Positive Clinical Results from More than 100 Patients Treated with Orca Bio's Lead Investigational High Precision Cell Therapy Presented at 63rd ASH Annual Meeting

Orca Bio, a clinical-stage biotechnology company developing purified, high-precision cell therapies for the treatment of cancer, autoimmune diseases and genetic blood disorders, today announced positive clinical data on its lead investigational cell therapy, Orca-T, were presented at the American Society of Hematology (ASH) Annual Meeting. The data presented on 109 patients with at least 90 days of follow-up in combined data from the Phase 1b and Phase 2 trials showed significantly higher graft-versus-host disease-free, relapse-free survival (GRFS) rates compared to patients who received standard of care.

"The lower rates of graft versus host disease and improved relapse-free survival suggest Orca-T has the potential to become a safer and more effective treatment option for patients living with serious blood cancers," said Ivan Dimov, Ph.D., cofounder and chief executive officer of Orca Bio. "We are further encouraged by the validation of our platform as we advance Orca-T into our pivotal Phase 3 trial, a significant step toward potential commercialization and, most importantly, to helping more patients in need."

Findings presented today in an oral presentation included pooled results from the single-center Phase 2 and multi-center Phase 1b trials from 109 patients with acute myeloid leukemia, acute lymphocytic leukemia, myelodysplastic syndromes, myelofibrosis and other hematological malignancies. Median follow-up for these patients was 617 days (single-center) and 209 days (multi-center). For comparison purposes, a contemporary, propensity-matched cohort of 95 matched patients undergoing standard of care allogeneic hematopoietic stem cell transplant (alloHSCT) served as the standard of care cohort ("SOC cohort"). Results demonstrated that:

• Patients who received Orca-T had a GRFS of 74%. When comparing this non-randomized data to the SOC cohort, the difference was significant (74% vs. 34%; p<0.0001).
• Orca-T showed the potential for lower rates of moderate-to-severe chronic graft versus host disease (GvHD) at 1 year post-transplant (3% vs. 43%; p<0.0005).
• Overall survival rates with Orca-T (90% vs. 78%; p<0.03) and rates of chronic-GvHD-free survival (87% vs. 45%; p<0.0001) were improved.
• Orca-T was manufactured reliably and delivered with vein-to-vein times of 72 hours or less across the continental U.S.

In a poster presentation at ASH, Orca Bio also shared an analysis of treatment impact in patients with myelofibrosis. The analysis compared eight patients with myelofibrosis who were treated with Orca-T with six patients who underwent standard of care (SOC) alloHSCT. Regression of marrow fibrosis to myelofibrosis grade 0 or 1 was observed by Day 100 post-transplant in all eight Orca-T recipients, but was observed in only one of the six SOC patients. Additionally, Orca-T recipients had lower incidence of acute and chronic GvHD.

Along with the positive Phase 1b/2 results, Orca Bio announced that it has completed a successful end of Phase 2 meeting with the U.S. Food and Drug Administration and plans to commence a Phase 3 trial for Orca-T in early 2022.

The full presentation is available on www.orcabio.com.

About Orca-T
Orca-T is an investigational high-precision allogeneic cellular therapy consisting of infusions containing regulatory T-cells, conventional T-cells and CD34+ stem cells derived from peripheral blood from either related or unrelated matched donors. Orca-T has received Regenerative Medicine Advanced Therapy (RMAT) designation from the U.S. Food and Drug Administration and is being studied to treat multiple hematologic malignancies.

About Orca Bio
Orca Bio is a clinical-stage biotechnology company developing purified, high-precision cell therapies for the treatment of cancer, autoimmune diseases and genetic blood disorders. Our investigational therapies are designed to deliver better survival rates with dramatically fewer risks than standard allogeneic stem cell transplants, like graft versus host disease and other debilitating transplant-related toxicities. At Orca Bio, we hope to not only replace patients' blood and immune systems with healthy ones, but restore their quality of life. For more information, visit www.orcabio.com and follow Orca Bio on Twitter: @orcabio.