The Next Decade In Gene Therapy Innovation â 6 Critical Questions (And Answers) By Kyle M. OâNeil and Brendan J. Wang, Back Bay Life Science Advisors As the gene therapy field has tackled delivery vectors as described in “An Analysis Of The Gene Therapy Viral Vector Landscape,” several clinical and commercial questions lowered expectations for gene therapy sales, leading sell-side forecasts to fall more than 50% since 2018. 1 However, more than $6.5 billion in 2026 projected gene therapy sales remain across Duchenne muscular dystrophy (DMD), hemophilia A/B, sickle cell disease, Fabry disease, Huntington’s disease, and Leber congenital amaurosis type 10 (LCA10) alone, putting pressure on industry-leading gene therapy companies to deliver.