FDA approves cell therapy to reduce GVHD risk after transplant
Tregzi is for certain adults with blood cancers undergoing transplant
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The U.S. Food and Drug Administration (FDA) has approved a new cell-based therapy designed to help restore the immune system and reduce the risk of a serious complication in certain adults with blood cancers who are undergoing stem cell transplant.
The newly approved therapy, called Tregzi (allogeneic regulatory T cell immunotherapy with HSPC and T cells-vldq), was developed by Orca Bio. It aims to help restore the blood-forming and immune systems following a matched-donor stem cell transplant, and also to reduce the risk of a serious transplant complication called chronic graft-versus-host disease (GVHD).
According to a press release from the FDA, Tregzi “addresses an important unmet need in transplantation, where curing the cancer is often only part of the challenge; avoiding chronic GVHD is equally important for long-term outcomes.”
Cell therapy designed for transplant
Blood cancers develop when immune cells or other blood cells start to grow out of control. A stem cell transplant, also called a bone marrow transplant, works by replacing the stem cells that produce new blood cells with stem cells from a healthy donor. In essence, the procedure is designed to eliminate diseased blood-forming cells and replace them with donor cells, which may offer a potential cure for some patients.
But even though a stem cell transplant may offer a potential cure for some blood cancers, it carries substantial risks. For one thing, the transplant requires intensive preparatory treatment that weakens a patient’s immune system, which can increase the risk of infections and other complications. Another notable risk is GVHD, in which donor immune cells mistakenly attack the patient’s own healthy tissue.
Tregzi is a personalized therapy that uses cells from a healthy donor, matched to a patient by various immune-related markers. The therapy uses three types of cells: purified hematopoietic stem and progenitor cells (HSPCs), regulatory T cells (Tregs), and conventional T cells (Tcons).
HSPCs are the stem cells that give rise to new blood cells. Tcons are immune cells that normally help protect the body from threats; these cells can help fight infections as well as kill off any lingering cancerous cells. Tregs help prevent inappropriate immune responses, reducing the risk of GVHD.
“For transplant physicians, one of our greatest challenges has long been preserving the vital graft-versus-leukemia effect while minimizing the risk of GVHD and infection,” Miguel-Angel Perales, MD, medical oncologist at Memorial Sloan Kettering Cancer Center, said in a press release from Orca Bio. “The FDA approval of TREGZI signals a new era in transplant medicine. This precision-engineered cell therapy is built on the foundational principles established by our early CD34 cell selection work and can now be delivered at scale, equipping providers with a new option to reduce serious toxicities and improve treatment outcomes.” CD34 cell selection is a method used to identify and isolate certain blood-forming stem and progenitor cells for transplant.
Trial showed lower chronic GVHD rates
FDA approval of Tregzi was based on data from a Phase 3 trial called Precision-T (NCT05316701). The study enrolled 187 adults with blood cancers, including acute myeloid leukemia, acute lymphoblastic leukemia, mixed-phenotype acute leukemia, and myelodysplastic syndrome, who were randomly assigned to receive Tregzi or a conventional stem cell transplant.
The main goal of the trial was to see how many people would be alive and free from chronic GVHD after one year. Results showed roughly three-quarters (78%) of patients given Tregzi met this endpoint, compared with only about a third (38%) who did not receive Tregzi. Rates of chronic GVHD were 13% with Tregzi and 44% without Tregzi, and patients given Tregzi also had higher overall survival rates (94% vs. 83%).
The proportion of patients who were alive without GVHD or relapse (recurrence of cancer) was also higher with Tregzi (63% vs. 31%). Patients given Tregzi also had lower rates of non-relapse mortality (3% vs. 13%) and severe infections (44% vs. 51%).
“Historically, surviving a blood cancer has often meant navigating serious, long-term effects that can shape patients’ lives well beyond treatment,” said Gwen Nichols, MD, executive vice president and chief medical officer at Blood Cancer United. “As a researcher, physician and a patient advocate, it’s exciting that patients will have a new option that may change what life after transplant can look like, including the potential to support recovery and quality of life.”
Safety findings aligned with transplant risks
According to the FDA, safety issues seen in patients given Tregzi were generally consistent with what’s expected for patients undergoing stem cell transplant, with the most common issue being infections. Mucositis, diarrhea, nausea, vomiting, rash, abdominal pain, bleeding, and swelling were also commonly reported, according to the therapy’s prescribing information.
“We founded Orca Bio on the audacious goal to engineer living cells into curative medicines, rooted in the belief that single-cell precision could fundamentally rewrite patient outcomes,” said Nate Fernhoff, PhD, Orca’s co-founder and CEO. “The FDA approval of TREGZI is a significant milestone that stands on the shoulders of decades of pioneering science. As we enter this next chapter, our focus turns to the immense responsibility of delivering TREGZI reliably, precisely and safely to the patients and families counting on us.”
