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), 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 in patients with higher-risk MDS, according to a release from the manufacturer.

Patients who had undergone reduced-intensity condition were administered Orca-T and demonstrated durable outcomes with a trend towards 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 were presented in 2 parts during the conference. Pooled results were compared in patients treated with Orca-T in clinical trials to 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 post-transplant cyclophosphamide, or PTCy, which is a widely used standard for graft versus host disease prophylaxis.

In a focused analysis of patients aged 18 to 65 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 compared with 80% in the 95 patient PTCy cohort. The 2 and 3-year overall survival rates were also 100% for Orca-T versus 70% and 62%, respectively, for PTCy. At 1 year, relapse-free survival was 95% with Orca-T versus 64% with PTCy, and the non-relapse mortality rate was 0% versus 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 School of Medicine at Stanford University in California.

When reviewing a broader analysis across multiple blood cancers, including MDS, acute myeloid leukemia (AML), and acute lymphoblastic leukemia (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 (n = 380) group. Further, 1-year overall survival was 94% vs 82%, respectively. At 3 years, it was 82% vs 65%, respectively. Non-relapse mortality rates at 1 year remained lower with Orca-T at 2.7% compared with 7.7% with PTCy. The researchers noted these favorable trends were maintained even in a subgroup of patients over 50 years of age.

Next Steps

The randomized phase 3 Precision T clinical trial (NCT05316701), directly compares Orca-T to 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

2. Villar-Prados A, Pavlova A, Fernhoff N, et al. Interim clinical outcomes in Orca-T with reduced intensity conditioning: an observational comparison to registry-based post-transplant cyclophosphamide patients. Presented at: 2026 Transplantation & Cellular Therapy Meetings. February 4-7, 2026. Salt Lake City, UT. Abstract 7.1