The terms, per the grant. On August 23, 2022, 4D Molecular Therapeutics was issued US11419949B2, covering AAV variant capsids and methods of use. The CPC tags — C07K 14/005 (viral proteins), C12N 15/86 (viral vectors), A61K 48/0016 (gene therapy), plus A61P 27/02 (eye) — describe an engineered delivery vehicle with tissue-targeting properties.

Why the capsid is the franchise: in AAV gene therapy, the therapeutic gene varies by program, but the delivery capsid is the reusable asset that determines which tissues a therapy can reach and how well it evades immunity. An engineered-capsid grant is a platform asset — the kind of IP that gets licensed across many programs and carries a platform royalty.

“Provided herein are variant adeno-associated virus (AAV) capsid proteins having one or more modifications in amino acid sequence relative to a parental AAV capsid protein, which, when present in an AAV virion, confer increased infectivity of one or more types of retinal cells as compared to the infe…”— U.S. Patent No. 11,419,949 source

The structure point: a capsid-platform deal looks more like a tooling license than a single-drug license. The royalty base grows with each program that adopts the capsid, and the value is partly independent of any one therapeutic gene's clinical fate. For a model, that diversification is the premium.

What the grant does not promise: that any program using the capsid succeeds clinically, or that the capsid is free of competing delivery IP. It is an exclusivity claim on an engineered delivery vehicle — a real, reusable asset within a competitive delivery landscape.

The takeaway: when a gene-therapy deal crosses the desk, identify whether the value is in the gene or the delivery vehicle — because capsid platforms carry the broader, compounding royalty. 4D Molecular's August 2022 capsid grant is a dated example of delivery-platform IP.