Around the Helix: Cell and Gene Therapy Company Updates – May 21, 2025

The cell and gene therapy sectors are growing exponentially, with new players emerging daily and much progress being made both in and out of the lab. CGTLive®’s Around the Helix is your chance to catch up with the latest news in cell and gene therapies, including partnerships, pipeline updates, and more.

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

The FDA has accepted REGENXBIO’s biologics license application (BLA) clemidsogene lanparvovec (also known as RGX-121), an investigational adeno-associated virus vector-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.

2. Treating CPS1 Deficiency With Personalized Gene Editing

In February 2025 at between 6 and 7 months of age, a child named KJ was treated by Children’s Hospital of Philadelphia (CHOP) investigators in an n-of-1 clinical trial for a personalized CRISPR-based gene editing therapy intended to treat his severe carbamoyl phosphate synthetase 1 (CPS1) deficiency. CGTLive® spoke with trial investigators Kiran Musunuru, MD, PhD, a physician-scientist and Barry J. Gertz Professor for translational research in the Perelman School of Medicine at the University of Pennsylvania and CHOP and Rebecca Ahrens-Nicklas, MD, PhD, a physician-scientist and director of the Gene Therapy for Inherited Metabolic Disorders Frontier Program at CHOP, about the case.

3. Rocket’s PKP2-Arrhythmogenic Cardiomyopathy Gene Therapy RP-A601 Improves or Stabilizes Heart Function in Phase 1 Trial

Rocket Pharmaceuticals’ RP-A601, an investigational adeno-associated virus (AAV) vector-based gene therapy intended to treat plakophilin-2 related Arrhythmogenic Cardiomyopathy (PKP2-ACM), has demonstrated the ability to stabilize or improve heart function in patients treated in a phase 1 clinical trial (NCT05885412).

4. Conservative Management Following Treatment With DMD Gene Therapy Elevidys

A notable case study of a patient treated with Sarepta Therapeutics’ delandistrogene moxeparvovec-rokl (marketed as Elevidys) was presented by Ben Samelson-Jones, MD, PhD, an assistant professor of pediatric hematology at Perelman School of Medicine, University of Pennsylvania, and the associate director of clinical in vivo gene therapy at Children’s Hospital of Philadelphia (CHOP), at the American Society of Gene & Cell Therapy (ASGCT) 28th Annual Meeting, held May 13 to 17, 2024, in New Orleans, LA. CGTLive® spoke with Samelson-Jones about the case and its implications.

5. CRISPR and Sirius Therapeutics Team Up to Tackle Thromboembolic Disorders

CRISPR Therapeutics and Sirius Therapeutics have formed a new strategic partnership focused on the development of SRSD107, a long-acting Factor XI (FXI) small interfering RNA (siRNA) therapy that is intended to potentially treat multiple thromboembolic disorder indications. "SRSD107, which targets FXI, has the potential to be a best-in-class therapy, offering infrequent dosing and improved patient outcomes," Samarth Kulkarni, PhD, the chairman and CEO of CRISPR Therapeutics, said in a statement. "Sirius’ siRNA platform complements our existing capabilities and expands our therapeutic toolkit, enabling us to develop a broader range of transformative gene-based medicines.”

6. Anixa Makes Progress on Ovarian Cancer CER-T

In a letter to shareholders, Amit Kumar, PhD, the chairman and chief executive officer of Anixa Biosciences, provided updates on the status of the ongoing phase 1 clinical trial (NCT05316129) evaluating its novel follicle stimulating hormone receptor (FSHR)-targeting chimeric endocrine receptor (CER) T-cell therapy for the treatment of ovarian cancer. Kumar noted that the trial, which is being carried out in collaboration with Moffitt Cancer Center, has completed 3 dose-escalation cohorts and that a fourth is set to begin imminently.