Marker Therapeutics (MRKR) 10-Q 12 May 22 2022 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2022	May 01, 2022
Cover
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Entity File Number	001-37939
Document Period End Date	Mar. 31, 2022
Entity Registrant Name	MARKER THERAPEUTICS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-4497941
Entity Address, Address Line One	3200 Southwest Freeway
Entity Address, Address Line Two	Suite 2500
Entity Address, City or Town	Houston
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	77027
City Area Code	713
Local Phone Number	400-6400
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	MRKR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		83,599,187
Entity Central Index Key	0001094038
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($)	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 28,637,217	$ 42,351,145
Restricted cash	181,864	1,146,186
Prepaid expenses and deposits	2,196,225	2,484,634
Other receivables	2,185	237
Total current assets	31,017,491	45,982,202
Non-current assets:
Property, plant and equipment, net	10,276,936	10,096,861
Construction in progress	4,089,135	2,225,610
Right-of-use assets, net	9,572,572	9,830,461
Total non-current assets	23,938,643	22,152,932
Total assets	54,956,134	68,135,134
Current liabilities:
Accounts payable and accrued liabilities	7,348,680	11,134,913
Lease liability	683,969	620,490
Deferred Revenue	181,864	1,146,186
Total current liabilities	8,214,513	12,901,589
Non-current liabilities:
Lease liability, net of current portion	11,035,857	11,247,950
Total non-current liabilities	11,035,857	11,247,950
Total liabilities	19,250,370	24,149,539
Stockholders' equity:
Preferred stock - $0.001 par value, 5 million shares authorized and 0 shares issued and outstanding at March 31, 2022 and December 31,2021, respectively
Common stock, $0.001 par value, 150 million shares authorized, 83.5 million and 83.1 million shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	83,451	83,079
Additional paid-in capital	443,651,176	442,020,871
Accumulated deficit	(408,028,863)	(398,118,355)
Total stockholders' equity	35,705,764	43,985,595
Total liabilities and stockholders' equity	$ 54,956,134	$ 68,135,134

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares shares in Millions	Mar. 31, 2022	Dec. 31, 2021
CONDENSED CONSOLIDATED BALANCE SHEETS
Preferred stock par value	$ 0.001	$ 0.001
Preferred stock shares authorized	5	5
Preferred stock issued	0	0
Preferred stock outstanding	0	0
Common stock shares par value	$ 0.001	$ 0.001
Common stock shares authorized	150	150
Common stock shares issued	83.5	83.1
Common stock shares outstanding	83.5	83.1

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenues:
Total revenues	$ 964,322
Operating expenses:
Research and development	7,026,066	$ 5,643,029
General and administrative	3,733,001	3,137,958
Total operating expenses	10,759,067	8,780,987
Loss from operations	(9,794,745)	(8,780,987)
Other income (expenses):
Arbitration settlement	(118,880)
Interest income	3,117	1,537
Net loss	$ (9,910,508)	$ (8,779,450)
Net loss per share, basic	$ (0.12)	$ (0.16)
Net loss per share, diluted	$ (0.12)	$ (0.16)
Weighted average number of common shares outstanding, basic	83,107,649	56,470,247
Weighted average number of common shares outstanding, diluted	83,107,649	56,470,247
Grant income
Revenues:
Total revenues	$ 964,322

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($)	Common Stock	Additional Paid- in Capital	Accumulated Deficit	Total
Beginning Balance at Dec. 31, 2020	$ 50,731	$ 383,533,326	$ (356,239,484)	$ 27,344,573
Beginning Balance, Shares at Dec. 31, 2020	50,731,072
Issuance of common stock for cash (net of offering cost of $3.9 million)	$ 32,283	52,520,475		52,552,758
Issuance of common stock for cash (net of offering cost of $3.9 million), Shares	32,282,857
Stock-based compensation	$ 0	1,377,038	0	1,377,038
Stock-based compensation (in shares)	0
Net loss	$ 0	0	(8,779,450)	(8,779,450)
Ending Balance at Mar. 31, 2021	$ 83,014	437,430,839	(365,018,934)	72,494,919
Ending Balance, Shares at Mar. 31, 2021	83,013,929
Beginning Balance at Dec. 31, 2021	$ 83,079	442,020,871	(398,118,355)	43,985,595
Beginning Balance, Shares at Dec. 31, 2021	83,078,675
Stock-based compensation	$ 372	1,630,305	0	1,630,677
Stock-based compensation (in shares)	372,512
Net loss	$ 0	0	(9,910,508)	(9,910,508)
Ending Balance at Mar. 31, 2022	$ 83,451	$ 443,651,176	$ (408,028,863)	$ 35,705,764
Ending Balance, Shares at Mar. 31, 2022	83,451,187

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical) $ in Millions	3 Months Ended
	Mar. 31, 2021USD ($)
CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY
Offering costs	$ 3.9

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash Flows from Operating Activities:
Net loss	$ (9,910,508)	$ (8,779,450)
Reconciliation of net loss to net cash used in operating activities:
Depreciation and amortization	576,331	502,743
Stock-based compensation	1,630,677	1,377,038
Amortization of right-of-use assets	257,889	251,626
Changes in operating assets and liabilities:
Prepaid expenses and deposits	288,409	95,000
Other receivables	(1,948)	(308)
Accounts payable and accrued expenses	(3,953,976)	(1,482,473)
Deferred revenue	(964,322)	0
Lease liability	(148,614)	(64,329)
Net cash used in operating activities	(12,226,062)	(8,100,153)
Cash Flows from Investing Activities:
Purchase of property and equipment	(826,583)	(442,277)
Cash used for construction in progress	(1,625,605)	(958,965)
Net cash used in investing activities	(2,452,188)	(1,401,242)
Cash Flows from Financing Activities:
Proceeds from issuance of common stock, net	0	52,656,588
Net cash provided by financing activities	0	52,656,588
Net (decrease) increase in cash, cash equivlants and restricted cash	(14,678,250)	43,155,193
Cash, cash equivalents and restricted cash at beginning of the period	43,497,331	21,352,382
Cash, cash equivalents and restricted cash at end of the period	28,819,081	64,507,575
Supplemental schedule of non-cash financing and investing activities:
Offering cost not yet paid	0	103,830
Reclassifications between construction in progress and fixed assets	0	6,789,098
Capital expenditures included in accounts payable	$ 2,328,499	$ 220,168

NATURE OF OPERATIONS

NATURE OF OPERATIONS	3 Months Ended
	Mar. 31, 2022
NATURE OF OPERATIONS
NATURE OF OPERATIONS	NOTE 1: NATURE OF OPERATIONS Marker Therapeutics, Inc., a Delaware corporation (the “Company” or “we”), is a clinical-stage immuno-oncology company specializing in the development and commercialization of novel T cell-based immunotherapies and innovative peptide-based vaccines for the treatment of hematological malignancies and solid tumor indications. The Company’s MultiTAA T cell technology is based on the selective expansion of non-engineered, tumor-specific T cells that recognize tumor associated antigens, which are tumor targets, and kill tumor cells expressing those targets. These T cells are designed to recognize multiple tumor targets to produce broad spectrum anti-tumor activity.

BASIS OF PRESENTATION

BASIS OF PRESENTATION	3 Months Ended
	Mar. 31, 2022
BASIS OF PRESENTATION
BASIS OF PRESENTATION	NOTE 2: BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with the accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and pursuant to the instructions to Form 10-Q and Article 8 of Regulation S-X of the Securities and Exchange Commission (“SEC”) and on the same basis as the Company prepares its annual audited consolidated financial statements. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments, consisting of normal recurring adjustments, considered necessary for a fair presentation of such interim results. The results for the condensed consolidated statement of operations are not necessarily indicative of results to be expected for the year ending December 31, 2022 or for any future interim period. The condensed consolidated balance sheet at March 31, 2022 has been derived from unaudited financial statements; however, it does not include all of the information and notes required by U.S. GAAP for complete financial statements. The accompanying condensed consolidated financial statements should be read in conjunction with the consolidated financial statements for the year ended December 31, 2021 and notes thereto included in the Company’s annual report on Form 10-K filed on March 17, 2022.

LIQUIDITY , GOING CONCERN AND F

LIQUIDITY , GOING CONCERN AND FINANCIAL CONDITION	3 Months Ended
	Mar. 31, 2022
LIQUIDITY , GOING CONCERN AND FINANCIAL CONDITION
LIQUIDITY , GOING CONCERN AND FINANCIAL CONDITION	NOTE 3: LIQUIDITY , GOING CONCERN AND FINANCIAL CONDITION As of March 31, 2022, the Company had cash, cash equivalents and restricted cash of approximately $28.8 million. The Company’s activities since inception have consisted principally of acquiring product and technology rights, raising capital, and performing research and development. Successful completion of the Company’s development programs and, ultimately, the attainment of profitable operations are dependent on future events, including, among other things, its ability to access potential markets; secure financing; successfully progress its product candidates through preclinical and clinical development; obtain regulatory approval of one or more of its product candidates; maintain and enforce intellectual property rights; develop a customer base; attract, retain and motivate qualified personnel; and develop strategic alliances and collaborations. From inception, the Company has been funded by a combination of equity and debt financings. In August 2021, the Company entered into a Controlled Equity Offering Sales Agreement (the “ATM Agreement”) with Cantor Fitzgerald & Co. and RBC Capital Markets, LLC (the “Sales Agents”), pursuant to which the Company can offer and sell, from time to time at its sole discretion through the Sales Agents, shares of its common stock having an aggregate offering price of up to $75.0 million. Any shares of its common stock sold will be issued pursuant to the Company’s shelf registration statement on Form S-3 (File No. 333-258687), which the SEC declared effective on August 19, 2021. The shelf registration statement on Form S-3 includes a prospectus supplement covering the offering up to $19.8 million of shares of common stock over the 12 months ending March 18, 2023 in accordance with the ATM agreement. The Sales Agents will be entitled to compensation under the Sales Agreement at a commission rate equal to 3.0% of the gross sales price per share sold under the ATM Agreement, and the Company has provided each of the Sales Agents with indemnification and contribution rights. From April 1, 2022 to the date of this filing, the Company sold 148,000 shares of its common stock under the ATM Agreement for net proceeds of $63,600. In August 2021, the Company received notice of a Product Development Research award totaling approximately $13.1 million from the Cancer Prevention and Research Institute of Texas (“CPRIT”) to support the Company's Phase 2 clinical trial of its lead MultiTAA-specific T cell product MT-401. The CPRIT award is intended to support the adjuvant arm of the Company's Phase 2 clinical trial evaluating MT-401 when given as an adjuvant therapy to patients with acute myeloid leukemia following a hematopoietic stem cell transplant. The primary objectives of the adjuvant arm of the trial are to evaluate relapse-free survival after MT-401 treatment when compared with a randomized control group. To date, the Company has received $2.4 million of funds from the CPRIT grant. On April 21, 2022, the Company entered into a binding services agreement (the “Agreement”), effective April 12, 2022, with Wilson Wolf Manufacturing Corporation (“Wilson Wolf”). Wilson Wolf is in the business of creating products and services intended to simply and expedite the transition of cell therapies and gene-modified cell therapies to mainstream society (the “Wilson Wolf Mission”). Pursuant to the Agreement, Wilson Wolf made a cash payment to the Company in the amount of $8.0 million. The Company expects to continue to incur substantial losses over the next several years during its development phase. To fully execute its business plan, the Company will need to complete certain research and development activities and clinical trials. Further, the Company’s product candidates will require regulatory approval prior to commercialization. These activities will span many years and require substantial expenditures to complete and may ultimately be unsuccessful. Any delays in completing these activities could adversely impact the Company. The Company plans to meet its capital requirements primarily through issuances of debt and equity securities and, in the longer term, revenue from sales of its product candidates, if approved. Based on the Company’s clinical and research and development plans and its timing expectations related to the progress of its programs, the Company expects that its cash, cash equivalents and restricted cash as of March 31, 2022 will enable the Company to fund its operating expenses and capital expenditure requirements into the second quarter of 2023. The Company has based this estimate on assumptions that may prove to be wrong, and the Company could utilize its available capital resources sooner than it currently expects. Furthermore, the Company’s operating plan may change, and it may need additional funds sooner than planned in order to meet operational needs and capital requirements for product development and commercialization. Because of the numerous risks and uncertainties associated with the development and commercialization of the Company’s product candidates and the extent to which the Company may enter into additional collaborations with third parties to participate in their development and commercialization, the Company is unable to estimate the amounts of increased capital outlays and operating expenditures associated with its current and anticipated clinical trials. The Company’s future funding requirements will depend on many factors, as it: ● initiates or continues clinical trials of its product candidates; ● continues the research and development of its product candidates and seeks to discover additional product candidates; ● seeks regulatory approvals for any product candidates that successfully complete clinical trials; ● maintains and enforces intellectual property rights; ● establishes sales, marketing and distribution infrastructure and scale-up manufacturing capabilities to commercialize any product candidates that may receive regulatory approval; ● evaluates strategic transactions the Company may undertake; and ● enhances operational, financial and information management systems and hires additional personnel, including personnel to support development of product candidates and, if a product candidate is approved, commercialization efforts. We have no sources of revenue to provide incoming cash flows to sustain our future operations. As outlined above, our ability to pursue our planned business activities is dependent upon our successful efforts to raise additional capital. These factors raise substantial doubt regarding our ability to continue as a going concern. Our condensed consolidated financial statements have been prepared on a going concern basis, which implies that we will continue to realize our assets and discharge our liabilities in the normal course of business. Our financial statements do not include any adjustments to the recoverability and classification of recorded asset amounts and classification of liabilities that might be necessary should we be unable to continue as a going concern. In addition to the foregoing, based on the Company’s current assessment, the Company does not expect any material impact on its long-term liquidity due to the COVID-19 pandemic. However, the Company will continue to assess the effect of the pandemic on its operations, including its clinical programs. The extent to which the COVID-19 pandemic will impact the Company’s business and operations will depend on future developments that are highly uncertain and cannot be predicted with confidence, such as the geographic spread of the disease, the duration of the outbreak, the emergence of any new variant strains of COVID-19, the duration and effect of any future business disruptions in the United States and other countries to contain and treat the disease and the rate of public acceptance and efficacy of vaccines and other treatments. Further, disruption of global financial markets and a recession or market correction, including as a result of the COVID-19 pandemic and other global macroeconomic factors, could reduce the Company’s ability to access capital, which could in the future negatively affect the Company’s liquidity and could materially affect the Company’s business and the value of its common stock. On February 16, 2022, the Company received a notice from The Nasdaq Stock Market that the Company was not in compliance with Nasdaq’s Listing Rule 5450(a)(1), as the minimum bid price of its common stock had been below $1.00 per share for 30 consecutive business days. The Company has 180 calendar days, or until August 15, 2022, to regain compliance with the minimum bid price requirement. To regain compliance, the minimum bid price of the Company’s common stock must meet or exceed $1.00 per share for a minimum of ten consecutive business days during this 180-calendar day grace period. In the event the Company does not regain compliance with the minimum bid price requirement by August 15, 2022, the Company may be eligible for an additional 180-calendar day compliance period if it elects to transfer to the Nasdaq Capital Market to take advantage of the additional compliance period offered on that market. To qualify, the Company would be required to meet the continued listing requirement for market value of publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the bid price requirement, and would need to provide written notice of its intention to cure the bid price deficiency during the second compliance period.

SIGNIFICANT ACCOUNTING POLICIES

SIGNIFICANT ACCOUNTING POLICIES	3 Months Ended
	Mar. 31, 2022
SIGNIFICANT ACCOUNTING POLICIES
SIGNIFICANT ACCOUNTING POLICIES	NOTE 4: SIGNIFICANT ACCOUNTING POLICIES Prior Period Reclassification Certain reclassifications have been made to reclass certain non-cash capital expenditures on the condensed consolidated statements of cash flows from a cash outflow from investing activity to a non-cash investing activity. The Company has evaluated the materiality of this adjustment and concluded it was not material to the previously issued consolidated financial statements and had no impact to the reported condensed consolidated balance sheets, consolidated statements of operations or net loss per share. For the three months ended March 31, 2021, this immaterial adjustment had the effect of decreasing net cash used in operating activities and increasing net cash used in investing activities by $1.0 million from what was previously reported. Property and equipment - Construction in Progress During the third and fourth quarters of 2021, and in connection with the Company’s manufacturing facility in Houston, Texas, the Company incurred $2.2 million of costs pursuant to an agreement with a vendor to build and eventually install a second modular cleanroom. Additionally, during the first quarter of 2022, the Company incurred $1.9 million of costs related to the second modular cleanroom. Such costs were recorded in fixed assets – construction in progress on the balance sheet as of March 31, 2022. Upon completion and installation of the modular cleanroom, all costs associated with the buildout will be recorded as manufacturing equipment and amortized over the estimated useful life. Grant Income The Company recognizes grant income in accordance with the terms stipulated under the grant awarded to the Company’s collaborators at the Mayo Foundation from the U. S. Department of Defense. In various situations, the Company receives certain payments from the Mayo Foundation for reimbursement of clinical supplies. These payments are non-refundable and are not dependent on the Company’s ongoing future performance. The Company has adopted a policy of recognizing these payments when received and as revenue in accordance with Accounting Standards Update No. 2014 09, “Revenue from Contracts with Customers (Topic 606)” issued by FASB. In August 2021, the Company received notice of a Product Development Research award totaling approximately $13.1 million from CPRIT to support the Phase 2 clinical trial of MT-401. In accordance with ASC 730-20-25-8, the extent the financial risk associated with the research and development has been transferred to CPRIT, because repayment of the grant depends solely on the results of research and development having future economic benefit, the Company accounts for this obligation as a contract to perform research and development for others. The funds received from CPRIT will initially be recorded as a deferred credit in the Company’s balance sheet. Restricted cash received from grants in advance of incurring qualifying costs is recorded as deferred revenue and recognized as revenue when qualifying costs are incurred. The Company recorded $1.0 million of grant income related to the CPRIT grant as revenue for the three months ended March 31, 2022. At March 31, 2022, $0.2 million was recorded as restricted cash and deferred revenue on the Company’s condensed consolidated financial statements. New Accounting Standards From time to time, new accounting pronouncements are issued by FASB or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed, the Company does not believe that the impact of recently issued standards that are not yet effective will have a material impact on its consolidated financial position or results of operations upon adoption.

NET LOSS PER SHARE

NET LOSS PER SHARE	3 Months Ended
	Mar. 31, 2022
NET LOSS PER SHARE
NET LOSS PER SHARE	NOTE 5: NET LOSS PER SHARE Basic loss per common share is computed by dividing net loss by the weighted average number of common shares outstanding during the reporting period. Diluted loss per common share is computed similarly to basic loss per common share except that it reflects the potential dilution that could occur if dilutive securities or other obligations to issue common stock were exercised or converted into common stock. The following table sets forth the computation of net loss per share for the three months ended March 31, 2022 and 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Numerator: ​ ​ ​ ​ ​ ​ Net loss ​ $ (9,910,508) ​ $ (8,779,450) ​ ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ Weighted average common shares outstanding ​ 83,107,649 ​ 56,470,247 ​ ​ ​ ​ ​ ​ ​ Net loss per share: ​ ​ ​ ​ Basic and diluted ​ $ (0.12) ​ $ (0.16) ​ The following securities, rounded to the nearest thousand, were not included in the diluted net loss per share calculation because their effect was anti-dilutive for the periods presented: ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Common stock options 9,389,000 7,490,000 Common stock purchase warrants 19,830,000 20,830,000 Potentially dilutive securities 29,219,000 28,320,000 ​

PROPERTY AND EQUIPMENT

PROPERTY AND EQUIPMENT	3 Months Ended
	Mar. 31, 2022
PROPERTY AND EQUIPMENT.
PROPERTY AND EQUIPMENT	NOTE 6: PROPERTY AND EQUIPMENT Property and equipment consist of the following as of March 31, 2022 and December 31, 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ Estimated Useful Lives 2022 2021 Lab and manufacturing equipment ​ 5 Years ​ $ 8,460,000 ​ $ 7,851,000 Computers, equipment and software 3-5 Years ​ ​ 1,064,000 ​ ​ 1,020,000 Office furniture 5 Years ​ 896,000 ​ 793,000 Leasehold improvements ​ Lesser of lease term or estimated useful life ​ ​ 3,173,000 ​ ​ 3,173,000 Total ​ ​ 13,593,000 ​ ​ 12,837,000 Less: accumulated depreciation ​ (3,316,000) ​ (2,740,000) Construction in progress ​ ​ ​ ​ 4,089,000 ​ ​ 2,226,000 Total fixed assets, net ​ $ 14,366,000 ​ $ 12,323,000 ​ During the third and fourth quarters of 2021, and in connection with the Company’s manufacturing facility in Houston, Texas, the Company incurred $2.2 million of costs pursuant to an agreement with a vendor to build and eventually install a second modular cleanroom. Additionally, during the first quarter of 2022, the Company incurred $1.9 million of costs related to the second modular cleanroom. Such costs were recorded in fixed assets – construction in progress on the balance sheet as of March 31, 2022. Upon completion and installation of the modular cleanroom, all costs associated with the buildout will be recorded as manufacturing equipment and amortized over the estimated useful life. Depreciation expense for the three months ended March 31, 2022 and 2021 was approximately $0.6 million and $0.5 million, respectively. $2.3 million of property and equipment transactions are included in accounts payable and accrued liabilities as of March 31, 2022.

LEASES

LEASES	3 Months Ended
	Mar. 31, 2022
LEASES
LEASES	NOTE 7: LEASES The Company leases manufacturing, research and administrative facilities under operating leases. The Company evaluates its contracts to determine if an arrangement is a lease at inception and classify it as a finance or operating lease. Currently, all of the Company’s leases are classified as operating leases. Leased assets and corresponding liabilities are recognized based on the present value of the lease payments over the lease term. The lease terms may include options to extend when it is reasonably certain that the Company will exercise that option. Topic ASC 842 requires the Company to recognize in the statement of financial position a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. Right-of-use assets are recorded in other assets on the Company’s condensed consolidated balance sheets. Current and non-current lease liabilities are recorded in other accruals within current liabilities and other non-current liabilities, respectively, on its condensed consolidated balance sheets. Costs associated with operating leases are recognized on a straight-line basis within operating expenses over the term of the lease. As of March 31, 2022, the Company had total operating lease liabilities of approximately $11.7 million and right-of-use assets of approximately $9.6 million, which were included in the condensed consolidated balance sheet. Such leases do not require any contingent rental payments, impose any financial restrictions, or contain any residual value guarantees. Certain of the Company’s leases include renewal options and escalation clauses; renewal options have not been included in the calculation of the lease liabilities and right-of-use assets as the Company is not reasonably certain to exercise the options. Variable expenses generally represent the Company’s share of the landlord’s operating expenses. The Company does not act as a lessor or have any leases classified as financing leases. The following summarizes quantitative information about the Company’s operating leases for the three months ended March 31, 2022 and 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Operating lease expense summary: ​ ​ ​ Operating lease expense ​ $ 425,000 ​ $ 425,000 Short-term lease expense ​ 3,000 ​ — Variable lease expense ​ 179,000 ​ 133,000 Total ​ $ 607,000 ​ $ 558,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ ​ 2022 ​ 2021 Other information: ​ ​ Operating cash flows - operating leases ​ $ 316,000 ​ $ 238,000 ​ The weighted-average remaining lease term as of March 31, 2022 and December 31, 2021 was approximately 8.2 years and 8.4 years, respectively. The weighted-average discount rate used to determine the operating lease liability as of March 31, 2022 and December 31, 2021 was approximately 5.7%. Maturities of our operating leases, excluding short-term leases, are as follows: ​ ​ ​ ​ ​ Nine months ending December 31, 2022 $ 961,000 Year ended December 31, 2023 ​ 1,542,000 Year ended December 31, 2024 ​ 1,826,000 Year ended December 31, 2025 ​ 1,874,000 Year ended December 31, 2026 ​ ​ 1,775,000 Thereafter ​ ​ 6,997,000 Total ​ ​ 14,975,000 Less present value discount ​ (3,255,000) Operating lease liabilities included in the Condensed Consolidated Balance Sheet at March 31, 2022 ​ $ 11,720,000 ​

ACCOUNTS PAYABLE AND ACCRUED LI

ACCOUNTS PAYABLE AND ACCRUED LIABILITIES	3 Months Ended
	Mar. 31, 2022
ACCOUNTS PAYABLE AND ACCRUED LIABILITIES
ACCOUNTS PAYABLE AND ACCRUED LIABILITIES	NOTE 8: ACCOUNTS PAYABLE AND ACCRUED LIABILITIES Accounts payable and accrued liabilities consist of the following as of March 31, 2021 and December 31, 2021, respectively: ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2022 ​ 2021 Accounts payable ​ $ 5,016,000 ​ $ 5,144,000 Compensation and benefits ​ 747,000 ​ 2,055,000 Process development expenses ​ ​ 500,000 ​ ​ 385,000 Professional fees ​ 595,000 ​ 644,000 Technology license fees ​ 250,000 ​ 250,000 Arbitration settlement fees ​ — ​ 2,407,000 Other ​ 241,000 ​ 250,000 Total accounts payable and accrued liabilities ​ $ 7,349,000 ​ $ 11,135,000 ​

STOCKHOLDERS' EQUITY

STOCKHOLDERS' EQUITY	3 Months Ended
	Mar. 31, 2022
STOCKHOLDERS' EQUITY
STOCKHOLDERS' EQUITY	NOTE 9: STOCKHOLDERS’ EQUITY Common Stock Transactions Issuance of Restricted Stock Units to Executives During the three months ended March 31, 2022, upon the recommendation of the compensation committee and pursuant to the Company’s 2020 Equity Incentive Plan, the Company’s board of directors approved the issuance of a total of 372,512 shares of common stock subject to restricted stock units, which were immediately vested upon grant, to certain executives as performance bonuses for 2021 performance Share Purchase Warrants A summary of the Company’s share purchase warrants as of March 31, 2022 and changes during the period is presented below: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ ​ Number of ​ Weighted Average ​ Remaining Contractual ​ Total Intrinsic ​ Warrants Exercise Price Life (in years) Value Balance - January 1, 2022 19,830,000 ​ $ 4.42 ​ 1.70 ​ $ — Warrants granted ​ — ​ ​ — ​ — ​ ​ — Expired or cancelled ​ — ​ ​ — ​ — ​ — Balance - March 31, 2022 ​ 19,830,000 ​ ​ 4.42 ​ 1.46 ​ ​ — ​

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	3 Months Ended
	Mar. 31, 2022
STOCK-BASED COMPENSATION
STOCK-BASED COMPENSATION	NOTE 10: STOCK-BASED COMPENSATION Stock Options 2022 Equity Incentive Awards On February 17, 2022, pursuant to the Company’s 2020 Equity Incentive Plan, the compensation committee of the Company’s board of directors approved a total of 1,250,000 options to purchase the Company’s common stock as equity-based incentive awards to the Company’s executive officers. Each option award was granted with an exercise price of $0.46 per share, the closing price of the Company’s common stock on the Nasdaq Global Market on February 17, 2022, with the option award vesting in 48 equal monthly installments over a four-year period, subject to such executive officer’s continued service on the applicable vesting date. Additionally, on February 17, 2022, the compensation committee of the Company’s board of directors approved a total of 395,000 options to purchase the Company’s common stock to non-executive employees of the Company as equity-based incentive awards. Each option award was granted with an exercise price of $0.46 per share, the closing price of the Company’s common stock on the Nasdaq Global Market on February 17, 2022, with the option award vesting in 48 equal monthly installments over a four-year period, subject to such employee’s continued service on the applicable vesting date. The above awards were in addition to 175,000 stock option awards issued during the three months ended March 31, 2021 to new employees upon their commencement of employment with the Company. Each option award was granted with an exercise price of $1.00 per share, the closing price of the Company's common stock on the Nasdaq Global Market on January 3, 2022, with 25% of the option award vesting in one year and the remaining 75% vesting in 36 equal monthly installments thereafter over a three-year period, subject to such employee’s continued service on the applicable vesting date. A summary of the Company’s stock option activity for the three months ended March 31, 2022 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Remaining ​ ​ ​ ​ Weighted Average ​ Total Intrinsic ​ Contractual ​ Number of Shares Exercise Price Value Life (in years) Outstanding as of January 1, 2022 7,686,233 ​ $ 5.47 ​ $ — ​ 7.7 Granted 1,820,000 ​ ​ 0.51 ​ ​ — ​ 9.8 Canceled/Expired (117,082) ​ ​ 2.60 ​ ​ — ​ — Outstanding as of March 31, 2022 9,389,151 ​ $ 4.54 ​ $ — ​ 7.9 Options vested and exercisable 4,798,325 ​ $ 6.48 ​ $ — ​ 7.1 ​ The Black-Scholes option pricing model is used to estimate the fair value of stock options granted under the Company’s share-based compensation plans. The weighted average assumptions used in calculating the fair values of stock options that were granted during the three months ended March 31, 2022 was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, 2022 Exercise price ​ $ 0.51 ​ Expected term (years) ​ 6.0 ​ Expected stock price volatility ​ 84 % Risk-free rate of interest ​ 2 % Expected dividend rate ​ 0 % ​ The following table sets forth stock-based compensation expenses recorded during the respective periods: ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Stock Compensation expenses: ​ ​ Research and development ​ $ 878,000 ​ $ 696,000 General and administrative ​ 753,000 ​ 681,000 Total stock compensation expenses ​ $ 1,631,000 ​ $ 1,377,000 ​ As of March 31, 2022, the total stock-based compensation cost related to unvested awards not yet recognized was $7.6 million. The expected weighted average period compensation costs to be recognized was approximately 1.9 years. Future option grants will impact the compensation expense recognized.

GRANT INCOME

GRANT INCOME	1 Months Ended
	Jan. 31, 2022
GRANT INCOME.
GRANT INCOME	NOTE 11: GRANT INCOME In August 2021, the Company received notice of a Product Development Research award totaling approximately $13.1 million from CPRIT to support the Company's Phase 2 clinical trial of MT-401. The CPRIT award is intended to support the adjuvant arm of the Company's Phase 2 clinical trial evaluating MT-401 when given as an adjuvant therapy to patients with acute myeloid leukemia following a hematopoietic stem cell transplant. The primary objectives of the adjuvant arm of the trial are to evaluate relapse-free survival after MT-401 treatment when compared with a randomized control group. During the fourth quarter of 2021, the Company received $2.4 million advancement of funds in relation to the CPRIT grant. The Company recorded $1.0 million of grant income related to the CPRIT grant as revenue for the three months ended March 31, 2022. At March 31, 2022, $0.2 million was recorded as Restricted Cash and Deferred

LEGAL PROCEEDINGS

LEGAL PROCEEDINGS	1 Months Ended
	Jan. 31, 2022
LEGAL PROCEEDINGS
LEGAL PROCEEDINGS	NOTE 12: LEGAL PROCEEDINGS From time to time, the Company may be party to ordinary, routine litigation incidental to their business. The Company knows of no material, active or pending legal proceedings against the Company, nor is the Company involved as a plaintiff in any material proceeding or pending litigation. There are no proceedings in which any of the Company’s directors, officers or affiliates, or any registered or beneficial shareholder, is an adverse party or has a material interest adverse to the Company’s interest. An arbitration proceeding was brought against the Company before the Financial Industry Regulatory Authority, Inc. (“FINRA”) by a broker seeking to be paid compensation for two financing transactions that occurred in 2018, a warrant conversion and a private placement brokered by another broker. The broker’s claims were based on a placement agent agreement for a private placement it brokered in 2017, under which it alleged it was entitled to compensation for the 2018 transactions. The FINRA panel found in favor of the broker and awarded the broker $2.4 million for compensation, interest and attorney fees. As of December 31, 2021, the Company recorded an accrual of $2.4 million in accrued liabilities on its consolidated balance sheet and a $2.4 million charge to other expenses. On September 17, 2021, the broker filed a petition to confirm the FINRA arbitration award in the Supreme Court of New York for the County of New York. The Company removed the case to the United States District Court for the Southern District of New York on September 27, 2021. On October 22, 2021, the Company filed a motion in federal court to vacate the award. On March 9, 2022, the Company was notified that its motion to vacate the award was denied and the broker was awarded an additional $0.1 million in interest. Post judgment interest accrued at 1.02% until the judgement was paid. The Company paid the $2.5 million judgement on March 24, 2022.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	3 Months Ended
	Mar. 31, 2022
RELATED PARTY TRANSACTIONS
RELATED PARTY TRANSACTIONS	NOTE 13: RELATED PARTY TRANSACTIONS The following table sets forth related party transaction expenses recorded for the three months ended March 31, 2022 and 2021, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Baylor College of Medicine ​ $ 856,000 ​ $ 422,000 Bio-Techne Corporation ​ ​ 101,000 ​ ​ 46,000 Wilson Wolf Manufacturing Corporation ​ ​ 55,000 ​ ​ 34,000 Total Research and development ​ $ 1,012,000 $ 502,000 ​ $0.9 million of related party transactions are included in accounts payable and accrued liabilities as of March 31, 2022. Agreements with The Baylor College of Medicine (“BCM”) . In November 2018, January 2020 and February 2020, the Company entered in Sponsored Research Agreements with BCM, which provided for the conduct of research for the Company by credentialed personnel at BCM’s Center for Cell and Gene Therapy. In September 2019, May 2020 and July 2021, the Company entered into Clinical Supply Agreements with BCM, which provided for BCM to provide to the Company multi tumor antigen specific products. In October 2019, the Company entered in a Workforce Grant Agreement with BCM, which provided for BCM to provide to the Company manpower costs of projects for manufacturing, quality control testing and validation run activities. In August 2020, the Company entered in a Clinical Trial Agreement with BCM, which provided for BCM to provide to the Company investigator-initiated research studies. The Company has also entered into a Clinical Site Agreement with BCM, which provided for BCM to conduct clinical trials for the Company. Purchases from Bio-Techne Corporation . The Company is currently utilizing Bio-Techne Corporation and two of its brands for the purchases of reagents, primarily cytokines. Mr. David Eansor is a member of the Company’s board of directors and was serving as the President of the Protein Sciences Segment of Bio-Techne Corporation. Mr. Eansor resigned from Bio-Techne Corporation on March 1. 2022, and as such, two months of transactions in 2022 are included in the table above. Purchases from Wilson Wolf Manufacturing Corporation . The Company is currently utilizing Wilson Wolf Manufacturing Corporation for the purchases of cell culture devices called G-Rexes. Mr. John Wilson is a member of the Company’s board of directors and is serving as the CEO of Wilson Wolf Manufacturing Corporation. Wilson Wolf Manufacturing became a related party during fiscal year 2021 due to the amounts of the Company’s purchases and as such, $34,000 of purchases for the period ended March 31, 2021 were included in the table above.

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	1 Months Ended
	Jan. 31, 2022
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	NOTE 14: SUBSEQUENT EVENTS On April 21, 2022, the Company entered into a binding services agreement (the “Agreement”), effective April 12, 2022, with Wilson Wolf Manufacturing Corporation (“Wilson Wolf”). Wilson Wolf is in the business of creating products and services intended to simply and expedite the transition of cell therapies and gene-modified cell therapies to mainstream society (the “Wilson Wolf Mission”). Pursuant to the Agreement, Wilson Wolf made a cash payment to the Company in the amount of $8.0 million, allocated as follows: ● $2.0 million as a prepaid expense for non-exclusive training of Wilson Wolf to make, use, and sell Marker’s cell culture non-proprietary media formulation that has been cleared in an FDA investigational new drug application in pursuit of the Wilson Wolf Mission; ● $1.0 million as a prepaid expense for non-exclusive training of Wilson Wolf to replicate Marker’s quality management system inclusive of all underlying documents related thereto, none of which shall include unique information specific to the manufacture of Marker’s MultiTAA product candidates such as direct peptide stimulation, which Wilson Wolf shall use as it sees fit in pursuit of the Wilson Wolf Mission; ● $2.0 million as a prepaid expense for non-exclusive training of Wilson Wolf to be able to replicate Marker’s cGMP-compliant, linearly scalable, G-Rex based T-cell manufacturing process which Wilson Wolf shall use as it sees fit in pursuit of the Wilson Wolf Mission; and ● $3.0 million as a prepaid expense under the hired to invent doctrine for Marker to train Wilson Wolf on its expertise in the optimization of T-cell therapy manufacturing processes using G-Rex and to conduct CAR T and TCR G-Rex Optimization Work under the direction of Wilson Wolf (the “Work Direction”), whereunder all intellectual property provided by Wilson Wolf or created or derived by Marker will be solely owned by Wilson Wolf, and whereby Marker will make good faith efforts to complete the conduct of such work as soon as practicable within 18 months from the date of the agreement. Wilson Wolf has agreed to pay Marker an additional $1.0 million if the Work Direction is completed within one year from the onset of the Agreement. The Agreement shall continue until the fulfillment of all of Marker’s obligations set forth in the Agreement or in any mutually agreed upon subsequent agreements. All intellectual property created or derived under the Work Direction will be owned by Wilson Wolf. The Agreement contains certain representations made by Marker, as well as a mutual confidentiality provision and an indemnification provision by Wilson Wolf in favor of Marker. Pursuant to the Agreement, in the event that Marker becomes insolvent, goes out of business, or an event other than force majeure occurs that cannot allow the Agreement to be fulfilled, Wilson Wolf will have right of first offer and right of first refusal for Marker’s manufacturing facility provided it is able and willing to meet whatever financial obligations are required to do so and provided further that such clause will not apply in the event of a merger, reorganization or consolidation of Marker with a third party that results in the outstanding voting securities of Marker immediately prior thereto ceasing to represent, or being converted into or exchanged for voting securities that do not represent, at least fifty percent (50%) of the combined voting power of the voting securities of the surviving entity or the parent corporation of the surviving entity immediately after such merger, reorganization or consolidation, or the sale or other transfer of all or substantially all of Marker’s business or assets. Marker agrees to assist as needed to the extent permitted under any applicable law (including bankruptcy or insolvency statutes). Further, prior to Marker undertaking any financing that would encumber any of Marker’s assets necessary for Marker’s performance under this Agreement, Wilson Wolf shall have the first right to provide such financing on equal terms to what Marker can obtain elsewhere.

SIGNIFICANT ACCOUNTING POLICI_2

SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2022
SIGNIFICANT ACCOUNTING POLICIES
Prior Period Reclassification	Prior Period Reclassification Certain reclassifications have been made to reclass certain non-cash capital expenditures on the condensed consolidated statements of cash flows from a cash outflow from investing activity to a non-cash investing activity. The Company has evaluated the materiality of this adjustment and concluded it was not material to the previously issued consolidated financial statements and had no impact to the reported condensed consolidated balance sheets, consolidated statements of operations or net loss per share. For the three months ended March 31, 2021, this immaterial adjustment had the effect of decreasing net cash used in operating activities and increasing net cash used in investing activities by $1.0 million from what was previously reported.
Property and equipment - Construction in Progress	Property and equipment - Construction in Progress During the third and fourth quarters of 2021, and in connection with the Company’s manufacturing facility in Houston, Texas, the Company incurred $2.2 million of costs pursuant to an agreement with a vendor to build and eventually install a second modular cleanroom. Additionally, during the first quarter of 2022, the Company incurred $1.9 million of costs related to the second modular cleanroom. Such costs were recorded in fixed assets – construction in progress on the balance sheet as of March 31, 2022. Upon completion and installation of the modular cleanroom, all costs associated with the buildout will be recorded as manufacturing equipment and amortized over the estimated useful life.
Grant Income	Grant Income The Company recognizes grant income in accordance with the terms stipulated under the grant awarded to the Company’s collaborators at the Mayo Foundation from the U. S. Department of Defense. In various situations, the Company receives certain payments from the Mayo Foundation for reimbursement of clinical supplies. These payments are non-refundable and are not dependent on the Company’s ongoing future performance. The Company has adopted a policy of recognizing these payments when received and as revenue in accordance with Accounting Standards Update No. 2014 09, “Revenue from Contracts with Customers (Topic 606)” issued by FASB. In August 2021, the Company received notice of a Product Development Research award totaling approximately $13.1 million from CPRIT to support the Phase 2 clinical trial of MT-401. In accordance with ASC 730-20-25-8, the extent the financial risk associated with the research and development has been transferred to CPRIT, because repayment of the grant depends solely on the results of research and development having future economic benefit, the Company accounts for this obligation as a contract to perform research and development for others. The funds received from CPRIT will initially be recorded as a deferred credit in the Company’s balance sheet. Restricted cash received from grants in advance of incurring qualifying costs is recorded as deferred revenue and recognized as revenue when qualifying costs are incurred. The Company recorded $1.0 million of grant income related to the CPRIT grant as revenue for the three months ended March 31, 2022. At March 31, 2022, $0.2 million was recorded as restricted cash and deferred revenue on the Company’s condensed consolidated financial statements.
New Accounting Standards	New Accounting Standards From time to time, new accounting pronouncements are issued by FASB or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed, the Company does not believe that the impact of recently issued standards that are not yet effective will have a material impact on its consolidated financial position or results of operations upon adoption.

NET LOSS PER SHARE (Tables)

NET LOSS PER SHARE (Tables)	3 Months Ended
	Mar. 31, 2022
NET LOSS PER SHARE
Schedule of computation of loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Numerator: ​ ​ ​ ​ ​ ​ Net loss ​ $ (9,910,508) ​ $ (8,779,450) ​ ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ Weighted average common shares outstanding ​ 83,107,649 ​ 56,470,247 ​ ​ ​ ​ ​ ​ ​ Net loss per share: ​ ​ ​ ​ Basic and diluted ​ $ (0.12) ​ $ (0.16)
Schedule of anti-dilutive securities	​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Common stock options 9,389,000 7,490,000 Common stock purchase warrants 19,830,000 20,830,000 Potentially dilutive securities 29,219,000 28,320,000

PROPERTY AND EQUIPMENT (Tables)

PROPERTY AND EQUIPMENT (Tables)	3 Months Ended
	Mar. 31, 2022
PROPERTY AND EQUIPMENT.
Schedule of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ Estimated Useful Lives 2022 2021 Lab and manufacturing equipment ​ 5 Years ​ $ 8,460,000 ​ $ 7,851,000 Computers, equipment and software 3-5 Years ​ ​ 1,064,000 ​ ​ 1,020,000 Office furniture 5 Years ​ 896,000 ​ 793,000 Leasehold improvements ​ Lesser of lease term or estimated useful life ​ ​ 3,173,000 ​ ​ 3,173,000 Total ​ ​ 13,593,000 ​ ​ 12,837,000 Less: accumulated depreciation ​ (3,316,000) ​ (2,740,000) Construction in progress ​ ​ ​ ​ 4,089,000 ​ ​ 2,226,000 Total fixed assets, net ​ $ 14,366,000 ​ $ 12,323,000

LEASES (Tables)

LEASES (Tables)	3 Months Ended
	Mar. 31, 2022
LEASES
Schedule of quantitative information about operating leases	​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Operating lease expense summary: ​ ​ ​ Operating lease expense ​ $ 425,000 ​ $ 425,000 Short-term lease expense ​ 3,000 ​ — Variable lease expense ​ 179,000 ​ 133,000 Total ​ $ 607,000 ​ $ 558,000 ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ ​ 2022 ​ 2021 Other information: ​ ​ Operating cash flows - operating leases ​ $ 316,000 ​ $ 238,000
Schedule of maturities of operating leases	​ ​ ​ ​ ​ Nine months ending December 31, 2022 $ 961,000 Year ended December 31, 2023 ​ 1,542,000 Year ended December 31, 2024 ​ 1,826,000 Year ended December 31, 2025 ​ 1,874,000 Year ended December 31, 2026 ​ ​ 1,775,000 Thereafter ​ ​ 6,997,000 Total ​ ​ 14,975,000 Less present value discount ​ (3,255,000) Operating lease liabilities included in the Condensed Consolidated Balance Sheet at March 31, 2022 ​ $ 11,720,000

ACCOUNTS PAYABLE AND ACCRUED _2

ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Tables)	3 Months Ended
	Mar. 31, 2022
ACCOUNTS PAYABLE AND ACCRUED LIABILITIES
Schedule of accounts payable and accrued liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, December 31, ​ ​ 2022 ​ 2021 Accounts payable ​ $ 5,016,000 ​ $ 5,144,000 Compensation and benefits ​ 747,000 ​ 2,055,000 Process development expenses ​ ​ 500,000 ​ ​ 385,000 Professional fees ​ 595,000 ​ 644,000 Technology license fees ​ 250,000 ​ 250,000 Arbitration settlement fees ​ — ​ 2,407,000 Other ​ 241,000 ​ 250,000 Total accounts payable and accrued liabilities ​ $ 7,349,000 ​ $ 11,135,000

STOCKHOLDERS' EQUITY (Tables)

STOCKHOLDERS' EQUITY (Tables)	3 Months Ended
	Mar. 31, 2022
STOCKHOLDERS' EQUITY
Schedule of share purchase warrants	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ ​ Number of ​ Weighted Average ​ Remaining Contractual ​ Total Intrinsic ​ Warrants Exercise Price Life (in years) Value Balance - January 1, 2022 19,830,000 ​ $ 4.42 ​ 1.70 ​ $ — Warrants granted ​ — ​ ​ — ​ — ​ ​ — Expired or cancelled ​ — ​ ​ — ​ — ​ — Balance - March 31, 2022 ​ 19,830,000 ​ ​ 4.42 ​ 1.46 ​ ​ —

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	3 Months Ended
	Mar. 31, 2022
STOCK-BASED COMPENSATION
Summary of the Company's stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Remaining ​ ​ ​ ​ Weighted Average ​ Total Intrinsic ​ Contractual ​ Number of Shares Exercise Price Value Life (in years) Outstanding as of January 1, 2022 7,686,233 ​ $ 5.47 ​ $ — ​ 7.7 Granted 1,820,000 ​ ​ 0.51 ​ ​ — ​ 9.8 Canceled/Expired (117,082) ​ ​ 2.60 ​ ​ — ​ — Outstanding as of March 31, 2022 9,389,151 ​ $ 4.54 ​ $ — ​ 7.9 Options vested and exercisable 4,798,325 ​ $ 6.48 ​ $ — ​ 7.1
Schedule or Description of Weighted Average Discount Rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, 2022 Exercise price ​ $ 0.51 ​ Expected term (years) ​ 6.0 ​ Expected stock price volatility ​ 84 % Risk-free rate of interest ​ 2 % Expected dividend rate ​ 0 %
Schedule of stock-based compensation expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Stock Compensation expenses: ​ ​ Research and development ​ $ 878,000 ​ $ 696,000 General and administrative ​ 753,000 ​ 681,000 Total stock compensation expenses ​ $ 1,631,000 ​ $ 1,377,000

RELATED PARTY TRANSACTIONS (Tab

RELATED PARTY TRANSACTIONS (Tables)	3 Months Ended
	Mar. 31, 2022
RELATED PARTY TRANSACTIONS
Schedule of related party transaction expenses recorded during the respective periods	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ For the Three Months Ended ​ ​ March 31, ​ 2022 2021 Baylor College of Medicine ​ $ 856,000 ​ $ 422,000 Bio-Techne Corporation ​ ​ 101,000 ​ ​ 46,000 Wilson Wolf Manufacturing Corporation ​ ​ 55,000 ​ ​ 34,000 Total Research and development ​ $ 1,012,000 $ 502,000

LIQUIDITY , GOING CONCERN AND_2

LIQUIDITY , GOING CONCERN AND FINANCIAL CONDITION (Details)	Aug. 15, 2022USD ($)$ / shares	Apr. 21, 2022USD ($)	Feb. 16, 2022USD ($)$ / shares	Aug. 31, 2021USD ($)	Mar. 31, 2022USD ($)shares	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)
Proceeds from issuance of common stock, net					$ 0	$ 52,656,588
Amount of notice received				$ 13,100,000
Cash, cash equivalents and restricted cash					28,800,000
Funds received from CPRIT grant				2,400,000
Restricted cash					181,864		$ 1,146,186
Deferred Revenue					181,864		$ 1,146,186
Revenue from CPRIT					$ 1,000,000
Minimum Bid Price Of Its Common Stock | $ / shares			$ 1
Threshold Consecutive Business Days For Which Notice Received From NASDAQ For Not Maintaining The Minimum Bid Price			30
Subsequent event
Minimum Bid Price Of Its Common Stock | $ / shares	$ 1
Grace Period	180
Minimum Consecutive Business Days For Which Bid Price Must Meet Or Exceed $1.00 Per Share To Regain Compliance	10
ATM Agreement
Aggregate offering price				75,000,000
ATM Agreement | Sales Agents
Aggregate offering price				$ 19,800,000
Commission rate				3.00%
Number of shares issued | shares					148,000
Proceeds from issuance of common stock, net					$ 63,600
Binding Services Agreement | Subsequent event | Wilson Wolf Manufacturing Corporation
Total amount of cash received from Wilson Wolf		$ 8,000,000

SIGNIFICANT ACCOUNTING POLICI_3

SIGNIFICANT ACCOUNTING POLICIES- Additional Information (Details) - USD ($)	1 Months Ended	3 Months Ended
	Aug. 31, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Sep. 30, 2021
Receipt of product development research award	$ 13,100,000
Funds received from CPRIT grant			$ 2,400,000
Revenue from CPRIT		$ 1,000,000
Restricted Cash And Investment		200,000
Property and equipment - Construction in Progress		4,089,135	2,225,610
The effect of adjustment in Net cash used in Operating and Investing activities				$ 1,000,000
Manufacturing facility in Houston, Texas
Property and equipment - Construction in Progress		$ 1,900,000	$ 2,200,000		$ 2,200,000

SIGNIFICANT ACCOUNTING POLICI_4

SIGNIFICANT ACCOUNTING POLICIES (Details) - USD ($)	1 Months Ended	3 Months Ended
	Aug. 31, 2021	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
SIGNIFICANT ACCOUNTING POLICIES
Funds received from CPRIT grant	$ 2,400,000
Revenue from CPRIT		$ 1,000,000
Restricted Cash And Investment		200,000
Deferred Revenue		181,864	$ 1,146,186
Cash and cash equivalents		28,637,217	42,351,145
Restricted cash		181,864	1,146,186
Total cash, cash equivalents and restricted cash shown in statements of cash flows		$ 28,819,081	$ 43,497,331	$ 64,507,575	$ 21,352,382

NET LOSS PER SHARE - Computatio

NET LOSS PER SHARE - Computation of loss per Share (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (9,910,508)	$ (8,779,450)
Denominator:
Weighted average common shares outstanding, Basic	83,107,649	56,470,247
Weighted Average Number of Shares Outstanding, Diluted	83,107,649	56,470,247
Net loss per share:
Net loss per share, basic	$ (0.12)	$ (0.16)
Net loss per share, diluted	$ (0.12)	$ (0.16)

NET LOSS PER SHARE - Dilutive S

NET LOSS PER SHARE - Dilutive Securities (Details) - shares	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Potentially dilutive securities	29,219,000	28,320,000
Common stock options
Common stock purchase warrants	9,389,000	7,490,000
Common stock purchase warrants
Common stock purchase warrants	19,830,000	20,830,000

PROPERTY AND EQUIPMENT (Details

PROPERTY AND EQUIPMENT (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total	$ 13,593,000	$ 12,837,000
Less: accumulated depreciation	(3,316,000)	(2,740,000)
Construction in progress	4,089,000	2,226,000
Total fixed assets, net	14,366,000	12,323,000
Lab and manufacturing equipment
Property, Plant and Equipment [Line Items]
Total	$ 8,460,000	7,851,000
Estimated Useful Lives	5 years
Computers, equipment and software
Property, Plant and Equipment [Line Items]
Total	$ 1,064,000	1,020,000
Computers, equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	3 years
Computers, equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Estimated Useful Lives	5 years
Office furniture
Property, Plant and Equipment [Line Items]
Total	$ 896,000	793,000
Estimated Useful Lives	5 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total	$ 3,173,000	$ 3,173,000

PROPERTY AND EQUIPMENT - Additi

PROPERTY AND EQUIPMENT - Additional Information (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Sep. 30, 2021
Depreciation	$ 600,000	$ 500,000
Property and equipment - Construction in Progress	4,089,135		$ 2,225,610
Property, plant and equipment, net	14,366,000		12,323,000
Manufacturing facility in Houston, Texas
Property and equipment - Construction in Progress	1,900,000		$ 2,200,000	$ 2,200,000
Accounts Payable and Accrued Liabilities
Property, plant and equipment, net	$ 2,300,000

LEASES - Quantitative Informati

LEASES - Quantitative Information About Operating Leases (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Operating lease expense summary:
Operating lease expense	$ 425,000	$ 425,000
Short-term lease expense	3,000
Variable lease expense	179,000	133,000
Total	607,000	558,000
Other information:
Operating cash flows - operating leases	$ 316,000	$ 238,000
Weighted-average remaining lease term - operating leases	8 years 2 months 12 days		8 years 4 months 24 days
weighted-average discount rate used to determine the operating lease liability	5.70%		5.70%

LEASES - Maturities of Operatin

LEASES - Maturities of Operating Leases (Details)	Mar. 31, 2022USD ($)
LEASES
Year ended December 31, 2022	$ 961,000
Year ended December 31, 2023	1,542,000
Year ended December 31, 2024	1,826,000
Year ended December 31, 2025	1,874,000
Year ended December 31, 2026	1,775,000
Thereafter	6,997,000
Total	14,975,000
Less present value discount	(3,255,000)
Operating lease liabilities included in the Condensed Consolidated Balance Sheet at September 30, 2021	$ 11,720,000

LEASES - Additional Information

LEASES - Additional Information (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
LEASES
Total operating lease liabilities	$ 11,720,000
Operating lease, right-of-use asset	$ 9,572,572	$ 9,830,461

ACCOUNTS PAYABLE AND ACCRUED _3

ACCOUNTS PAYABLE AND ACCRUED LIABILITIES (Details) - USD ($)	Mar. 31, 2022	Dec. 31, 2021
ACCOUNTS PAYABLE AND ACCRUED LIABILITIES
Accounts payable	$ 5,016,000	$ 5,144,000
Compensation and benefits	747,000	2,055,000
Process development expenses	500,000	385,000
Professional fees	595,000	644,000
Technology license fees	250,000	250,000
Arbitration settlement fees		2,407,000
Other	241,000	250,000
Total accounts payable and accrued liabilities	$ 7,348,680	$ 11,134,913

STOCKHOLDERS' EQUITY - Share Pu

STOCKHOLDERS' EQUITY - Share Purchase Warrants (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
STOCKHOLDERS' EQUITY
Number of Warrants, Beginning balance	19,830,000
Number of Warrants, Ending balance	19,830,000	19,830,000
Weighted Average Exercise Price, Beginning Balance	$ 4.42
Weighted Average Exercise Price, Ending Balance	$ 4.42	$ 4.42
Weighted Average Remaining Contractual Life (in years)	1 year 5 months 15 days	1 year 8 months 12 days

STOCKHOLDERS' EQUITY - Underwri

STOCKHOLDERS' EQUITY - Underwritten Public Offering (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Proceeds from issuance of common stock, net	$ 0	$ 52,656,588
Aggregate proceeds from shares issued under the purchase agreement		$ 52,552,758
Exercise of Stock Warrants
Common Stock Capital Shares Reserved For Future Issuance [Line Items]
Issuance of shares of common stock	372,512

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock Option Activity (Details) - Common stock options - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Number of Shares Outstanding, Beginning Balance	7,686,233
Number of Shares, Granted	1,820,000
Number of Shares, Cancelled / Expired	(117,082)
Number of Shares Outstanding, Ending Balance	9,389,151	7,686,233
Number of Shares, Options vested and exercisable	4,798,325
Weighted Average Exercise Price per Share Outstanding, Beginning Balance	$ 5.47
Weighted Average Exercise Price per Share, Granted	0.51
Weighted Average Exercise Price per Share, Cancelled / Expired	2.60
Weighted Average Exercise Price per Share Outstanding, Ending Balance	4.54	$ 5.47
Weighted Average Exercise Price, Options vested and exercisable	$ 6.48
Weighted Average Remaining Contractual Life, Outstanding	7 years 10 months 24 days	7 years 8 months 12 days
Weighted Average Remaining Contractual Life, Options granted	9 years 9 months 18 days
Weighted Average Remaining Contractual Life, Options vested and exercisable	7 years 1 month 6 days

STOCK-BASED COMPENSATION - Weig

STOCK-BASED COMPENSATION - Weighted Average Assumptions (Details)	3 Months Ended
	Mar. 31, 2022$ / shares
STOCK-BASED COMPENSATION
Exercise price	$ 0.51
Expected term (years)	6 years
Expected stock price volatility	84.00%
Risk-free rate of interest	2.00%
Expected dividend rate	0.00%

STOCK-BASED COMPENSATION - St_2

STOCK-BASED COMPENSATION - Stock-based compensation expenses (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Total stock compensation expenses	$ 1,631,000	$ 1,377,000
Research and development
Total stock compensation expenses	878,000	696,000
General and administrative
Total stock compensation expenses	$ 753,000	$ 681,000

STOCK-BASED COMPENSATION - Addi

STOCK-BASED COMPENSATION - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 17, 2022	Jan. 03, 2022	Mar. 31, 2022	Mar. 31, 2021
Exercise price			$ 0.51
Compensation cost not yet recognized			$ 7.6
Compensation cost not yet recognized, period for recognition			1 year 10 months 24 days
2022 Equity Incentive Awards | Employees
Exercise price				$ 1
Award vesting period				3 years
Number of options to purchase shares				175,000
Vesting percentage		25.00%	75.00%
2022 Equity Incentive Awards | 2020 Equity Incentive Plan | Executive officer
Number of Shares, Granted	1,250,000
Exercise price	$ 0.46
Award vesting period	4 years
2022 Equity Incentive Awards | 2020 Equity Incentive Plan | Non-executive employees
Number of Shares, Granted	395,000
Exercise price	$ 0.46
Award vesting period	4 years

GRANT INCOME (Details)

GRANT INCOME (Details) - USD ($)	1 Months Ended	3 Months Ended
	Aug. 31, 2021	Mar. 31, 2022	Dec. 31, 2021
GRANT INCOME.
Receipt of product development research award	$ 13,100,000
Funds received from CPRIT grant			$ 2,400,000
Revenue from CPRIT		$ 1,000,000
Restricted cash		200,000
Deferred revenue		$ 200,000

LEGAL PROCEEDINGS (Details)

LEGAL PROCEEDINGS (Details) - USD ($) $ in Millions	Mar. 09, 2022	Mar. 31, 2022	Dec. 31, 2021	Mar. 24, 2022
LEGAL PROCEEDINGS
Compensation, interest and attorney fees		$ 2.4
Accrued liabilities			$ 2.4
Other expenses			$ 2.4
Legal Proceedings Broker Awarded Additional Interest Amount	$ 0.1
Percentage of accrual of post judgment interest	1.02%
Amount of accrual of post judgment				$ 2.5

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details) - USD ($)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
RELATED PARTY TRANSACTIONS
Total Research and development	$ 1,012,000	$ 502,000
Due to related party		900,000
Baylor College of Medicine
RELATED PARTY TRANSACTIONS
Total Research and development	856,000	422,000
Bio-Techne Corporation
RELATED PARTY TRANSACTIONS
Total Research and development	101,000	46,000
Wilson Wolf Manufacturing Corporation
RELATED PARTY TRANSACTIONS
Total Research and development	$ 55,000	$ 34,000

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent event - Wilson Wolf Manufacturing Corporation - Binding Services Agreement $ in Millions	Apr. 21, 2022USD ($)
Subsequent Event [Line Items]
Total amount of cash received from Wilson Wolf	$ 8
Advance received for non-exclusive training of Wilson Wolf to make, use, and sell Marker's cell culture non-proprietary media formulation	2
Advance received for non-exclusive training of Wilson Wolf to replicate Marker's quality management system inclusive of all underlying documents	1
Advance received for non-exclusive training of Wilson Wolf to replicate Marker's cGMP-compliant, linearly scalable, G-Rex based T-cell manufacturing process	2
Advance received under the hired to invent doctrine for Marker to train Wilson Wolf on its expertise in the optimization of T-cell therapy manufacturing processes	$ 3
Period for completion of optimization work under the direction of Wilson Wolf which Marker will make good faith efforts from the agreement date	18 months
Additional amount agreed to received from Wilson Wolf if the Work Direction is completed within one year from the onset of the agreement	$ 1