noncontrolling Interest [Roll Forward]
Noncontrolling interest at beginning of period	107	$ 221	221
Net loss attributable to noncontrolling interests	(28)		(114)
Deconsolidation of Kalyra	(79)			$ 0
Noncontrolling interest at end of period	$ 0		$ 107

Fair Value Measurement - Compon

Fair Value Measurement - Components of Available-for-sale Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 393,866	$ 452,686
Gross Unrealized Gains	827	2,299
Gross Unrealized Losses	(54)	(104)
Estimated Fair Value	394,639	454,881
Commercial paper
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	34,967	75,227
Gross Unrealized Gains	13	60
Gross Unrealized Losses	(9)	(15)
Estimated Fair Value	34,971	75,272
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	236,112	229,896
Gross Unrealized Gains	792	2,036
Gross Unrealized Losses	(15)	0
Estimated Fair Value	236,889	231,932
US government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	57,672	83,025
Gross Unrealized Gains	20	100
Gross Unrealized Losses	(13)	(78)
Estimated Fair Value	57,679	83,047
US treasury securities
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	65,115	64,538
Gross Unrealized Gains	2	103
Gross Unrealized Losses	(17)	(11)
Estimated Fair Value	$ 65,100	$ 64,630

Fair Value Measurement - Narrat

Fair Value Measurement - Narrative (Details) $ in Thousands	Mar. 31, 2024 USD ($) security potential_milestone_payment	Dec. 31, 2023 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Number of available-for-sale securities in unrealized loss position | security	17
Debt securities fair market value	$ 115,000
Fair market value of available-for-sale securities in unrealized loss position	$ 100
Number of available-for-sale securities in unrealized loss position for less than one year | security	17
Gross unrealized loss position for less than one year	$ 100
Number of available-for-sale securities in unrealized loss position for more than one year | security	0
Contingent consideration	$ 500	$ 500
Zentera | Collaborative Arrangement, Transaction with Party to Collaborative Arrangement
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500
Number of potential milestone payments | potential_milestone_payment	1

Fair Value Measurement - Contra

Fair Value Measurement - Contractual Maturities of Available-for-sale Debt Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value Disclosures [Abstract]
Due within one year	$ 255,964	$ 267,336
After one but within five years	138,675	187,545
Total	$ 394,639	$ 454,881

Fair Value Measurement - Fair V

Fair Value Measurement - Fair Value of Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financial assets:
Cash equivalents	$ 25,784	$ 4,755
Marketable securities, available-for-sale	394,639	454,881
Immunome equity securities	56,729
Total available-for-sale marketable securities:	451,368	454,881
Total assets measured at fair value	477,152	459,636
Financial liabilities:
Contingent consideration	500	500
Total financial liabilities	500	500
Level 1
Financial assets:
Cash equivalents	25,784	4,755
Immunome equity securities	56,729
Total available-for-sale marketable securities:	56,729	0
Total assets measured at fair value	82,513	4,755
Financial liabilities:
Contingent consideration
Total financial liabilities	0	0
Level 2
Financial assets:
Cash equivalents	0	0
Immunome equity securities	0
Total available-for-sale marketable securities:	394,639	454,881
Total assets measured at fair value	394,639	454,881
Financial liabilities:
Contingent consideration
Total financial liabilities	0	0
Level 3
Financial assets:
Cash equivalents	0	0
Immunome equity securities	0
Total available-for-sale marketable securities:	0	0
Total assets measured at fair value	0	0
Financial liabilities:
Contingent consideration	500	500
Total financial liabilities	500	500
Commercial paper
Financial assets:
Marketable securities, available-for-sale	34,971	75,272
Commercial paper | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
Commercial paper | Level 2
Financial assets:
Marketable securities, available-for-sale	34,971	75,272
Commercial paper | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
Corporate debt securities
Financial assets:
Marketable securities, available-for-sale	236,889	231,932
Corporate debt securities | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
Corporate debt securities | Level 2
Financial assets:
Marketable securities, available-for-sale	236,889	231,932
Corporate debt securities | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
US government agencies
Financial assets:
Marketable securities, available-for-sale	57,679	83,047
US government agencies | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
US government agencies | Level 2
Financial assets:
Marketable securities, available-for-sale	57,679	83,047
US government agencies | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
US treasury securities
Financial assets:
Marketable securities, available-for-sale	65,100	64,630
US treasury securities | Level 1
Financial assets:
Marketable securities, available-for-sale	0	0
US treasury securities | Level 2
Financial assets:
Marketable securities, available-for-sale	65,100	64,630
US treasury securities | Level 3
Financial assets:
Marketable securities, available-for-sale	0	0
Money market funds
Financial assets:
Cash equivalents	25,784	4,755
Money market funds | Level 1
Financial assets:
Cash equivalents	25,784	4,755
Money market funds | Level 2
Financial assets:
Cash equivalents	0	0
Money market funds | Level 3
Financial assets:
Cash equivalents	$ 0	$ 0

Fair Value Measurement - Measur

Fair Value Measurement - Measurement Inputs for Contingent Consideration Liability (Details) $ in Thousands	Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500	$ 500
Level 3
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500	$ 500
Level 3 | Discounted cash flow | Likelihood of occurrence | Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.010
Level 3 | Discounted cash flow | Likelihood of occurrence | Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.024
Level 3 | Milestone payment | Discount rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Measurement input	0.40
Level 3 | Milestone payment | Discounted cash flow
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Contingent consideration	$ 500

Fair Value Measurement - Activi

Fair Value Measurement - Activity for Contingent Consideration (Details) - Contingent Consideration Liability $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Contingent consideration, beginning balance	$ 500
Changes in the fair value of contingent consideration	0
Contingent consideration, ending balance	$ 500

Prepaid Expenses and Other As_3

Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid insurance	$ 192	$ 747
Prepaid software licenses and maintenance	574	691
Foreign R&D credit refund	765	500
Prepaid research and development expenses	13,098	13,640
Interest receivable	3,155	3,337
Sublease assets	852	1,471
Other prepaid expenses	3,037	231
Total prepaid expenses and other assets	21,673	20,617
Less long-term portion	6,851	6,818
Total prepaid expenses and other assets, current	$ 14,822	$ 13,799

Property and Equipment, net - S

Property and Equipment, net - Summary (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Subtotal	$ 9,084	$ 8,967
Accumulated depreciation and amortization	(3,405)	(3,148)
Property and equipment, net	5,679	5,819
Lab equipment
Property, Plant and Equipment [Line Items]
Subtotal	3,308	3,069
Leasehold improvements
Property, Plant and Equipment [Line Items]
Subtotal	4,168	4,235
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Subtotal	1,340	1,340
Computer equipment
Property, Plant and Equipment [Line Items]
Subtotal	150	150
Construction in progress
Property, Plant and Equipment [Line Items]
Subtotal	$ 118	$ 173

Property and Equipment, net - N

Property and Equipment, net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Property, Plant and Equipment [Abstract]
Depreciation and amortization	$ 324	$ 360

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Payables and Accruals [Abstract]
Accrued research and development expenses	$ 33,938	$ 36,261
Accrued employee expenses	6,626	14,477
Accrued general and administrative expenses	688	1,032
Lease liability	2,739	2,623
Contingent consideration	500	500
Income Taxes payable	403	281
Accrued legal expenses	696	1,047
Total accrued expenses	45,590	56,221
Less long-term portion	1,294	1,780
Total accrued expenses	$ 44,296	$ 54,441

Stockholders_ Equity - Narrativ

Stockholders’ Equity - Narrative (Details) - USD ($)		1 Months Ended	3 Months Ended
	Jun. 15, 2023	Apr. 30, 2020	Mar. 31, 2024	Mar. 31, 2023	Jul. 31, 2022
Class of Stock [Line Items]
Issuance of common stock upon exercise of options, net (in shares)			0
Shares issued upon vesting of certain RSAs (in shares)			949
Stock Options
Class of Stock [Line Items]
Generally expected vesting term of the option contract (in years)			10 years
Expected dividend yield			0%	0%
Options outstanding (in shares)			12,200,000
Employee Stock Purchase Plan
Class of Stock [Line Items]
Number of shares reserved for future issuance (in shares)			1,894,676
Expected dividend yield			0%
ESPP maximum percent of compensation to contribute			20%
Maximum contribution amount			$ 25,000
ESPP purchase price of common stock, percent of market price			85%
Offering period (in months)			6 months
RSUs
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			2,600,000
The 2020 Plan
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			12,375,531
Number of shares available for future grants (in shares)			2,011,553
2022 Inducement Plan
Class of Stock [Line Items]
Non-option equity instruments, outstanding (in shares)			2,409,241
Number of shares available for future grants (in shares)			840,759
Number of shares reserved for future issuance (in shares)					3,275,000
Follow On Offering
Class of Stock [Line Items]
Gross proceeds from issuance of common stock	$ 250,000,000
Expenses and fees from the issuance of common stock	$ 14,300,000
Common Stock | The 2020 Plan
Class of Stock [Line Items]
Shares authorized to be issued under plan (in shares)		5,600,000
Percent of common stock outstanding used as threshold to calculate shares available for issuance		5%
Common Stock | Follow On Offering
Class of Stock [Line Items]
Number of shares issued and sold (in shares)	11,032,656
Share price (in dollars per share)	$ 22.66
Common Class B | The 2020 Plan | Maximum
Class of Stock [Line Items]
Shares authorized to be issued under plan (in shares)		1,250,000

Stockholders_ Equity - Share-ba

Stockholders’ Equity - Share-based Compensation Expense by Expense Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 12,833	$ 13,733
Research and development expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	4,740	5,873
General and administrative expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 8,093	$ 7,860

Stockholders_ Equity - Share-_2

Stockholders’ Equity - Share-based Compensation Expense by Award Type (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 12,833	$ 13,733
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	9,874	10,609
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	53	105
RSAs and RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 2,906	$ 3,019

Stockholders_ Equity - Fair Val

Stockholders’ Equity - Fair Value Assumptions for Stock Options (Details) - Stock Options	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Expected volatility, minimum	75.30%	79%
Expected volatility, maximum	78.20%	80.80%
Risk-free interest rate, minimum	3.80%	3.40%
Risk-free interest rate, maximum	4.10%	4.20%
Expected dividend yield	0%	0%
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average expected term (in years)	6 years	5 years 6 months
Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Average expected term (in years)	6 years 1 month 6 days	6 years 1 month 6 days

Stockholders_ Equity - Fair V_2

Stockholders’ Equity - Fair Value Assumptions for ESPP (Details) - Employee Stock Purchase Plan	3 Months Ended
	Mar. 31, 2024
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Volatility	53.80%
Expected term (years)	6 months
Risk free rate	5.60%
Expected dividend yield	0%

Stockholders_ Equity - Unrecogn

Stockholders’ Equity - Unrecognized Compensation Cost (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, stock options	$ 96,655
Remaining Weighted-Average Recognition Period (years)	2 years 9 months 29 days
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than stock options	$ 34,822
Remaining Weighted-Average Recognition Period (years)	3 years 2 months 8 days
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized expense, other than stock options	$ 0
Remaining Weighted-Average Recognition Period (years)	0 years

Commitments and Contingencies -

Commitments and Contingencies - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
2024 (remaining)	$ 5,197
2025	7,002
2026	7,487
2027	7,606
2028	7,760
Thereafter	31,018
Total minimum lease payments:	66,070
Less: imputed interest	(20,715)
Total operating lease liabilities	45,355
Less: current portion	(2,739)	$ (2,623)
Lease liability, net of current portion	$ 42,616	$ 43,150

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2024 USD ($)
Commitments and Contingencies Disclosure [Abstract]
Operating lease, weighted-average remaining lease term (in years)	8 years 6 months
Sublease income	$ 0.4

Net Income (Loss) Per Common _3

Net Income (Loss) Per Common Share - Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Numerator:
Net income (loss) attributable to Zentalis	$ 10,068	$ (63,219)
Denominator:
Weighted average number of common shares outstanding for basic (in shares)	70,898	59,277
Dilutive potential common stock outstanding
Restricted Stock Units (in shares)	294	0
Weighted average number of common shares outstanding for diluted earnings per share (in shares)	71,192	59,277
Earnings per share
Basic (in dollars per share)	$ 0.14	$ (1.07)
Diluted (in dollars per share)	$ 0.14	$ (1.07)

Net Income (Loss) Per Common _4

Net Income (Loss) Per Common Share - Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	12,898	11,543
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)	12,233	9,895
Unvested RSAs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	0	82
Unvested RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per unit (in shares)	665	1,566