**Orca Bio Announces Orca-T® Phase 3 Data Published in Blood Demonstrate Significant Improvement in Survival Free from Chronic Graft versus Host Disease in Patients with Hematological Malignancies**

Investor Relations

Joshua Murray

Orca Bio to Present at the 44th Annual J.P. Morgan Healthcare Conference

MENLO PARK, CA, Jan. 5, 2026 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced that Nate Fernhoff, Ph.D., Orca Bio’s co-founder and chief executive officer, will present at the 44th Annual J.P. Morgan Healthcare Conference in San Francisco, CA.

The company presentation will take place on Monday, January 12, 2026, at 7:30AM PST at the Westin St. Francis in the Mission Bay Room on the 32nd floor.

About Orca Bio

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Kelsey Grossman

Investor Relations

Joshua Murray

Orca Bio Announces Orca-T® Phase 3 Data Published in Blood Demonstrate Significant Improvement in Survival Free from Chronic Graft versus Host Disease in Patients with Hematological Malignancies

**Orca Bio Announces Orca-T® Phase 3 Data Published in Blood Demonstrate Significant Improvement in Survival Free from Chronic Graft versus Host Disease in Patients with Hematological Malignancies**

Results from the Precision-T study showed Orca-T significantly improved survival free from chronic GvHD in patients with AML, ALL and MDS compared to a conventional allogeneic hematopoietic stem cell transplant

New findings demonstrate fewer rehospitalizations due to safety events and reduced rates of non-relapse mortality

Orca-T is the first Treg-based immunotherapy to demonstrate an improvement in patient outcomes including overall survival and GvHD and relapse-free survival (GRFS) in these conditions

Orca-T is being evaluated under Priority Review by the U.S. Food and Drug Administration (FDA) with a target action date of April 6, 2026

MENLO PARK, CA, Dec. 15, 2025 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced the publication of the Precision-T Phase 3 study results of its lead investigational allogeneic T-cell immunotherapy, Orca-T, in Blood, a journal of the American Society of Hematology (ASH). The study compared Orca-T to a conventional allogeneic hematopoietic stem cell transplant (alloHSCT) in patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), myelodysplastic syndrome (MDS) and mixed-phenotype acute leukemia (MPAL). These results were first presented on April 2, 2025, at the 51st Annual Meeting of The EBMT in Florence, Italy, and further analyses were presented at the 67th ASH Annual Meeting on December 6, 2025.

In the randomized Precision-T study, Orca-T plus single-agent tacrolimus (TAC) demonstrated a significant improvement in the primary endpoint of survival free from moderate-to-severe chronic graft versus host disease (cGFS) compared to alloHSCT plus tacrolimus/methotrexate (TAC/MTX). The rate for patients who received Orca-T was 78% (95% CI: 65%, 87%) compared to 38.4% (95% CI: 26%, 51%) for patients who received an alloHSCT (HR 0.26; p<0.00001), an improvement driven by a reduction in moderate-to-severe chronic graft versus host disease (cGvHD) and fewer patient deaths.

“Today, treating patients with serious blood cancers using conventional allogeneic stem cell transplants often forces a difficult risk–benefit trade-off, as clinicians work to cure the disease while avoiding life-threatening complications like GvHD,” said lead author Everett Meyer, M.D., Ph.D., hematologist and associate professor of medicine in Blood and Marrow Transplantation and Cellular Therapy at Stanford Medicine. “The Precision-T results showed that Orca-T can meaningfully shift that balance, delivering improved GvHD-free survival alongside less toxicity, including fewer serious infections and lower non-relapse mortality. Orca-T has the potential to become an important new therapy for patients and a valuable new option for the providers who care for them.”

In the study, all patients (n=187) with a median age of 43.6 years (range 19-65 years) were randomized 1:1 to Orca-T plus TAC or alloHSCT plus TAC/MTX. Patients across both groups received myeloablative conditioning and used a related or unrelated matched donor. Patients had a median follow-up time of 11.4 months (range 0.2-24.3 months) across both arms. Additional results from the Precision-T study at one year include:

A secondary endpoint of cumulative incidence of moderate-to-severe cGvHD was 12.6% (95% CI: 5%, 23%) and 44.0% (95% CI: 31%, 56%) in the Orca-T and alloHSCT arms, respectively (HR 0.19; p<0.00002).
The overall survival (OS), another secondary endpoint, was 93.7% (95% CI: 86%, 97%) in the Orca-T arm and 83.2% (95% CI: 73%, 90%) in the alloHSCT arm (HR 0.49; p=0.11823).
A secondary endpoint of GvHD and relapse-free survival (GRFS) was 63.1% and 30.9% with Orca-T and alloHSCT (p<0.001 in a post hoc analysis), respectively.
The cumulative incidence of non-relapse mortality (NRM) was 3.4% (95% CI: 0.9%, 8.8%) for Orca-T versus 13.2% (95% CI: 6.8%, 21.6%) for alloHSCT (HR 0.27 [95% CI: 0.08, 0.93]; p=0.03 in a post hoc analysis).

Additional safety findings were consistent with previous studies. The cumulative incidence for grade III or IV acute GvHD at day +180 was reduced with Orca-T with 6.2% (95% CI: 2.3, 12.9) versus 16.5% (95% CI: 9.4, 25.3) with alloHSCT (HR 0.37 [95% CI: 0.13, 1.02]; p=0.044 in a post hoc analysis). Grade 3+ infections were less common with Orca-T, with a one-year estimated incidence of 8.4% (95% CI: 3.6%, 16%) for Orca-T and 16.1% (95% CI: 9.2%, 25%) for alloHSCT.

An exploratory endpoint evaluated health-related quality of life (HRQoL) and hospitalization patterns and found Orca-T delivered marked improvements over conventional alloHSCT. In the data presented at ASH 2025, patients receiving Orca-T experienced faster recovery to, and higher improvement above, baseline HRQoL, fewer ICU stays, lower likelihood of rehospitalization and higher rehospitalization-free survival, suggesting better early post-treatment recovery and a lower burden of GvHD symptoms.

Rehospitalizations due to adverse events occurred less frequently among Orca-T recipients (27.3% [24] vs. 45.7% [43]), with fewer total hospitalization days per patient (30.6 vs. 40.8). Rehospitalization-free survival at 18 months was also significantly improved with Orca-T, reaching 66.4% (95% CI: 54.0, 76.2) compared to 33.8% (95% CI: 18.5, 49.9) for conventional alloHSCT (p=0.0096 in a post hoc analysis; HR 0.53 [0.32, 0.86]).

“As the first Treg-based immunotherapy to show improved outcomes for patients with acute leukemias and myelodysplastic syndrome compared with a conventional transplant, Orca-T has the potential to become a new standard of care,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer at Orca Bio. “The Phase 3 results published in Blood underscore our ability to potentially redefine how blood cancers are treated today. We look forward to continuing to work closely with the FDA on the review of our application with the goal of making Orca-T available to patients who need it.”

The safety and efficacy of Orca-T have not been determined by any regulatory authority. Orca-T is currently being evaluated under Priority Review by the U.S. Food and Drug Administration (FDA) with a Prescription Drug User Fee Act (PDUFA) target action date of April 6, 2026.

About Precision-T

Precision-T (NCT05316701) is a randomized, open-label multi-center study that evaluated the safety, efficacy and tolerability of Orca Bio’s lead investigational allogeneic T-cell immunotherapy, Orca-T, compared to conventional allogeneic hematopoietic stem cell transplant (alloHSCT). Orca Bio received guidance from the U.S. Food and Drug Administration on the design of Precision-T, which evaluated Orca-T in patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), high-risk myelodysplastic syndrome (MDS) and mixed-phenotype acute leukemia (MPAL). There are 19 leading treatment centers participating in the trial, which enrolled 187 patients across the U.S.

About Orca-T

About Orca Bio

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Joshua Murray

Orca Bio Presents New Clinical Data on its Pipeline of High-Precision Cell Therapies including Orca-Q® Without GvHD Prophylaxis and Orca-T/CAR-T Combination Therapy at the 67th ASH Annual Meeting

Orca-Q, Orca Bio’s second investigational allogeneic T-cell immunotherapy, showed low rates of acute and chronic GvHD, infections and non-relapse mortality with and without GvHD prophylaxis

Orca-T plus CAR-T combination therapy, OrCAR-T™, showed improved relapse and overall survival rates compared to autologous CAR19/22 treatment in patients with B-ALL

MENLO PARK, CA, December 8, 2025 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced positive new data from its pipeline of allogeneic T-cell immunotherapies at the 67th American Society of Hematology (ASH) Annual Meeting.

Orca-Q with and Without the Use of GvHD Prophylaxis

A subset of the multi-center Phase 1 clinical trial evaluated Orca-Q, Orca Bio’s second-generation investigational allogeneic T-cell immunotherapy, in patients with acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), chronic myeloid leukemia (CML), myelofibrosis (MF), myelodysplastic syndrome (MDS) and mixed phenotype acute leukemia (MPAL) with HLA-matched related and unrelated donors. New data evaluating Orca-Q with and without the use of pharmacological graft versus host disease (GvHD) prophylaxis showed encouraging outcomes including rapid neutrophil recovery and low rates of acute and chronic GvHD, relapse and non-relapse mortality (NRM).

“Controlling alloreactivity and reducing GvHD following a conventional stem cell transplant typically requires multi-agent immunosuppression. However, this can impair immune reconstitution and increase the risk of organ toxicity, infection and relapse,” said presenting author Samer Srour, M.D., Department of Stem Cell Transplantation and Cellular Therapy, The University of Texas MD Anderson Cancer Center. “In these new findings, Orca-Q demonstrated encouraging outcomes even without the use of any pharmacological GvHD prophylaxis. While ongoing enrollment is important to further validate these results, the data suggest that Orca-Q may be able to control alloreactivity and potentially offer a platform to improve transplant outcomes through controlling GvHD and infection and reducing non-relapse mortality without increasing the risk of relapse.”

Patients on Arm A received Orca-Q and single-agent tacrolimus (tac, n=18) while patients on Arm C received Orca-Q and no immune suppression (n=26). Median time to neutrophil engraftment was 15 days for patients who received tac and 11 days for patients who did not. Orca-Q was well-tolerated with 94% overall survival (OS) at one year for patients with tac and 87% for patients without tac. At one year, GvHD-and-relapse-free survival (GRFS) was 77% with tac and 79% without tac, and NRM was 6% and 0% with tac and without tac, respectively. Relapse-free survival (RFS) at one year was 88% with tac and 87% without tac. At Day 180, moderate-to-severe chronic GvHD was 12% with tac and 0% without tac. Grade 3-4 acute GvHD was 8% and 6% with and without tac, respectively.

Importantly, Orca-Q patients treated without GvHD prophylaxis demonstrated more rapid immune reconstitution and improved control of infections. Specifically, BMT CTN Grade 2+ infections at one year were 33% with tac and 17% without tac.

Orca-T and CAR-T Combination Treatment Versus Autologous CAR-T

A second oral presentation compared the results from two separate Phase 1 trials in adults with high-risk relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (B-ALL). The first trial evaluated OrCAR-T (n=16), a treatment that combines Orca-T and allogeneic CD19/CD22 CAR-T cells, and the second trial evaluated an autologous CD19/22 (n=17). At 18 months, progression-free survival (PFS) and OS were 100% and 100% with OrCAR-T, and 38.5% and 77% in the autologous cohort. Toxicities were mild across both cohorts, with no grade 3-4 CAR-related toxicities reported. At a median follow-up of 2.5 years, there were no relapses or patient deaths with OrCAR-T and seven deaths with autologous, six from refractory B-ALL.

“Among adults with B-ALL, CAR-T therapy is often followed by a consolidative allogeneic transplant to achieve long-term remission,” said Lori Muffly, M.D., associate professor in the Division of Blood and Marrow Transplantation-Cellular Therapies at Stanford Health Care. “Emerging data showing improved progression-free survival in patients with a prior transplant has prompted interest in exploring whether combining a high-precision allogeneic therapy like Orca-T with CAR-T cells could provide a feasible, all-in-one treatment. While these findings are early, they suggest this approach has the potential to benefit patients across a range of hematologic diseases.”

“Our team is encouraged by these new findings from our broader pipeline programs, including results that highlight the potential to eliminate the need for GvHD prophylaxis while preserving immune reconstitution with Orca-Q,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer at Orca Bio. “The durability of Orca-T when combined with CAR-T therapy exemplifies how our high-precision approach may be applied to expand treatment options both within and beyond hematologic malignancies. Overall, these results reinforce our continued focus on advancing our pipeline to bring this high-precision platform to more patients who could potentially benefit.”

About Orca-Q

Orca-Q is Orca Bio’s second-generation investigational allogeneic T-cell immunotherapy under evaluation 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.

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Joshua Murray

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Orca Bio Presents New Clinical Data on Orca-T® in Older Patients Using Reduced Intensity Conditioning Plus New Analyses from the Precision-T Phase 3 Study at the 67th ASH Annual Meeting

Patients aged 60-75 treated with Orca-T and a reduced intensity conditioning regimen (RIC) experienced low incidence of acute and chronic GvHD with low rates of disease relapse

Results also highlight the encouraging early use of RIC Orca-T in the outpatient setting for the first time

An observational analysis comparing Phase 3 outcomes to PTCy found Orca-T delivered favorable overall survival and lower non-relapse mortality

New Precision-T analyses suggest the benefit of Orca-T extends to older patients and those with higher-risk disease

Patient reported outcomes demonstrate favorable health-related quality of life metrics, fewer ICU stays and lower likelihood of rehospitalizations with Orca-T

MENLO PARK, CA, December 6, 2025 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced new data presented on its lead investigational allogeneic T-cell immunotherapy, Orca-T, at the 67th American Society of Hematology (ASH) Annual Meeting.

Orca-T with Reduced Intensity Conditioning

The new results of a single-center, open-label Phase 1 investigator-sponsored trial evaluating Orca-T in patients aged 60-75 (median 68 years) with a reduced intensity conditioning regimen (RIC) for the treatment of acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL), myelodysplastic syndrome (MDS) and myeloproliferative neoplasm (MPN) showed a low incidence of both acute and chronic graft versus host disease (aGvHD, cGvHD) while maintaining a low rate of disease relapse.

“Many older patients with hematological malignancies are not eligible for myeloablative allogeneic stem cell transplant due to the significant toxicities associated with it. A conventional reduced intensity alloHSCT can be safer and more tolerable, but it may also reduce the curative potential,” said Everett Meyer, M.D., Ph.D., hematologist and associate professor of medicine in Blood and Marrow Transplantation and Cellular Therapy at Stanford Health Care. “These early results suggest Orca-T following reduced intensity conditioning may preserve a meaningful graft-versus-leukemia effect while achieving low rates of toxicities, including acute and chronic GvHD. While additional research is needed, these findings support Orca-T as a potentially feasible option for older adults with blood cancer.”

Highlighted in an oral session, patients (n=46) with 8/8 matched donors were conditioned with fludarabine/melphalan/total body irradiation (TBI) (n=11) or fludarabine/thiotepa/TBI (n=12). Conditioning was further reduced where 23 patients were enrolled in a cohort eligible for outpatient treatment. Also included in the analyses was a cohort of patients (n=7) with 7/8 matched donors receiving fludarabine/thiotepa/TBI.

All patients (n=53) had successful neutrophil engraftment at a median of 15 days (range 9-39). At one year, there was no aGvHD grade 3-4 observed, and the rate of aGvHD grade 2 was 12.3% (95% CI, 5-23%). The rate of moderate-to-severe cGvHD was 9.6% (95% CI, 3-21%). At one year, relapse-free survival (RFS) and graft versus host disease relapse-free survival (GRFS) were 82% (95% CI, 72-94%) and 72% (95% CI, 60-87%), respectively. The overall survival (OS) was 88% (95% CI, 79-98%) and non-relapse mortality (NRM) was 10% (95% CI, 4-20%). The outpatient-eligible cohort experienced NRM of 0%, RFS of 80% (95% CI, 65-100%) and OS of 95% (95% CI, 87-100%).

“We are energized by these new data, which reinforce our belief that Orca-T has the potential to expand curative treatment options to many more people living with serious blood cancers, including those who may not be eligible for a myeloablative transplant today, and even patients treated in the outpatient setting,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer at Orca Bio. “Our Serene-T Phase 2 study evaluating Orca-T with RIC recently opened for enrollment and is the next step towards understanding if Orca-T may provide a path to treatment for more patients in need of therapeutic options.”

New Analyses from the Precision-T Phase 3 Study

Retrospective Comparison of Orca-T versus PTCy-Based GvHD Prophylaxis

An observational analysis compared a dataset derived from patients who received Orca-T in the Precision-T Phase 3 study (n=45) to a historical PTCy patient cohort (n=475) derived from the Center for International Blood and Marrow Transplant Research (CIBMTR).

At one year, OS was 94% with Orca-T compared to 81% with PTCy. RFS was 86% and 70% for Orca-T and PTCy, respectively. There was 0% NRM with Orca-T and 9.7% with PTCy, which achieved statistical significance. There was 13.8% relapse in the Orca-T cohort and 21% in the PTCy cohort. The rate of cGvHD was 14.7% with Orca-T versus 8.2% with PTCy. Of note, the OS in patients over the age of 50 was 100% with Orca-T compared to 75% with PTCy.

These outcomes were achieved using only single-agent tacrolimus for pharmacological GvHD prophylaxis for Orca-T recipients, in contrast to the triple-agent regimen used with PTCy, implicating the potential role of immune reconstitution in both disease control and mitigating posttransplant complications.

Orca-T Improved GvHD-free Survival Across Patient Demographics

In subset analyses from the Precision-T Phase 3 study comparing Orca-T to a conventional alloHSCT plus tacrolimus and methotrexate (Tac/MTX), Orca-T demonstrated improved clinical outcomes overall and across subgroups with varied demographic and clinical features. For all patients, the rate of survival free from cGvHD (cGFS) was 78% and 38% for Orca-T and Tac/MTX, respectively. For patients over the age of 50, the rate of cGFS was 74% and 35% for Orca-T and Tac/MTX, respectively. For all patients, the rate of GRFS was 63% and 31% for Orca-T and Tac/MTX respectively, and 59% and 23% for patients over the age of 50 with Orca-T and Tac/MTX, respectively.

Notably, OS and NRM were similar for patients aged 51-65 as in the entire safety population. For patients over the age of 50 at one year, OS was 94% (77%, 98%) for Orca-T patients (n=31) versus 80% (61%, 91%) for Tac/MTX patients (n=32) (HR=0.48 [0.12, 1.89]). Rates of NRM were 6.5% (1.1%, 19%) with Orca-T vs 16% with Tac/MTX (5.7%, 31%) (HR=0.49 [0.11, 2.06]). Together, these data suggest that the results of Orca-T extend to older patients and those with high-risk disease.

Health-Related Quality of Life: Patient Reported Outcomes

An exploratory endpoint from the Precision-T Phase 3 study evaluating health-related quality of life (HRQoL) and hospitalization patterns showed that Orca-T delivered marked improvements over conventional alloHSCT. Patients receiving Orca-T experienced faster recovery to, and higher improvement above, baseline HRQoL, fewer ICU stays, lower likelihood of rehospitalization and higher rehospitalization-free survival, suggesting better early post-treatment recovery and a lower burden of GvHD symptoms.

FACT-BMT total scores were consistently higher for Orca-T recipients across all time points, with Orca-T recipients exceeding baseline scores across physical well-being, functional well-being and transplant-specific subscales by day 100, while the alloHSCT arm did not surpass baseline until day 365. By day 365, Orca-T scores across these domains were higher by a magnitude of two or more compared to the control arm.

“The additional analyses from our Phase 3 study further highlight Orca-T’s potential superiority across critical measures, from lower rehospitalization rates to improved outcomes in older patients,” said Scott McClellan, M.D., chief medical officer at Orca Bio. “These results continue to strengthen our conviction that Orca-T has the potential to transform the transplant experience and meaningfully raise the standard of care for patients and providers.”

About Precision-T

About Orca-T

About Orca Bio

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Orca Bio to Present New Clinical Data on Its High-Precision Cell Therapies at the 67th American Society of Hematology Annual Meeting

New data evaluating Orca-T® with reduced intensity conditioning for the treatment of hematological malignancies in patients 60 to 75 years of age

Clinical findings of Orca-Q® with and without the use of GvHD prophylaxis in patients with hematological malignancies including AML, ALL and MDS

Expanded feasibility data on the combination of Orca-T and an allogeneic CAR-T (OrCAR-T™) in patients with high-risk B-ALL

Additional presentations will highlight overall survival and non-relapse mortality with Orca-T versus PTCy, and additional subsets from the pivotal Phase 3 study including relapse-free survival and patient-reported outcomes

MENLO PARK, CA, November 3, 2025 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced that new clinical data will be presented in three oral and three poster sessions at the American Society of Hematology (ASH) Annual Meeting from December 6-9 in Orlando, FL. The presentations will span its pipeline of investigational allogeneic T-cell immunotherapies for the treatment of multiple hematological malignancies including Orca-T, Orca-Q and the Orca-T and allogeneic CAR-T combination therapy, OrCAR-T.

“Our ongoing clinical evaluation of our pipeline across diverse patient populations, conditioning regimens and donor types underscores our commitment to advancing care for people with blood cancer,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer of Orca Bio. “We look forward to presenting new and expanded evidence from the pivotal Phase 3 study of our lead T-cell immunotherapy, Orca-T, along with data highlighting the potential of our next-generation candidate, Orca-Q, to enable treatment without GvHD prophylaxis. Overall, these findings mark meaningful progress toward our goal of delivering our high-precision approach to more patients who may benefit.”

The ASH abstracts are now available at www.hematology.org. Details of the Orca Bio oral and poster presentations follow:

Oral Session: 721. Allogeneic Transplantation: Conditioning Regimens, Engraftment, and Acute Toxicities: Improving Outcomes by Decreasing Transplant-Related Complications

Title: Allogeneic HSC and Regulatory T cell (Orca-T) Engineered Cell Therapy Following Reduced Intensity Conditioning: Results of a Single Center Phase 1 Study

Abstract Number: 111

Date and Time: December 6, 2025 at 10:00 AM EST

Location: OCCC - Chapin Theater (320)

Oral Session: 732. Allogeneic Transplantation: Disease Response and Comparative Treatment Studies: Biologic Predictors and Novel Platforms Integrating CAR T with Transplant

Title: Superior Efficacy and Persistence of Orca-T-Allogeneic CAR19/22 Versus Autologous CAR19/22 in High-Risk Adult B-ALL

Abstract Number: 514

Date and Time: December 7, 2025 at 10:15 AM EST

Location: OCCC - Chapin Theater (320)

Oral Session: 722. Allogeneic Transplantation: Acute and Chronic GVHD and Immune Reconstitution: GVHD Prevention: Post-transplant cyclophosphamide and beyond

Title: Preliminary Safety and Efficacy of Myeloablative Orca-Q with Tacrolimus or without GVHD Prophylaxis for Treatment of Advanced Hematologic Malignancies

Abstract Number: 932

Date and Time: December 8, 2025 at 3:00 PM EST

Location: OCCC - W331

Poster Session: 722. Allogeneic Transplantation: Acute and Chronic GVHD and Immune Reconstitution: Poster I

Title: Orca-T Improves cGVHD-free Survival in Patients with a Broad Range of Demographic and Clinical Variables: Results of Randomized, Phase 3 Trial

Abstract Number: 2477

Date and Time: December 6, 2025 at 5:30 PM - 7:30 PM EST

Location: OCCC - West Halls B3-B4

Poster Session: 722. Allogeneic Transplantation: Acute and Chronic GVHD and Immune Reconstitution: Poster I

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)

Abstract Number: 2473

Date and Time: December 6, 2025 at 5:30 PM - 7:30 PM EST

Location: OCCC - West Halls B3-B4

Poster Session: 722. Allogeneic Transplantation: Acute and Chronic GVHD

and Immune Reconstitution: Poster III

Title: Observational Comparison of Orca-T to Registry-Based Post-Transplant Cyclophosphamide Patients using Matched Unrelated Donor

Abstract Number: 6029

Date and Time: December 8, 2025 at 6:00 PM - 8:00 PM EST

Location: OCCC - West Halls B3-B4

About Orca-T

About Orca-Q

About Orca Bio

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Joshua Murray

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Orca Bio Announces FDA Acceptance and Priority Review of the Biologics License Application (BLA) for Orca-T® to Treat Hematological Malignancies

FDA assigns PDUFA target action date of April 6, 2026

If approved, Orca-T would be the first allogeneic T-cell immunotherapy for the treatment of hematological malignancies including acute myeloid leukemia, acute lymphoblastic leukemia and myelodysplastic syndromes

MENLO PARK, CA, October 6, 2025 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced the U.S. Food and Drug Administration (FDA) has accepted for Priority Review the Biologics License Application (BLA) seeking approval for Orca-T, its lead investigational allogeneic T-cell immunotherapy, for the treatment of hematological malignancies including acute myeloid leukemia (AML), acute lymphoblastic leukemia (ALL) and myelodysplastic syndromes (MDS).

The FDA granted the BLA Priority Review with a Prescription Drug User Fee Act (PDUFA) target action date of April 6, 2026.

"A stem cell transplant has been the only potentially curative option for many people with AML, ALL or MDS, however treatment-related toxicities too often hinder patient recovery. Acceptance of the Orca-T BLA marks a pivotal moment in our ability to deliver a first-in-class therapy designed to improve survival free from complications like graft versus host disease,” said Nate Fernhoff, Ph.D., co-founder and chief executive officer at Orca Bio. “Supported by positive Phase 3 clinical data, today’s regulatory milestone reflects important recognition of the transformative potential of Orca-T. We look forward to working collaboratively with the FDA on the review of our application with the goal of advancing Orca-T and making it available to patients in need.”

The BLA submission for Orca-T is supported by positive results from the pivotal Phase 3 study, Precision-T (NCT04013685), a randomized, open-label multi-center study that evaluated the safety, efficacy and tolerability of Orca-T compared to conventional allogeneic hematopoietic stem cell transplant (alloHSCT) in patients with AML, ALL and MDS. The study met its primary endpoint of a statistically significant improvement in survival free of moderate-to-severe chronic graft versus host disease (cGvHD) with Orca-T versus alloHSCT.

About Orca-T

Orca-T is an investigational allogeneic T-cell immunotherapy being evaluated for the treatment of multiple hematological 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.

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 www.orcabio.com.

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Orca Bio Appoints Key Executives Including Steve Gavel as Chief Commercial Officer

MENLO PARK, CA, June 4, 2025 – Orca Bio, a late-stage biotechnology company committed to transforming the lives of patients through high-precision cell therapy, today announced the appointment of senior leaders to support the company as it advances its lead investigational allogeneic T-cell immunotherapy, Orca-T®, toward potential commercial launch.

Steve Gavel has joined Orca Bio as Chief Commercial Officer after most recently serving as Senior Vice President, Global Cell Therapy Commercial Development at Legend Biotech. Orca Bio has also strengthened its broader commercial organization with the addition of several senior leaders with extensive cell therapy experience to oversee Market Access, Commercial Operations and Medical Affairs.

In addition to these key commercial appointments, Allison Frisbee has joined Orca Bio as a Senior Vice President, Legal, following roles at Kronos Bio, Jazz Pharmaceuticals and Bristol Myers Squibb, and as outside counsel to life science companies at Orrick, Herrington and Sutcliffe.

Steve Gavel - Chief Commercial Officer

Gavel brings over 30 years of experience in the biotechnology and pharmaceutical sectors, with deep expertise in the commercialization of cell and gene therapies having led strategy and execution since the earliest days of the field.

“We are thrilled to welcome Steve to the Orca Bio team. Steve is a cell therapy veteran with a proven track record of building and scaling organizations in preparation for commercialization,” said Nate Fernhoff, Ph.D., Co-founder and Chief Executive Officer at Orca Bio. “As we prepare for the commercial launch of Orca-T, Steve brings a perfect combination of background, experience and strategic vision to lead Orca Bio into this next phase of growth and maturation.”

At Legend Biotech, Gavel grew and scaled its commercial organization across multiple CAR-T therapies, including leading the successful global launch of Carvykti®, a treatment for patients with relapsed or refractory multiple myeloma. There he oversaw the global commercial development efforts including launch readiness, market access and commercial operations. Prior to Legend Biotech, Gavel led U.S. commercial strategy and development at Celgene (now Bristol Myers Squibb). Before then, he held commercial roles of increasing seniority at companies including Millennium Pharmaceuticals, IMS Health, West Pharmaceutical Services and Discovery Labs.

“I’m honored to join Orca Bio as it prepares to bring its groundbreaking cell therapy to patients with high-risk blood cancers, including acute myeloid leukemia and myelodysplastic syndrome,” said Steve Gavel, Chief Commercial Officer at Orca Bio. “The company’s pioneering team has achieved remarkable progress, and with approximately 500 patients treated on trial to date, the potential of its novel high-precision platform is already being realized. I look forward to joining the company as we work to unlock new opportunities for growth and transform the therapeutic landscape for patients with blood cancer.”

Allison Frisbee - Senior Vice President, Legal

Frisbee joins with strong experience as a legal and operations leader in the life science industry, with a focus on translating complex legal and regulatory challenges into clear, strategic solutions. Prior to joining Orca Bio, Frisbee served as the Chief Administrative Officer at Kronos Bio, where she oversaw a broad portfolio including Legal, HR, Facilities, IT and Compliance. Before joining Kronos, she held senior legal roles at Jazz Pharmaceuticals and Bristol Myers Squibb.

“I’m thrilled to join the team at Orca Bio and help continue shaping a thoughtful, values-driven legal and compliance function,” said Allison Frisbee, Senior Vice President, Legal at Orca Bio. “It’s a privilege to partner with teams who are not only advancing transformative therapies, but leading with a deep commitment to integrity, accountability and an unwavering commitment to doing what’s right for patients.”

About Orca Bio

Orca Bio is a late-stage biotechnology company developing high-precision cell therapies for the treatment of 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 www.orcabio.com.

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Contact:

Corporate Communications

Kelsey Grossman

Investor Relations

Joshua Murray