The terms, per the grant. On April 12, 2022, Daiichi Sankyo was issued US11298359B2, covering an anti-HER3 antibody-drug conjugate. The CPC stack is heavy on the conjugation series — A61K 47/6803/6851/6855/6857/6861/6863/6869 — alongside the anti-HER3 antibody claims (C07K 16/2863 and related), showing the linker-payload architecture as the protected core.
Why a teardown separates the payload layer: in ADCs, the same linker-payload technology can be deployed against many different antibody targets. That makes the conjugation IP a reusable platform asset, whereas the antibody claims are target-specific. The durable, compounding royalty value often lives in the payload-and-linker layer because it touches every program built on the platform.
The structure point: a conjugate deal can be priced as a target-specific license (the antibody) plus a platform license (the linker-payload). For a model, the platform component is the higher-multiple asset because its royalty base grows with each new target the technology is applied to.
What the grant does not promise: a clinical outcome, an approval, or exclusivity over all conjugation chemistries. It is an exclusivity claim on a specific anti-HER3 conjugate, sitting within a field where multiple payload-and-linker platforms compete.
The takeaway: in any ADC term teardown, value the linker-payload IP separately from the antibody, because that is where reusable, compounding royalties sit. Daiichi Sankyo's April 2022 HER3-ADC grant is a dated example of the conjugation-centered architecture.