CASI Pharmaceuticals Announces Update and Additional Results from Phase 1 Study of CID-103 in Adult Patients with Chronic Immune Thrombocytopenia

• Additional proof of concept data consistent and strengthen data set shared at ASH 2025

• Management to host meetings at JP Morgan 44th Annual Healthcare Conference 2026

SAN FRANCISCO, CALIFORNIA / ACCESS Newswire / January 12, 2026 / CASI Pharmaceuticals, Inc. (NASDAQ:CASI), a clinical-stage biopharmaceutical company developing CID-103, a potentially best-in-class, anti-CD38 monoclonal antibody, for patients with organ transplant rejection and autoimmune diseases, today announced additional data from its Phase 1 open-label study of CID-103 in adult patients with immune thrombocytopenia (ITP). Initial clinical data from this study were presented at the 67th American Society of Hematology Annual Meeting and Exposition on December 7, 2025, in Orlando, Florida. Updated safety and efficacy data can be found on the CASI website here.

The update includes additional safety and efficacy data based on:

• CID-103 at 30 mg (n=1), 150 mg (n=1), 300 mg (n=3), 600 mg (n=5), and 900 mg (n=6)

• ~5 weeks of additional dosing / follow up for the ongoing patients in all cohorts

• 3 additional patients enrolled in 900 mg cohort

  • 2 patients are at Week 5 of study treatment

  • 1 patient is at Week 3 of study treatment

• 2 additional patients enrolled and one patient is in screening in 600 mg cohort

  • 1 patient is at Week 3 of study treatment

  • 1 patient is at Week 2 of study treatment

Interim Results:

• CID-103 demonstrated a manageable safety profile with only two Grade 3 treatment-related events and no dose limiting toxicities observed

• All infusion-related reactions (IRR) occurred with priming dose and are due to low grade AEs

• Primary Efficacy Endpoint achieved in 12 of 15 evaluable (80%) patients

  • 10 of 15 evaluable (66%) patients achieved Complete Response (CR) with platelet improvement observed as early as one week post dose

• Reduction of PD markers (decreased anti-platelet antibodies, immunoglobulins, NK and plasma cells) is consistent with the presumed CID-103 MOA resulting in the observed platelet response

"We are pleased with the safety and tolerability of CID-103 and encouraged by the 80% of patients achieving the primary efficacy endpoint, and plan to report additional updates as the study progresses" said Alex Zukiwski, M.D., Global Chief Medical Officer of CASI. "Importantly, this study provides important clinical proof of concept supporting further development of CID-103 in autoimmune disorders, solid organ transplant rejection, and other CD38 mediated diseases with large unmet medical need."

Separately, the Company announced that its board of directors (the "Board") received a preliminary non-binding proposal, dated January 7, 2026,which was further amended by an updated preliminary non-binding proposal dated January 9, 2026 from Dr. Wei-Wu He (the "Proposal"), to acquire all of the outstanding ordinary shares, par value US$0.0001 per share, of the Company (the "Ordinary Shares"), that are not already beneficially owned by Dr. He for a proposed purchase price of US$1.15 per Ordinary Share. The proposed price represents a 30% premium to the average closing price during the last 30 trading days. Full details of the proposals can be found here.

CASI Board cautions the Company's shareholders and others considering trading the Company's securities that no decisions have been made with respect to the Proposal. There can be no assurance that any definitive offer will be received, that any definitive agreement will be executed relating to the transaction contemplated by the Proposal, or that the transaction contemplated by the Proposal, or any other similar transaction will be approved or consummated. The Company does not undertake any obligation to provide any updates with respect to any transaction, except as required under applicable law.

About Phase 1 Dose-Escalation Study

In this multicenter, open-label, Phase 1 study, an estimated maximum of approximately 30 adults between 18 and 65 with primary ITP who had received at least two previous lines of treatment and whose mean platelet count was ≤ 35 x 10⁹/L on at least two measurements at least one week apart may be enrolled. This dose escalation study incorporated both accelerated escalation and standard 3+3 design. Patients were assigned to sequential dose cohorts of CID-103 at 30 mg, 150 mg, 300 mg, 600 mg, and 900 mg, with a priming dose of CID-103, of either 30 mg or 150 mg administered prior to the cohort dose. Primary efficacy endpoint is the proportion of patients achieving a platelet response, defined as a platelet count ≥ 50 x 10⁹/L and ≥ 20 x 10⁹/L above baseline on at least 2 consecutive measurements at least 7 days apart within the first twelve weeks of treatment. Other endpoints were evaluated including pharmacokinetic and pharmacodynamic markers. As of cut-off date of January 6, sixteen (16) patients have been enrolled and dosed.

Protocol incorporates multiple adaptive design elements such as intra-patient dose escalation and dose expansion as deemed appropriate by the Safety Monitoring Committee (SMC).

This studyis conducted under an FDA approved IND and a Clinical Trial Application (CTA) approved by the Chinese Center for Drug Evaluation (CDE).

About CASI Pharmaceuticals

CASI Pharmaceuticals, Inc. is a public biopharmaceutical company developing CID-103, an anti-CD38 monoclonal antibody for organ transplant rejection and autoimmune diseases.

CID-103 is a fully human IgG1, potentially best-in-class, clinical stage, anti-CD38 monoclonal antibody which targets a unique epitope and has demonstrated an encouraging pre-clinical efficacy and clinical safety profile compared to other anti-CD38 monoclonal antibodies, and for which CASI owns exclusive global rights. CASI received FDA IND clearance to conduct a Phase 1 study in renal allograft antibody-mediated rejection (AMR) in the U.S. In parallel, CASI is actively recruiting and dosing patients in an ongoing Phase 1 study in immune thrombocytopenia (ITP). In addition, CASI is assessing multiple technologies for development of a stable, high concentration protein solution for subcutaneous formulation.

More information on CASI is available at https://www.casipharmaceuticals.com.

Forward Looking Statements

This announcement contains forward-looking statements. These statements are made under the "safe harbor" provisions of the U.S. Private Securities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as "will," "expects," "future," "intends," "plans," "believes," and similar statements. Among other things, the business outlook and quotations from management in this announcement, as well as the Company's strategic and operational plans, contain forward-looking statements. The Company may also make written or oral forward-looking statements in its periodic reports to the U.S. Securities and Exchange Commission (the "SEC"), in its annual report to shareholders, in press releases and other written materials and in oral statements made by its officers, directors or employees to third parties. Statements that are not historical facts, including statements about the Company's beliefs and expectations, are forward-looking statements. Forward-looking statements involve inherent risks and uncertainties. A number of factors could cause actual results to differ materially from those contained in any forward-looking statement, including but not limited to the following: the possibility that we may be delisted from trading on The Nasdaq Capital Market if we fail to regain compliance during the compliance period; uncertainties related to the Proposal; uncertainties related to the possibility that the transaction for the divestiture of certain assets in China (the "Transaction") will not occur as planned if events arise that result in the termination of the Equity and Assets Transfer Agreement, or if one or more of the various closing conditions to the Transaction are not satisfied or waived; the possibility that our plan with respect to our business operations after the consummation of the Transaction can be implemented successfully; our recurring operating losses have raised substantial doubt regarding our ability to continue as a going concern; 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 on a global basis including China; our inability to enter into strategic partnerships for the development, commercialization, manufacturing and distribution of our proposed product candidates or future candidates; legal or regulatory developments in China that adversely affect our ability to operate in China; 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, European Medicines Agency, PRC National Medical Products Administration, or other regulatory authorities; our inability to receive approval for renewal of license of our existing products; 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; the risk related to the Company's ongoing development of and regulatory application for CID-103 with respect to the treatment of antibody-mediated rejection for organ transplant and the license arrangements of CID-103; risks relating to interests of our largest shareholder and our Chairman that differ from our other shareholders; risks related to the development of a new manufacturing facility by CASI Pharmaceuticals (Wuxi) Co., Ltd.; and risks related to our disagreement with Acrotech with respect to the termination of agreements regarding EVOMELA^®. Further information regarding these and other risks is included in the Company's filings with the SEC. All information provided herein is as of the date of this announcement, and the Company undertakes no obligation to update any forward-looking statement, except as required under applicable law. We caution readers not to place undue reliance on any forward-looking statements contained herein.

EVOMELA^® is proprietary to Acrotech Biopharma Inc. and its affiliates. FOLOTYN^®is proprietary to Acrotech Biopharma Inc and its affiliates. The Company is currently involved in disputes and legal proceedings related to certain pipeline products, including EVOMELA^® and CNCT-19.Please refer to the Company's earlier SEC filing for further information.

COMPANY CONTACT:

Ingrid Choong, [email protected]

SOURCE: CASI Pharmaceuticals