CASI Pharmaceuticals (CASI) 10-Q 13 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	Apr. 30, 2021
Cover
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2021
Entity File Number	0-20713
Entity Registrant Name	CASI PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	58-1959440
Entity Address, Address Line One	9620 Medical Center Drive
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Rockville
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	20850
City Area Code	240
Local Phone Number	864-2600
Title of 12(b) Security	Common Stock
Trading Symbol	CASI
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
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000895051
Current Fiscal Year End Date	--12-31
Entity Common Stock, Shares Outstanding		139,797,487

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 68,117	$ 57,064
Investment in equity securities, at fair value	10,948	9,309
Accounts receivable, net of $0 allowance for doubtful accounts	5,838	4,645
Inventories	2,994	1,356
Prepaid expenses and other	1,117	1,651
Total current assets	89,014	74,025
Property, plant and equipment, net	1,876	2,062
Intangible assets, net	12,834	13,210
Long-term investments	34,870	29,442
Right of use assets	8,323	8,696
Other assets	1,176	299
Total assets	148,093	127,734
Current liabilities:
Accounts payable	5,741	3,669
Accrued and other current liabilities	2,238	3,015
Bank borrowings	1,525	826
Notes payable	466	466
Total current liabilities	9,970	7,976
Deferred income	2,331	2,351
Other liabilities	13,596	13,834
Total liabilities	25,897	24,161
Commitments and contingencies (Note 19)
Redeemable noncontrolling interest, at redemption value (Note 11)	22,164	22,033
Stockholders' equity:
Preferred stock, $1.00 par value: 5,000,000 shares authorized and 0 shares issued and outstanding	0	0
Common stock, $0.01 par value: 250,000,000 shares authorized at March 31, 2021 and December 31, 2020; 139,877,032 shares and 124,023,374 shares issued at March 31, 2021 and December 31, 2020, respectively; 139,797,487 shares and 123,943,829 shares outstanding at March 31, 2021 and December 31, 2020, respectively	1,399	1,240
Additional paid-in capital	690,018	658,246
Treasury stock, at cost: 79,545 shares held at March 31, 2021 and December 31, 2020	(8,034)	(8,034)
Accumulated other comprehensive income	485	589
Accumulated deficit	(583,836)	(570,501)
Total stockholders' equity	100,032	81,540
Total liabilities, redeemable noncontrolling interest and stockholders' equity	$ 148,093	$ 127,734

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Condensed Consolidated Balance Sheets
Allowance for doubtful accounts	$ 0	$ 0
Preferred Stock, Par or Stated Value Per Share (in dollars per share)	$ 1	$ 1
Preferred Stock, Shares Authorized (in shares)	5,000,000	5,000,000
Preferred Stock, Shares Outstanding (is shares)	0	0
Common Stock, Par Value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, Shares Authorized (in shares)	250,000,000	250,000,000
Common Stock, Shares Issued (in shares)	139,877,032	124,023,374
Common Stock, Shares Outstanding (in shares)	139,797,487	123,943,829
Treasury stock, Shares Held (in shares)	79,545	79,545

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Product sales	$ 5,700	$ 3,372
Lease income	36	34
Total revenues	5,736	3,406
Costs and expenses:
Costs of revenues	2,358	3,211
Research and development	5,258	3,017
General and administrative	5,502	4,058
Selling and marketing	2,715	1,260
Gain on disposal of intangible assets		(450)
Acquired in-process research and development	5,500	1,081
Total costs and expenses	21,333	12,177
Loss from operations	(15,597)	(8,771)
Non-operating income/(expense):
Interest income, net	106	190
Other income	20
Foreign exchange gains	219	363
Change in fair value of investments	1,568	(15)
Net loss	(13,684)	(8,233)
Less: loss attributable to redeemable noncontrolling interest	(349)	(109)
Accretion to redeemable noncontrolling interest redemption value	548	317
Net loss attributable to CASI Pharmaceuticals, Inc.	$ (13,883)	$ (8,441)
Net loss per share (basic and diluted)	$ (0.11)	$ (0.09)
Weighted average number of common shares outstanding (basic and diluted)	124,825	98,773
Comprehensive loss:
Net loss	$ (13,684)	$ (8,233)
Foreign currency translation adjustment	(172)	(826)
Total comprehensive loss	(13,856)	(9,059)
Less: Comprehensive loss attributable to redeemable noncontrolling interest	(417)	(109)
Comprehensive loss attributable to common stockholders	$ (13,439)	$ (8,950)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Stockholders' Equity - USD ($)	Preferred Stock	Common Stock	Additional Paid-in Capital	Treasury Stock	Accumulated Other Comprehensive Loss	Accumulated Deficit	Total
Balance at Dec. 31, 2019	$ 0	$ 979,000	$ 606,686,000	$ (8,034,000)	$ (2,728,000)	$ (523,908,000)	$ 72,995,000
Balance (in shares) at Dec. 31, 2019	0	97,771,698
Issuance of common stock for options and warrants exercised		$ 27,000	3,805,000				3,832,000
Issuance of common stock for options and warrants exercised (in shares)		2,708,795
Repurchase of stock options to satisfy tax withholding obligations	$ 0	$ 0	(251,000)	0	0	0	(251,000)
Issuance of common stock pursuant to financing agreements		$ 4,000	1,395,000				1,399,000
Issuance of common stock pursuant to financing agreements (in shares)		434,336
Stock issuance costs	0	$ 0	(251,000)	0	0	0	(251,000)
Stock-based compensation expense, net of forfeitures	0	0	1,905,000	0	0	0	1,905,000
Foreign currency translation adjustment	0	0	0	0	(826,000)	0	(826,000)
Net loss attributable to CASI Pharmaceuticals, Inc.	0	0	(317,000)	0	0	(8,124,000)	(8,441,000)
Balance at Mar. 31, 2020	$ 0	$ 1,010,000	612,972,000	(8,034,000)	(3,554,000)	(532,032,000)	70,362,000
Balance (in shares) at Mar. 31, 2020	0	100,914,829
Balance at Dec. 31, 2020	$ 0	$ 1,240,000	658,246,000	(8,034,000)	589,000	(570,501,000)	81,540,000
Balance (in shares) at Dec. 31, 2020	0	123,943,829
Issuance of common stock pursuant to financing agreements		$ 159,000	32,341,000	0	0	0	32,500,000
Issuance of common stock pursuant to financing agreements (in shares)		15,853,658
Stock issuance costs			(2,019,000)	0	0	0	(2,019,000)
Stock-based compensation expense, net of forfeitures	$ 0	$ 0	1,998,000	0	0	0	1,998,000
Foreign currency translation adjustment	0	0	0	0	(104,000)	0	(104,000)
Net loss attributable to CASI Pharmaceuticals, Inc.	0	0	(548,000)	0	0	(13,335,000)	(13,883,000)
Balance at Mar. 31, 2021	$ 0	$ 1,399,000	$ 690,018,000	$ (8,034,000)	$ 485,000	$ (583,836,000)	$ 100,032,000
Balance (in shares) at Mar. 31, 2021	0	139,797,487

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (13,684)	$ (8,233)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation for property, plant and equipment	179	146
Amortization of intangible assets	337	377
Reduction in the carrying amount of the right-of-use assets	348	314
Gain on disposal of intangible assets		(450)
Stock-based compensation expense	1,998	1,905
Acquired in-process research and development	5,500	1,081
Change in fair value of investments	(1,568)	15
Changes in operating assets and liabilities:
Accounts receivable	(1,193)	(579)
Inventories	(1,638)	2,533
Prepaid expenses and other assets	637	6
Accounts payable	2,073	(729)
Accrued liabilities and other liabilities	(978)	(1,020)
Deferred income	(12)
Net cash used in operating activities	(8,001)	(4,634)
CASH FLOWS FROM INVESTING ACTIVITIES
Proceeds from disposal of intangible assets		450
Purchases of property, plant and equipment	(981)	(1)
Cash paid to acquire in-process research and development	(5,500)
Net cash (used in) provided by investing activities	(12,067)	449
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from bank borrowings	709
Stock issuance costs	(2,019)	(42)
Proceeds from sale of common stock	32,500	1,399
Proceeds from exercise of stock options		3,832
Repurchase of stock options to satisfy tax withholding obligations		(251)
Net cash provided by financing activities	31,190	4,938
Effect of exchange rate change on cash and cash equivalents	(69)	(489)
Net increase in cash and cash equivalents	11,053	264
Cash and cash equivalents at beginning of year	57,064	53,621
Cash and cash equivalents at end of year	68,117	53,885
Supplemental disclosure of cash flow information:
Interest paid	0	0
Income taxes paid	0	0
Non-cash investing activity:
Accrual for acquisition of in-process research and development		$ 1,081
Black Belt Tx Limited
CASH FLOWS FROM INVESTING ACTIVITIES
Cash paid to acquire convertible loan	(86)
Cleave Therapeutics, Inc
CASH FLOWS FROM INVESTING ACTIVITIES
Cash paid to acquire convertible loan	$ (5,500)

Basis of Presentation, Organiza

Basis of Presentation, Organization and Principal Activities	3 Months Ended
	Mar. 31, 2021
Basis of Presentation, Organization and Principal Activities
Basis of Presentation, Organization and Principal Activities	1. Basis of Presentation, Organization and Principal Activities Basis of Presentation CASI Pharmaceuticals, Inc. (“CASI” or the “Company”) (Nasdaq: CASI) is a U.S. biopharmaceutical company focused on developing and commercializing innovative therapeutics and pharmaceutical products in China, the United States, and throughout the world. The Company is focused on acquiring, developing and commercializing products that augment its hematology oncology therapeutic focus as well as other areas of unmet medical need. The Company is executing its plan to become a biopharmaceutical leader by launching medicines in the greater China market leveraging its China-based regulatory, clinical and commercial competencies and its global drug development expertise. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries, in which CASI, directly or indirectly, has a controlling financial interest. These subsidiaries include Miikana Therapeutics, Inc. (“Miikana”), CASI Pharmaceuticals (China) Co., Ltd. (“CASI China”), CASI Pharmaceuticals (Wuxi) Co., Ltd. (“CASI Wuxi”), and CASI Biopharmaceuticals (WUXI) Co., Ltd. (“CASI Biopharmaceuticals”). CASI China is a non-stock Chinese entity with 100% of its interest owned by CASI. CASI China received approval for a business license from the Beijing Industry and Commercial Administration in August 2012 and has operating facilities in Beijing. CASI Biopharmaceuticals is a wholly owned subsidiary of CASI Wuxi and was established in April 2019. The Company controls CASI Wuxi through 80% voting rights (see Note 11). Accordingly, the financial statements of CASI Wuxi have been consolidated in the Company’s consolidated financial statements since its inception. All inter-company balances and transactions have been eliminated in consolidation. The Company currently operates in one operating segment, which is the development of innovative therapeutics addressing cancer and other unmet medical needs for the global market. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles for interim financial information and in accordance with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, such condensed consolidated financial statements do not include all of the information and disclosures required by U.S. generally accepted accounting principles for complete consolidated financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. The accompanying December 31, 2020 financial information was derived from the Company’s audited financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. The accompanying unaudited condensed consolidated financial statements should be read in conjunction with the consolidated balance sheet of the Company as of December 31, 2020 and the related consolidated statements of operations and comprehensive loss, stockholders’ equity and cash flows for the year then ended. Overview The Company launched its first commercial product, EVOMELA® (Melphalan for Injection), in China in August 2019. In China, EVOMELA® is approved for use as a conditioning treatment prior to stem cell transplantation and as a palliative treatment for patients with multiple myeloma. The other core hematology/oncology assets in the Company’s pipeline include: ● CNCT19 is an autologous CD19 CAR-T investigative product (CNCT19) being developed by the Company’s partner Juventas Cell Therapy Ltd (“Juventas”) for which the Company has co-commercial and profit-sharing rights. CNCT19 is being developed as a potential treatment for patients with hematological malignancies which express CD19 including, B-cell acute lymphoblastic leukemia (“B-ALL”) and B-cell non-Hodgkin lymphoma (“B-NHL”). CNCT19’s Phase 1 studies of B-ALL and B-NHL in China have been substantially completed by Juventas, with the Phase 2 B-NHL registration study and the Phase 2 B-ALL registration study of CNCT19 both currently enrolling in China. ● BI-1206 is an antibody which has a novel mode-of-action, blocking the inhibitory antibody checkpoint receptor FcγRIIB to unlock anti-cancer immunity in both hematological malignancies and solid tumors for which the Company has licensed exclusive greater China rights from BioInvent International (“BioInvent”). AB BI-1206 is being investigated by BioInvent in a Phase 1/2 trial, in combination with anti-PD1 therapy Keytruda® (pembrolizumab), in solid tumors, and in a Phase 1/2a trial in combination with MabThera® (rituximab) in patients with relapsed/refractory non-Hodgkin lymphoma (NHL). BioInvent International AB, released positive interim results from its Phase 1/2a trial that suggests that novel anti-FcyRIIB antibody BI-1206 restores activity of rituximab in patients with relapsed/refractory non-Hodgkin’s lymphoma. An FDA End of Phase 1 meeting for the NHL development program is planned for the third quarter of 2021. ● CB-5339 is a novel VCP/p97 inhibitor focused on valosin-containing protein (VCP)/p97 as a novel target in protein homeostasis, DNA damage response and other cellular stress pathways for therapeutic use in cancer. The Company entered into an exclusive license on March 21, 2021 with Cleave Therapeutics, Inc. (Cleave”) for the development and commercialization of CB-5339 in Mainland China, Hong Kong, Macau and Taiwan . CB-5339, an oral second-generation, small molecule VCP/p97 inhibitor, is being evaluated in a Phase 1 clinical trial in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) and in a Phase 1 clinical trial of patients with solid tumors and lymphomas. ● CID-103 is a full human IgG1 anti-CD38 monoclonal antibody recognizing a unique epitope that has demonstrated encouraging preclinical efficacy and safety profile compared to other anti-CD38 monoclonal antibodies for which the Company has exclusive global rights. CID-103 is being developed for the treatment of patients with multiple myeloma. The Company has achieved in May 2021 the First-Patient-In (FPI) in the Phase 1 dose escalation and expansion study of CID-103, in patients with previously treated, relapsed or refractory multiple myeloma. The Company also has greater China rights to ZEVALIN® (Ibritumomab Tiuxetan), a CD20-directed radiotherapeutic antibody that is approved in the U.S. to treat patients with non-Hodgkin lymphoma (“NHL”) and MARQIBO® (vincristine sulfate LIPOSOME injection) a novel, sphingomyelin/cholesterol liposome-encapsulated, formulation of vincristine sulfate, a microtubule inhibitor, approved by the FDA for the treatment of adult patients with Philadelphia chromosome-negative (Ph-) acute lymphoblastic leukemia (ALL) in second or greater relapse or whose disease has progressed following two or more anti-leukemia therapies. However, due to the evolving standard of care environment, the rare and niche indication for these products, and the Company’s commitment to prioritize resources, the Company is currently evaluating its options for these products. In addition, the Company’s assets include a few FDA-approved ANDAs which the Company is evaluating due to generic drug pricing reforms by the Chinese government and its impact on the pricing and competitiveness of these products. The Company’s business development strategy is currently focused on acquiring additional targeted drugs and immuno-oncology therapeutics through licensing that will expand its hematology-oncology franchise. In many cases its business development strategy includes direct equity investments in the licensor company. The Company intends for its pipeline to reflect a diversified and risk-balanced set of assets that include (1) late-stage clinical drug candidates in-licensed for China regional rights, (2) proprietary or licensed innovative drug candidates, and (3) select high quality pharmaceuticals that fit its therapeutic focus. The Company uses a market-oriented approach to identify pharmaceutical/biotechnology candidates that the Company believes to have the potential for gaining widespread market acceptance, either globally or in China, and for which development can be accelerated under the Company’s global drug development strategy. Although oncology with a focus on hematological malignancies is its principal clinical and commercial target, the Company is opportunistic about other therapeutic areas that can address unmet medical needs. Liquidity Risks and Management’s Plans Since its inception in 1991, the Company has incurred significant losses from operations and, as of March 31, 2021, has incurred an accumulated deficit of $583.8 million. In 2012, with new leadership, the Company shifted its business strategy to China and has since built an infrastructure in China that includes sales and marketing, medical affairs, regulatory and clinical development and in the foreseeable future, manufacturing. In 2014, the Company changed its name to “CASI Pharmaceuticals, Inc.” The majority of the Company’s operations are now located in China. The Company expects to continue to incur operating losses for the foreseeable future due to, among other factors, its continuing clinical and development activities and expansion of the Company’s operations. The Company’s Beijing office is primarily responsible for the Company’s day-to-day operations and the Company’s commercial team of over 80 hematology and oncology sales and marketing specialists based in China. CASI Wuxi is part of the long-term strategy to support the Company’s future clinical and commercial manufacturing needs, to manage the Company’s supply chain for certain products, and to develop a GMP manufacturing facility in China. The Company has primarily funded its operations through the proceeds from the sales of common stock and, to a lesser extent, asset sales and government grants. To date, the Company has minimal product revenue and management expects operating losses to continue for the foreseeable future. On March 26, 2021, the Company closed an underwritten public offering of 15,853,658 shares of the Company’s common stock (the “Offering”) at a price to the public of $2.05 per share. The gross proceeds to CASI from the Offering were $32.5 million before deducting the underwriting discounts and commissions and offering expenses payable by CASI. See Note 12 -- Stockholders’ Equity. Taking into consideration the cash and cash equivalents balance as of March 31, 2021, the Company believes that it has sufficient resources to fund its operations at least one year beyond the date that the unaudited condensed consolidated financial statements are issued. As of March 31, 2021, the Company had a consolidated cash balance of $68.1 million; $45.4 million was held by the Company (excluding its subsidiaries), and the Company’s subsidiaries held $4.8 million (CASI China), $17.7 million (CASI Wuxi), and $0.2 million (other subsidiaries). The Company intends to continue to exercise tight controls over operating expenditures and will continue to pursue opportunities, as required, to raise additional capital and will also actively pursue non- or less-dilutive capital raising arrangements. Risks and Uncertainties The Company has experienced operational interruptions as a result of COVID-19, including the temporary disruption of operations in China during the first three months of 2020 due to a Chinese government mandated quarantine protocol, including mandatory business closures, social distancing measures, and various travel restrictions. In the first quarter 2020, during which the peak of the pandemic occurred in China, the Company experienced some disruptions to its EVOMELA® marketing and sales activities due to travel restrictions and the prioritization of hospitals and physicians to attend to patients with COVID-19 infection. Although the Company's operations in China have normalized, there can be no assurance that such operations will continue to do so. To the extent that such events occur, demand for the Company's products may decline, and the Chinese government or other governments may impose additional restrictions resulting in further shutdowns, further work restrictions, and the disruption of the Company’s supply and distribution channels; there can be no assurance that such restrictions will not be imposed again. The Company currently relies on a single source for its supply of EVOMELA®. Due to COVID-19, the Company experienced a disruption to its supply chain for EVOMELA®. That disruption, along with a change in 2020 in the manufacturer of EVOMELA® , contributed to a decrease in the Company's revenue for the second quarter of 2020. The Company returned to expected levels of sales in the second half of 2020. If suppliers refuse or are unable to provide products for any reason (including the occurrence of an event like the COVID-19 pandemic that makes delivery impractical), the Company would be required to negotiate an agreement with a substitute supplier, which would likely interrupt the manufacturing of EVOMELA® , cause delays and increase costs. The COVID-19 pandemic has adversely affected, and may continue to adversely affect, the economies and financial markets of many countries, which may result in a period of regional, national, and global economic slowdown or regional, national, or global recessions that could affect the Company's ability to continue to commercialize and expand distribution of EVOMELA® (Melphalan For Injection) or other drugs in the Company’s existing product pipeline. The effectiveness of the Company's sales teams may be negatively impacted by the lack of travel and their reduced ability to engage with decision-makers. In addition, economic and other uncertainties may adversely affect other parties' willingness to negotiate and execute product licenses and thus hamper the Company's ability to in-license clinical-stage and late-stage drug candidates in China or elsewhere. Clinical trials, whether planned or ongoing, may be affected by the COVID-19 pandemic. The Company's partner, Juventas, experienced some delay in conducting the CNCT19 trials due to the COVID-19 pandemic. The COVID-19 pandemic has also impacted the Company's targeted start time of its CID-103 trial due to the lock-down of many medical facilities in Europe. Study procedures (particularly any procedures that may be deemed non-essential), site initiation, participant recruitment and enrollment, participant dosing, shipment of the Company's product candidates, distribution of clinical trial materials, study monitoring, site inspections and data analysis may be paused or delayed due to changes in hospital or research institution policies, federal, state or local regulations, prioritization of hospital and other medical resources toward COVID-19 efforts, or other reasons related to the pandemic. In addition, there could be a potential effect of COVID-19 on the operations of the health regulatory authorities, which could result in delays of reviews and approvals, including with respect to the Company's product candidates. Any prolongation or de-prioritization of the Company's clinical trials or delay in regulatory review resulting from such disruptions could materially affect the development and study of the Company's product candidates.

License and Distribution Agreem

License and Distribution Agreements	3 Months Ended
	Mar. 31, 2021
License and Distribution Agreements
License and Distribution Agreements	2. License and Distribution Agreements China Resources Guokang Pharmaceuticals Co., Ltd: The Company has product rights and perpetual exclusive licenses from Acrotech Biopharma L.L.C. (“Acrotech”) to develop and commercialize its commercial product EVOMELA® in the greater China region (which includes China, Taiwan, Hong Kong and Macau). On December 3, 2018, the Company received NMPA’s approval for importation, marketing and sales in China, and in August 2019 the Company launched EVOMELA® in China. The NMPA required post-marketing study is ongoing and is actively recruiting. In March 2019, the Company entered into a three-year exclusive distribution agreement with China Resources Guokang Pharmaceuticals Co., Ltd (“CRGK”) to appoint CRGK on an exclusive basis as its distributor to distribute EVOMELA® in the territory of the People’s Republic of China (excluding Hong Kong, Taiwan and Macau), subject to certain terms and conditions. The Company’s internal marketing and sales team will continue to be responsible for commercial activities, including, for example, direct interaction with Key Opinion Leaders (KOL), physicians, hospital centers and the generating of sales. Commercial sales of EVOMELA® were launched in August 2019. For the three months ended March 31, 2021 and 2020, the Company recognized $5.7 million and $3.4 million of revenues, respectively, from sales of EVOMELA® under this arrangement Juventas Cell Therapy: In June 2019, the Company entered into a license agreement for exclusive worldwide license to commercialize an autologous anti-CD19 T-cell therapy product (CNCT19) from Juventas Cell Therapy Ltd. (“Juventas”) (the “Juventas license agreement”). Juventas is a China-based company engaged in cell therapy. In September 2020, Juventas and its shareholders (including CASI Biopharmaceuticals) agreed to certain terms and conditions required by a new third-party investor to facilitate the Series B financing of Juventas, pursuant to which the Company agreed to amend and supplement the original licensing agreement (the "Supplementary Agreement") by agreeing to pay Juventas certain percentage of profits generated from commercial sales of CNCT19. The Supplementary Agreement also specifies a minimum annual target net profit to be distributed to Juventas and certain other terms and obligations. In return, the Company obtained additional equity interests in Juventas (see Note 4). Under the Supplementary Agreement, Juventas and the Company will jointly market CNCT19, including, but not limited to, establishing medical teams, developing medical strategies, conducting post-marketing clinical studies, establishing Standardized Cell Therapy Centers, establishing and training providers with respect to cell therapy, testing for cell therapy, and monitoring quality controls (cell collection and transfusion, etc.), and patient management (adverse reactions treatment, patients’ follow-up visits, and establishment of a database). The Company also will reimburse Juventas for a portion of Juventas’ marketing expenses as reviewed and approved by a joint commercial committee to be constituted. The Company will continue to be responsible for recruiting and establishing a sales team to commercialize CNCT19. BioInvent International AB In October 2020, the Company entered into an exclusive licensing agreement with BioInvent International AB (“BioInvent”) for the development and commercialization of novel anti-FcγRIIB antibody, BI-1206, in mainland China, Taiwan, Hong Kong and Macau. BioInvent is a biotechnology company focused on the discovery and development of first-in-class immune-modulatory antibodies for cancer immunotherapy. BI-1206 is BioInvent’s lead drug candidate and is being investigated in a Phase 1/2 trial, in combination with anti-PD1 therapy Keytruda® (pembrolizumab), in solid tumors, and in a Phase 1/2a trial in combination with MabThera® (rituximab) in patients with relapsed/refractory non-Hodgkin lymphoma (NHL). Under the terms of the agreement, BioInvent and CASI will develop BI-1206 in both hematological malignancies and solid tumors, with CASI responsible for commercialization in China and associated markets. CASI made a $5.9 million upfront payment in November 2020 to BioInvent and will pay up to $83 million in development and commercial milestone payments plus tiered royalties in the high-single to mid-double-digit range on net sales of BI-1206. Because BI-1206 underlying the acquired rights has not reached technological feasibility and has no alternative uses, the Company expensed $5.9 million as acquired in-process research and development in the fourth quarter of 2020. Black Belt Therapeutics Limited: In April 2019, the Company entered into a license agreement with Black Belt Therapeutics Limited (“Black Belt”) for exclusive worldwide rights to CID-103, an investigational anti-CD38 monoclonal antibody (Mab) (formerly known as TSK011010). The CID-103 Phase 1 study began in the EU in March 2021. The Company expects that its clinical materials and commercial inventory will be supplied by one or more contract manufacturers with whom the Company is in current discussions. Under the terms of the agreement, CASI obtained global rights to CID-103 for an upfront payment of 5 million euros ($5.7 million) as well as certain milestone and royalty payments. Because CID-103 underlying the acquired rights has not reached technological feasibility and has no alternative uses, the Company expensed 5 million euros as acquired in-process research and development in the consolidated statement of operations and comprehensive loss for the year ended December 31, 2019. Cleave Therapeutics, Inc. In March 2021, the Company entered into an exclusive license with Cleave Therapeutics, Inc. (“Cleave”) for the development and commercialization of CB-5339, an oral novel VCP/p97 inhibitor, in both hematological malignancies and solid tumors, in Mainland China, Hong Kong, Macau and Taiwan. Cleave is a clinical-stage biopharmaceutical company focused on valosin-containing protein (VCP)/p97 as a novel target in protein homeostasis, DNA damage response and other cellular stress pathways for therapeutic use in cancer. CB-5339 is being evaluated in a Phase 1 clinical trial in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), while the National Cancer Institute (NCI) is sponsoring and will be evaluating CB-5339 in a future Phase 1 clinical trial of patients with solid tumors and lymphomas. Because CB-5339 has not reached technological feasibility and has no alternative uses, the Company expensed $5.5 million as acquired in-process research and development in the accompanying consolidated statements of operations and comprehensive loss for the three months ended March 31, 2021. Pharmathen Global BV On October 29, 2019, the Company entered into an exclusive distribution agreement with Pharmathen Global BV ("Pharmathen") for the development and distribution of octreotide long acting injectable (Octreotide LAI) microsphere in China. Octreotide LAI formulations, which are approved in various European countries, are considered a standard of care for the treatment of acromegaly and the control of symptoms associated with certain neuroendocrine tumors. Subject to regulatory and marketing approvals, the Company intends to advance and commercialize these established products in China. The terms of the agreement include an upfront payment of 1 million euros which was paid by the Company in 2019, and up to 2 million euros of additional milestone payments, of which 1.5 million euros ( $1.7 million) was expensed in the year ended December 31, 2020 as acquired in-process research and development following Pharmathen’s achievement of certain milestones. CASI is responsible for the development, import drug registration, product approval and commercialization in China. CASI has a 10-year non-royalty exclusive distribution period after the product launch at agreed supply costs for the first three years . Riemser Pharma GmbH In August 2019, the Company entered into a distribution agreement in China with Riemser Pharma GmbH (“Riemser”) to a novel formulation of thiotepa, a chemotherapeutic agent, which has multiple indications including use as a conditioning treatment for use prior to allogenic hematopoietic stem cell transplantation. Thiotepa has a long history of established use in the hematology/oncology setting. Pursuant to the distribution agreement, CASI obtained the exclusive distribution right of the products in China, and Riemser will be responsible for manufacturing and supplying CASI with clinical materials and commercial inventory. Subject to regulatory and marketing approvals, the Company intends to advance and commercialize these established products in China. ​

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies Revenue Recognition Product sales recognized in the consolidated statements of operations are considered revenue from contracts with customers and, accordingly, the Company recognizes revenue using the following steps: ● Identification of the contract, or contracts, with a customer; ● Identification of the performance obligations in the contract; ● Determination of the transaction price, including the identification and estimation of variable consideration; ● Allocation of the transaction price to the performance obligations in the contract; and ● Recognition of revenue when the Company satisfies a performance obligation. The Company recognizes revenue on sales of EVOMELA® when the control of the product is transferred to the distributor, which occurs upon delivery of the product to the carrier appointed by the distributor, in an amount that reflects the consideration to which the Company expects to be entitled to in exchange for the product, excluding amounts collected on behalf of third parties (e.g. value-added taxes). Payment terms for these sales are due within 90 days. The arrangement does not include any variable consideration. The costs of assurance type warranties that provide the customer the right to exchange purchased product that does not meet appropriate quality standards are recognized when they are probable and are reasonably estimable. As of March 31, 2021, the Company did not incur, and therefore did not defer, any material costs to obtain or fulfill contracts. The Company did not have any contract assets or contract liabilities as of March 31, 2021. Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company’s significant accounting estimates relate to recoverability of operating lease right-of-use assets, intangible assets and long-term investments, net realizable value and obsolescence allowance for inventory, deferred tax assets and valuation allowance, allowance for doubtful accounts, stock-based arrangements and fair value of investments. Management bases its estimates on historical experience and on various other assumptions that it believes are reasonable under the circumstances. Actual results may differ from those estimates, and such differences may be material to the consolidated financial statements.

Investment in equity securities

Investment in equity securities, at fair value and long-term investments	3 Months Ended
	Mar. 31, 2021
Investment in equity securities, at fair value and long-term investments
Investment in equity securities, at fair value and long-term investments	4. Investment in equity securities, at fair value and long-term investments Investment in equity securities, at fair value MaxCyte Inc. The Company has an equity investment in the common stock of MaxCyte, a publicly traded company. The Company’s investment in this equity security is carried at its fair value, with changes in fair value reported in the statement of operations each reporting period. ​ BioInvent International AB In October 2020, in conjunction with its license agreement entered into with BioInvent (see Note 2), a publicly traded company, CASI made a $6.3 million investment (equivalent to SEK 53.8 million) to acquire 1.2 million new shares (after 25:1 reverse stock split) of BioInvent, and 14,700,000 warrants, each warrant with a right to subscribe for 0.04 shares (after 25:1 reverse stock split) in BioInvent within a period of five years. The investments in the ordinary shares and warrants of BioInvent are carried at fair value, with changes in fair value reported in the statement of operations each reporting period. The fair value of the ordinary shares was measured using its quoted market price, a Level 1 input, and was $6.4 million as of March 31, 2021 and $6.6 million as of December 31, 2020 (see Note 16). The fair value of the warrants was measured using observable market-based inputs other than quoted prices in active markets for identical assets or liabilities, level 2 inputs. The Company uses the Black-Scholes-Merton valuation model to estimate the fair value of warrants. The fair value of the warrants was $769,000 as of March 31, 2021 and $840,000 as of December 31, 2020 (see Note 16), with assumptions including an expected life of 4.66 years, an assumed volatility of 47.2%, and a risk-free interest rate of -0.14 %. The following table summarizes the Company’s investment in equity securities at Fair Value as of March 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ ​ ​ (In thousands) ​ ​ ​ ​ ​ ​ unrealized ​ Aggregate fair Description Classification Cost gains value MaxCyte - equity interest Investment ​ $ — ​ $ 4,591 ​ $ 4,591 BioInvent - equity interest Investment ​ $ 5,661 ​ $ 696 ​ $ 6,357 ​ Unrealized gains or (losses) on the Company’s equity investment for the three months ended March 31, 2021 and 2020 were $1,568,000 and $(15,000), respectively. Unrealized gains or (losses) on the Company’s equity investment are recognized as change in fair value of investment in equity securities in the accompanying unaudited condensed consolidated statements of operations and comprehensive loss. Long-term investments Long-term investments consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ (In thousands) 2021 2020 ​ Available-for-sale debt securities: ​ ​ ​ Black Belt Tx Limited - convertible loan ​ $ 169 ​ $ 83 ​ Securities measured at fair value: ​ ​ ​ ​ ​ ​ ​ BioInvent International AB - warrants ​ ​ 769 ​ ​ 840 ​ Cleave Therapeutics, Inc. - convertible loan ​ ​ 5,500 ​ ​ — ​ Equity securities without readily determinable fair value: ​ ​ ​ ​ Black Belt Tx Limited - equity interest ​ 2,250 ​ 2,250 ​ Juventas Cell Therapy Ltd - equity interest ​ 25,973 ​ 26,059 ​ Juventas Cell Therapy Ltd - put option ​ 209 ​ 210 ​ Total ​ $ 34,870 ​ $ 29,442 ​ ​ Black Belt Tx Limited In April 2019, in conjunction with its license agreement the Company entered into with Black Belt (see Note 2), the Company made a 2 million euros ($2,249,600) equity investment in the ordinary shares of a newly established, privately held UK Company, Black Belt Tx Limited ("Black Belt Tx"), representing a 14.1% equity interest with the right to appoint a non-voting board observer. As the Company does not have significant influence over operating and financial policies of Black Belt Tx, and the equity interests do not have readily determinable fair value, the investment in Black Belt Tx is stated at cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment. The Company did not record any adjustments or impairments during the three months ended March 31, 2021 related to this investment. In July 2020, the Company entered into a three-year convertible loan agreement with Black Belt Tx (the "Black Belt Tx Loan") in the amount of 211,800 euros ($250,000) with a non-compounding annual interest rate of 6% payable, together with the principal balance, at maturity. The loan principal will be disbursed in three equal installments of 70,600 euros. The first tranche of 70,600 euros ($83,000) was disbursed upon execution of the loan agreement in August 2020. The second tranche of 70,600 euros ($86,000) was disbursed in February 2021. In the first quarter of 2021, Black Belt Tx reached certain operational targets as stipulated in the loan agreement, and Black Belt Tx’s Board of Directors met in February 2021 to approve disbursement of the second tranche. The third tranche will be disbursed if Black Belt Tx reaches certain additional operational targets as stipulated in the loan agreement, subject to approval by Black Belt Tx's Board of Directors. In the event that Black Belt Tx, on or prior to the maturity date, completes an equity financing round of at least 5,000,000 euros ($5.9 million), then the outstanding principal amount shall be automatically converted into such shares at 80% of the price per share issued divided by a compensating factor based on the number of years that the Black Belt Tx Loan has been outstanding. The investment in convertible loan is accounted for as investment in debt securities as available-for-sale instrument. Juventas Cell Therapy Ltd In June 2019, in conjunction with its license agreement entered into with Juventas (see Note 2), the Company, through CASI Biopharmaceuticals, made an RMB 80 million ($11,788,000) investment in Juventas, a privately held, China-based company, in Juventas’ Series A plus equity, which represented a 16.327% equity interest on a fully diluted basis, and the right to appoint a non-voting board observer. The Company is entitled to substantive liquidation preference over the founding shareholder of Juventas. In addition, the Juventas’ founding shareholder provided a put option to the Company pursuant to which the Company can put the equity investment to the founding shareholder at a fixed return of 8% per annum upon occurrence of certain events. The investment in the equity interests of the Juventas and the investment in put option to the founding shareholder were accounted for as investments in equity securities using the measurement alternative at its cost, minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer, as the fair value of the equity securities of Juventas is not readily determinable. The consideration of RMB 80 million ($11,788,000) was allocated into investment in equity interests and investment in put option based on their relative fair value on the transaction date. In September 2020, in conjunction with the Supplementary Agreement entered into with Juventas (see Note 2), the Company obtained additional Series A plus equity interest in Juventas with substantive liquidation preference over Juventas' founding shareholder, resulting in the Company's equity ownership increasing to 16.45% (post-Juventas Series B financing) on a fully diluted basis. CASI Biopharmaceuticals is also entitled to appoint a director to Juventas’ board of directors. Juventas’ founding shareholder also provided a put option to the Company pursuant to which the Company can put the additional equity investment to the founding shareholder at RMB 70 million plus a fixed return of 8% per annum upon occurrence of certain events. The transaction closed on September 29, 2020. The fair value of the Company’s additional equity interest in Juventas and the new put option was RMB 83.7 million ($12.3 million) and RMB 0.4 million ($64,000) on September 29, 2020, respectively, which was estimated using significant estimates and assumptions, including multiples of selected comparable companies in applying the market approach model. Since the equity interest with substantive liquidation preference is not in-substance common stock, the investment in the additional equity interests of Juventas was accounted for as an investment in equity securities at transaction date fair value with a corresponding credit to Other Liabilities. The profit-sharing liability represents the Company’s obligation to pay an increased share of future profits pursuant to the Supplementary Agreement (see Note 2) which was conveyed by the Company in exchange for the additional equity interests in Juventas. The Company views this as a payment from a vendor that should reduce cost of revenues over the period of royalty payments. The long-term liability will be derecognized as payments are made on a systematic and rational basis representing the pattern in which the Company expects to settle the profit-sharing payment during the commercialization period of CNCT19. The investments are measured using the measurement alternative at its cost, minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for the identical or a similar investment of the same issuer, as the fair value of the equity securities of Juventas is not readily determinable. The Company did not record any adjustments or impairments during the three months ended March 31, 2021 related to this investment. In June 2020, the Company entered into a one-year loan agreement with Juventas in the amount of RMB 30,000,000 ($4,243,000) with an annual interest rate of 20%. In August 2020, the Company entered into another one-year ​ Cleave Therapeutics, Inc. In March 2021, Cleave and the Company entered into a license agreement. Cleave and the Company will develop CB-5339 in both hematological malignancies and solid tumors, with CASI responsible for development and commercialization in China and associated markets. Cleave received a $5.5 million upfront payment and is eligible to receive up to $74 million in development and commercial milestone payments plus tiered royalties in the high-single to mid-double-digit range on net sales of CB-5339. In addition to the upfront cash payment, CASI made a $5.5 million investment in Cleave through a three-year convertible note with a non-compounding annual interest rate of 3% payable at maturity. The principal balance is also due at maturity. The proceeds will support and advance Cleave’s programs and general operations. In the event that Cleave, on or prior to the maturity date, completes an equity financing round of preferred stock of at least $10.0 million, then the outstanding principal amount and accrued interest shall be automatically converted into such shares at 80% of the price per share issued. The investment in the convertible loan is designated an investment measured at fair value through profit or loss.

Inventories

Inventories	3 Months Ended
	Mar. 31, 2021
Inventories
Inventories	5. Inventories Inventories at March 31, 2021 and December 31, 2020 consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) ​ March 31, 2021 ​ December 31, 2020 Finished goods $ 2,994 $ 1,356 ​ Raw materials ​ — ​ — ​ Total ​ $ 2,994 ​ $ 1,356 ​ ​ No provisions to write down the carrying amount of inventory have been recorded in the three months ended March 31, 2021 and 2020.

Leases

Leases	3 Months Ended
	Mar. 31, 2021
Leases
Leases	6. Leases Operating lease ROU assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Rent expense is recognized on a straight-line basis over the lease term. Operating lease liabilities (see below) are included in accrued liabilities and other liabilities (noncurrent) in the unaudited condensed consolidated balance sheets as of March 31, 2021 and December 31, 2020. All of the Company’s existing leases as of March 31, 2021 are classified as operating leases. For the quarter ended March 31, 2021, the Company had seven material operating leases for land, facilities and office equipment with remaining terms expiring from 2021 through 2069 and a weighted average remaining lease term of 38.12 In November 2019, CASI Wuxi entered into a fifty-year lease agreement for the right to use state-owned land in China for the construction of a manufacturing facility. The land parcel is 74,028.40 square meters. The Company classifies this lease as an operating lease. The Company prepaid all of the lease payments for the land use right in 2019 in the amount of RMB 45 million (equivalent to $6.5 million). In the first quarter of 2021, one operating lease expired. Since the office space was no longer needed, it was not renewed. Rent expense for the three months ended March 31, 2021 and 2020 was $400,000 and $377,000, respectively. There were no variable lease costs or sublease income for leased assets for the three months ended March 31, 2021 and 2020. Right of use assets and liabilities as of March 31, 2021 and December 31, 2020 in the condensed consolidated balance sheets were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, (In thousands) 2021 2020 ​ Right of use assets ​ $ 8,323 ​ $ 8,696 ​ ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ $ 814 ​ $ 939 ​ Other liabilities ​ 769 ​ 965 ​ Total lease liabilities ​ $ 1,583 ​ $ 1,904 ​ ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (In thousands) ​ 2021 ​ 2020 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ Operating cash flows ​ $ 370 ​ $ 377 ​ A maturity analysis of the Company’s operating leases as of March 31, 2021 follows: Future undiscounted cash flows: ​ ​ ​ ​ ​ (In thousands) ​ 2021 (remaining nine months) ​ $ 682 2022 ​ 626 2023 ​ 280 Thereafter ​ 42 Total ​ 1,630 ​ ​ ​ ​ Discount factor ​ (47) Lease liability ​ 1,583 Amounts due within 12 months ​ 814 Non-current lease liability ​ $ 769 ​

Intangible Assets

Intangible Assets	3 Months Ended
	Mar. 31, 2021
Intangible Assets
Intangible Assets	7. Intangible Assets Intangible assets include ANDAs that were acquired as part of 2018 asset acquisitions of U.S. marketed generic products and capitalized costs related to a cloud computing arrangement (CCA). These intangible assets were originally recorded at relative estimated fair values based on the purchase price for the asset acquisitions and are stated net of accumulated amortization and impairment, if any. The ANDAs are amortized over their estimated useful lives of 13 years, using the straight-line method. The CCA is being amortized over its useful life of 5 years. In February 2020, the Company entered into an agreement with Chartwell Rx Sciences, LLC (“Chartwell”) in which the Company sold and transferred the control of seven U.S. FDA-approved ANDAs to Chartwell in exchange for $450,000 in cash, which the Company received in March 2020. These ANDAs had a net book value of $0 at the time of sale. The Company is entitled to an additional $1 million, contingent upon Chartwell receiving certain FDA approvals relating to certain of these ANDAs. The Company recognized a gain on disposal of intangible assets in the amount of $450,000 in the accompanying unaudited condensed consolidated statement of operations and comprehensive loss for the three months ended March 31, 2020. The additional $1 million is treated as variable consideration. Because the amount of variable consideration is highly susceptible to factors outside the Company's influence and the Company’s experience with similar types of contracts is limited, the Company did not include the amount of variable consideration in recognition of gain on disposal of intangible assets for the three months ended March 31, 2020. The Company will recognize the variable consideration and additional gain on disposal of intangible assets when the constraint on variable consideration is resolved, i.e., Chartwell receives relevant FDA approvals. As of March 31, 2021, no FDA approvals has been made to Chartwell on those products. ​ Intangible assets at March 31, 2021 consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) ​ ​ ​ ​ ​ ​ ​ ​ Asset Purchase Price Accumulated Amortization Estimated useful lives ANDAs ​ $ 15,832 ​ $ (3,086) 13 years Others ​ ​ 197 ​ ​ (109) ​ 5 years Total ​ $ 16,029 ​ $ (3,195) ​ The changes in intangible assets for three months ended March 31, 2021 are as follows: ​ ​ ​ ​ ​ (In thousands) ​ Balance as of December 31, 2020 ​ $ 13,210 Amortization expense ​ (337) Foreign currency translation adjustment ​ ​ (39) Balance as of March 31, 2021 ​ $ 12,834 ​ Expected future amortization expense, is as follows: ​ ​ ​ ​ ​ (In thousands) ​ ​ ​ 2021 (remaining nine months) ​ $ 987 2022 ​ 1,316 2023 ​ 1,316 2024 ​ 1,284 2025 ​ 1,284 2026 and thereafter ​ 6,647 ​

Grants

Grants	3 Months Ended
	Mar. 31, 2021
Grants
Grants	8. Grants In April 2020, CASI Wuxi received RMB 15.9 million (equivalent to $2.2 million) from the Jiangsu Province Wuxi Huishan Economic Development Zone as a government grant for this development project which was recorded as deferred income in April 2020. The grant will be amortized over the term of the lease of the land. Since April 2020, the Company has recognized RMB 321,000 in deferred income as of March 31, 2021, and therefore, RMB 15.6 million (equivalent to $2.4 million) remain as deferred income in the unaudited condensed balance sheet as of March 31, 2021. The Company recognized $12,000 and $0 of other income during the three months ended March 31, 2021 and 2020, respectively.

Bank Borrowings

Bank Borrowings	3 Months Ended
	Mar. 31, 2021
Bank Borrowings
Bank Borrowings	9. Bank Borrowings On November 3, 2020, Beijing Branch of China CITIC Bank Corporation Limited approved a guaranteed line of Credit (“Bank Borrowings) to the Company with maximum borrowings of RMB 10.0 million ($1.5 million). The joint and several liability guarantee was provided by Beijing Capital Financing Guarantee Co, Ltd. At December 31, 2020, the Company had outstanding borrowings under the Bank Borrowings of RMB 5.4 million ($826,000), which matures on November 7, 2021, and bears interest at a fixed rate of 3.35% per annum. On February 3, 2021, the Company had additional bank borrowings of RMB 4.6 million ($0.7 million), of which RMB 3.0 million ($0.5 million) matures on September 2, 2021 and the remainder balance matures on November 7, 2021. These additional bank borrowings bear interest at a fixed rate of 3.72% per annum. Interest expense of $11,000 was recorded in the three months ended March 31, 2021.

Notes Payable

Notes Payable	3 Months Ended
	Mar. 31, 2021
Notes Payable
Notes Payable	10. Notes Payable On April 27, 2020, M&T Bank approved a $465,595 loan to the Company under the Paycheck Protection Program (PPP) pursuant to the Coronavirus Aid, Relief and Economic Security (CARES) Act that was signed into law on March 27, 2020. The loan, evidenced by a promissory note to M&T Bank as lender and dated April 29, 2020, has a term of two years, is unsecured, and is guaranteed by the Small Business Administration (SBA). The loan bears interest at a fixed rate of one percent per annum. Some or all of the loan may be forgiven if the Company complies with certain relevant conditions. In June 2020, the PPP was amended through enactment of the Paycheck Protection Program Flexibility Act of 2020 (PPPFA). Under the new act, the Company’s payments of principal and interest are deferred until October 2021. The Company has until August 2021 to apply for loan forgiveness before potential loan payments would begin. Interest expense of $1,000 was recorded in the three months ended March 31, 2021. ​

Redeemable Noncontrolling Inter

Redeemable Noncontrolling Interest	3 Months Ended
	Mar. 31, 2021
Redeemable Noncontrolling Interest
Redeemable Noncontrolling Interest	11. Redeemable Noncontrolling Interest On December 26, 2018, the Company, together with Wuxi Jintou Huicun Investment Enterprise, a limited partnership organized under Chinese law (“Wuxi LP”) established CASI Wuxi to build and operate a manufacturing facility in the Wuxi Huishan Economic Development Zone in Jiangsu Province, China. The Company holds 80% of the equity interests in CASI Wuxi and will invest, over time, $80 million in CASI Wuxi. The Company’s investment will consist of (i) $21 million in cash (paid in February 2019), (ii) a transfer of selected ANDAs valued at $30 million (transferred in May 2019), and (iii) an additional $29 million cash payment within three years from the date of establishment of CASI Wuxi. Wuxi LP holds 20% of the equity interest in CASI Wuxi through its investment in RMB of $20 million in cash (paid in March 2019). As the transfer of ANDAs valued at $30 million was to the Company’s consolidated subsidiary (CASI Wuxi), the Company recognized the transfer of the ANDAs at their carrying value and did not recognize a gain on the transfer. Pursuant to the investment contract between the Company and Wuxi LP and Articles of Association of CASI Wuxi, the Company has the call option to purchase the 20% equity interest in CASI Wuxi held by Wuxi LP at any time within 5 years from the date of establishment of CASI Wuxi (i.e. up to December 26, 2023). Wuxi LP has the put option to require the Company to redeem the 20% equity interest in CASI Wuxi at any time after December 26, 2023. The redemption value under both the Company’s embedded put option and Wuxi LP’s embedded call option is equal to $20 million plus interest at the bank loan interest rate issued by the People's Bank of China for the period beginning with the initial capital contribution by Wuxi LP to the date of redemption. In addition, Wuxi LP has the put option to require the Company to redeem the 20% equity interest in CASI Wuxi at $20 million upon the occurrence of any of the following conditions: (i) the Company fails to fulfill its investment obligation to CASI Wuxi; (ii) CASI Wuxi suffers serious losses, discontinued operation, dissolution, goes into process of bankruptcy liquidation; or (iii) the Company substantially violates the investment contract and Articles of Association of CASI Wuxi. The investment of Wuxi LP in CASI Wuxi is treated as redeemable noncontrolling interest and is classified outside of permanent equity on the consolidated balance sheets because (1) the noncontrolling interest is not mandatorily redeemable financial instruments, and (2) it is redeemable at the option of the holder, or upon the occurrence of an event that is not solely within the control of the Company. The Company initially recorded the redeemable noncontrolling interest at its fair value of $20 million. The carrying amount of the redeemable noncontrolling interest is subsequently recorded at the greater of the amount of (1) the initial carrying amount, increased or decreased for the redeemable noncontrolling interest’s share of net income or loss in CASI Wuxi or (2) the redemption value, assuming the noncontrolling interest is redeemable at the balance sheet date. Changes in redeemable noncontrolling interest during the three month period ended March 31, 2021 and 2020 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ (In thousands) ​ 2021 ​ 2020 ​ Balance at beginning of period ​ $ 22,033 $ 20,670 ​ Cash contribution by Wuxi LP ​ — ​ — ​ Share of CASI Wuxi net (loss)/income ​ (349) ​ (109) ​ Accretion of redeemable noncontrolling interest ​ 548 ​ 317 ​ Foreign currency translation adjustment ​ ​ (68) ​ ​ — ​ Balance at end of period ​ $ 22,164 $ 20,878 ​ ​

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2021
Stockholders' Equity
Stockholders' Equity	12. Stockholders’ Equity March 2021 Underwritten Public Offering ​ On March 26, 2021, the Company closed an underwritten public offering of 15,853,658 shares of the Company’s common stock (the “Offering”) at a price to the public of $2.05 per share. The gross proceeds to CASI from the Offering were $32.5 million before deducting the underwriting discounts and commissions and offering expenses payable by CASI. Pursuant to the underwriting agreement, the Company’s directors and executive officers entered into agreements in substantially the form agreed to by the Underwriters providing for a 90-day As a result of the Company’s failure to timely file a periodic report with the SEC in connection with the adoption of its amended and restated bylaws, the Company is ineligible to use the current shelf registration or file new short form registration statements on Form S-3 until October 1, 2021, assuming the Company continues to timely file the Company’s required Exchange Act reports. In the interim, however, the Company may raise capital pursuant to a registration statement on Form S-1 or on a private placement basis. The Company is using the net proceeds of this offering for working capital and general corporate purposes, which include, but are not limited to advancing the Company’s product portfolio, acquiring the rights to new product candidates and general and administrative expenses. Common Stock Sales Agreements The Company has a Common Stock Sales Agreement (the “Sales Agreement”) with H.C. Wainwright & Co., LLC (“HCW”). On July 19, 2019, the Company entered into an amendment to the Sales Agreement reducing the maximum amount that may be sold under the Sales Agreement to $20 million. As of March 31, 2021, subject to complying with its terms and conditions, $19.5 million remained available under the Sales Agreement. On July 19, 2019, the Company entered into an Open Market Sale Agreement SM The Offering is being made by means of a written prospectus supplement and accompanying prospectus forming part of a shelf registration statement on Form S-3, previously filed with the SEC on November 20, 2020, which was declared effective on December 2, 2020. We have filed a final prospectus supplement, dated March 24, 2021, with the SEC relating to the Offering. Pursuant to the Underwriting Agreement, our directors and executive officers entered into agreements in substantially the form agreed to by the Underwriters providing for a 90-day Stock purchase warrants activity for the three months ended March 31, 2021 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Weighted Average ​ Warrants Exercise Price Outstanding at December 31, 2020 8,271,709 ​ $ 4.58 Issued — ​ $ — Exercised — ​ $ — Expired — ​ $ — Outstanding at March 31, 2021 8,271,709 ​ $ 4.58 Exercisable at March 31, 2021 8,271,709 ​ $ 4.58 ​ All outstanding warrants are equity classified.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2021
Net Loss Per Share
Net Loss Per Share	13. Net Loss Per Share The following table sets forth the basic and diluted net loss per share computation and provides a reconciliation of the numerator and denominator for the periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended (In thousands, except per share data) March 31, 2021 ​ March 31, 2020 Numerator: ​ ​ ​ ​ Net loss attributable to CASI Pharmaceuticals, Inc. ​ $ (13,883) ​ $ (8,441) ​ Denominator: ​ ​ ​ ​ ​ Weighted average number of common shares ​ 124,825 ​ 98,773 ​ Denominator for basic and diluted net loss per share calculation ​ 124,825 ​ 98,773 ​ Net loss per share ​ ​ ​ ​ ​ — Basic and diluted ​ $ (0.11) ​ $ (0.09) ​ ​ As of March 31, 2021, and 2020, outstanding stock options totaling 15,989,238 and 15,815,052, respectively, and outstanding warrants totaling 8,271,709 and 9,761,416, respectively, were anti-dilutive, and therefore, were not included in the computation of weighted average shares used in computing diluted loss per share.

Stock-Based Compensation

Stock-Based Compensation	3 Months Ended
	Mar. 31, 2021
Stock-Based Compensation
Stock-Based Compensation	14. Stock-Based Compensation As of March 31, 2021, a total of 10,722,923 shares remained available for grant under the Company’s 2011 Long-Term Incentive Plan. The Company’s net loss for the three months ended March 31, 2021 and 2020 includes $2.0 million and $1.9 million, respectively, of non-cash compensation expense related to the Company’s share-based compensation awards. The compensation expense related to the Company’s share-based compensation arrangements is recorded as components of general and administrative expense, selling and marketing expense, and research and development expense, as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ (In thousands) 2021 2020 Research and development ​ $ 75 ​ $ 116 ​ Sales and Marketing ​ ​ 33 ​ ​ — ​ General and administrative ​ 1,890 ​ 1,789 ​ Share-based compensation expense ​ $ 1,998 ​ $ 1,905 ​ ​ Compensation expense related to stock options is recognized over the requisite service period, which is generally the option vesting term of up to five years. Awards with performance conditions are expensed when it is probable that the performance condition will be achieved. For the three month periods ended March 31, 2021 and 2020, $26,000 and $21,000 was expensed for stock option awards with performance conditions that were probable during the period, respectively. The Company uses the Black-Scholes-Merton valuation model to estimate the fair value of service based and performance-based stock options granted to employees. Option valuation models, including Black-Scholes-Merton, require the input of highly subjective assumptions, and changes in the assumptions used can materially affect the grant date fair value of an award. These assumptions include the risk-free interest rate, expected dividend yield, expected volatility, and the expected life of the award. Following are the weighted-average assumptions used in valuing the stock options granted to employees during the three month periods ended March 31, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ ​ 2021 2020 Expected volatility 80.43 % 75.84 % ​ Range of risk free interest rate 0.72% to 0.76 % 1.77 % ​ Expected term of option 6.25 years 6.25 years ​ Expected dividend yield 0.00 % 0.00 % ​ ​ The weighted average fair value of stock options granted during the three month periods ended March 31, 2021 and 2020 were $2.45 and $2.10, respectively. A summary of changes in options under the Company’s stock option plans during the three month period ended March 31, 2021 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ Number of Options Exercise Price Outstanding at December 31, 2020 16,746,238 ​ $ 2.71 ​ Exercised — ​ $ — ​ Granted 395,000 ​ $ 3.55 ​ Expired (331,500) ​ $ 4.81 ​ Forfeited (820,500) ​ $ 2.63 ​ Cancelled ​ — ​ $ — ​ Outstanding at March 31, 2021 15,989,238 ​ $ 2.69 ​ Vested and expected to vest at March 31, 2021 ​ 15,989,238 ​ $ 2.69 ​ Exercisable at March 31, 2021 9,465,817 ​ $ 2.29 ​ ​ Cash received from option exercises under all share-based payment arrangements for the three month periods ended March 31, 2021 and 2020 was $0 million and $3.8 million, respectively.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Taxes
Income Taxes	15. Income Taxes At December 31, 2020, the Company had a $2.1 million unrecognized tax benefit. The Company recorded a full valuation allowance on the deferred tax asset after offsetting unrecognized tax benefit recognized in the consolidated financial statements as of December 31, 2020. During the three months ended March 31, 2021, there were no material changes to the measurement of unrecognized tax benefits in various tax jurisdictions.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Measurements
Fair Value Measurements	16. Fair Value Measurements The majority of the Company’s financial instruments (consisting of cash and cash equivalents, accounts receivable, accounts payable, accrued liabilities, notes payable and bank borrowings) are carried at cost which approximates their fair values due to the short-term nature of the instruments. The Company’s investments in equity securities are carried at fair value, and investments in convertible loans are carried at fair value (see Note 4). ​ Fair value is the price that would be received from the sale of an asset or paid to transfer a liability assuming an orderly transaction in the most advantageous market at the measurement date. U.S. GAAP establishes a hierarchical disclosure framework which prioritizes and ranks the level of observability of inputs used in measuring fair value. These tiers include: ● Level 1—Quoted prices (unadjusted) in active markets that are accessible at the measurement date for identical assets or liabilities. The fair value hierarchy gives the highest priority to Level 1 inputs. ● Level 2—Observable market-based inputs other than quoted prices in active markets for identical assets or liabilities. ● Level 3—Unobservable inputs are used when little or no market data is available. The fair value hierarchy gives the lowest priority to Level 3 inputs. Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company evaluates financial assets and liabilities subject to fair value measurements on a recurring basis to determine the appropriate level at which to classify them each reporting period. This determination requires the Company to make subjective judgments as to the significance of inputs used in determining fair value and where such inputs lie within the hierarchy. The Company has equity investments in the common stock of two publicly traded companies. The Company’s investments in these equity securities are carried at their estimated fair value, with changes in fair value reported in the consolidated statement of operations and comprehensive loss each reporting period (see Note 4). The fair value of the common stock is based on quoted market price for the investees’ common stock, a Level 1 input. The Company has an equity investment in the warrants of a publicly traded company. The Company’s investment is carried at its estimated fair value, with changes in fair value reported in the consolidated statement of operations and comprehensive loss each reporting period (see Note 4). The fair value of the warrants was measured using observable market-based inputs other than quoted prices in active markets for identical assets or liabilities, level 2 inputs. The Company uses the Black-Scholes-Merton valuation model to estimate the fair value of warrants. Option valuation models, including Black-Scholes-Merton, require the input of highly subjective assumptions, and changes in the assumptions used can materially affect the fair value determination of a warrant. The Company has an investment in the convertible debt of a privately held UK Company. The Company’s investment is carried at its estimated fair value, with changes in fair value reported in the consolidated statement of operations and comprehensive loss each reporting period (see Note 4) using Level 3 input The Company has an investment in the convertible debt of a privately held California Company. The Company’s investment is carried at its estimated fair value, with changes in fair value reported in the consolidated statement of operations and comprehensive loss each reporting period (see Note 4) using Level 3 input. The following tables present the Company’s financial assets and liabilities accounted for at fair value on a recurring basis as of March 31, 2021 and December 31, 2020, by level within the fair value hierarchy: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) ​ Fair Value at ​ ​ ​ ​ ​ ​ ​ ​ ​ Description March 31, 2021 Level 1 Level 2 Level 3 Investments in Current and non-Current Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments in common stock ​ $ 10,948 ​ $ 10,948 ​ $ — ​ $ — Investment in warrants -Designated as investment measured at FVTPL ​ $ 769 ​ $ — ​ $ 769 ​ $ — Investment in convertible loan-AFS ​ $ 169 ​ $ — ​ $ — ​ $ 169 Investment in convertible loan-Designated as investment measured at FVTPL ​ $ 5,500 ​ $ — ​ $ — ​ $ 5,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) Fair Value at ​ ​ ​ ​ ​ ​ ​ ​ ​ Description December 31, 2020 Level 1 Level 2 Level 3 Investments in Current and non-Current Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments in common stock ​ $ 9,309 ​ $ 9,309 ​ $ — ​ $ — Investment in warrants-Designated as investment measured at FVTPL ​ ​ 840 ​ $ — ​ $ 840 ​ $ — Investment in convertible loan-AFS ​ $ 83 ​ $ — ​ $ — ​ $ 83 ​ Financial Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The Company has no financial assets and liabilities ​ Non-Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company has no non-financial assets and liabilities Non-Financial Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis The Company has no non-financial assets and liabilities

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2021
Related Party Transactions
Related Party Transactions	17. Related Party Transactions Juventas. one Spectrum/Acrotech ​ BioCheck. Since the Company required additional office space, in January 2020, the agreement was amended for annualized rents in the amount of $144,000 ($12,000 a month) with a stipulation that the new rent was retroactive to October 1, 2019. The lease expires on June 9, 2021. The Company has provided BioCheck a notification of non-renewal as per the lease agreement. During the three months ended March 31, 2021, the Company recognized rent expense of $36,000 and expects to recognize $27,000 of additional rent expense in 2021 related to the remainder of this lease. March 2021 Underwritten Public Offering Transactions. ETP Global Fund L.P. (“ETP Global”), whose founding and managing member is CASI's Chairman and CEO, purchased shares of common stock in the Offering at the public offering price and on the same terms as the other purchasers in the Offering. ETP Global, which is a current shareholder of CASI, purchased 3,000,000 shares at the public offering price of $2.05 per share for a total of $6.15 million.

Commitments

Commitments	3 Months Ended
	Mar. 31, 2021
Commitments
Commitments	18. Commitments In conjunction with the Cleave agreement entered into during 2021 (see Note 2), the Company is responsible for certain milestone and royalty payments. As of March 31, 2021, no milestones have been achieved. In conjunction with the BioInvent agreement entered into during 2020 (see Note 2), the Company is responsible for certain milestone and royalty payments. As of March 31, 2021, no milestones have been achieved. In conjunction with the Black Belt agreement entered into during 2019 (see Note 2), the Company is responsible for certain milestone and royalty payments. As of March 31, 2021, no milestones have been achieved. In conjunction with the Pharmathen agreement entered into during 2019 (see Note 2), the Company is responsible for one remaining milestone payment. As of March 31, 2021, the remaining milestone has not been achieved. In conjunction with the Laurus Labs agreement entered into during 2018, the Company is responsible for certain remaining milestone payments. As of March 31, 2021, the remaining milestones have not been met. In November 2019, CASI Wuxi entered into a lease agreement for the right to use state-owned land in China for the construction of a manufacturing facility. On August 27, 2020, CASI Wuxi entered into a Construction Project Contract (the "Construction Contract") with China Electronic System Engineering No. 2 Construction Co., Ltd. ("China Engineering"). Pursuant to the Construction Contract, CASI Wuxi will pay a contract price of RMB 74,588,000 (equivalent to $10,923,000) to retain China Engineering to complete the phase 1 project of CASI Wuxi's research and development production base, consisting of construction and installation of a combined factory building, warehouse, guard house and public works. The estimated completion date is October 2023. The Company is subject in the normal course of business to various legal proceedings in which claims for monetary or other damages may be asserted. Management does not believe such legal proceedings, unless otherwise disclosed herein, are material.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	3 Months Ended
	Mar. 31, 2021
Summary of Significant Accounting Policies
Revenue Recognition	Revenue Recognition Product sales recognized in the consolidated statements of operations are considered revenue from contracts with customers and, accordingly, the Company recognizes revenue using the following steps: ● Identification of the contract, or contracts, with a customer; ● Identification of the performance obligations in the contract; ● Determination of the transaction price, including the identification and estimation of variable consideration; ● Allocation of the transaction price to the performance obligations in the contract; and ● Recognition of revenue when the Company satisfies a performance obligation. The Company recognizes revenue on sales of EVOMELA® when the control of the product is transferred to the distributor, which occurs upon delivery of the product to the carrier appointed by the distributor, in an amount that reflects the consideration to which the Company expects to be entitled to in exchange for the product, excluding amounts collected on behalf of third parties (e.g. value-added taxes). Payment terms for these sales are due within 90 days. The arrangement does not include any variable consideration. The costs of assurance type warranties that provide the customer the right to exchange purchased product that does not meet appropriate quality standards are recognized when they are probable and are reasonably estimable. As of March 31, 2021, the Company did not incur, and therefore did not defer, any material costs to obtain or fulfill contracts. The Company did not have any contract assets or contract liabilities as of March 31, 2021.
Use of Estimates	Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. The Company’s significant accounting estimates relate to recoverability of operating lease right-of-use assets, intangible assets and long-term investments, net realizable value and obsolescence allowance for inventory, deferred tax assets and valuation allowance, allowance for doubtful accounts, stock-based arrangements and fair value of investments. Management bases its estimates on historical experience and on various other assumptions that it believes are reasonable under the circumstances. Actual results may differ from those estimates, and such differences may be material to the consolidated financial statements.

Investment in equity securiti_2

Investment in equity securities, at fair value and long-term investments (Tables)	3 Months Ended
	Mar. 31, 2021
Investment in equity securities, at fair value and long-term investments
Schedule of investment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ ​ ​ (In thousands) ​ ​ ​ ​ ​ ​ unrealized ​ Aggregate fair Description Classification Cost gains value MaxCyte - equity interest Investment ​ $ — ​ $ 4,591 ​ $ 4,591 BioInvent - equity interest Investment ​ $ 5,661 ​ $ 696 ​ $ 6,357
Schedule of components of long-term investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, ​ (In thousands) 2021 2020 ​ Available-for-sale debt securities: ​ ​ ​ Black Belt Tx Limited - convertible loan ​ $ 169 ​ $ 83 ​ Securities measured at fair value: ​ ​ ​ ​ ​ ​ ​ BioInvent International AB - warrants ​ ​ 769 ​ ​ 840 ​ Cleave Therapeutics, Inc. - convertible loan ​ ​ 5,500 ​ ​ — ​ Equity securities without readily determinable fair value: ​ ​ ​ ​ Black Belt Tx Limited - equity interest ​ 2,250 ​ 2,250 ​ Juventas Cell Therapy Ltd - equity interest ​ 25,973 ​ 26,059 ​ Juventas Cell Therapy Ltd - put option ​ 209 ​ 210 ​ Total ​ $ 34,870 ​ $ 29,442 ​

Inventories (Tables)

Inventories (Tables)	3 Months Ended
	Mar. 31, 2021
Inventories
Schedule of components of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) ​ March 31, 2021 ​ December 31, 2020 Finished goods $ 2,994 $ 1,356 ​ Raw materials ​ — ​ — ​ Total ​ $ 2,994 ​ $ 1,356 ​

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2021
Leases
Schedule of right of use assets and liabilities on condensed balance sheet	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ March 31, ​ December 31, (In thousands) 2021 2020 ​ Right of use assets ​ $ 8,323 ​ $ 8,696 ​ ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ $ 814 ​ $ 939 ​ Other liabilities ​ 769 ​ 965 ​ Total lease liabilities ​ $ 1,583 ​ $ 1,904 ​
Schedule of supplemental cash flow information	​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, (In thousands) ​ 2021 ​ 2020 Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ Operating cash flows ​ $ 370 ​ $ 377
Schedule of future undiscounted cash flows	​ ​ ​ ​ ​ (In thousands) ​ 2021 (remaining nine months) ​ $ 682 2022 ​ 626 2023 ​ 280 Thereafter ​ 42 Total ​ 1,630 ​ ​ ​ ​ Discount factor ​ (47) Lease liability ​ 1,583 Amounts due within 12 months ​ 814 Non-current lease liability ​ $ 769

Intangible Assets (Tables)

Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2021
Intangible Assets
Schedule of net definite-lived intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) ​ ​ ​ ​ ​ ​ ​ ​ Asset Purchase Price Accumulated Amortization Estimated useful lives ANDAs ​ $ 15,832 ​ $ (3,086) 13 years Others ​ ​ 197 ​ ​ (109) ​ 5 years Total ​ $ 16,029 ​ $ (3,195)
Schedule of changes in intangible assets	​ ​ ​ ​ ​ (In thousands) ​ Balance as of December 31, 2020 ​ $ 13,210 Amortization expense ​ (337) Foreign currency translation adjustment ​ ​ (39) Balance as of March 31, 2021 ​ $ 12,834
Schedule of expected future amortization expense	​ ​ ​ ​ ​ (In thousands) ​ ​ ​ 2021 (remaining nine months) ​ $ 987 2022 ​ 1,316 2023 ​ 1,316 2024 ​ 1,284 2025 ​ 1,284 2026 and thereafter ​ 6,647

Redeemable Noncontrolling Int_2

Redeemable Noncontrolling Interest (Tables)	3 Months Ended
	Mar. 31, 2021
Redeemable Noncontrolling Interest
Schedule of changes in redeemable noncontrolling interest	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ (In thousands) ​ 2021 ​ 2020 ​ Balance at beginning of period ​ $ 22,033 $ 20,670 ​ Cash contribution by Wuxi LP ​ — ​ — ​ Share of CASI Wuxi net (loss)/income ​ (349) ​ (109) ​ Accretion of redeemable noncontrolling interest ​ 548 ​ 317 ​ Foreign currency translation adjustment ​ ​ (68) ​ ​ — ​ Balance at end of period ​ $ 22,164 $ 20,878 ​

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2021
Stockholders' Equity
Schedule of stock purchase warrants activity	​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Weighted Average ​ Warrants Exercise Price Outstanding at December 31, 2020 8,271,709 ​ $ 4.58 Issued — ​ $ — Exercised — ​ $ — Expired — ​ $ — Outstanding at March 31, 2021 8,271,709 ​ $ 4.58 Exercisable at March 31, 2021 8,271,709 ​ $ 4.58

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Net Loss Per Share
Schedule of basic and diluted net loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended (In thousands, except per share data) March 31, 2021 ​ March 31, 2020 Numerator: ​ ​ ​ ​ Net loss attributable to CASI Pharmaceuticals, Inc. ​ $ (13,883) ​ $ (8,441) ​ Denominator: ​ ​ ​ ​ ​ Weighted average number of common shares ​ 124,825 ​ 98,773 ​ Denominator for basic and diluted net loss per share calculation ​ 124,825 ​ 98,773 ​ Net loss per share ​ ​ ​ ​ ​ — Basic and diluted ​ $ (0.11) ​ $ (0.09) ​

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	3 Months Ended
	Mar. 31, 2021
Stock-Based Compensation
Schedule of compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ (In thousands) 2021 2020 Research and development ​ $ 75 ​ $ 116 ​ Sales and Marketing ​ ​ 33 ​ ​ — ​ General and administrative ​ 1,890 ​ 1,789 ​ Share-based compensation expense ​ $ 1,998 ​ $ 1,905 ​
Schedule of weighted-average assumptions used in valuing the stock options	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended March 31, ​ ​ ​ 2021 2020 Expected volatility 80.43 % 75.84 % ​ Range of risk free interest rate 0.72% to 0.76 % 1.77 % ​ Expected term of option 6.25 years 6.25 years ​ Expected dividend yield 0.00 % 0.00 % ​
Schedule of stock option plans and of changes in options outstanding under the plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted Average ​ ​ Number of Options Exercise Price Outstanding at December 31, 2020 16,746,238 ​ $ 2.71 ​ Exercised — ​ $ — ​ Granted 395,000 ​ $ 3.55 ​ Expired (331,500) ​ $ 4.81 ​ Forfeited (820,500) ​ $ 2.63 ​ Cancelled ​ — ​ $ — ​ Outstanding at March 31, 2021 15,989,238 ​ $ 2.69 ​ Vested and expected to vest at March 31, 2021 ​ 15,989,238 ​ $ 2.69 ​ Exercisable at March 31, 2021 9,465,817 ​ $ 2.29 ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Measurements
Schedule of assets and liabilities measured at fair value on recurring and nonrecurring basis	The following tables present the Company’s financial assets and liabilities accounted for at fair value on a recurring basis as of March 31, 2021 and December 31, 2020, by level within the fair value hierarchy: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) ​ Fair Value at ​ ​ ​ ​ ​ ​ ​ ​ ​ Description March 31, 2021 Level 1 Level 2 Level 3 Investments in Current and non-Current Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments in common stock ​ $ 10,948 ​ $ 10,948 ​ $ — ​ $ — Investment in warrants -Designated as investment measured at FVTPL ​ $ 769 ​ $ — ​ $ 769 ​ $ — Investment in convertible loan-AFS ​ $ 169 ​ $ — ​ $ — ​ $ 169 Investment in convertible loan-Designated as investment measured at FVTPL ​ $ 5,500 ​ $ — ​ $ — ​ $ 5,500 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (In thousands) Fair Value at ​ ​ ​ ​ ​ ​ ​ ​ ​ Description December 31, 2020 Level 1 Level 2 Level 3 Investments in Current and non-Current Assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Investments in common stock ​ $ 9,309 ​ $ 9,309 ​ $ — ​ $ — Investment in warrants-Designated as investment measured at FVTPL ​ ​ 840 ​ $ — ​ $ 840 ​ $ — Investment in convertible loan-AFS ​ $ 83 ​ $ — ​ $ — ​ $ 83 ​

Basis of Presentation, Organi_2

Basis of Presentation, Organization and Principal Activities (Details) $ / shares in Units, $ in Thousands	Mar. 26, 2021USD ($)$ / sharesshares	Mar. 31, 2021USD ($)segmentperson	Dec. 31, 2020USD ($)
Description of Business and Basis of Presentation
Number of operating segments | segment		1
Accumulated deficit		$ (583,836)	$ (570,501)
Additional shares of common stock purchase | shares	15,853,658
Offering price per share | $ / shares	$ 2.05
Gross proceeds from the offering	$ 32,500
Cash and cash equivalents		68,117	$ 57,064
Parent Entity
Description of Business and Basis of Presentation
Cash and cash equivalents		45,400
Other subsidiaries
Description of Business and Basis of Presentation
Cash and cash equivalents		$ 200
Offering
Description of Business and Basis of Presentation
Offering price per share | $ / shares	$ 2.05
Minimum
Description of Business and Basis of Presentation
Number of hematology and oncology sales and marketing specialist | person		80
March 2021 Offering
Description of Business and Basis of Presentation
Additional shares of common stock purchase | shares	15,853,658
Offering price per share | $ / shares	$ 2.05
Gross proceeds from the offering	$ 32,500
CASI China
Description of Business and Basis of Presentation
Percentage of ownership interest held by the parent entity in the non stock subsidiary		100.00%
Cash and cash equivalents		$ 4,800
CASI Wuxi
Description of Business and Basis of Presentation
Percentage of ownership interest held by the parent entity in the non stock subsidiary		80.00%
Cash and cash equivalents		$ 17,700

License and Distribution Agre_2

License and Distribution Agreements (Details) $ in Thousands, € in Millions

Oct. 29, 2019

Mar. 31, 2021USD ($)

Nov. 30, 2020USD ($)

Apr. 30, 2019USD ($)

Apr. 30, 2019EUR (€)

Mar. 31, 2019

Mar. 31, 2021USD ($)

Dec. 31, 2020USD ($)

Mar. 31, 2020USD ($)

Dec. 31, 2020USD ($)

Dec. 31, 2020EUR (€)

Dec. 31, 2019EUR (€)

License and Distribution Agreements

Acquired in-process research and development

$ 5,500

$ 1,081

Revenues

5,736

3,406

Black Belt Therapeutics Ltd

License and Distribution Agreements

Upfront payment

$ 5,700

€ 5

€ 5

Guokang Pharmaceuticals Co., Ltd

License and Distribution Agreements

Non Royalty Exclusive Distribution Period

3 years

Revenues

5,700

$ 3,400

Pharmathen Global BV

License and Distribution Agreements

Upfront payment | €

1

Non Royalty Exclusive Distribution Period

10 years

10 years

Non Royalty Exclusive Distribution, Supply Cost Determination, Period Considered

3 years

Additional milestone payments paid

$ 1,700

€ 2

Potential milestones up to | €

€ 1.5

Cleave Therapeutics, Inc

License and Distribution Agreements

Upfront payment

$ 5,500

Acquired in-process research and development

$ 5,500

Potential milestone of up to

$ 74,000

BioInvent International AB

License and Distribution Agreements

Upfront payment

$ 5,900

Potential milestones and royalties of up to

$ 83,000

Acquired in-process research and development

$ 5,900

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Summary of Significant Accounting Policies
Allowance for doubtful accounts	$ 0	$ 0

Investment in equity securiti_3

Investment in equity securities, at fair value and long-term investments (Details) kr in Millions	Sep. 29, 2020USD ($)	Sep. 29, 2020CNY (¥)	Mar. 31, 2021USD ($)	Feb. 28, 2021USD ($)	Feb. 28, 2021EUR (€)	Nov. 30, 2020USD ($)	Oct. 31, 2020USD ($)shares	Sep. 30, 2020	Aug. 31, 2020USD ($)	Aug. 31, 2020EUR (€)	Aug. 31, 2020CNY (¥)	Jul. 31, 2020USD ($)	Jul. 31, 2020EUR (€)	Jun. 30, 2020USD ($)	Jun. 30, 2020CNY (¥)	Jun. 30, 2019USD ($)	Jun. 30, 2019CNY (¥)	Apr. 30, 2019USD ($)	Apr. 30, 2019EUR (€)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)	Oct. 31, 2020SEK (kr)	Sep. 29, 2020CNY (¥)	Jul. 31, 2020EUR (€)
Change in fair value of investment in equity securities																				$ 1,568,000	$ (15,000)
BioInvent International AB
Investment to be made							$ 6,300,000																kr 53.8
Number of shares subscribed (in shares) | shares							1,200,000
Reverse stock split							25
Number of new warrants subscribed | shares							14,700,000
Number of shares subscribed per warrant							0.04																0.04
Subscription period for warrants							5 years
Fair value of warrants outstanding			$ 769,000																	$ 769,000		$ 840,000
Warrants contractual life			4 years 7 months 28 days																	4 years 7 months 28 days		4 years 7 months 28 days
Upfront payment						$ 5,900,000
BioInvent International AB | Volatility
Warrants , Measurement Input			47.2																	47.2		47.2
BioInvent International AB | Risk Free Interest Rate
Warrants , Measurement Input			(0.14)																	(0.14)		(0.14)
Juventas Cell Therapy Ltd.
Fair value of additional equity interest	$ 12,300,000																							¥ 83,700,000
Payments to acquire equity Investments																$ 11,788,000	¥ 80,000,000
Equity ownership (as a percent)								16.45%								16.327%	16.327%
Interest rate (as a percent)								8.00%								8.00%	8.00%
Additional equity investment | ¥		¥ 70,000,000
Juventas Cell Therapy Ltd. | June 2020 Loan Agreement
Term of loan provided														1 year	1 year
Interest rate (as a percent)														20.00%	20.00%
Loans advanced to related party														$ 4,243,000	¥ 30,000,000
Juventas Cell Therapy Ltd. | August 2020 Loan Agreement
Term of loan provided									1 year	1 year	1 year
Interest rate (as a percent)									20.00%	20.00%	20.00%
Loans advanced to related party									$ 5,790,000		¥ 40,000,000
Juventas Cell Therapy Ltd. | Put option
Payments to acquire equity Investments	$ 64,000	¥ 400,000
Black Belt Tx Limited
Payments to acquire equity Investments																		$ 2,249,600	€ 2,000,000
Convertible loan tranches | €													€ 70,600
Minimum equity financing												$ 5,900,000													€ 5,000,000
Percentage of price per share issued at which the outstanding principal loan is to be converted												80.00%	80.00%
Equity ownership (as a percent)																		14.10%	14.10%
Interest rate (as a percent)												6.00%	6.00%
Term of loan												3 years	3 years
Loan to be advanced												$ 250,000	€ 211,800
Black Belt Tx Limited | Black Belt Tx Loan - Tranche One
Convertible loan tranches									$ 83,000	€ 70,600
Black Belt Tx Limited | Black Belt Tx Loan - Tranche Two
Convertible loan tranches				$ 86,000	€ 70,600
Cleave Therapeutics, Inc
Term of loan provided			3 years
Interest rate (as a percent)			3.00%
Minimum equity financing round amount			$ 10,000,000																	$ 10,000,000
Percentage of per share price at which the loans advanced will be converted			80.00%																	80.00%
Upfront payment			$ 5,500,000
Investment in Convertible Note			5,500,000																	$ 5,500,000
Level 1
Fair value of additional equity interest																						$ 2,700,000
Level 1 | MaxCyte Inc.
Fair value of additional equity interest			4,600,000																	4,600,000
Level 1 | BioInvent International AB
Fair value of additional equity interest			$ 6,400,000																	$ 6,400,000		$ 6,600,000

Investment in equity securiti_4

Investment in equity securities, at fair value and long-term investments - Summary of Investments (Details) - Common Stock $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
MaxCyte Inc.
Gross unrealized gains equity securities at fair value	$ 4,591
Aggregate equity securities at fair value	4,591
BioInvent International AB
Cost	5,661
Gross unrealized gains equity securities at fair value	696
Aggregate equity securities at fair value	$ 6,357

Investment in equity securiti_5

Investment in equity securities, at fair value and long-term investments - Summary of Long-term investments (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule Of Long Term Investments
Total	$ 34,870	$ 29,442
Black Belt Tx Limited | Convertible loan
Schedule Of Long Term Investments
Available-for-sale debt securities	169	83
Black Belt Tx Limited | Equity Securities
Schedule Of Long Term Investments
Equity securities without readily determinable fair value	2,250	2,250
Juventas Cell Therapy Ltd. | Equity Securities
Schedule Of Long Term Investments
Equity securities without readily determinable fair value	25,973	26,059
Juventas Cell Therapy Ltd. | Put option
Schedule Of Long Term Investments
Equity securities without readily determinable fair value	209	210
BioInvent International AB | Warrants
Schedule Of Long Term Investments
Securities measured at fair value	769	$ 840
Cleave Therapeutics, Inc | Convertible loan
Schedule Of Long Term Investments
Securities measured at fair value	$ 5,500

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Inventories
Finished goods	$ 2,994		$ 1,356
Total	2,994		$ 1,356
Inventory write down	$ 0	$ 0

Leases - (Details)

Leases - (Details) ¥ in Millions	1 Months Ended		3 Months Ended
	Nov. 30, 2019USD ($)m²	Nov. 30, 2019CNY (¥)m²	Mar. 31, 2021USD ($)lease	Mar. 31, 2020USD ($)
Number of Operating Leases | lease			7
Weighted average remaining lease term			38 years 1 month 13 days
Weighted average discount rates			3.55%
Number of expired leases | lease			1
Rent expenses			$ 400,000	$ 377,000
Variable lease costs			0	0
Sublease income			$ 0	$ 0
CASI Wuxi
Term of lease contract	50 years	50 years
Land parcel area (in square meters) | m²	74,028.40	74,028.40
Prepaid lease payments for the land use right	$ 6,500,000	¥ 45

Leases - Right of Use Assets an

Leases - Right of Use Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Right of use assets	$ 8,323	$ 8,696
Operating Lease, Liability	1,583	1,904
Accrued Liabilities-Current
Operating Lease, Liability	814	939
Other Liabilities-Long Term
Operating Lease, Liability	$ 769	$ 965

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows	$ 370	$ 377

Leases - Future Undiscounted Ca

Leases - Future Undiscounted Cash Flows (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Leases
2021 (remaining nine months)	$ 682
2022	626
2023	280
Thereafter	42
Total	1,630
Discount factor	(47)
Lease liability	1,583	$ 1,904
Amounts due within 12 months	814
Non-current lease liability	$ 769

Intangible Assets - Additional

Intangible Assets - Additional Information (Details)	1 Months Ended	3 Months Ended
	Feb. 29, 2020USD ($)item	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2020USD ($)
Finite-Lived Intangible Assets
Net book value		$ 12,834,000		$ 13,210,000
(Gain) loss on disposal of intangible assets			$ 450,000
ANDA
Finite-Lived Intangible Assets
Estimated useful lives		13 years
Cloud Computing Arrangement
Finite-Lived Intangible Assets
Estimated useful lives		5 years
Chartwell | ANDA
Finite-Lived Intangible Assets
Number of intangible assets sold | item	7
Aggregate consideration on sale of intangible assets	$ 450,000
Net book value	0
(Gain) loss on disposal of intangible assets	450,000
Remaining potential milestone of up to	$ 1,000,000

Intangible Assets - Net Definit

Intangible Assets - Net Definite-lived Intangible Assets (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Finite-Lived Intangible Assets
Purchase Price	$ 16,029
Accumulated Amortization	(3,195)
ANDA
Finite-Lived Intangible Assets
Purchase Price	15,832
Accumulated Amortization	$ (3,086)
Estimated useful lives	13 years
Others
Finite-Lived Intangible Assets
Purchase Price	$ 197
Accumulated Amortization	$ (109)
Estimated useful lives	5 years

Intangible Assets - Intangible

Intangible Assets - Intangible Assets Rollforward (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Intangible Assets
Beginning balance	$ 13,210
Amortization expenses	(337)
Foreign currency translation adjustments	(39)
Ending balance	$ 12,834

Intangible Assets - Expected Fu

Intangible Assets - Expected Future Amortization Expense (Details) $ in Thousands	Mar. 31, 2021USD ($)
Intangible Assets
2021 (remaining nine months)	$ 987
2022	1,316
2023	1,316
2024	1,284
2025	1,284
2026 and thereafter	$ 6,647

Grants (Details)

Grants (Details)	1 Months Ended		3 Months Ended		11 Months Ended
	Apr. 30, 2020USD ($)	Apr. 30, 2020CNY (¥)	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Mar. 31, 2021CNY (¥)	Mar. 31, 2021CNY (¥)	Dec. 31, 2020USD ($)
Grants, Disclosure [Line Items]
Deferred income			$ 2,331,000				$ 2,351,000
CASI Wuxi
Grants, Disclosure [Line Items]
Government grant received	$ 2,200,000	¥ 15,900,000
Recognized deferred income | ¥					¥ 321,000
Deferred income			2,400,000			¥ 15,600,000
Other income			$ 12,000	$ 0

Bank Borrowings (Details)

Bank Borrowings (Details) ¥ in Millions	Sep. 02, 2021USD ($)	Sep. 02, 2021CNY (¥)	Feb. 03, 2021USD ($)	Feb. 03, 2021CNY (¥)	Mar. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2020CNY (¥)	Nov. 03, 2020USD ($)	Nov. 03, 2020CNY (¥)
Bank Borrowings
Proceeds from Lines of Credit					$ 709,000
Interest expense					1,000,000
China CITIC Bank Corporation Limited
Bank Borrowings
Maximum Borrowing								$ 1,500,000	¥ 10
Amount outstanding						$ 826,000	¥ 5.4
Interest rate						3.35%	3.35%
Proceeds from Lines of Credit			$ 700,000	¥ 4.6
Interest expense					$ 11,000,000
China CITIC Bank Corporation Limited | Subsequent Events
Bank Borrowings
Interest rate	3.72%	3.72%
Proceeds from Lines of Credit	$ 500,000	¥ 3

Notes Payable (Details)

Notes Payable (Details) - USD ($) $ in Thousands	Apr. 29, 2020	Mar. 31, 2021	Apr. 27, 2020
Notes Payable
Interest expense		$ 1,000
M & T Bank
Notes Payable
Loan approved under Paycheck Protection Program (PPP)			$ 465,595
Interest rate	1.00%
Term of loan	2 years

Redeemable Noncontrolling Int_3

Redeemable Noncontrolling Interest (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	May 31, 2019	Mar. 31, 2021	Mar. 31, 2019	Feb. 28, 2019	Dec. 26, 2018
Noncontrolling Interest
Value of transfer of selected ANDAs		$ 30
CASI Wuxi
Noncontrolling Interest
Equity ownership (as a percent)					80.00%
Investment commitment					$ 80
Initial cash investment				$ 21
Value of transfer of selected ANDAs	$ 30
Committed amount of cash payment within three years		$ 29
Call option purchase investment period		5 years
Payments to acquire investments		$ 20	$ 20
CASI Wuxi | Call Option
Noncontrolling Interest
Equity ownership (as a percent)		20.00%
CASI Wuxi | Put option
Noncontrolling Interest
Equity ownership (as a percent)		20.00%
CASI Wuxi
Noncontrolling Interest
Payments to acquire investments		$ 20

Redeemable Noncontrolling Int_4

Redeemable Noncontrolling Interest - Changes in Redeemable Noncontrolling Interest (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Redeemable Noncontrolling Interest
Balance at beginning of period	$ 22,033	$ 20,670
Cash contribution by Wuxi LP	0	0
Share of CASI Wuxi net (loss)/income	(349)	(109)
Accretion to redeemable non-controlling interest redemption value	548	317
Foreign currency translation adjustment	(68)
Balance at end of period	$ 22,164	$ 20,878

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 26, 2021	Mar. 24, 2021	Jul. 19, 2019	Mar. 31, 2021
Additional shares of common stock purchase	15,853,658
Offering price per share	$ 2.05
Gross proceeds from the offering	$ 32.5
Securities lock up period	90 days
Open Market Sale Agreement
Maximum Sales Price from Issuance of Common Stock			$ 30
Remaining amount available under the sales agreement				$ 28.4
Amendment To Open Sale Agreement
Maximum Sales Price from Issuance of Common Stock			$ 20
Remaining amount available under the sales agreement				$ 19.5
Sale Agreement And Open Market Agreement
Shares issued				0
Securities lock up period		90 days

Stockholders' Equity - Warrants

Stockholders' Equity - Warrants Activity (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Number of Warrants
Beginning balance | shares	8,271,709
Issued | shares	0
Exercised | shares	0
Expired | shares	0
Ending balance | shares	8,271,709
Exercisable | shares	8,271,709
Weighted Average Exercise Price
Beginning balance | $ / shares	$ 4.58
Issued | $ / shares	0
Exercised | $ / shares	0
Expired | $ / shares	0
Ending balance | $ / shares	4.58
Exercisable | $ / shares	$ 4.58

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Options
Antidilutive securities excluded from computation of earnings per share amount	15,989,238	15,815,052
Warrant
Antidilutive securities excluded from computation of earnings per share amount	8,271,709	9,761,416

Net Loss Per Share - Basic and

Net Loss Per Share - Basic and diluted net loss per share computation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss attributable to CASI Pharmaceuticals, Inc.	$ (13,883)	$ (8,441)
Denominator:
Weighted average number of common shares	124,825	98,773
Denominator for basic and diluted net loss per share calculation	124,825	98,773
Net loss per share - basic and diluted (in dollars per share)	$ (0.11)	$ (0.09)

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,998	$ 1,905
Research and Development Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	75	116
Sales and Marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	33
General and Administrative Expense
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,890	$ 1,789

Stock-Based Compensation - Weig

Stock-Based Compensation - Weighted-Average Assumptions (Details)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Stock-Based Compensation
Expected volatility	80.43%	75.84%
Risk free interest rate		1.77%
Range of risk free interest rate, Minimum	0.72%
Range of risk free interest rate, Maximum	0.76%
Expected term of option	6 years 3 months	6 years 3 months
Expected dividend yield	0.00%	0.00%

Stock-Based Compensation - Opti

Stock-Based Compensation - Options Outstanding (Details)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding
Beginning Balance | shares	16,746,238
Exercised | shares	0
Granted | shares	395,000
Expired | shares	(331,500)
Forfeited | shares	(820,500)
Cancelled | shares	0
Ending Balance | shares	15,989,238
Vested and expected to vest | shares	15,989,238
Exercisable | shares	9,465,817
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price
Beginning balance | $ / shares	$ 2.71
Exercised | $ / shares	0
Granted | $ / shares	3.55
Expired | $ / shares	4.81
Forfeited | $ / shares	2.63
Cancelled | $ / shares	0
Ending Balance | $ / shares	2.69
Vested and expected to vest | $ / shares	2.69
Exercisable | $ / shares	$ 2.29

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation	$ 1,998,000	$ 1,905,000
Performance Share Based Compensation Expense	$ 26,000	$ 21,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 2.45	$ 2.10
Share Based Payment Cash Received from Stock Option Exercises	$ 0	$ 3,800,000
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Granted Expire Terms	5 years
Long Term Incentive Plan 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant	10,722,923

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Income Taxes
Unrecognized tax benefits	$ 0	$ 2.1

Fair Value Measurements (Detail

Fair Value Measurements (Details) $ in Thousands	Mar. 31, 2021USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Financial assets, measured at fair value	$ 0
Financial liabilities, measured at fair value	0
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Non-financial assets, measured at fair value	0
Non-financial liabilities, measured at fair value	0
Non-recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Non-financial assets, measured at fair value	0
Non-financial liabilities, measured at fair value	$ 0

Fair Value Measurements - Finan

Fair Value Measurements - Financial and Non-Financial Assets and Liabilities (Details) - Recurring - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investment in common stock	$ 10,948	$ 9,309
Investment in warrants -Designated as investment measured at FVTPL	769	840
Investment in convertible loan-AFS	169	83
Investment in convertible loan-Designated as investment measured at FVTPL	5,500
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investment in common stock	10,948	9,309
Investment in warrants -Designated as investment measured at FVTPL	0
Investment in convertible loan-AFS	0	0
Investment in convertible loan-Designated as investment measured at FVTPL	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investment in common stock	0	0
Investment in warrants -Designated as investment measured at FVTPL	769	840
Investment in convertible loan-AFS	0	0
Investment in convertible loan-Designated as investment measured at FVTPL	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis
Investment in common stock	0	0
Investment in convertible loan-AFS	169	$ 83
Investment in convertible loan-Designated as investment measured at FVTPL	$ 5,500

Related Party Transactions (Det

Related Party Transactions (Details)	Mar. 26, 2021USD ($)$ / sharesshares	Jul. 01, 2019CNY (¥)	Jul. 01, 2019USD ($)	Jan. 31, 2020USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2021CNY (¥)	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Related Party Transaction
Lessee, Operating Lease, Existence of Option to Extend [true false]						true	true
Offering price per share | $ / shares	$ 2.05
Spectrum
Related Party Transaction
Payable to related party										$ 200,000
Expense incurred										2,600,000
Spectrum | EVOMELA
Related Party Transaction
Equity ownership (as a percent)											6.80%
Related Party Transaction, Purchase Obligation Commitments											$ 9,200,000
BioCheck Inc.
Related Party Transaction
Term of lease contract					1 year
Lease payments				$ 12,000	$ 5,000		$ 36,000	$ 27,000	$ 144,000	$ 60,000
Emerging Technology Partners LLC | Minimum
Related Party Transaction
Equity ownership (as a percent)						5.00%	5.00%
Juventas Cell Therapy Ltd.
Related Party Transaction
Term of lease contract		1 year	1 year
Lease payments		¥ 80,000	$ 15,000
Lease income | ¥						¥ 240,000
Additional lease income | ¥						¥ 240,000
Offering
Related Party Transaction
Shares issued | shares	15,853,658
Offering price per share | $ / shares	$ 2.05
Net proceeds from issuance of common stock	$ 32,500,000
Chairman and Chief Executive Officer | Emerging Technology Partners LLC
Related Party Transaction
Shares issued | shares	3,000,000
Offering price per share | $ / shares	$ 2.05
Net proceeds from issuance of common stock	$ 6,150,000

Commitments (Details)

Commitments (Details)	3 Months Ended
	Mar. 31, 2021Milestone	Aug. 27, 2020CNY (¥)	Aug. 27, 2020USD ($)
Number of milestones achieved	0
CASI Wuxi
Construction project contract amount		¥ 74,588,000	$ 10,923,000
BioInvent International AB
Number of milestones achieved	0
Black Belt Tx Limited
Number of milestones achieved	0
Pharmathen Global BV
Number of milestone payments yet to be paid	1