The Clinical-Stage Gene Therapy Landscape
Gene therapy has moved from laboratory promise to clinical reality. As of 2026, over 180 companies are actively developing more than 200 gene therapies across clinical stages, with nearly 3,500 gene, cell, and RNA therapies in preclinical and clinical development worldwide, according to the ASGCT-Citeline landscape reports.
Platform Technologies Driving the Pipeline
The field is dominated by three core delivery and editing platforms, each with distinct clinical profiles:
- AAV Vectors
- Adeno-associated virus remains the workhorse for in vivo gene replacement. BioMarin's Roctavian (hemophilia A) and Ultragenyx's DTX401 (glycogen storage disease) exemplify the AAV approach — single-infusion therapies delivering functional gene copies to target tissues. Five-year Phase 3 data for Roctavian showed 81.3% of participants remaining off prophylaxis.
- CRISPR/Cas9 and Base Editing
- CRISPR Therapeutics' Casgevy became the first CRISPR-based therapy to gain FDA approval (December 2023) for sickle cell disease. Intellia Therapeutics is advancing in vivo CRISPR editing for transthyretin amyloidosis in Phase 3, while Beam Therapeutics is pioneering single-base editing without double-strand DNA cuts.
- Lentiviral Vectors
- Bluebird bio (now Genetix Biotherapeutics) has three FDA-approved lentiviral gene therapies — Zynteglo (beta-thalassemia), Skysona (adrenoleukodystrophy), and Lyfgenia (sickle cell disease) — representing over 1,000 patient-years of follow-up data.
Therapeutic Focus Areas
A notable shift is underway: 51% of newly initiated gene therapy trials now target non-oncology indications, up from 39% year-over-year. Key areas include:
| Therapeutic Area | Representative Companies | Notable Programs |
|---|---|---|
| Rare Neurological | Passage Bio, Ultragenyx | FTD-GRN (PBFT02), Angelman Syndrome (GTX-102) |
| Hematology | BioMarin, CRISPR Therapeutics | Hemophilia A, Sickle Cell Disease |
| Cardiovascular | Rocket Pharmaceuticals, Verve | Danon Disease, Hypercholesterolemia |
| Metabolic | Ultragenyx, Kriya Therapeutics | GSD Type Ia, MASH |
| Ophthalmology | MeiraGTx, Kriya Therapeutics | Inherited Retinal Dystrophy, Geographic Atrophy |
Regulatory and Commercial Milestones
The FDA has signaled increasing comfort with gene therapy approvals. Key upcoming decisions include Ultragenyx's DTX401 BLA (PDUFA date: March 2026) and the resubmission of UX111 for Sanfilippo syndrome. Meanwhile, safety monitoring remains a central concern — the FDA placed clinical holds on Sarepta's limb-girdle muscular dystrophy programs in late 2025 following adverse events, highlighting the ongoing need for rigorous post-market surveillance.
Investment Activity
Capital continues to flow into the space. Kriya Therapeutics closed a $320M Series D in 2025, while Tune Therapeutics raised $175M for its epigenomic controller platform targeting chronic hepatitis B. These financings reflect investor confidence that the field is transitioning from proof-of-concept to durable commercial execution.