Akeso's Ligufalimab (CD47 mAb) Receives FDA Orphan Drug Designation for Acute Myeloid Leukemia (AML)

HONG KONG, Sept. 15, 2025 /PRNewswire/ -- Akeso Inc. (9926.HK) today announced that its proprietary next-generation humanized IgG4 monoclonal antibody targeting CD47, ligufalimab (AK117), has been granted Orphan Drug Designation (ODD) by the U.S. FDA for the treatment of acute myeloid leukemia (AML).

The Orphan Drug Designation is a program established by the FDA to incentivize the development of therapies for rare diseases. Drugs with this designation benefit from comprehensive FDA guidance during development, tax incentives, and up to seven years of market exclusivity upon approval.

Akeso is actively advancing the international clinical development for ligufalimab, which is being evaluated in both hematologic malignancies and solid tumors. In addition to its application in AML, patient enrollment has been completed in a randomized, double-blind, multicenter Phase II study assessing ligufalimab combined with azacitidine in higher-risk myelodysplastic syndromes (HR-MDS).

Ligufalimab is also the first CD47 monoclonal antibody to enter registrational Phase III trials in solid tumors. Two Phase III studies are currently ongoing: one evaluating the combination of ligufalimab and ivonescimab as first-line treatment for PD-L1-positive head and neck squamous cell carcinoma (HNSCC), and another study assessing this combination as first-line therapy for pancreatic cancer.

Acute Myeloid Leukemia (AML) is a heterogeneous hematologic malignancy characterized by the clonal proliferation of myeloid blasts in the bone marrow, peripheral blood, and extramedullary tissues. It is the most common type of acute leukemia in adults. Treatment strategies for AML, as outlined in the NCCN Guidelines^®, are primarily based on whether patients are eligible for intensive induction chemotherapy. For those ineligible for such chemotherapy, treatment options remain limited.

The FDA has currently approved venetoclax in combination with azacitidine, decitabine, or low-dose cytarabine for newly diagnosed AML patients aged 75 years or older, or for those with comorbidities that preclude intensive chemotherapy. However, more than half of these patients relapse within 6–9 months, with a median overall survival of approximately one year, highlighting a significant unmet clinical need.

Ligufalimab is a humanized IgG4 monoclonal antibody that binds specifically to CD47 expressed on tumor cells, blocking its interaction with the SIRPα receptor. This disrupts the "don't eat me" signal, thereby enhancing macrophage-mediated phagocytosis of tumor cells and inhibiting tumor growth. Ligufalimab's unique design prevents red blood cell agglutination and demonstrates significantly improved safety and efficacy compared to other CD47-targeting agents.

Preclinical studies have shown that ligufalimab, when combined with azacitidine or venetoclax, synergistically enhances the expression of "eat me" signals (such as calreticulin), leading to more efficient activation of phagocytic immune responses. This combination may thus offer a promising treatment option for AML patients ineligible for standard induction chemotherapy.

Clinical trials have demonstrated that ligufalimab combined with azacitidine shows a favorable safety profile and promising efficacy in first-line AML treatment. Even at high doses (up to 45 mg/kg, administered biweekly), ligufalimab was well tolerated, with no significant safety differences observed across patient groups. The complete remission (CR) rate at the target dose reached 50%, and the composite complete remission (cCR) rate was 55%.

Building on these encouraging results, Akeso has launched a Phase II study to further investigate the safety and efficacy of ligufalimab in combination with venetoclax and azacitidine for first-line AML patients ineligible for intensive chemotherapy.

Forward-Looking Statement of Akeso, Inc.

This announcement by Akeso, Inc. (9926.HK, "Akeso") contains "forward-looking statements". These statements reflect the current beliefs and expectations of Akeso's management and are subject to significant risks and uncertainties. These statements are not intended to form the basis of any investment decision or any decision to purchase securities of Akeso. There can be no assurance that the drug candidate(s) indicated in this announcement or Akeso's other pipeline candidates will obtain the required regulatory approvals or achieve commercial success. If underlying assumptions prove inaccurate or risks or uncertainties materialize, actual results may differ materially from those set forth in the forward-looking statements.

Risks and uncertainties include but are not limited to, general industry conditions and competition; general economic factors, including interest rate and currency exchange rate fluctuations; the impact of pharmaceutical industry regulation and health care legislation in P.R.China, the United States and internationally; global trends toward health care cost containment; technological advances, new products and patents attained by competitors; challenges inherent in new product development, including obtaining regulatory approval; Akeso's ability to accurately predict future market conditions; manufacturing difficulties or delays; financial instability of international economies and sovereign risk; dependence on the effectiveness of the Akeso's patents and other protections for innovative products; and the exposure to litigation, including patent litigation, and/or regulatory actions.

Akeso does not undertake any obligation to publicly revise these forward-looking statements to reflect events or circumstances after the date hereof, except as required by law.

About Akeso

Akeso (HKEX: 9926.HK) is a leading biopharmaceutical company committed to the research, development, manufacturing and commercialization of the world's first or best-in-class innovative biological medicines. Founded in 2012, the company has created a unique integrated R&D innovation system with the comprehensive end-to-end drug development platform (ACE Platform) and bi-specific antibody drug development technology (Tetrabody) as the core, a GMP-compliant manufacturing system and a commercialization system with an advanced operation mode, and has gradually developed into a globally competitive biopharmaceutical company focused on innovative solutions. With fully integrated multi-functional platform, Akeso is internally working on a robust pipeline of over 50 innovative assets in the fields of cancer, autoimmune disease, inflammation, metabolic disease and other major diseases. Among them, 24 candidates have entered clinical trials (including 15 bispecific/multispecific antibodies and bispecific ADCs. Additionally, 7 new drugs are commercially available. Through efficient and breakthrough R&D innovation, Akeso always integrates superior global resources, develops the first-in-class and best-in-class new drugs, provides affordable therapeutic antibodies for patients worldwide, and continuously creates more commercial and social values to become a global leading biopharmaceutical enterprise.

For more information, please visit https://www.akesobio.com/en/about-us/corporate-profile/ and follow us on Linkedin.

SOURCE Akeso, Inc.