Gene Therapy Intelligence Report Q4 2026
Gene therapy works, but two high-dose AAV drugs carry most of the market, and the commercial misses came from eligible patients who never got treated. Sleuth's November 2026 map covers 465 clinical programs, 33 approved products, and 188 deals since 2021.
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Gene therapy has proven it can work. The harder question now is commercial: who actually gets treated?
We mapped all 465 clinical gene therapy programs, the 33 products approved since 2003, 2025 sales and 188 deals since 2021 for Sleuth's Gene Therapy Intel Hub. The headline is that value sits in a narrow corner of the field, and the next few quarters will test whether it can break out.
Some takeaways:
- Two drugs carry the market. Zolgensma and Elevidys make up ~$2.5B of ~$3.5B in 2025 sales. Both are high-dose AAV given into the bloodstream, the same approach behind 6 of the 8 in vivo deaths we tracked since January 2025. After two deaths, Elevidys' label was narrowed and US quarterly sales fell by more than half.
- The misses were mostly commercial, not scientific. Roctavian had ~5,700 eligible severe hemophilia A patients in the US and EU, but only dozens were treated. Antibodies screen out 58-67% of patients, and about half of those surveyed prefer to stay on chronic therapy.
- The pipeline is moving to where the problems are smaller. AAV still holds 64% of programs, but new AAV starts favor local sites like the brain and inner ear. LNP's share of new programs more than doubled to ~12%, nearly all of it in vivo editing.
- Deals are fewer but pickier. Volume fell ~40% from the 2023 peak, yet late-stage assets rose from 5% to 12% of deals and editing drew the largest share of value (~45%). Lilly led all buyers with 20 deals.
16 of the 19 dated catalysts on our calendar land by mid-2027. Lonvo-z could become the first approved in vivo gene editor (March 2027 PDUFA), AMT-130 has an FDA goal date in Huntington's in May, and three pivotal wet AMD readouts will show whether a one-time therapy can compete where a chronic drug already works.
Gene therapy's next chapter will be decided less by whether the science works, and more by whether enough of the right patients choose it.
The full report covers:
- Approvals and the pipeline by phase and region
- Sales and commercial misses by product
- In vivo editing by chemistry, with a map of 35 companies
- Safety by delivery vehicle
- Catalysts through 2027 and our predictions
