FDA Approves Tregzi for Patients with Blood Cancer Undergoing Stem Cell Transplant

The Food and Drug Administration (FDA) on June 30, 2026, approved Tregzi, the first treatment made with specialized donor immune cells that is designed to lower the risk of chronic graft-versus-host disease (GVHD) in adults with certain blood cancers receiving a donor stem cell transplant. Tregzi is manufactured by Orca Biosystems, Inc.

The treatment is approved for adults with blood cancers, including acute leukemia and myelodysplastic syndrome (MDS), who are receiving a stem cell transplant from a closely matched donor.

A stem cell transplant can be a life-saving treatment for many blood cancers. However, one of the biggest risks after transplant is chronic graft-versus-host disease (GVHD), a condition in which the donor's immune cells attack healthy tissues in the patient's body. Chronic GVHD can affect the skin, mouth, eyes, lungs, liver and other organs, sometimes causing long-term health problems.

How Tregzi Works

Tregzi is made using stem cells and immune cells collected from a donor whose tissue type closely matches the patient's.

The treatment contains several types of cells, including regulatory T cells, or Tregs. These are specialized immune cells that help keep the immune system balanced and prevent it from attacking healthy tissues.

By adding these cells to the transplant, Tregzi is designed to help the new immune system grow while lowering the risk of chronic GVHD, without reducing its ability to fight cancer.

Patients receive Tregzi after chemotherapy and as part of their stem cell transplant.

The PRECISION-T Clinical Trial

The approval was based on the PRECISION-T clinical trial, which included 187 adults with blood cancers such as acute leukemia and myelodysplastic syndrome.

Participants were randomly assigned to receive either Tregzi or a standard donor stem cell transplant.

The main goal of the study was to see how many patients were alive without developing moderate or severe chronic GVHD during the first two years after their transplant.

Clinical Trial Results

The study showed that patients who received Tregzi were much less likely to develop chronic GVHD.

After one year:

• 78% of patients who received Tregzi were alive without moderate or severe chronic GVHD.
• 38.4% of patients who received a standard stem cell transplant achieved the same result.

Researchers also found that:

• 12.6% of patients treated with Tregzi developed moderate or severe chronic GVHD within one year.
• 44% of patients who received a standard transplant developed moderate or severe chronic GVHD during that time.

These results showed that Tregzi significantly reduced the risk of one of the most serious long-term complications of stem cell transplantation.

How Tregzi Is Given

Tregzi is given one time as part of a donor stem cell transplant.

Before receiving the transplant, patients first undergo chemotherapy to destroy cancer cells and make room for the donor's healthy blood-forming cells. Tregzi is then infused into the bloodstream along with the donor stem cells to help rebuild the immune system.

Side Effects and Safety Information

The side effects seen with Tregzi were similar to those commonly expected after a stem cell transplant.

The most common side effect was:

• Infections

In the clinical trial:

• No patients experienced severe reactions during the infusion.
• No cases of graft failure, meaning the donor cells did not successfully grow and produce healthy blood cells, were reported.

Patients should talk with their healthcare team about the potential benefits and risks of Tregzi and review the full prescribing information before treatment.

References

1. "FDA Approves New Treatment That Uses Donor Immune Cells to Prevent Serious Complications in Blood Cancer Patients." U.S. Food and Drug Administration. June 30, 2026.

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