Advances in gene therapy: Mapping the treatment landscape, from hematology to hearing loss
Industry Buzz
Gene therapies are one of the most exciting things to hit our field in a long time... If tests continue to show the safety and benefit the early results suggest, this could be a game-changer and something that moves toward a routine referral.
—Shelley Duncan, AuD, audiologist at Akron Children's
Gene therapy used to be treated like a last-resort option that only got discussed after everything else failed, and only for a tiny group of patients who met very narrow approval rules. But of late, gene therapy is increasingly approached as a defined care pathway rather than a late-stage option.
Physician Maria Knobel, MD, says, “The transition from very narrowly focused approvals to the earlier intervention pathways with more specific referral criteria has become the most practice-changing gene therapy development of 2024 and 2025. Such a change helped in reducing the time to diagnosis and bringing the subject of gene therapy closer to the preliminary evaluation by the specialist rather than an option of last resort.”
Gene therapy news in the last two years has shifted from single-disease headlines to repeatable patterns across specialties.
Hematology
CRISPR-based ex vivo editing entered routine care in sickle cell disease and transfusion-dependent beta thalassemia after U.S. approvals in December 2023 for Casgevy and Lyfgenia.[]
The next step over the last year has been label expansion work, plus longer follow-up on vaso-occlusive crises and transfusion independence. The FDA press announcement describes Casgevy as the first FDA-approved therapy using CRISPR/Cas9 genome editing, and outlines the stem cell collection, editing, and reinfusion process.
In late 2025, CSL published 5-year follow-up data from the HOPE-B program for Hemgenix (etranacogene dezaparvovec). The National Bleeding Disorders Foundation highlighted the publication in The New England Journal of Medicine, and framed the trial results as a durability milestone for an AAV liver-directed product already on the market.[][]
However, toxicity still centers on conditioning and transplant-like supportive care. Program design now places more weight on patient selection, organ reserve, and center experience.
Related: The diagnosis gap in pediatric hearing loss: Why one-size-fits-all protocols fall shortNeurology
Recently, the FDA approved Lenmeldy (atidarsagene autotemcel) for children with specific pre-symptomatic or early symptomatic metachromatic leukodystrophy (MLD). This approval matters beyond MLD itself because neurologic gene therapy discussions often stall around brain delivery. Lenmeldy avoids direct CNS delivery by restoring ARSA enzyme activity through autologous hematopoietic stem cells, then relying on cross-correction over time.[]
FDA CBER director Peter Marks, MD, PhD, portrayed the milestone in practical terms: “This is the first FDA-approved treatment option for children who have this rare genetic disease.”[]
For neurology teams, the workflow implication is front-loaded diagnosis. The window for pre-symptomatic treatment pushes screening, rapid referral, and early transplant-style coordination.
Neuromuscular disease
Following the FDA’s expanded-use approval of Elevidys for Duchenne muscular dystrophy to both ambulatory and non-ambulatory individuals age 4 and older with a confirmed DMD mutation,[] safety monitoring for the drug has received more attention. In November 2025, the FDA added a Boxed Warning to the label after fatal liver injuries were reported, and restricted its use to ambulatory patients only.[]
For clinicians, the story is risk governance, with clearer monitoring requirements and post-treatment follow-up expectations.
Ophthalmology
Retina gene therapy programs have targeted wet AMD to reduce injection burden. At AAO 2024, Arshad Khanani, MD, described bilateral dosing results for ABBV-RGX-314 and tied the update to feasibility in routine practice: “The fellow eye dosing data with ABBV-RGX-314 is a milestone for the field of gene therapy for common retinal diseases, as this is the first time we have performed bilateral treatment for wet AMD patients.”[]
Reported outcomes from the Phase 2 fellow-eye sub-study included a 97% reduction in annualized anti-VEGF treatment burden and 78% injection-free status at 9 months.
The practical signal for retina specialists is durability with familiar outcome measures, plus local safety readouts.
Hearing loss
Results for DB-OTO gene therapy in OTOF-related deafness were also reported in 2025.[] Treated patients achieved improved hearing, and a subset of patients gained normalization of hearing sensitivity. This sits inside a wider shift toward genotype-driven pediatric hearing pathways, since eligibility depends on fast molecular diagnosis.
Shelley Duncan, AuD, audiologist at Akron Children's, weighs in on the vast potential of gene therapy, stating, “Gene therapies are certainly one of the most exciting things to hit our field in a long time. This is just now emerging as a potential treatment but is showing promising early results. If tests continue to show the safety and benefit the early results suggest, this could be a game-changer and something that moves toward a routine referral.”
Immunology and oncology
The last two years also brought more credible in vivo immune cell engineering. A 2025 report in The New England Journal of Medicine describes in vivo CD19 CAR T-cell therapy in refractory systemic lupus erythematosus.[8] This line of work aims to remove weeks of ex vivo manufacturing and broaden access, especially for autoimmune indications where speed and logistics matter.
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Across specialties, the common pressure points for the application of gene therapy look consistent: earlier genetic confirmation, procedure-ready delivery routes, and structured safety monitoring. The new standard is not “gene therapy exists.” The new standard is systems design that incorporates gene therapy as a care pathway, with referral rules, peri-procedural protocols, and longitudinal outcome tracking.
Speaking broadly about gene-therapy candidate counseling and long-term follow-up expectations, Dr. Knobel states, “One of the most widespread misconceptions is that one-time treatment is supposed to be long-term. Gene therapy does not tend to cancel any further medical supervision, and in fact tends to alter the course of a disease. This point needs to be made time and again in meetings.”