Orca Bio Presents Promising Data on Orca-T in Two Oral Presentations at the 2024 Tandem Meetings of ASTCT® and CIBMTR®

Orca Bio, a late-stage biotechnology company developing high-precision cell therapies for the treatment of cancer, autoimmune diseases and genetic blood disorders, today announced positive data on its lead investigational high-precision cell therapy, Orca-T, presented at the 2024 Tandem Meetings, Transplantation & Cellular Therapy Meetings of the American Society for Transplantation and Cellular Therapy (ASTCT) and the Center for International Blood and Marrow Transplant Research (CIBMTR).

In the first of two oral presentations, findings from a retrospective analysis compared historical outcomes between Orca-T and a standard of care allogeneic stem cell transplant (alloHSCT) plus post-transplant cyclophosphamide (PTCy)-based graft versus host disease (GvHD) prophylaxis in patients with hematologic malignancies receiving myeloablative conditioning (MAC). Within the non-randomized cohorts of varying conditioning regimens and disease types, Orca-T demonstrated favorable results across clinical outcomes including relapse-free survival (RFS), non-relapse mortality (NRM) and overall survival (OS).

"When treating hematological malignancies, physicians are often faced with compromising between the risk of relapse and the risk of serious toxicities, all of which can impact overall patient survival," said Alexandra Gomez-Arteaga, MD, Assistant Professor of Medicine at Weill Cornell Medicine, hematologist oncologist in the Bone Marrow Transplant and Cellular Therapy Program at NewYork-Presbyterian/Weill Cornell Medical Center, and presenting author. "While advances in prophylaxis agents have demonstrated improvements in reducing the rate of graft versus host disease, the findings of this retrospective analysis suggest Orca-T may also provide benefits across key survival metrics, further highlighting the importance of identifying novel approaches that may offer enhancements across all patient outcomes."

The analysis further compared a subgroup of 48 patients from Orca Bio's multi-center Phase 1b trial who received a MAC Orca-T with single-agent tacrolimus (TAC) and a conditioning regimen of busulfan, fludarabine and thiotepa (BFT) which is being used in the pivotal Phase 3 clinical study of Orca-T, with 61 patients from the CIBMTR literature-based cohort¹ who received an alloHSCT with a combination of PTCy, calcineurin inhibitor (CNI) and mycophenolate mofetil (MMF). The analysis included patients with acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) who had a median follow-up time of 15 months and 12 months in the Orca-T and PTCy cohorts, respectively. The outcomes at 12 months are summarized in the table below:

In a second oral presentation, results were shared from a subgroup analysis of Orca Bio's ongoing multi-center Phase 1b clinical trial of patients with AML, MDS and acute lymphocytic leukemia (ALL) who received Orca-T and BFT conditioning. The findings demonstrated Orca-T's potential ability to deliver similar outcomes in older patients (55+ years of age, n=25) and younger patients (18-54 years of age, n=39) undergoing MAC. Notably, Orca-T delivered similar results across RFS (84.8% in younger patients and 82.3% in older patients), NRM (0% in both groups) and OS (100% and 95.5% in the younger and older patient groups, respectively). Across all patients, Orca-T continued to be manufactured reliably and delivered with vein-to-vein times of 72 hours or less across the U.S. These data were previously presented at the 65th American Society of Hematology (ASH) Annual Meeting in December 2023.

"We are pleased to present findings that reinforce the potential for Orca-T to address the balancing act that providers encounter when working to achieve a lasting cure while reducing toxicities," said Scott McClellan, MD, PhD, Chief Medical Officer at Orca Bio. "The ability of Orca-T to potentially treat the disease while also lowering treatment-related mortality, including for patients of a more advanced age, could arm physicians with an important new therapeutic option. We look forward to continued investigation of Orca-T in our randomized Phase 3 study, Precision-T."

About Orca-T

Orca-T is an investigational high-precision allogeneic cell therapy being evaluated in clinical trials for the treatment of multiple hematologic malignancies. Orca-T includes infusions containing regulatory T-cells, CD34+ stem cells and conventional T-cells derived from peripheral blood from either related or unrelated matched donors. Orca-T is currently being evaluated in a pivotal Phase 3 clinical trial at leading transplant centers across the U.S. and has received Regenerative Medicine Advanced Therapy (RMAT) designation from the U.S. Food and Drug Administration.

About Orca Bio

Orca Bio is a late-stage biotechnology company developing high-precision cell therapies for the treatment of cancer, autoimmune diseases and genetic blood disorders. Our investigational products are designed to safely replace a patient's diseased blood and immune system with a healthy one, delivering significantly better outcomes with dramatically fewer risks than the standard of care. Our manufacturing platform uses single-cell precision to create proprietary, uniquely-defined products that have the potential to transform allogeneic cell therapy. At Orca Bio, our mission is to make curative cell therapies both more effective and safer, and in doing so, push past the field's current boundaries and redefine its future. For more information, visit www.orcabio.com and follow Orca Bio on Twitter: @OrcaBio.

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¹ Gooptu et al, Biol Blood Marrow Transplant 25 (2019) 21432151