FDA Activity Recap: October 2025 Features New Platform Technology Designation, RDEA Pilot Program Selection, and More

Last month, October 2025, the CGTLive^® team was diligently tracking the FDA's activities related to the development of cell and gene therapies for the treatment of rare, complex, and otherwise challenging diseases and disorders.

The agency has continued to ramp up its activities around these therapies as more of them progress through the pipeline in tandem. Last month proved no different, with the FDA granting platform technology designation to Krystal Biotech for the genetically modified, nonreplicating herpes simplex virus type 1 (HSV-1) viral vector used in its gene therapy KB801 and selecting Abeona Therapeutics’ ABO-503 for its Rare Disease Endpoint Advancement (RDEA) Pilot Program. Our team has highlighted these, and several other important actions, below.

Click the read more buttons for more details and information about each update.

Krystal Biotech’s Neurotrophic Keratitis Gene Therapy Viral Vector Secures FDA Platform Technology Designation

October 15, 2025 — Krystal Biotech has received a platform technology designation from the FDA for the genetically modified, nonreplicating HSV-1 viral vector used in KB801, an investigational gene therapy intended to treat neurotrophic keratitis (NK).

KB801, which takes the form of a redosable eye drop, is currently being evaluated in the randomized, placebo-controlled phase 1/2 EMERALD-1 clinical trial (NCT06999733). KB801 is intended to allow epithelial cells located in the front of the eye to consistently produce nerve growth factor (NGF). Current treatment options for NK include NGF eye drops, but according to Krystal, these have a high burden of treatment because of the need for “intensive administration” 6 times daily to achieve ideal results.

“Receiving a platform technology designation from the FDA is a tremendous milestone for our development team and Krystal, both as recognition of the reproducibility and scalability of our HSV-1 gene delivery platform and for the potential product development benefits it may provide,” Suma Krishnan, MSc, MBA, the president of research and development at Krystal Biotech, said in a statement. “We are excited to work with the FDA under this program to identify potential efficiencies, including opportunities to leverage our prior experience with FDA-approved Vyjuvek [beremagene geperpavec-svdt, also known as B-VEC] to accelerate the development of our genetic medicines pipeline, starting with KB801 for the treatment of NK.”

FDA Picks Abeona’s XLRS Gene Therapy ABO-503 for RDEA Pilot Program

October 14, 2025 — Abeona Therapeutics’ ABO-503, an investigational adeno-associated virus (AAV) vector-based gene therapy intended to treat X-linked retinoschisis (XLRS), has been chosen by the FDA for its RDEA Pilot Program.

The RDEA program is meant to support use of novel end points for measuring efficacy in clinical studies for therapies aimed at treating rare diseases. It will allow the company to obtain frequent advice from the FDA and have conversations as needed with the agency in order to help establish product-specific efficacy end points for the program.

“XLRS is an underserved area with a large unmet need,” Vish Seshadri, PhD, the CEO of Abeona, said in a statement. “We are honored that ABO-503 gene therapy for XLRS has been chosen for the FDA’s highly competitive RDEA Pilot Program. We believe our participation will meaningfully improve the success rate of our XLRS clinical development efforts and, more broadly, could help facilitate pipeline innovation by using novel efficacy end points in new therapy development across other inherited retinal diseases.”

BLA for Rocket’s LAD-I Gene Therapy Under Review by FDA Again

October 14, 2025 — The FDA has accepted Rocket Pharmaceuticals’ resubmission of a biologics license application (BLA) for marnetegragene autotemcel (RP-L201, to be marketed as Kresladi), a genetically modified autologous hematopoietic stem cell therapy intended to treat leukocyte adhesion deficiency type 1 (LAD-I).

The FDA has set the Prescription Drug User Fee Act (PDUFA) action date for the BLA at March 28, 2026. Data from a global phase 1/2 clinical trial (NCT03812263) that showed a 100% overall survival rate in all enrolled patients for at least 1 year post treatment, and through the entire duration of follow-up, support the BLA. According to Rocket, this trial met all of its primary and secondary end points, with the incidence of significant infections having decreased substantially in comparison with levels before treatment and observed indications of skin lesion improvement and restored wound-healing capability. With regard to safety, Rocket noted that Kresladi was “well tolerated” and that there were no serious adverse events deemed related to treatment reported in the now completed study.

“We value the continued dialogue with the FDA and believe the BLA moves Rocket closer to our goal of delivering a onetime gene therapy to patients facing the devastating effects of severe LAD-I,” Gaurav Shah, MD, the CEO of Rocket, said in a statement. “For these patients, survival beyond childhood is uncommon. Bone marrow transplant is currently the only treatment option; has substantial morbidity, mortality, and cost; and may not be available in time for these children. As we approach our new PDUFA date, we are focused on the opportunity to make this therapy available to patients who need it most.”

Umoja Biopharma's In Situ CAR T Therapy UB-VV111 Fast-Tracked for Several R/R B-Cell Malignancy Indications

October 2, 2025 — The FDA has granted fast track designation to Umoja Biopharma's UB-VV111, a gene therapy product intended to create CD19-directed chimeric antigen receptor (CAR) T cells within the body, for the treatment of relapsed/refractory (R/R) large B-cell lymphoma that has previously been treated with at least 2 prior lines of therapy and for the treatment of R/R chronic lymphocytic leukemia that has previously been treated with at least 2 prior lines of therapy.

UB-VV111 is currently being evaluated in a phase 1 clinical trial (NCT06528301) for adult patients with R/R CD19-positive B-cell malignancies. The study, which launched on March 10, 2025, includes 2 treatment arms: an arm in which patients receive UB-VV111 alone and an arm in which patients receive UB-VV111 and subsequent rapamycin.

UB-VV111, an off-the-shelf treatment, is intended to overcome some of the drawbacks associated with the standard ex vivo approach to CAR T therapy, such as long wait times and high-cost manufacturing. Notably, under an existing agreement, the biopharmaceutical company AbbVie has the exclusive option to license UB-VV111 and Umoja’s other CD19-directed in vivo CAR T therapy candidates.

Tr1X's Multiple Sclerosis Cell Therapy TRX319 Cleared for US Trial

October 15, 2025 — The FDA has cleared an investigational new drug (IND) application for Tr1X's TRX319, an allogeneic CAR-engineered type 1 regulatory (Tr1 Treg) cell therapy intended to treat progressive multiple sclerosis (MS).

In light of the IND clearance, Tr1X intends to go forward with plans for a phase 1/2a dose-escalation clinical trial, which it expects to launch early next year. According to Tr1X, TRX319 is intended to restore immune balance via active anti-inflammatory signaling, T-cell regulation, and targeted B-cell control. The planned multicenter, open-label study will primarily focus on safety, but will also include evaluation of pharmacodynamics, clinical disability, and biomarkers. Tr1X highlighted findings from preclinical research on TRX319 indicating its ability to suppress key proinflammatory cytokines and to penetrate the central nervous system in a “robust” manner. Additionally, the preclinical TRX319 data demonstrated CD19-specific cytotoxicity and IL-10–associated regulatory activity across self-reactive T-cells and activated microglia.

“An approach that targets B-cell biology while actively modulating inflammatory signaling within a regulatory cell-therapy framework is a distinct and promising hypothesis in progressive MS,” Bruce Cree, MD, PhD, MAS, the George A. Zimmermann endowed professor in multiple sclerosis in the Department of Neurology at the University of California San Francisco, said in a statement. “I look forward to studying TRX319 in this dose-escalation trial to further understand the potential of this cell therapy.”