Orca Q

RMAT designation based on promising preliminary Phase 1 clinical data, including positive outcomes across overall survival, acute and chronic GVHD and non-relapse mortality Phase 1 trial was recently expanded to include additional cohorts of patients receiving reduced intensity or non-myeloablative conditioning with either matched, 7/8 mismatched or haploidentical donors New clinical findings and longer follow-up data expected in 2026 MENLO PARK, CA, April 28, 2026 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced that the U.S. Food and Drug Administration (FDA) has granted Regenerative Medicine Advanced Therapy (RMAT) designation to Orca-Q, Orca Bio’s second-generation investigational allogeneic T-cell immunotherapy for the treatment of high-risk hematologic malignancies. "The FDA’s RMAT designation for Orca-Q recognizes the significant unmet need for patients with serious hematologic malignancies and validates the promising clinical findings from our ongoing Phase 1 study,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer at Orca Bio. “As this is our second cell therapy candidate to receive RMAT status, we have experienced firsthand how this program can support accelerated development and enhanced communication with the FDA. With our newly expanded Phase 1 study continuing to enroll patients and additional data expected later this year, we remain focused on advancing our high-precision approach to deliver an important new treatment to patients with blood cancer.” The RMAT application included data from the ongoing Phase 1 clinical trial (NCT03802695) evaluating Orca-Q for the treatment of hematologic malignancies across six treatment cohorts, including in patients with haploidentical donors, and in patients receiving non-myeloablative or reduced intensity conditioning. Clinical findings demonstrated durability and encouraging outcomes across key metrics, including overall survival, acute and chronic graft versus host disease (GVHD) and non-relapse mortality. Enrollment is ongoing, with new data expected to be presented at upcoming scientific congresses. Additional details can be found on www.ClinicalTrials.gov. RMAT designation is a specialized FDA program created to accelerate the development and review of promising new therapies, including cell therapies, intended to treat serious or life-threatening conditions. To qualify, a therapy must demonstrate preliminary clinical evidence suggesting the potential to address unmet medical needs. This designation provides important opportunities during the drug development process, including increased FDA guidance and eligibility for priority and rolling reviews, as well as accelerated approval pathways. By streamlining these regulatory milestones, the program aims to bring transformative innovations to patients more quickly. Orca-Q is Orca Bio’s second-generation investigational allogeneic T-cell immunotherapy being evaluated in clinical trials for the treatment of multiple hematologic malignancies, including in patients with haploidentical and mismatched donors. Orca-Q is a proprietary composition of stem cells combined with specific T-cell subsets derived from healthy donors and engineered by Orca Bio’s high-precision platform. Orca Bio is a late-stage biotechnology company developing high-precision cell therapies for the treatment of blood cancer and autoimmune diseases. The company’s manufacturing platform uses single-cell precision to create personalized cell therapy products intended to replace a patient’s diseased blood and immune system with a healthy one. At Orca Bio, we are on a mission to redefine what’s possible for patients by transforming the field of curative allogeneic cell therapy. For more information, visit www.orcabio.com. Trademarks or registered trademarks used in this press release are the property of their respective owners. Corporate Communications Kelsey Grossman media@orcabio.com Investor Relations Joshua Murray ir@orcabio.com

Patient reported outcomes with Orca-T ® from the pivotal Precision-T Phase 3 study will be presented including quality of life and rates of rehospitalizations compared to conventional alloHSCT Data evaluating the use of Orca-T with reduced intensity conditioning versus PTCy for the treatment of hematologic malignancies will be shared Additional presentations will highlight the manufacturing and nationwide distribution data reported on Orca–T and clinical findings of Orca-Q ® in patients with haploidentical donors MENLO PARK, Calif.--(BUSINESS WIRE)--Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced that clinical data will be presented in seven oral and poster sessions at the 52nd Annual Meeting of the EBMT from March 22-25 in Madrid. The encore presentations will include data on the company's pipeline of investigational allogeneic T-cell immunotherapies for the treatment of multiple hematologic malignancies, including Orca-T and Orca-Q. “Our participation at this year’s meeting of the EBMT provides an important opportunity to engage directly with the global transplant community as we continue our shared efforts to advance the field of allogeneic stem cell transplant,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer of Orca Bio. “As we progress toward the potential FDA approval of Orca-T, the strength and consistency of our data reinforce our commitment to delivering a new therapy for patients with blood cancer. We look forward to being in Madrid to connect with clinicians and partners from around the world and to participate in scientific exchange focused on improving patient outcomes.” The EBMT abstracts are now available at . Details of the Orca Bio presentations follow: Oral Session : OS14 | Graft Manipulation and Conditioning Title: Orca-T Demonstrates Favorable Quality of Life and Healthcare Resource Use Compared to Standard AlloHSCT plus Tac/MTX for GVHD Prevention in a Randomized Phase 3 Clinical Trial (Precision-T) Date and Time : Wednesday, March 25 at 08:30 AM – 08:39 AM CET Location : N107 Oral Session : OS14 | Graft Manipulation and Conditioning Title: Clinical Outcomes in Orca-T and Registry-Based Post-Transplant Cyclophosphamide Patients: An Observational Comparison Date and Time : Wednesday, March 25 at 08:39 AM – 08:48 AM CET Location : N107 Oral Session : OS12 | Acute GVHD - Clinical Title : Cost-Effectiveness of Orca-T vs Allo-HCT with Conventional GVHD Prophylaxis for the Treatment of Advanced Hematologic Malignancies in the United States Date and Time: Tuesday, March 24 at 2:39 PM – 2:48 PM CET Location : N101-102 Poster Session : A Title : Interim Clinical Outcomes in Orca-T with Reduced Intensity Conditioning: An Observational Comparison to Registry-Based Post-Transplant Cyclophosphamide Patients Presentation ID : A038 Date and Time : Monday, March 23 at 6:00 PM – 7:00 PM CET Location : Pavilion 9 Poster Session : A Title : Scalable Manufacturing and Nationwide Distribution of Orca-T: A Precision-Engineered Allogeneic Immune Cell Therapy Presentation ID : A145 Date and Time : Monday, March 23 at 6:00 PM – 7:00 PM CET Location : Pavilion 9 Poster Session : A Title : Preliminary Safety and Efficacy of Myeloablative Orca-Q in Patients with Haploidentical Donors Presentation ID : A043 Date and Time : Monday, March 23 at 6:00 PM – 7:00 PM CET Location : Pavilion 9 Poster Session : A Title : Clinical Outcomes in Myelodysplastic Syndrome Patients Treated with Orca-T or Post-Transplant Cyclophosphamide Patients: A Registry-Based Comparison Presentation ID : A085 Date and Time : Monday, March 23 at 6:00 PM – 7:00 PM CET Location : Pavilion 9 About Orca-T Orca-T is an investigational allogeneic T-cell immunotherapy being evaluated for the treatment of multiple hematologic malignancies including acute leukemias and myelodysplastic syndromes. Orca-T is composed of highly purified regulatory T-cells, hematopoietic stem cells and conventional T-cells derived from peripheral blood from either related or unrelated matched donors. Orca-T has received Regenerative Medicine Advanced Therapy (RMAT) and Orphan Drug Designation for the prevention of graft versus host disease or death in patients eligible for hematopoietic stem cell transplant from the U.S. Food and Drug Administration (FDA). The Biologics License Application (BLA) for Orca-T is currently under Priority Review with the FDA with a PDUFA target action date of April 6, 2026. About Orca-Q Orca-Q is Orca Bio’s second-generation investigational allogeneic T-cell immunotherapy being evaluated in clinical trials for the treatment of multiple hematologic malignancies, including in patients with haploidentical and mismatched donors. Orca-Q is a proprietary composition of stem cells combined with specific T-cell subsets derived from healthy donors and engineered by Orca Bio’s high-precision platform. About Orca Bio Orca Bio is a late-stage biotechnology company developing high-precision cell therapies for the treatment of blood cancer and autoimmune diseases. The company’s manufacturing platform uses single-cell precision to create proprietary, uniquely-defined products designed to replace a patient’s diseased blood and immune system with a healthy one. At Orca Bio, we are on a mission to redefine what’s possible for patients by transforming the field of curative allogeneic cell therapy. For more information, visit . Trademarks or registered trademarks used in this press release are the property of their respective owners. Contacts Corporate Communications Kelsey Grossman media@orcabio.com Investor Relations Joshua Murray ir@orcabio.com