FDA Activity Recap: May 2025 Features BLA Acceptance in MPS II, AdComm Announcement for DMD Cell Therapy, and More

Last month, May 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. Although last month proved a bit slower with major announcements, several noteworthy actions still took place, with the FDA accepting REGENXBIO’s biologics license application (BLA) clemidsogene lanparvovec (also known as RGX-121), an investigational adeno-associated virus (AAV) vector-based gene therapy intended to treat mucopolysaccharidosis type 2 (MPSII, also known as Hunter syndrome) and announcing that an advisory committee (AdComm) meeting will be held regarding the biologics license application (BLA) for Capricor Therapeutics' Deramiocel (also known as CAP-1002), an investigational allogeneic cardiosphere-derived cell therapy intended to treat Duchenne muscular dystrophy (DMD) cardiomyopathy. Our team has highlighted these and another important action below.

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

REGENXBIO’s BLA for MPS II Gene Therapy RGX-121 Accepted for Priority Review by the FDA

May 15, 2025 — The FDA has accepted REGENXBIO’s BLA clemidsogene lanparvovec (also known as RGX-121), an investigational AAV-based gene therapy intended to treat mucopolysaccharidosis type 2 (MPSII, also known as Hunter syndrome). The BLA was accepted for priority review and its Prescription Drug User Fee Act (PDUFA) action date has been set as November 9, 2025.

"Acceptance of the RGX-121 BLA marks an exciting milestone on our path to bring the MPS II patient community a one-time treatment with the potential to address both the neurodevelopmental and systemic effects of Hunter syndrome," Curran M. Simpson, the president and chief executive officer of REGENXBIO, said in a statement. "Supported by positive biomarker data and long-term outcomes, RGX-121 has the potential to be a first-in-class gene therapy that could dramatically transform the MPS II treatment landscape and reduce the significant burden patients and families currently face with weekly enzyme replacement therapy."

The FDA has previously granted RGX-121 orphan drug, rare pediatric disease, fast track, and regenerative medicine advanced therapy designations. The European Medicines Agency has granted it advanced therapy medicinal products classification.

Ocugen’s Gene Therapy OCU410ST Nets Rare Pediatric Disease Designation for ABCA4-Associated Retinopathies

May 28, 2025 — Ocugen has received rare pediatric disease designation from the FDA for OCU410ST, an investigational AAV vector-based gene therapy, for the treatment of ABCA4-associated retinopathies, including Stargardt disease, retinitis pigmentosa 19, and cone-rod dystrophy 3.

Alongside the announcement, Ocugen noted that it intends to initiate a phase 2/3 confirmatory clinical trial for OCU410ST in the coming weeks and that it anticipates submitting a BLA for the therapy to the FDA in 2027. OCU410ST has previously been granted orphan drug designations for ABCA4-associated retinopathies by both the FDA and European Medicines Agency (EMA).

“This latest designation for OCU410ST reaffirms the urgency of providing a therapeutic option to Stargardt patients who have no FDA-approved treatment available,” Shankar Musunuri, PhD, the chairman, chief executive officer, and cofounder of Ocugen, said in a statement. “This inherited retinal disease presents itself most often in childhood—making Stargardt disease a diagnosis that not only affects the patient but impacts the entire family.”

FDA States Advisory Committee Meeting Will be Held for Capricor’s BLA for DMD Cardiomyopathy Cell Therapy Deramiocel

May 9, 2025 — In a mid-cycle review meeting between the FDA and Capricor Therapeutics regarding the latter’s BLA for Deramiocel (also known as CAP-1002), an investigational allogeneic cardiosphere-derived cell therapy intended to treat DMD cardiomyopathy, the agency stated its intent to hold an advisory committee meeting regarding the BLA.

Alongside this, however, the FDA noted in the meeting that the review committee had found no major deficiencies with the BLA package. The date for the advisory committee meeting has not yet been determined.

“The successful completion of our mid-cycle review meeting along with the upcoming advisory committee meeting represents major milestones on the path towards approval of deramiocel,” Linda Marbán, PhD, the chief executive officer of Capricor, said in a statement. “Deramiocel is a first-in-class cellular therapy with the potential to halt or slow the progression of DMD-cardiomyopathy, and we are pleased to have the opportunity to present the efficacy and safety data to the advisory committee. We have been actively preparing for an advisory committee meeting, and we look forward to providing the physician and patient perspectives to highlight the weight of evidence supporting the transformative potential of deramiocel in treating DMD-cardiomyopathy.”