CASI Pharmaceuticals Announces Results from CID-103 Immune Thrombocytopenia Study at the 67th American Society of Hematology (ASH) Annual Meeting

Rhea-AI Summary

CASI Pharmaceuticals (NASDAQ:CASI) reported Phase 1 interim results for CID-103 in adult immune thrombocytopenia presented at ASH on December 7, 2025. As of a November 28 cut-off, 11 patients were dosed across 30–900 mg cohorts with priming doses of 30 mg or 150 mg.

Key readouts: the primary platelet response endpoint was met in 8 of 11 (73%) patients; 6 of 8 (75%) responders achieved complete response; platelet improvement observed as early as one week; pharmacodynamic markers decreased consistent with the drug's MOA. Safety showed a manageable profile with two Grade 3 treatment-related events and no dose-limiting toxicities; infusion reactions occurred with the priming dose.

Positive

• Primary endpoint met in 8 of 11 patients (73%)
• Complete responses in 6 of 8 responders (75%)
• Platelet improvement observed as early as one week
• Pharmacodynamic markers reduced consistent with CID-103 MOA
• No dose-limiting toxicities observed

Negative

• Study enrolled a limited sample size of 11 patients
• Two Grade 3 treatment-related events reported
• All infusion-related reactions occurred with priming dose

Key Figures

Patients enrolled 11 patients Phase 1 open-label ITP study as of November 28 cutoff

Dose levels 30, 150, 300, 600, 900 mg Sequential intravenous CID-103 dose-escalation cohorts

Primary endpoint responders 8 of 11 patients (73%) Platelet response within first 12 weeks

Complete responses 6 of 8 responders (75%) Complete Response with platelet improvement from one week post dose

Platelet threshold ≥ 50 x 10^9/L and ≥ 20 x 10^9/L above baseline Definition of primary platelet response endpoint

Treatment window 12 weeks Window for primary efficacy assessments

Grade 3 treatment-related events 2 events Safety profile; no dose limiting toxicities observed

Market Reality Check

$0.8435 Last Close

Volume Volume 33,936 is about 1.11x the 20-day average of 30,515. normal

Technical Price $0.9601 is trading below the 200-day MA at $1.79 and near the 52-week low of $0.93.

Peers on Argus 1 Down

Peers show mixed moves: some up (e.g., ANTX, ESLA) and others down (e.g., LSB, KLTO). Only KLTO appears in momentum scans with a -5.03% move and no news, suggesting CASI’s situation is more stock-specific than a broad biotechnology sector move.

Historical Context

Date	Event	Sentiment	Move	Catalyst
Nov 19	Board governance change	Neutral	-0.8%	Board leadership shift with new Non-Executive Chairman and focus on CID-103.
Nov 14	Earnings and pipeline	Negative	-5.6%	Q3 2025 results with revenue decline, net loss, low cash and ATM funding.
Nov 10	Nasdaq delisting appeal	Negative	+3.0%	Nasdaq MVLS non-compliance and company appeal that stayed suspension.
Nov 04	Conference participation	Neutral	-4.3%	Planned fireside chat and investor meetings at Guggenheim conference.
Nov 03	Upcoming CID-103 data	Positive	-3.5%	Announcement of upcoming CID-103 ITP data presentation at ASH 2025.

Pattern Detected

Recent CASI news often saw negative or mixed price reactions, including to earnings and conference updates, while the Nasdaq delisting appeal was the only clearly negative event that drew a positive move.

Recent Company History

Over the last few months, CASI has focused investors on CID-103 while navigating governance and listing challenges. A November 6-K detailed a Nasdaq delisting determination and appeal, and Q3 2025 results showed revenue of $3.1M with a net loss of $10.9M and cash of $4.7M. The company also highlighted upcoming ASH 2025 CID-103 data. Today’s Phase 1 ITP results provide early clinical efficacy and safety detail following that earlier preview.

Market Pulse Summary

This announcement delivers detailed Phase 1 CID-103 data in ITP, with 73% of patients reaching the primary platelet endpoint and 75% of responders achieving complete response alongside a manageable safety profile. In recent months, CASI also reported revenue pressure, a Nasdaq delisting appeal, and low cash levels. Investors may watch for larger, controlled trials, updated financing plans, and future regulatory milestones to contextualize these early results within the wider risk profile.

Key Terms

immune thrombocytopenia medical

"Phase 1 open-label study of CID-103 in adult patients with immune thrombocytopenia (ITP)"

Immune thrombocytopenia is a blood disorder in which the body's immune system mistakenly destroys platelets, the small cells that help blood clot, causing easy bruising, bleeding and a low platelet count. Investors care because the condition drives demand for diagnostic tests, treatments and clinical trials, affects regulatory and reimbursement decisions, and can influence revenue and risk profiles for companies developing therapies—think of it as the immune system removing the repair crew needed to stop leaks.

monoclonal antibody medical

"anti-CD38 monoclonal antibody, for patients with organ transplant rejection"

A monoclonal antibody is a laboratory-made protein designed to recognize and attach to a specific target in the body, such as a disease-causing substance or cell. It functions like a highly precise lock-and-key tool, helping to treat or detect illnesses. For investors, companies developing monoclonal antibodies can represent promising opportunities in the healthcare sector, especially as these treatments often address unmet medical needs.

pharmacokinetic medical

"Other endpoints were evaluated including pharmacokinetic and pharmacodynamic markers."

Pharmacokinetic describes how a drug moves through and leaves the body — how it is absorbed, spread to tissues, broken down and excreted — like tracking a package from pickup to delivery and disposal. For investors, these properties determine effective dose, safety risks, how often a medicine must be taken, and how reliably it works, which in turn influence clinical trial success, regulatory approval chances, production complexity and a drug’s commercial value.

pharmacodynamic medical

"Other endpoints were evaluated including pharmacokinetic and pharmacodynamic markers."

Pharmacodynamic describes how a drug acts on the body — the biological effects it produces, how strong those effects are, and how long they last. For investors, pharmacodynamic data show whether a treatment actually works and at what dose, shaping expectations about a drug’s safety, effectiveness, regulatory success and market potential; think of it like testing how well a key turns a lock and whether it reliably opens the door.

complete response medical

"6 of 8 (75%) patients achieved Complete Response (CR) with platelet improvement"

A complete response is a positive outcome in which a company’s efforts to address issues or questions fully resolve the problem, often meaning that no further action or investigation is needed. For investors, it signals that concerns have been thoroughly addressed, which can boost confidence in the company's stability or decision-making. Think of it like a doctor fully treating an illness, leaving no remaining symptoms.

platelet count medical

"defined as a platelet count ≥ 50 x 109/L and ≥ 20 x 109/L above baseline"

Platelet count measures how many platelets — tiny blood cells that help stop bleeding by clumping to form clots — are present in a specific volume of blood. Investors watch platelet counts because changes can signal drug side effects, hospital risks, or diagnostic value: too few or too many platelets can lead to dangerous bleeding or clotting, which can affect clinical trial outcomes, regulatory approval, treatment use, and ultimately a healthcare company’s revenue. Think of platelets as the body’s sandbags against leaks; the right amount matters.

nk medical

"decreased anti-platelet antibodies, immunoglobulins, NK and plasma cells"

NK refers to natural killer cells, a type of immune cell that patrols the body and destroys infected or cancerous cells much like security guards removing threats. Investors care because companies developing NK‑based therapies aim to harness or enhance this natural defense to treat disease; progress, trial results, manufacturing advances, or regulatory setbacks can strongly affect a biotech firm’s value and partnership prospects.

AI-generated analysis. Not financial advice.

SOUTH SAN FRANCISCO, CALIFORNIA / ACCESS Newswire / December 8, 2025 / 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 data presented from its Phase 1 open-label study of CID-103 in adult patients with immune thrombocytopenia (ITP) at the 67th American Society of Hematology Annual Meeting and Exposition on December 7, 2025, in Orlando, Florida.

This open-label Phase 1 dose escalation study assigned patients to sequential dose-escalating cohorts of intravenous infusions of CID-103 at 30 mg (n=1), 150 mg (n=1), 300 mg (n=3), 600 mg (n=3), and 900 mg (n=3), with a priming dose of CID-103 of either 30 mg or 150 mg administered prior to the cohort dose. Primary objective is to evaluate safety and tolerability of multiple escalating doses of CID-103. 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 November 28, eleven (11) patients have been enrolled and dosed.

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 8 of 11 (73%) patients

  • 6 of 8 (75%) 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 73% of patients achieving the primary efficacy endpoint," 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."

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.

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 study is 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 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," "anticipates," "future," "intends," "plans," "believes," "estimates," "confident" 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: 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 possibility that we may be delisted from trading on The Nasdaq Capital Market if we fail to satisfy applicable continued listing standards; 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, PhD
650-619-6115
ingridc@casipharmaceuticals.com

SOURCE: CASI Pharmaceuticals

View the original press release on ACCESS Newswire

FAQ

What were the CID-103 Phase 1 ITP results announced by CASI (NASDAQ:CASI) on December 7, 2025?

As of November 28 cut-off, CID-103 met the primary platelet response in 8 of 11 (73%) patients with 6 of 8 achieving complete response.

How many patients were enrolled in CASI's CID-103 ITP Phase 1 study (NASDAQ:CASI)?

Eleven patients were enrolled and dosed across escalating cohorts ranging from 30 mg to 900 mg.

What safety findings did CASI report for CID-103 at ASH 2025 (NASDAQ:CASI)?

CID-103 showed a manageable safety profile with two Grade 3 treatment-related events, no dose-limiting toxicities, and infusion reactions at priming dose.

How quickly did platelet counts improve in CASI's CID-103 ITP study (NASDAQ:CASI)?

Platelet improvement was observed as early as one week after dosing in some patients.

What pharmacodynamic changes were reported for CID-103 in the ITP study (NASDAQ:CASI)?

The study reported reductions in anti-platelet antibodies, immunoglobulins, NK cells, and plasma cells consistent with the proposed MOA.