Ligufalimab Gains FDA Orphan Drug Status for Acute Myeloid Leukemia

Author(s):

Spencer Feldman

Fact checked by:

Alex Biese

Key Takeaways

Ligufalimab targets CD47, enhancing macrophage-mediated cancer cell destruction, and avoids red blood cell clumping, improving safety and efficacy.
Early trials show ligufalimab, combined with Vidaza or Venclexta, is safe and effective, achieving high remission rates in AML patients.
Ligufalimab is the first CD47-targeting antibody in phase 3 trials for solid tumors, including head and neck squamous cell carcinoma and pancreatic cancer.
New therapies like ligufalimab are crucial for AML patients, especially those unable to tolerate intensive chemotherapy, due to limited current treatment options.

The FDA granted orphan drug designation to ligufalimab for AML, reflecting its potential as an immune-based therapy that may offer new options for patients.

The FDA granted orphan drug designation to ligufalimab for AML, reflecting its potential as an immune-based therapy that may offer new options for patients.

Ligufalimab (AK117), a next-generation antibody that targets a protein on cancer cells, has been granted orphan drug designation by the U.S. Food and Drug Administration (FDA) for the treatment of acute myeloid leukemia (AML), according to a news release from Akesobio.

The orphan drug designation program was created by the FDA to encourage the development of therapies for rare diseases. Drugs with this status receive support from the FDA during development, tax incentives and, if approved, up to seven years of market exclusivity. For patients, this means the agency sees promise in a treatment that could help meet an unmet medical need.

How Ligufalimab Works

Ligufalimab is a type of immunotherapy called a monoclonal antibody. It works by targeting CD47, a protein on the surface of cancer cells. Normally, CD47 sends a “don’t eat me” signal to the immune system, allowing cancer to hide. By blocking CD47, ligufalimab helps immune cells called macrophages better recognize and destroy cancer cells, slowing or stopping tumor growth.

Unlike other CD47-targeting drugs, ligufalimab is designed to avoid clumping with red blood cells, a problem that can make treatments less safe and less effective.

Early Results in AML

In laboratory studies, ligufalimab worked especially well when combined with other drugs such as Vidaza (azacitidine) or Venclexta (venetoclax). These combinations made it easier for the immune system to attack leukemia cells, which may be especially important for patients who cannot receive standard chemotherapy.

Early clinical trials have also shown positive results. When ligufalimab was given with Vidaza as an initial treatment for AML, the drug was generally safe and well tolerated, even at higher doses. About half of patients achieved a complete remission, and more than half had a strong overall response to treatment.

Other Ongoing Research

Ligufalimab is also being studied in solid tumors, making it the first CD47-targeting antibody to reach large, late-stage phase 3 trials in this setting. Two studies are ongoing: one in patients with head and neck squamous cell carcinoma whose tumors express PD-L1, and another in pancreatic cancer.

Why New Therapies Are Needed in AML

Treatment options for AML remain limited, especially for older patients or those who cannot tolerate intensive chemotherapy. The FDA has approved combinations of Venclexta with drugs such as Vidaza, Dacogen (decitabine), or low-dose cytarabine for these patients. While these regimens have extended survival for some, more than half relapse within months, and average survival remains about one year.

This highlights the need for new approaches, especially ones like ligufalimab that use the immune system in a different way.

What Is AML?

AML is the most common type of acute leukemia in adults. It develops when immature white blood cells, called myeloid blasts, grow uncontrollably in the bone marrow and blood. These abnormal cells crowd out healthy ones and may spread outside the bone marrow. Treatment often depends on a patient’s overall health. Some can receive intensive chemotherapy, while others may need less aggressive approaches. For patients who cannot tolerate strong treatments, new therapies under study offer hope.

Looking Ahead

Beyond AML, ligufalimab is also being evaluated in patients with higher-risk myelodysplastic syndromes (HR-MDS). A phase 2 trial testing the drug in combination with Vidaza has completed enrollment. The study is carefully designed so that neither patients nor doctors know who is receiving which treatment, helping ensure results are reliable.

With its new orphan drug designation and encouraging early data, ligufalimab represents a potential new option in the pipeline for patients with AML who urgently need better therapies.