The FDA has postponed the target date for a decision on Orca Bio’s blood cancer cell therapy candidate Orca-T by three months to July 6.
Orca Bio CEO Dr. Nate Fernhoff told Fiers that the extension comes after the company submitted additional chemical, manufacturing and control (CMC) data several weeks ago at the agency’s request.
Fernhoff declined to specify the exact nature of the FDA’s questions, but said the company believes “none of these questions are fundamental or unaddressable.”
The delay comes at a time when the biopharmaceutical industry has become highly sensitive to FDA actions regarding cell and gene therapies, following a series of regulatory surprises that led to the planned resignation of Dr. Vinay Prasad, director of the FDA’s Center for Biologics Evaluation and Research (CBER).
In July, the FDA denied approval of Replimune’s oncolytic immunotherapy RP1 to treat melanoma. As an engineered virotherapy, RP1 falls within the scope of CBER. However, the decision to reject RP1 was reportedly sought not by CBER, but by Dr. Richard Pazdur, then director of the FDA’s Oncology Center of Excellence, according to Statistic.
The FDA has since accepted Replimune’s resubmission, with a decision expected by April 10, but Pazdur left the agency following internal disagreements over new policy proposals regarding clinical trials.
Fernhoff acknowledged that Orca Bio’s ongoing CMC-related interactions with the FDA are with CBER.
The essence of the FDA’s concerns is “CMC and drug management and whether it fully meets regulatory standards,” he said.
Fernhoff emphasized that the issue is not about clinical data or the therapeutic efficacy of Orca-T.
Orca Bio’s Orca-T is an engineered allogeneic cell therapy designed to improve blood cancer patients’ tolerance to transplant therapy. It utilizes hematopoietic stem cells and regulatory T (Treg) cells, followed by conventional T cells, but a typical stem cell transplant involves a mix of different cell types, including those that can cause graft-versus-host disease (GVHD).
In the phase 3 Precision-T trial, the 1-year chronic GVHD-free survival rate for a diverse group of patients with hematologic cancers was 78%, significantly better than the 38.4% for patients who received traditional allogeneic stem cell transplants.
In a composite endpoint measuring patients free of both GVHD and cancer recurrence, the Orca-T group had a significantly better outcome, with a 1-year outcome rate of 63% compared to 31% for the control group.
Although this trial was positive, it may raise questions about the design of the control group, in which patients receive standard tacrolimus and methotrexate combination therapy to prevent GVHD. However, after the launch of Precision-T, cyclophosphamide-based regimens emerged as a better post-transplant GVHD prevention option.
Fernhoff argued that the Phase 3 trial’s control group consisted entirely of patients in the United States, meeting the gold standard for clinical trials. Again, as emphasized by Orca Bio CEO, the FDA extension is not about clinical efficacy data.
Because the delay disrupted Orca Bio’s commercial plans, Fernhoff said the California biotech is working with the FDA to launch an expanded access program to make Orca-T available to patients in the interim before approval is granted.
In early 2026, Orca Bio announced a Series F funding round to close in December 2025 to support Orca-T’s launch readiness and pipeline advancement.
Fernhoff declined to comment on the potential impact of the upcoming CBER leadership change on the Orca-T review, but noted frequent engagement with the FDA review team, highlighting multiple interactions and “good conversations along the way.”
The field of cancer cell therapy faces many CMC-related challenges, including recurring debates between pharmaceutical companies and the FDA regarding product specifications and efficacy. Thankfully for Orca Bio, efficacy doesn’t seem to be a lingering issue for Orca-T.
Although the FDA is holding off on the topic of product specifications until final label discussions, Fernhoff said he does not expect Orca-T to be subject to efficacy assay challenges. In cell therapy, potency assays are used to measure the biological activity of therapeutic cells to confirm the strength of the final product. As the FDA notes in its industry guidance (PDF), “The complexity of CGT products can pose significant challenges to establishing efficacy assays.”
