Compass Therapeutics (CMPX) 10-Q 12 Nov 21 2021 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2021	Nov. 05, 2021
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Entity Registrant Name	COMPASS THERAPEUTICS, INC.
Entity Central Index Key	0001738021
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Common Stock, Shares Outstanding		98,031,565
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity File Number	001-39696
Entity Tax Identification Number	82-4876496
Entity Address, Address Line One	80 Guest St.
Entity Address, Address Line Two	Suite 601
Entity Address, City or Town	Boston
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02135
City Area Code	617
Local Phone Number	500-8099
Entity Incorporation, State or Country Code	DE
Document Quarterly Report	true
Document Transition Report	false
Title of each class	Common Stock, $0.0001 par value per share
Trading Symbol	CMPX
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 25,509	$ 47,076
Prepaid expenses and other current assets	3,063	3,126
Total current assets	28,572	50,202
Property and equipment, net	1,435	1,126
Restricted cash	210	263
Operating lease, right-of-use ("ROU") asset	4,362	0
Other assets	320	320
Total assets	34,899	51,911
Current liabilities:
Accounts payable	868	1,061
Accrued expenses	1,998	1,571
Operating lease obligations, current portion	1,073	0
Current portion of long-term debt	3,744	7,467
Total current liabilities	7,683	10,099
Long-term debt, net of current portion	0	1,867
Operating lease obligations, long-term portion	3,328	0
Total liabilities	11,011	11,966
Stockholders' equity:
Preferred stock, $0.0001 par value; 10,000 shares authorized and no shares issued and outstanding as of September 30, 2021 and December 31, 2020	0	0
Common stock, $0.0001 par value: 300,000 shares authorized; 62,323 and 52,117 shares issued at September 30, 2021 and December 31, 2020, respectively; 61,760 and 51,221 shares outstanding at September 30, 2021 and December 31, 2020, respectively	6	5
Additional paid-in-capital	244,490	191,348
Accumulated deficit	(220,608)	(151,408)
Total stockholders' equity	23,888	39,945
Total liabilities and stockholders' equity	$ 34,899	$ 51,911

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) (unaudited) - $ / shares	Sep. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	62,323,000	52,117,000
Common stock, shares outstanding	61,760,000	51,221,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating expenses:
Research and development	$ 3,154	$ 3,670	$ 10,763	$ 10,498
General and administrative	2,700	5,291	7,500	9,364
In-process R&D	0	0	50,618	0
Total operating expenses	5,854	8,961	68,881	19,862
Loss from operations	(5,854)	(8,961)	(68,881)	(19,862)
Other expense, net	(121)	(189)	(306)	(1,215)
Loss before income tax expense	(5,975)	(9,150)	(69,187)	(21,077)
Income tax expense	0	0	(13)	(32)
Net loss	$ (5,975)	$ (9,150)	$ (69,200)	$ (21,109)
Net loss per share - basic and diluted	$ (0.10)	$ (0.18)	$ (1.26)	$ (0.88)
Basic and diluted weighted average shares outstanding	61,694	50,940	55,003	23,968

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Convertible Preferred Stock
Beginning Balance at Dec. 31, 2019	$ (118,603)	$ 1	$ 3,304	$ (121,908)
Temporary equity, Beginning Balance, Shares at Dec. 31, 2019					207,164
Temporary equity, Beginning Balance at Dec. 31, 2019					$ 129,870
Beginning Balance, Shares at Dec. 31, 2019		7,034
Vesting of share-based awards		88
Stock-based compensation	247		247
Net loss	(6,402)			(6,402)
Ending Balance at Mar. 31, 2020	(124,758)	$ 1	3,551	(128,310)
Temporary equity, Ending Balance, Shares at Mar. 31, 2020					207,164
Temporary equity, Ending Balance at Mar. 31, 2020					$ 129,870
Ending Balance, Shares at Mar. 31, 2020		7,122
Vesting of share-based awards		62
Stock-based compensation	183		183
Common shares issued, net of issuance costs of $6,902		12,097
Common shares issued, net of issuance costs of $6,902	53,581	$ 1	53,580
Common shares issued for acquisitions, Shares		1,000
Temporary equity, Conversion of Compass Therapeutics LLC preferred into common shares, Shares					(207,164)
Temporary equity, Conversion of Compass Therapeutics LLC preferred into common shares					$ (129,870)
Conversion of compass Therapeutics LLC preferred into common shares	129,870	$ 3	129,867
Conversion of compass Therapeutics LLC preferred into common shares, Shares		30,630
Payment to non-participating Compass Therapeutics LLC members	(69)		(69)
Payment to non-participating Compass Therapeutics LLC members, Shares		(14)
Net loss	(5,557)			(5,557)
Ending Balance at Jun. 30, 2020	53,250	$ 5	187,112	(133,867)
Temporary equity, Ending Balance, Shares at Jun. 30, 2020					0
Temporary equity, Ending Balance at Jun. 30, 2020					$ 0
Ending Balance, Shares at Jun. 30, 2020		50,897
Vesting of share-based awards		127
Stock-based compensation	2,536		2,536
Adjustment to issuance costs related to June 2020 private placement	651		651
Net loss	(9,150)			(9,150)
Ending Balance at Sep. 30, 2020	47,287	$ 5	190,299	(143,017)
Temporary equity, Ending Balance, Shares at Sep. 30, 2020					0
Temporary equity, Ending Balance at Sep. 30, 2020					$ 0
Ending Balance, Shares at Sep. 30, 2020		51,024
Beginning Balance at Dec. 31, 2020	39,945	$ 5	191,348	(151,408)
Temporary equity, Beginning Balance, Shares at Dec. 31, 2020					0
Temporary equity, Beginning Balance at Dec. 31, 2020					$ 0
Beginning Balance, Shares at Dec. 31, 2020		51,221
Vesting of share-based awards		92
Stock-based compensation	948		948
Net loss	(7,422)			(7,422)
Ending Balance at Mar. 31, 2021	33,471	$ 5	192,296	(158,830)
Temporary equity, Ending Balance, Shares at Mar. 31, 2021					0
Temporary equity, Ending Balance at Mar. 31, 2021					$ 0
Ending Balance, Shares at Mar. 31, 2021		51,313
Vesting of share-based awards		88
Stock-based compensation	908		908
Common shares issued for acquisitions	50,300	$ 1	50,299
Common shares issued for acquisitions, Shares		10,265
Net loss	(55,804)			(55,804)
Ending Balance at Jun. 30, 2021	28,875	$ 6	243,503	(214,634)
Temporary equity, Ending Balance, Shares at Jun. 30, 2021					0
Temporary equity, Ending Balance at Jun. 30, 2021					$ 0
Ending Balance, Shares at Jun. 30, 2021		61,666
Vesting of share-based awards		94
Stock-based compensation	987		987
Net loss	(5,975)			(5,975)
Ending Balance at Sep. 30, 2021	$ 23,888	$ 6	$ 244,490	$ (220,608)
Temporary equity, Ending Balance, Shares at Sep. 30, 2021					0
Temporary equity, Ending Balance at Sep. 30, 2021					$ 0
Ending Balance, Shares at Sep. 30, 2021		61,760

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Changes in Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) $ in Thousands	3 Months Ended
	Jun. 30, 2020USD ($)
Stock issuance costs	$ 6,902

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities:
Net loss	$ (69,200)	$ (21,109)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	442	1,335
Loss (gain) on disposal of equipment	(75)	8
Noncash interest expense	35	72
Share-based compensation	2,843	2,966
Writeoff of in process R&D	50,618	0
Change in fair value of derivative liability	0	556
ROU asset amortization	786	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	63	(1,379)
Other long-term assets	0	25
Accounts payable	(193)	194
Accrued expenses	427	(1,848)
Operating lease liability	(747)
Settlement of derivative liability	0	(1,050)
Net cash used in operating activities	(15,001)	(20,230)
Cash flows from investing activities:
Purchases of property and equipment	(791)	(23)
Asset acquisition costs	(318)	0
Proceeds from sale of equipment	115	55
Net cash (used in) provided by investing activities	(994)	32
Cash flows from financing activities:
Proceeds from issuance of common stock	0	60,482
Issuance costs from issuance of common stock	0	(6,319)
Repayment of borrowings under loan	(5,625)	(3,750)
Net cash (used in) provided by financing activities	(5,625)	50,413
Net change in cash, cash equivalents and restricted cash	(21,620)	30,215
Cash, cash equivalents and restricted cash at beginning of period	47,339	25,566
Cash, cash equivalents and restricted cash at end of period	25,719	55,781
Supplemental disclosure of cash flow information
Cash paid for interest	226	686
Supplemental disclosure of financing activities
Deferred offering costs included in accrued expenses	0	(116)
Conversion of preferred units	0	129,870
Payment to non-participating Compass LLC investors, within accrued expenses	0	(69)
ROU asset acquired through operating leases	5,148	0
Acquisition of Trigr Therapeutics, Inc.	$ 50,300	$ 0

Nature of Business and Basis of

Nature of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of Business and Basis of Presentation	1. Nature of Business and Basis of Presentation Compass Therapeutics, Inc. (“Compass” or the “Company”) is a clinical-stage, oncology-focused biopharmaceutical company developing proprietary antibody-based therapeutics to treat multiple human diseases. Our scientific focus is on the relationship between angiogenesis and the immune system. Our pipeline includes novel product candidates that leverage our understanding of the tumor microenvironment, including both angiogenesis-targeted agents and immune-oncology focused agents. These product candidates are designed to optimize critical components required for an effective anti-tumor response to cancer. These include modulation of the microvasculature via angiogenesis-targeted agents; induction of a potent immune response via activators on effector cells in the tumor microenvironment; and alleviation of immunosuppressive mechanisms used by tumors to evade immune surveillance. We plan to advance our product candidates through clinical development as both standalone therapies and in combination with our proprietary drug candidates as long as their continued development is supported by clinical and nonclinical data. References to Compass or the Company herein include Compass Therapeutics, Inc. and its wholly-owned subsidiaries. The Company was incorporated as Olivia Ventures, Inc. (“Olivia”) in the State of Delaware on March 20, 2018 . Prior to the Company’s reverse merger with Compass Therapeutics LLC (the “Merger”), Olivia was a “shell company” (as defined in Rule 12b-2 of the Securities Exchange Act of 1934, as amended). The Company is subject to risks and uncertainties common to companies in the biotechnology and pharmaceutical industries. There can be no assurance that the Company’s research and development will be successfully completed, that adequate protection for the Company’s technology will be obtained, that any products developed will obtain necessary government regulatory approval or that any approved products will be commercially viable. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies. In addition, the Company is dependent upon the services of its employees and consultants. In the opinion of management, the accompanying unaudited condensed consolidated financial statements include all normal and recurring adjustments (which consist primarily of accruals, estimates and assumptions that impact the financial statements) considered necessary to present fairly the Company’s financial position as of September 30, 2021 and its results of operations and changes in convertible preferred stock and stockholders’ equity (deficit) for the three and nine months ended September 30, 2021 and 2020 and cash flows for the nine months ended September 30, 2021 and 2020. Operating results for the nine months ended September 30, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. The unaudited condensed consolidated financial statements include the accounts of Compass Therapeutics, Inc. and its subsidiaries, and have been prepared by the Company in conformity with accounting principles generally accepted in the United States of America (“GAAP”) and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”) for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The condensed consolidated balance sheet at December 31, 2020 has been derived from the audited consolidated financial statements at that date, but does not include all of the information and footnotes required by GAAP for complete financial statements. Accordingly, these condensed consolidated financial statements should be read in conjunction with the Company’s audited financial statements in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 (the “Annual Report”). Liquidity Since our inception, we have devoted substantially all of our efforts to organizing and staffing our Company, business planning, raising capital, research and development activities, building our intellectual property portfolio and providing general and administrative support for these operations. To date, we have funded our operations primarily with proceeds from the sale of our equity securities and borrowings from debt arrangements. Through September 30, 2021, we have received $ 132.0 million in gross proceeds from the sale of equity securities and $ 15.0 million in term loan borrowings under the Credit Facility. Following the completion of the Merger, we completed a private placement of our common stock and received net proceeds of $ 54.2 million. As of September 30, 2021, we had cash and cash equivalents of $ 25.5 million. In November 2021, the Company completed an underwritten public offering which raised a net of $ 117.3 million (see footnote 13). Based on our research and development plans, we expect that such cash resources will enable us to fund our operating expenses and capital expenditure requirements through the fourth quarter of 2024. COVID-19 Update We have been carefully monitoring the COVID-19 pandemic and its potential impact on our business and have taken important steps to help ensure the safety of our employees and to reduce the spread of COVID-19 community-wide. We are ensuring that essential staffing levels at our operations remain in place, including maintaining key personnel in our laboratory facilities. We have implemented stringent safety measures designed to create a safe and clean environment for our employees as we continue to comply with applicable federal, state and local guidelines instituted in response to the COVID-19 pandemic. We have been able to continue to pursue patient dosing and monitoring of our Phase 1 clinical trial of CTX-471 without significant delays. However, we have experienced increased delays in patient enrollment in several of our trial sites. In order to address the reduction in patient enrollment, we have added additional sites. In addition, there have been delays in sourcing of selected supplies required for the manufacturing of material to be used in our future clinical trials, and these delays have impacted and may continue to impact the timing of our future clinical trials. We expect that COVID-19 may continue to directly or indirectly impact (i) our employees and business operations or personnel at third-party suppliers and other vendors in the U.S. and other countries; (ii) the availability, cost or supply of materials; and (iii) the timeline for our ongoing clinical trial and potential future trials. We are continuing to assess the potential impact of the COVID-19 pandemic on our current and future business and operations, including our expenses and clinical trials, as well as on our industry and the healthcare system.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies There have been no material changes to the significant accounting policies previously disclosed in the Company’s Annual Report, except as noted below. Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016‑02, Leases , which requires a lessee to record a right‑of‑use asset and a corresponding lease liability on the balance sheet for all leases with terms longer than 12 months. A modified retrospective transition approach is required, applying the new standard to all leases existing at the date of initial application. An entity may choose to use either (1) its effective date or (2) the beginning of the earliest comparative period presented in the condensed consolidated financial statements as its date of initial application. If an entity chooses the second option, the transition requirements for existing leases also apply to leases entered into between the date of initial application and the effective date. The Company adopted this standard on January 1, 2021. See Note 7 for additional details on the Company’s accounting for leases. Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12"), which is intended to simplify the accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. The new standard will be effective beginning January 1, 2022 . The Company does not expect the adoption of ASU 2019-12 to have a material impact on its financial position and results of operations upon adoption.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair Value Measurements The following tables present information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements as of September 30, 2021 Using: Quoted Prices Significant Significant Fair Value Assets Cash equivalents - money market $ 24,474 $ — $ — $ 24,474 Total assets $ 24,474 $ — $ — $ 24,474 Fair Value Measurements as of December 31, 2020 Using: Quoted Prices Significant Significant Fair Value Assets Cash equivalents - money market $ 43,631 $ — $ — $ 43,631 Total assets $ 43,631 $ — $ — $ 43,631

Property and Equipment

Property and Equipment	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Property and Equipment	4. Property and Equipment Property and equipment consist of the following (in thousands): September 30, December 31, Equipment $ 5,351 $ 5,356 Software 364 180 Leasehold improvements 600 896 Furniture and fixtures 22 629 Total property and equipment–at cost 6,337 7,061 Less: Accumulated depreciation ( 4,902 ) ( 5,935 ) Property and equipment, net $ 1,435 $ 1,126 Total depreciation expense for three months ended September 30, 2021 and 2020 was $ 0.1 million and $ 0.4 million, respectively. Total depreciation expense for nine months ended September 30, 2021 and 2020 was $ 0.4 million and $ 1.3 million, respectively.

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Accrued Expenses	5. Accrued Expenses Accrued expenses consist of the following (in thousands): September 30, December 31, 2021 2020 Compensation and benefits $ 799 $ 976 Research and development expenses 734 212 Leasehold improvements 320 - Legal and professional fees 75 326 Other 70 57 Total accrued expenses $ 1,998 $ 1,571

Debt

Debt	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Debt	6. Debt The aggregate principal amount of debt outstanding consisted of the following (in thousands): September 30, December 31, 2021 2020 Current portion of debt $ 3,750 $ 7,500 Less: unamortized debt discount ( 6 ) ( 33 ) Current portion of debt, net of debt $ 3,744 $ 7,467 Long-term debt, net of current portion $ — $ 1,875 Less: unamortized debt discount — ( 8 ) Long-term debt, net of current portion $ — $ 1,867 The Company entered into, and subsequently amended, a term loan facility with Pacific Western Bank, Inc. (the “Credit Facility”), and received $ 15.0 million debt proceeds. The loan bears interest at the greater of (i) 6.25 % and (ii) the prime rate plus an applicable margin of 2.0 %. The interest rate was 6.25 % at September 30, 2021. In an event of default, as defined in the Credit Facility, the interest rate applicable to borrowings would be increased by 5.0 %. The Company made interest-only payments through March 31, 2020. In April 2020 , the Company became obligated to make equal monthly principal payments of $ 625,000 through March 31, 2022 when the notes mature. The Credit Facility allows for prepayment of the outstanding principal at any time, subject to a prepayment charge that is dependent on the prepayment date. The Credit Facility agreement contains a provision whereby the Company was obligated to pay a success fee of $ 1.1 million upon the achievement of certain liquidity events. Upon consummation of the Merger, the Company success fee payment became due and was paid in its entirety in September 2020. The Credit Facility contains a negative pledge on the Company’s intellectual property and also contains customary indemnification obligations and customary events of default, including, among other things, (i) non‑payment, (ii) breach of warranty, (iii) non‑performance of covenants and obligations, (iv) default on other indebtedness, (v) judgments, (iv) change of control, (vii) bankruptcy and insolvency, (viii) impairment of security, (ix) key permit events, (x) key person event, (xi) regulatory matters, and (xii) key contracts. In addition, the Company must maintain a minimum cash balance of $ 6.0 million beginning in April 2020. In the event of default under the Credit Facility, the Company would be required to pay interest on principal and all other due and unpaid obligations at the current rate in effect plus 5 %. The borrowings are collateralized by substantially all of the Company’s assets, excluding intellectual property, and contains affirmative and negative covenants including restrictions on the Company’s ability to incur additional indebtedness, pay dividends, encumber its property, or engage in certain fundamental business transactions, such as mergers or acquisitions of other businesses. The Company was in compliance with its covenants as of September 30, 2021. The Company recognized interest expense of $ 0.1 million and $ 0.2 million during the three months ended September 30, 2021 and 2020, respectively. The Company recognized interest expense of $ 0.3 million and $ 0.7 million during the nine months ended September 30, 2021 and 2020, respectively. As of September 30, 2021, the aggregate minimum future principal payments due in connection with the Credit Facility, as amended, are as follows (in thousands): Year Ending December 31, 2021 $ 1,875 2022 1,875 Total $ 3,750

Leases

Leases	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Leases	7. Leases The Company adopted ASU 2016-02, Leases (Topic 842) , or ASU 2016-02, effective January 1, 2021, using the modified retrospective transition method, in which the new standard is applied as of the date of initial adoption. The Company recognized and measured agreements executed prior to the date of initial adoption that were considered leases on January 1, 2021. No cumulative effect adjustment of initially applying the standard to the opening balance of retained earnings was made upon adoption. The Company elected the package of practical expedients permitted under the transition guidance that will retain the lease classification and initial direct costs for any leases that exist prior to adoption of the standard. In addition, the Company elected the accounting policy of not recording short-term leases with a lease term at the commencement date of 12 months or less on the condensed consolidated balance sheet as permitted by the new standard. The Company has evaluated its leases and determined that it has one lease that is classified as an operating lease. The classification of this lease is consistent with the Company’s determination under the previous accounting standard. When available, the Company will use the rate implicit in the lease to discount lease payments to present value; however, the Company’s current lease does not provide an implicit rate. Therefore, the Company used its incremental borrowing rate to discount the lease payments based on the date of the lease commencement. The Company has one operating lease for its corporate office and laboratory facility (“Facility”) that was signed in December 2020. The Company moved into the Facility in January 2021. The Facility lease has an initial term of four years and five months , beginning on January 1, 2021. The Facility lease contains scheduled rent increases over the lease term. The discount rate used for the Facility lease is 6.25 %, and the remaining lease term of the Facility lease is three years and eight months as of September 30, 2021. The table below presents the undiscounted cash flows for the lease term. The undiscounted cash flows are reconciled to the operating lease liabilities recorded on the condensed consolidated balance sheet: (000's) Remainder of 2021 $ 429 Years ending December 31, 2022 1,315 2023 1,348 2024 1,382 2025 426 Total minimum lease payments 4,900 Less: amount of lease payments representing interest ( 499 ) Present value of future minimum lease payments 4,401 Less: operating lease obligations, current portion ( 1,073 ) Operating lease obligations, long-term portion $ 3,328

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	8. Stock-Based Compensation In June 2020, the Company’s board of directors adopted the 2020 Stock Option and Incentive Plan (the “2020 Plan”) and reserved 2.93 million shares of common stock for issuance under this plan. The 2020 Plan includes automatic annual increases. The increase on January 1, 2021 was 2.08 million shares. As of September 30, 2021, 1.5 million shares remain available for future grant. The 2020 Plan authorizes the board of directors or a committee of the board to grant incentive stock options, nonqualified stock options and restricted stock awards to eligible officers, employees, consultants and directors of the Company. Options generally vest over a period of four years and have a contractual life of ten years from the date of grant. Stock-based compensation expense for the nine months ended September 30, 2021 and 2020 was classified in the condensed consolidated statement of operations as follows: Nine Months Ended September 30, 2021 2020 (000’s) Research and development $ 476 $ 486 General and administrative 2,367 2,480 Total $ 2,843 $ 2,966 As of September 30, 2021, remaining unrecognized compensation cost related to options and restricted stock awards to be recognized in future periods totaled $ 8.6 million. Restricted Stock Prior to the adoption of the 2020 Plan, the Company issued restricted stock. A summary of the Company’s restricted stock activity during the nine months ended September 30, 2021 is as follows: Shares Fair Value Weighted Average Fair Value (000’s) Per Share Unvested, December 31, 2020 896 $ 1.78 Granted — $ — Vested ( 273 ) $ 1.82 Forfeited or canceled ( 63 ) $ 1.62 Unvested, September 30, 2021 560 $ 1.78 As of September 30, 2021, the total unrecognized compensation cost related to stock compensation expense for restricted stock is $ 1.0 million, expected to be recognized over a weighted average period of 1.9 years. Stock Options The following table summarizes the stock option activity for the 2020 Plan: Weighted Weighted Number of Average Average Unvested Exercise Remaining Options Price Contractual (000’s) Per Share Life (in years) Outstanding at December 31, 2020 2,159 $ 5.00 9.1 Granted 1,647 $ 5.15 9.5 Exercise — $ 5.00 — Forfeited/cancelled ( 286 ) $ 5.00 — Outstanding at September 30, 2021 3,520 $ 5.07 9.2 Vested at September 30, 2021 1,208 $ 5.00 8.9 For the nine months ended September 30, 2021, the weighted average grant date fair value for options granted was $ 3.82 . There was no intrinsic value for options vested and outstanding as of September 30, 2021. As of September 30, 2021, stock option expense for options is expected to be recognized over a weighted average period of 2.9 years. As of September 30, 2021, the total unrecognized compensation cost related to outstanding options was $ 7.6 million, expected to be recognized over a weighted average period of 2.1 years. The total unrecognized compensation cost related to outstanding restricted stock and stock options was $ 8.6 million. For the nine months ended September 30, 2020, the weighted average grant date fair value for options granted was $ 3.42 . There was no intrinsic value for options vested and outstanding as of and for the nine months ended September 30, 2020. The weighted average assumptions used in the Black-Scholes pricing model to determine the fair value of stock options granted during the nine months ended September 30, 2021 and 2020 were as follows: Nine Months Ended September 30, 2021 2020 Expected term (in years) 6.1 6.0 Risk-free rate 0.79 % 0.36 % Expected volatility 90 % 140 %

Merger Transaction

Merger Transaction	9 Months Ended
	Sep. 30, 2021
Business Combinations [Abstract]
Merger Transaction	9. Merger Transaction On May 11, 2021 the Company and Trigr Therapeutics, Inc. (“TRIGR”), a private biotechnology company, entered into a definitive merger agreement (the “Merger Agreement”). Pursuant to the Merger Agreement, the Company, through its wholly owned subsidiaries and a two-step merger structure, acquired all of the outstanding shares of TRIGR (the “TRIGR Merger”). On June 25, 2021, the TRIGR Merger was consummated. Consideration payable to TRIGR shareholders at closing totaled an aggregate of 10,265,133 shares of the Company’s common stock with a fair value of $ 50.3 million (after giving effect to elimination of fractional shares that would otherwise be issued). In addition, TRIGR shareholders are eligible to receive up to $ 9.0 million, representing earnout payments based on three independent events. The first potential earnout payment is $ 2.0 million related to a milestone payment under the Elpiscience agreement, due to the Company upon IND approval of CTX-009 in China, and remitted to the TRIGR shareholders. The Company will act as a conduit to this transaction and will remit to the former TRIGR shareholders up to $2 million related to this milestone payment received from Elpiscience. The second potential earnout payment of $ 2 million is contingent upon the Company entering into a regional license agreement with a specific third party. Since the Company has not entered into a regional license agreement with that third party and assesses the probability of reaching such agreement with that party to be low, no provision is being made. The third and last potential earnout is $ 5 million which is dependent on the Company successfully filing a biologics license application and being granted marketing approval for the product candidate acquired in the transaction, CTX-009. As CTX-009 is in early clinical development and the clinical development of CTX-009 and regulatory strategy are subject to substantial risk, it is not probable that this payment will be made and as such, no provision is being made. To determine whether the transaction meets the definition of a business acquisition or an asset acquisition in accordance with ASC 805-10-55, we had to assess the nature of the transaction and the fair value of the assets acquired in the transaction. Our assessment suggest that the fair value of the transaction is substantially concentrated in a license to a single identifiable asset, CTX-009, and a potential financial interest (in the form of royalties) in an additional set of early-stage similar assets. The guidance further requires a business acquisition to include, at a minimum, an input and a substantive process that together significantly contribute to the ability to create outputs. Because all asset acquisitions include inputs, the existence of a substantive process is what distinguishes a business acquisition from an asset acquisition. Our assessment is that there is no process or outputs that are being acquired with the TRIGR acquisition. As a result, the TRIGR acquisition is considered to fall under the guidance of an asset acquisition rather than a business acquisition. Accordingly, the Company allocated the $ 50.3 million transaction amount and $ 0.3 million of transaction costs to the acquired license. As the license is considered in-process R&D, the Company expensed the acquired asset on the transaction date.

Related Parties and Related-Par

Related Parties and Related-Party Transactions	9 Months Ended
	Sep. 30, 2021
Related Party Transactions [Abstract]
Related Parties and Related-Party Transactions	10. Related Parties and Related-Party Transactions On October 16, 2014, the Company entered into a collaboration agreement with Adimab, LLC. The Company’s co-founder has a direct ownership interest in Adimab, LLC. The Company recorded no research and development expenses in connection with this agreement during the nine months ended September 30, 2021 and 2020. In connection with the acquisition of TRIGR and upon consummation of the merger agreement on June 25, 2021, Miranda Toledano, who previously served as the Chief Financial Officer and Chief Operating Officer of TRIGR, was appointed to Compass Board of Directors as an independent director. Additionally, to facilitate the transition of CTX-009 from TRIGR, the Company entered into a consulting agreement with Ms. Toledano on June 25, 2021 for a period of six months.

Other Expense

Other Expense	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Other Expense	11. Other Expense Other income and expense consisted of the following: Three Months Ended Nine Months Ended September 30, September 30, 2021 2020 2021 2020 (000's) (000's) Interest income $ 1 $ 22 $ 25 $ 70 Interest expense ( 78 ) ( 212 ) ( 331 ) ( 730 ) Change in fair value of derivative liability — — — ( 556 ) Other income (expenses) ( 44 ) 1 — 1 Total other income (expenses) $ ( 121 ) $ ( 189 ) $ ( 306 ) $ ( 1,215 )

License, Research and Collabora

License, Research and Collaboration Agreements	6 Months Ended
	Jun. 30, 2021
License Research And Collaboration Agreements [Abstract]
License, Research and Collaboration Agreements	12. License, Research and Collaboration Agreements Collaboration Agreements ABL Bio Corporation ("ABL Bio") Agreements In November 2018, the Company's wholly owned subsidiary TRIGR and ABL Bio, a South Korean biotechnology company, entered into an exclusive global (excluding South Korea) license agreement (the “TRIGR License Agreement”) which granted TRIGR a license to ABL001, ABL Bio’s bispecific antibody targeting DLL4 and VEGF-A (renamed CTX-009). Under the terms of the agreement, ABL Bio and TRIGR would jointly develop CTX-009, with ABL Bio responsible for development of CTX-009 throughout the end of Phase 1 clinical trials and TRIGR responsible for the development of CTX-009 from Phase 2 and onward. ABL Bio received a $ 5 million upfront payment and is eligible to receive up to $ 110 million of development and regulatory milestone payments, up to $ 295 million of commercial milestone payments and tiered single-digit royalties on net sales of CTX-009 in Oncology. ABL Bio is also eligible to receive up to $ 185 million in development, regulatory and commercial milestone payments and tiered, single-digit royalties on net sales of CTX-009 in Ophthalmology. The financial terms of the agreement were amended in May 2021 but remain substantially similar to the terms in the TRIGR License Agreement. As a result of the TRIGR acquisition in 2021, the TRIGR License Agreement was assigned to the Company and the Company has assumed all the rights and liabilities of the agreement. See Note 9 for further information on the TRIGR transaction. In May 2021, TRIGR and ABL Bio terminated license agreements to several preclinical assets. As a result of the return of these assets to ABL Bio and termination of the license agreements, the Company is eligible to receive royalty payments if ABL Bio develops or licensees two bispecific antibodies (ABL101 and ABL103) that were previously licensed to TRIGR. Adimab Agreement The Company entered into a collaboration agreement with Adimab, LLC on October 16, 2014 . The agreement includes provisions for payment of royalties at rates ranging in the single digits as a percentage of future net sales within a specified term from the first commercial sale. There were no milestone payments made during the first nine months of 2021. As of September 30, 2021, future potential milestone payments in connection with this agreement amounted to $ 2.0 million. Other License and Research Agreements FUJIFILM Diosynth Biotechnologies ("Fujifilm") Agreement The Company entered into a scope of work (“SOW”) under a master services agreement with Fujifilm on July 20, 2020. The Company made cash payments of $ 0.1 million and recorded $ 25 thousand in research and development expense during the three months ended September 30, 2021 related to this agreement. The Company made cash payments of $ 1.3 million and recorded approximately $ 1.0 million in research and development expense during the nine months ended September 30, 2021 related to this agreement. As of September 30, 2021, future payments in connection with the SOW amounted to $ 1.2 million and prepayments for future work to be performed amounted to $ 1.8 million, for a total expense to be recognized of $ 3.0 million.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	13. Subsequent events On November 1, 2021, the Company announced that it priced an underwritten public offering (the "Offering") to sell 35,715,000 shares of common stock at a public offering price of $ 3.50 per share. In addition, the Company granted the underwriters a 30 -day option to purchase up to an additional 5,357,250 shares of common stock at the Offering price, less the underwriting discount. In connection with the Offering, the Company also announced that its common stock would begin trading on the Nasdaq Capital Market under the symbol “CMPX” at the opening of trading on November 2, 2021. The Offering closed on November 4, 2021. The Company received net proceeds from the Offering, after deducting the underwriting discounts and commissions and other estimated offering expenses payable by the Company, of approximately $ 117.3 million. On November 8, 2021, the Company paid off the balance of its notes, and terminated the Credit Facility (see Note 6). After this pay off, the Company has no additional debt facilities.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2021
Accounting Policies [Abstract]
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In February 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016‑02, Leases , which requires a lessee to record a right‑of‑use asset and a corresponding lease liability on the balance sheet for all leases with terms longer than 12 months. A modified retrospective transition approach is required, applying the new standard to all leases existing at the date of initial application. An entity may choose to use either (1) its effective date or (2) the beginning of the earliest comparative period presented in the condensed consolidated financial statements as its date of initial application. If an entity chooses the second option, the transition requirements for existing leases also apply to leases entered into between the date of initial application and the effective date. The Company adopted this standard on January 1, 2021. See Note 7 for additional details on the Company’s accounting for leases.
Recently Accounting Pronouncements	Recent Accounting Pronouncements In December 2019, the FASB issued ASU No. 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes ("ASU 2019-12"), which is intended to simplify the accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. The new standard will be effective beginning January 1, 2022 . The Company does not expect the adoption of ASU 2019-12 to have a material impact on its financial position and results of operations upon adoption.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities are Measured at Fair Value on Recurring Basis	The following tables present information about the Company’s financial assets and liabilities that are measured at fair value on a recurring basis and indicate the level of the fair value hierarchy utilized to determine such fair values (in thousands): Fair Value Measurements as of September 30, 2021 Using: Quoted Prices Significant Significant Fair Value Assets Cash equivalents - money market $ 24,474 $ — $ — $ 24,474 Total assets $ 24,474 $ — $ — $ 24,474 Fair Value Measurements as of December 31, 2020 Using: Quoted Prices Significant Significant Fair Value Assets Cash equivalents - money market $ 43,631 $ — $ — $ 43,631 Total assets $ 43,631 $ — $ — $ 43,631

Property and Equipment (Tables)

Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment	Property and equipment consist of the following (in thousands): September 30, December 31, Equipment $ 5,351 $ 5,356 Software 364 180 Leasehold improvements 600 896 Furniture and fixtures 22 629 Total property and equipment–at cost 6,337 7,061 Less: Accumulated depreciation ( 4,902 ) ( 5,935 ) Property and equipment, net $ 1,435 $ 1,126

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2021
Payables and Accruals [Abstract]
Components of Accrued Expenses	Accrued expenses consist of the following (in thousands): September 30, December 31, 2021 2020 Compensation and benefits $ 799 $ 976 Research and development expenses 734 212 Leasehold improvements 320 - Legal and professional fees 75 326 Other 70 57 Total accrued expenses $ 1,998 $ 1,571

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of Aggregate Principal Amount of Debt Outstanding	The aggregate principal amount of debt outstanding consisted of the following (in thousands): September 30, December 31, 2021 2020 Current portion of debt $ 3,750 $ 7,500 Less: unamortized debt discount ( 6 ) ( 33 ) Current portion of debt, net of debt $ 3,744 $ 7,467 Long-term debt, net of current portion $ — $ 1,875 Less: unamortized debt discount — ( 8 ) Long-term debt, net of current portion $ — $ 1,867
Schedule of Aggregate Minimum Future Principal Payments	As of September 30, 2021, the aggregate minimum future principal payments due in connection with the Credit Facility, as amended, are as follows (in thousands): Year Ending December 31, 2021 $ 1,875 2022 1,875 Total $ 3,750

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2021
Leases [Abstract]
Schedule of Undiscounted Cash Flows Reconciled to Operating Lease Liabilities	The table below presents the undiscounted cash flows for the lease term. The undiscounted cash flows are reconciled to the operating lease liabilities recorded on the condensed consolidated balance sheet: (000's) Remainder of 2021 $ 429 Years ending December 31, 2022 1,315 2023 1,348 2024 1,382 2025 426 Total minimum lease payments 4,900 Less: amount of lease payments representing interest ( 499 ) Present value of future minimum lease payments 4,401 Less: operating lease obligations, current portion ( 1,073 ) Operating lease obligations, long-term portion $ 3,328

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense for the nine months ended September 30, 2021 and 2020 was classified in the condensed consolidated statement of operations as follows: Nine Months Ended September 30, 2021 2020 (000’s) Research and development $ 476 $ 486 General and administrative 2,367 2,480 Total $ 2,843 $ 2,966
Schedule of Restricted Share Activity	A summary of the Company’s restricted stock activity during the nine months ended September 30, 2021 is as follows: Shares Fair Value Weighted Average Fair Value (000’s) Per Share Unvested, December 31, 2020 896 $ 1.78 Granted — $ — Vested ( 273 ) $ 1.82 Forfeited or canceled ( 63 ) $ 1.62 Unvested, September 30, 2021 560 $ 1.78
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Schedule of Weighted Average Assumptions on Grant Date Fair Value for Options Granted	The weighted average assumptions used in the Black-Scholes pricing model to determine the fair value of stock options granted during the nine months ended September 30, 2021 and 2020 were as follows: Nine Months Ended September 30, 2021 2020 Expected term (in years) 6.1 6.0 Risk-free rate 0.79 % 0.36 % Expected volatility 90 % 140 %
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Summary of Stock Option Activity	The following table summarizes the stock option activity for the 2020 Plan: Weighted Weighted Number of Average Average Unvested Exercise Remaining Options Price Contractual (000’s) Per Share Life (in years) Outstanding at December 31, 2020 2,159 $ 5.00 9.1 Granted 1,647 $ 5.15 9.5 Exercise — $ 5.00 — Forfeited/cancelled ( 286 ) $ 5.00 — Outstanding at September 30, 2021 3,520 $ 5.07 9.2 Vested at September 30, 2021 1,208 $ 5.00 8.9

Other Expense (Tables)

Other Expense (Tables)	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Schedule of Other Income and Expense	Other income and expense consisted of the following: Three Months Ended Nine Months Ended September 30, September 30, 2021 2020 2021 2020 (000's) (000's) Interest income $ 1 $ 22 $ 25 $ 70 Interest expense ( 78 ) ( 212 ) ( 331 ) ( 730 ) Change in fair value of derivative liability — — — ( 556 ) Other income (expenses) ( 44 ) 1 — 1 Total other income (expenses) $ ( 121 ) $ ( 189 ) $ ( 306 ) $ ( 1,215 )

Nature of Business and Basis _2

Nature of Business and Basis of Presentation - Additional Information (Details) - USD ($) $ in Thousands	Nov. 01, 2021	Sep. 30, 2021	Dec. 31, 2020
Class Of Stock [Line Items]
Entity incorporation, date of incorporation		Mar. 20, 2018
Gross proceeds from the sale of equity securities		$ 132,000
Debt proceeds		15,000
Cash and cash equivalents		25,509	$ 47,076
Subsequent Event
Class Of Stock [Line Items]
Proceeds from underwritten public offering	$ 117,300
Private Placement Offering | Common Stock
Class Of Stock [Line Items]
Net proceeds from private placement		$ 54,200

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - ASU 2016-02	Sep. 30, 2021
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adopted	true
Change in accounting principle, accounting standards update, adoption date	Jan. 1, 2022

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities are Measured at Fair Value on Recurring Basis (Details) - Fair Value Measurements Recurring - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Assets
Total assets	$ 24,474	$ 43,631
Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Total assets	24,474	43,631
Significant Other Observable Inputs (Level 2)
Assets
Total assets	0	0
Significant Unobservable Inputs (Level 3)
Assets
Total assets	0	0
Money Market
Assets
Cash equivalents - money market	24,474	43,631
Money Market | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets
Cash equivalents - money market	24,474	43,631
Money Market | Significant Other Observable Inputs (Level 2)
Assets
Cash equivalents - money market	0	0
Money Market | Significant Unobservable Inputs (Level 3)
Assets
Cash equivalents - money market	$ 0	$ 0

Property and Equipment - Schedu

Property and Equipment - Schedule of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	$ 6,337	$ 7,061
Less: Accumulated depreciation	(4,902)	(5,935)
Property and equipment, net	1,435	1,126
Equipment
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	5,351	5,356
Software
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	364	180
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	600	896
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment–at cost	$ 22	$ 629

Property and Equipment - Additi

Property and Equipment - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Property, Plant and Equipment [Abstract]
Depreciation	$ 0.1	$ 0.4	$ 0.4	$ 1.3

Accrued Expenses - Components o

Accrued Expenses - Components of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Payables and Accruals [Abstract]
Compensation and benefits	$ 799	$ 976
Research and development expenses	734	212
Leasehold Improvements	320	0
Legal and professional fees	75	326
Other	70	57
Total accrued expenses	$ 1,998	$ 1,571

Debt - Schedule of Aggregate Pr

Debt - Schedule of Aggregate Principal Amount of Debt Outstanding (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Debt Disclosure [Abstract]
Current portion of debt	$ 3,750	$ 7,500
Less: unamortized debt discount	(6)	(33)
Current portion of debt, net of debt discount	3,744	7,467
Long-term debt, net of current portion	0	1,875
Less: unamortized debt discount	0	(8)
Long-term debt, net of current portion	$ 0	$ 1,867

Debt - Additional Information (

Debt - Additional Information (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Debt proceeds			$ 15,000,000
Credit Facility | Pacific Western Bank, Inc
Debt Instrument [Line Items]
Debt proceeds			$ 15,000,000
Debt instrument, interest rate	6.25%		6.25%
Debt instrument, interest rate during period			6.25%
Increase in interest rate in case of default			5.00%
Term loan facility payment terms			The Company made interest-only payments through March 31, 2020. In April 2020, the Company became obligated to make equal monthly principal payments of $625,000 through March 31, 2022 when the notes mature.
Frequency of periodic payment			monthly
Date of first required payment			2020-04
Equal monthly principal payments			$ 625,000
Debt instrument, maturity date			Mar. 31, 2022
Success fee payment due	$ 1,100,000		$ 1,100,000
Minimum cash balance	$ 6,000,000		$ 6,000,000
Debt instrument, interest rate, effect plus percentage	5.00%		5.00%
Interest expense	$ 100,000	$ 200,000	$ 300,000	$ 700,000
Prime Rate | Credit Facility | Pacific Western Bank, Inc
Debt Instrument [Line Items]
Debt instrument, applicable margin interest rate			2.00%

Debt - Schedule of Aggregate Mi

Debt - Schedule of Aggregate Minimum Future Principal Payments (Details) - Credit Facility $ in Thousands	Sep. 30, 2021USD ($)
Debt Instrument [Line Items]
2021	$ 1,875
2022	1,875
Long-term debt	$ 3,750

Leases - Additional Information

Leases - Additional Information (Details)	9 Months Ended
	Sep. 30, 2021Leases
Leases [Abstract]
Number of operating lease	1
Operating lease initial term	4 years 5 months
Discount rate	6.25%
Operating lease remaining lease term	3 years 8 months

Leases - Schedule of Undiscount

Leases - Schedule of Undiscounted Cash Flows Reconciled to Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Leases [Abstract]
Remainder of 2021	$ 429
2022	1,315
2023	1,348
2024	1,382
2025	426
Total minimum lease payments	4,900
Less: amount of lease payments representing interest	(499)
Present value of future minimum lease payments	4,401
Less: operating lease obligations, current portion	(1,073)	$ 0
Operating lease obligations, long-term portion	$ 3,328	$ 0

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, shares in Thousands	Jan. 01, 2021	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020	Jun. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested stock expected to be recognized over a weighted-average period		2 years 10 months 24 days
Weighted average grant date fair value for options granted		$ 3.82	$ 3.42
Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost relating to unvested restricted stock awards		$ 8,600,000
Unvested stock expected to be recognized over a weighted-average period		1 year 10 months 24 days
Unrecognized compensation cost relating to stock compensation expense for restricted stock awards, total		$ 1,000,000
Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested stock expected to be recognized over a weighted-average period		2 years 1 month 6 days
Aggregate intrinsic value for options vested and outstanding		$ 0	$ 0
Unrecognized compensation cost relating to outstanding options		7,600,000
Restricted stock and Stock options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation cost relating to outstanding options		$ 8,600,000
2020 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of common stock reserved for issuance					2,930
Automatic increases common stock for issuance	2,080
Number of common stock reserved for issuance		1,500
Stock options, vesting period		4 years
Stock options, contractual life		10 years
2020 Plan | Stock Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, contractual life		9 years 2 months 12 days		9 years 1 month 6 days
Stock options granted		1,647

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,843	$ 2,966
Research and Development
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	476	486
General and Administrative
Employee Service Share Based Compensation Allocation of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 2,367	$ 2,480

Stock-Based Compensation - Sc_2

Stock-Based Compensation - Schedule of Restricted Share Activity (Details) - Restricted Stock shares in Thousands	9 Months Ended
	Sep. 30, 2021$ / sharesshares
Shares
Unvested at the beginning | shares	896
Unvested, Granted | shares	0
Unvested, Vested | shares	(273)
Unvested, Forfeited or canceled | shares	(63)
Unvested at the ending | shares	560
Estimated Fair Value Per Share
Unvested at the beginning | $ / shares	$ 1.78
Unvested, Granted | $ / shares	0
Unvested, Vested | $ / shares	1.82
Unvested, Forfeited or canceled | $ / shares	1.62
Unvested at the ending | $ / shares	$ 1.78

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Stock Option Activity (Details) - 2020 Plan - $ / shares shares in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Weighted Average Remaining Contractual Life (in years)
Outstanding, Weighted Average Remaining Contractual Life	10 years
Stock Options
Number of Unvested Options
Outstanding at December 31, 2020	2,159
Granted	1,647
Exercise	0
Forfeited/cancelled	(286)
Outstanding at September 30, 2021	3,520	2,159
Vested at September 30, 2021	1,208
Weighted Average Exercise Price Per Share
Outstanding at December 31, 2020	$ 5
Granted	5.15
Exercise	5
Forfeited/cancelled	5
Outstanding at September 30, 2021	5.07
Vested at September 30, 2021	$ 5
Weighted Average Remaining Contractual Life (in years)
Outstanding, Weighted Average Remaining Contractual Life	9 years 2 months 12 days	9 years 1 month 6 days
Granted , Weighted Average Remaining Contractual Life	9 years 6 months
Vested, Weighted Average Remaining Contractual Life at September 30, 2021	8 years 10 months 24 days

Stock-Based Compensation - Sc_3

Stock-Based Compensation - Schedule of Weighted Average Assumptions on Grant Date Fair Value for Options Granted (Details) - Stock Options	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected term (in years)	6 years 1 month 6 days	6 years
Risk-free rate	0.79%	0.36%
Expected volatility	90.00%	140.00%

Merger Transaction - Additional

Merger Transaction - Additional Information (Details) - TRIGR [Member] - USD ($)	Jun. 25, 2021	May 11, 2021	Sep. 30, 2021
Business Acquisition [Line Items]
Merger date		May 11, 2021
Stock issued on merger	10,265,133
Maximum eligible earnout payment	$ 9,000,000
Earnout payment to third party	2,000,000
Provision of earnout payment for third party	0
Business Combination, Consideration Transferred			$ 50,300,000
In Process Research and Development [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred			50,300,000
Legal Fees			$ 300,000
CTX OO9 [Member]
Business Acquisition [Line Items]
Earnout payment on license application approval	5,000,000
Provisions for earnout payment for license application approval	0
Elpiscience [Member]
Business Acquisition [Line Items]
Earnout payment on license application approval	$ 2,000,000

Related Parties and Related-P_2

Related Parties and Related-Party Transactions - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Adimab, LLC | Collaboration Agreement
Related Party Transaction [Line Items]
Research and development expense	$ 0	$ 0

Other Expense - Schedule of Oth

Other Expense - Schedule of Other Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Income and Expenses [Abstract]
Interest income	$ 1	$ 22	$ 25	$ 70
Interest expense	(78)	(212)	(331)	(730)
Change in fair value of derivative liability		0	0	(556)
Other income		1	0	1
Other (expenses)	(44)
Total other income (expenses)	$ (121)	$ (189)	$ (306)	$ (1,215)

License, Research and Collabo_2

License, Research and Collaboration Agreements - Additional Information (Details)	3 Months Ended	9 Months Ended
	Sep. 30, 2021USD ($)	Sep. 30, 2021USD ($)
ABL Bio Corporation Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received		$ 5,000,000
ABL Bio Corporation Agreements | Oncology
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Eligible to receive development milestone payments		110,000,000
Eligible to receive commercial milestone payments		295,000,000
ABL Bio Corporation Agreements | Ophthalmology
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Milestone payment and royalties received		$ 185,000,000
Adimab Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Collaboration agreement date		Oct. 16, 2014
Milestone payments		$ 0
Future milestone payments	$ 2,000,000	2,000,000
FUJIFILM Diosynth Biotechnologies ("Fujifilm") Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Future milestone payments	1,200,000	1,200,000
Prepayments for future work		1,800,000
Total expense to be recognized		3,000,000
Cash payment for license agreement	100,000	1,300,000
Research and development	$ 25,000	$ 1,000,000

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) - Subsequent Event $ / shares in Units, $ in Millions	Nov. 01, 2021USD ($)$ / sharesshares
Subsequent Event [Line Items]
Common shares issued under initial public offering	35,715,000
Public offering price per share | $ / shares	$ 3.50
Option to underwriter to purchase additional shares of common stock	5,357,250
Initial public offering description	common stock would begin trading on the Nasdaq Capital Market under the symbol “CMPX” at the opening of trading on November 2, 2021. The Offering closed on November 4, 2021.
Proceeds from the Offering, net of underwriting discounts and commissions and other offering expenses | $	$ 117.3
Granted period to purchase option	30 days