UNITED STATESSECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE13a-16 OR 15d-16 UNDERTHE SECURITIES EXCHANGE ACT OF 1934

For the month of August,2023

Commission File Number  001-41666

CASI PHARMACEUTICALS, INC.

(Translation of registrant’s name into English)

1701-1702, China Central Office Tower 1

No. 81 Jianguo Road, Chaoyang District

Beijing, 100025

People’s Republic of China

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.  Form 20-F  x Form 40-F  ¨

EXHIBIT INDEX

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Exhibit 99.1

CASI PHARMACEUTICALS ANNOUNCES

SECOND QUARTER 2023 BUSINESS AND FINANCIAL UPDATES

BEIJING, China (August11, 2023) CASI Pharmaceuticals, Inc. (Nasdaq: CASI), a biopharmaceutical company focused on developing and commercializing innovative therapeutics and pharmaceutical products, today reported financial results for the quarter ended June 30, 2023.

Wei-Wu He, Ph.D., CASI’s Chairman and Chief Executive Officer, commented, “We are pleased to report $9.8 million sales revenue for the second quarter of 2023. This is a 15% increase compared to the same period last year and an 18% of increase from the first quarter of 2023.”

Dr. He continued, “Advancement, development, and commercialization of the portfolio remains our strategic focus. We have achieved a major milestone with our partner Juventas Biotechnology (Tianjin) Co., Ltd. (“Juventas”) on the CNCT-19 CAR-T Cell therapy. CNCT-19’s New Drug Application (NDA) was accepted by National Medical Products Administration (NMPA) in December 2022. We are now diligently preparing for the anticipated CNCT-19 launch in China. We are advancing the clinical development of BI-1206 in combination with rituximab and presently undertaking the enrollment of patients for the second cohort of the phase I trial in China. We are transitioning the development of CID-103 into China for the malignant hematology indications. In addition, we acquired global rights for CB-5339 from Cleave Therapeutics in July. On August 1^st^, we announced the transfer of license of Folotyn^®^ in China from Mundipharma International Corporation Limited, Mundipharma Medical Company, and Acrotech Biopharma Inc. We continue to advance our portfolio by executing on several milestones as well as bringing in new potential opportunities for synergy in the quarters ahead.”

Second Quarter 2023 Financial Highlights

About CASI Pharmaceuticals

CASI Pharmaceuticals, Inc. is a 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 intends to execute its plan to become a leader by launching medicines in the greater China market, leveraging the Company’s China-based regulatory and commercial competencies and its global drug development expertise. The Company’s operations in China are conducted through its wholly-owned subsidiary, CASI Pharmaceuticals (China) Co., Ltd., located in Beijing, China. More information on CASI is available at www.casipharmaceuticals.com.

Forward-Looking Statements

This news release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act with respect to the outlook for expectations for future financial or business performance, strategies, expectations, and goals. Forward-looking statements are subject to numerous assumptions, risks, and uncertainties, which change over time. Forward-looking statements speak only as of the date they are made, and no duty to update forward-looking statements is assumed. Actual results could differ materially from those currently anticipated due to a number of factors, including: the risk that we may be unable to continue as a going concern as a result of our inability to raise sufficient capital for our operational needs; the possibility that we may be delisted from trading on The Nasdaq Capital Market; the volatility in the market price of our ordinary shares; the risk of substantial dilution of existing shareholders in future share issuances; the difficulty of executing our business strategy in China; our inability to enter into strategic partnerships for the development, commercialization, manufacturing and distribution of our proposed product candidates or future candidates, including with respect to BI-1206, CB-5339 and CID-103; our lack of experience in manufacturing products and uncertainty about our resources and capabilities to do so on a clinical or commercial scale; risks relating to the commercialization, if any, of our products and proposed products (such as marketing, safety, regulatory, patent, product liability, supply, competition and other risks); our inability to predict when or if our product candidates will be approved for marketing by the U.S. Food and Drug Administration (FDA), National Medical Products Administration (NMPA), or other regulatory authorities; our inability to enter into strategic partnerships for the development, commercialization, manufacturing and distribution of our proposed product candidates or future candidates, including with respect to our partnerships with Juventas and BioInvent; the risks relating to the need for additional capital and the uncertainty of securing additional funding on favorable terms; the risks associated with our product candidates, and the risks associated with our other early-stage products under development; the risk that result in preclinical and clinical models are not necessarily indicative of clinical results; uncertainties relating to preclinical and clinical trials, including delays to the commencement of such trials; our ability to protect our intellectual property rights; the lack of success in the clinical development of any of our products; and our dependence on third parties; the risks related to our dependence on Juventas to conduct the clinical development of CNCT19 and to partner with us to co-market CNCT19; risks related to our dependence on Juventas to ensure the patent protection and prosecution for CNCT19; risks relating to the commercialization, if any, of our proposed products (such as marketing, safety, regulatory, patent, product liability, supply, competition and other risks); risks relating to interests of our largest shareholders and our Chairman and CEO that differ from our other shareholders; and risks related to the development of a new manufacturing facility by CASI Wuxi. Such factors, among others, could have a material adverse effect upon our business, results of operations, and financial condition. We caution readers not to place undue reliance on any forward-looking statements, which only speak as of the date made. Additional information about the factors and risks that could affect our business, financial condition, and results of operations, are contained in our filings with the U.S. Securities and Exchange Commission, which are available at www.sec.gov.

EVOMELA^®^ is proprietaryto Acrotech Biopharma Inc. and its affiliates. FOLOTYN^®^is proprietaryto Mundipharma International Corporation Limited and its affiliates.

COMPANY CONTACT:

Rui Zhang

CASI Pharmaceuticals, Inc.

Phone: 240.864.2643

Email: [email protected]

#

CASI Pharmaceuticals, Inc.

Unaudited Condensed Consolidated Balance Sheets

(In thousands, except share and per share data)

CASI Pharmaceuticals, Inc.

Unaudited Condensed Consolidated Statements of Operations and Comprehensive Loss

(In thousands, except share and per share data)