Orca-T Shows Improved Survival Rates Over SOC in MDS

A novel cellular therapy, Orca-T, demonstrated superior survival rates compared with the current standard of care for patients with myelodysplastic syndromes (MDS) and other hematologic malignancies undergoing stem cell transplant, according to a recent post hoc analysis. The findings, presented at the 2026 Transplantation & Cellular Therapy Meetings (Tandem) in February, suggest that Orca-T could represent a significant advance in allogeneic transplantation if validated in ongoing phase 3 trials. The promising findings could represent an important advance, especially for patients with higher-risk MDS, according to a news release from the manufacturer.¹

Patients who had undergone reduced-intensity condition were administered Orca-T and demonstrated durable outcomes with a trend toward decreased incidence of acute graft-vs-host disease (aGVHD), acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), or MDS.¹

The analysis of the data was presented in 2 parts during the conference. Pooled results from patients treated with Orca-T in clinical trials were compared with a historical control cohort from the Center for International Blood and Marrow Transplant Research registry. The control patients had received a conventional allogeneic transplant with posttransplant cyclophosphamide, or PTCy, which is a widely used standard for GVHD prophylaxis.

In a focused analysis of patients aged 18 to 65 years with MDS receiving a myeloablative, HLA-matched transplant, the differences were pronounced. As presented at TANDEM, the Orca-T cohort of 25 patients showed a 1-year overall survival of 100%. This compares with 80% in the 95-patient PTCy cohort. The 2- and 3-year overall survival rates were also 100% for Orca-T vs 70% and 62%, respectively, for PTCy. At 1 year, relapse-free survival was 95% with Orca-T vs 64% with PTCy, and the nonrelapse mortality rate was 0% vs 9.9%.

“[This highlights] how the flexibility of Orca-T can help play with different conditioning regimens, and you can tailor it depending on the specific patient you’re taking to transplant,” Alejandro Villar-Prados, MD, PhD, said in a presentation of the data.

Villar-Prados is a translational investigator in the Department of Medicine at the Stanford University School of Medicine in California.

When reviewing a broader analysis across multiple blood cancers, including MDS, AML, and ALL, investigators reported a consistent, though slightly attenuated, advantage for Orca-T.

In this larger group, the 1-year overall survival was 94% for patients in the Orca-T group (n = 164) vs 82% in the PTCy group (n = 380). Further, 1-year overall survival was 94% vs 82%, respectively. At 3 years, it was 82% vs 65%, respectively. Nonrelapse mortality rates at 1 year remained lower with Orca-T at 2.7% vs 7.7% with PTCy. The researchers noted these favorable trends were maintained even in a subgroup of patients older than 50 years.

Next Steps

The randomized phase 3 Precision T clinical trial (NCT05316701) is directly comparing Orca-T vs standard-of-care (SOC) regimens, including those based on PTCy. This gold standard study design will provide the evidence needed to determine the therapy's true efficacy and safety profile.

REFERENCES

1. Orca Bio presents new data at the 2026 Tandem Meetings of ASTCT and CIBMTR reinforcing Orca-T as a durable, high-precision cell therapy for hematological malignancies. News release. February 5, 2026. Accessed February 9, 2026. https://tinyurl.com/y79r33w4