ALLO-329 gets FDA fast track designation for diffuse scleroderma

Car T-cell therapy aims for off-shelf cell supply by Marisa Wexler, MS | April 8, 2025

The U.S. Food and Drug Administration (FDA) has granted fast track designation to the cell therapy ALLO-329 to treat active refractory (resistant to treatment) diffuse scleroderma, also known as diffuse systemic sclerosis (SSc).

The FDA also gave ALLO-329 fast track designation as a potential treatment for two other inflammatory diseases: myositis, which is characterized by muscle inflammation, and lupus, which is marked by antibodies that attack the body’s healthy tissues.

Fast track designation is designed to speed the development of new treatments that have the potential to address unmet medical needs for serious or life-threatening diseases. With these designations, ALLO-329’s developer Allogene Therapeutics will get access to benefits including more frequent interactions with the FDA throughout the drug development process.

“Receiving these designations for ALLO-329 underscores the versatility and transformative promise of this next-generation allogeneic CAR T investigational product in redefining the autoimmune treatment landscape,” said Zachary Roberts, MD, PhD, executive vice president of research and development and chief medical officer of Allogene, said in a company press release.
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ALLO-329 is a CAR T-cell therapy. T-cells are immune cells that are able to kill other types of cells. CAR T-cell treatments involve engineering T-cells to equip them with a chimeric antigen receptor (CAR), a molecular weapon that directs a T-cell to attack other cells bearing specific molecular markers. ALLO-329 uses a CAR that targets CD19 and CD70, two proteins that are present, respectively, on the surface of B-cells and T-cells, both of which are immune cells involved in the development of many autoimmune diseases.

Ready supply of T-cells for treatment
Traditionally, CAR T-cell treatments work by collecting T-cells from a patient and taking them to a lab to equip them with the CAR. Before the modified cells can be infused back into the patient, the patient needs to undergo lymphodepletion, a round of chemotherapy that aims to wipe out the immune system before receiving the modified cells.

ALLO-329 is being developed as an allogeneic, or off-the-shelf, therapy, with the goal of creating a ready supply of cells that can be used to treat all patients. Allogene says the cell therapy is also being designed to minimize the need for lymphodepletion.

“Leveraging our extensive expertise, we’ve developed this off-the-shelf CAR T specifically for autoimmune diseases, prioritizing both scalability and the reduction or elimination of lymphodepletion — a key barrier in this patient population,” Roberts said.
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Allogene said it plans to launch in mid-2025 a Phase 1 clinical trial called RESOLUTION to test ALLO-329 in people with scleroderma, myositis, and lupus. The trial will test the therapy with lymphodepletion using a single chemotherapy drug called cyclophosphamide, and also without lymphodepletion. The company expects to have proof-of-concept data from the study by the end of the year.