Press release

Menlo Park, CA

Orca Bio Announces the Precision-T Phase 3 Study is Open and Enrolling Patients at Transplant Centers Across the U.S.

– The pivotal Precision-T Study is evaluating the safety and efficacy of Orca Bio’s investigational Orca-T compared to standard of care allogeneic hematopoietic stem cell transplant – 

– Precision-T is expected to enroll approximately 174 patients across more than 20 clinical trial sites –

MENLO PARK, CA, August 2, 2022 – Orca Bio, a late-stage biotechnology company developing high-precision cell therapies for the treatment of cancer, genetic blood disorders and autoimmune diseases, today announced Precision-T, its pivotal Phase 3 study, is open, enrolling and treating patients at clinical trial sites including Stanford Health Care, City of Hope, Winship Cancer Institute of Emory University, Sarah Cannon Research Institute, Ronald Reagan UCLA Medical Center and Oregon Health & Science University. Precision-T is expected to enroll approximately 174 patients at more than 20 transplant centers across the U.S.

Precision-T (NCT05316701) is a randomized, open-label multi-center study that is evaluating the safety and efficacy of Orca Bio’s lead investigational high-precision cell therapy, Orca-T, compared to standard of care allogeneic hematopoietic stem cell transplant (standard allo-HSCT). Orca Bio received guidance from the Food and Drug Administration on the design of Precision-T, which will evaluate Orca-T in patients with acute myeloid leukemia (AML), acute lymphocytic leukemia (ALL) and high-risk myelodysplastic syndromes (MDS). 

“By precision engineering the donor graft, we aim to create a cell therapy that retains the benefits of transplant without serious complications like graft versus host disease and disease relapse,” said Robert Negrin, M.D., professor of medicine at the Stanford School of Medicine. “This has been demonstrated by the recent results of the Phase 1b/2 single-arm trials with Orca-T, and we are pleased to be evaluating this novel cell therapy in a randomized Phase 3 clinical trial.”

The primary endpoint of the Precision-T study is the rate of moderate-to-severe chronic GvHD-free survival. The secondary endpoints are graft-versus-host-disease and relapse-free survival (GRFS), moderate-to-severe chronic GvHD and relapse-free survival. The randomized Phase 3 trial is being conducted concurrently with Orca Bio’s ongoing single-arm Phase 1b trial of Orca-T.

“The Precision-T study is an important step forward for patients battling deadly blood cancers like AML and ALL, which are often aggressive and for which standard allo-HSCT treatment carries significant risks,” said Ivan Dimov, Ph.D., co-founder and chief executive officer of Orca Bio. “We are pleased to collaborate with these clinical trial centers and the broader blood cancer community to advance this study with the ultimate goal of delivering a safe and effective therapy to the patients who need it.” 

Orca-T is a first-in-class high-precision cell therapy that combines purified cells from a matched donor. It is designed to replace a patient’s diseased blood and immune system with a healthy one while lowering the risk of developing GvHD and other life-threatening transplant-related side effects. Almost 200 patients have been treated to date with Orca-T in single-arm trials with extremely encouraging results, which were recently presented at the European Hematology Association (EHA) 2022 Congress, the 2022 Transplantation & Cellular Therapy ASTCT and CIBMTR Tandem Meetings and the American Society of Hematology (ASH) Annual Meeting.

More information about the Precision-T study can be found at or   

About Orca Bio

Orca Bio is a late-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 the standard of care. 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 and follow Orca Bio on Twitter: @orcabio.


Corporate Communications

Kelsey Grossman


Investor Relations

Joshua Murray