When a biologic's core composition patent is aging, the franchise's remaining exclusivity often lives in method-of-use grants, and US10617755B2 - "Combination therapy for the treatment of glioblastoma," issued April 14, 2020 to Genentech - is a clean example of the type. It claims using an anti-VEGF antibody in a defined combination for a specific cancer.

The first point a careful reader makes: this is a use patent, not a composition patent, so it does not extend the term of the antibody molecule itself. What it does is protect a particular therapeutic application. A competitor free of the composition claim may still face this grant if it markets the same combination for the same indication.

“This invention concerns methods of treating a patient diagnosed with glioblastoma comprising administering to said patient a therapy comprising an effective amount of an anti-VEGF antibody and a chemotherapeutic.”— U.S. Patent No. 10,617,755 source

That layering is how franchises stretch effective exclusivity past the headline expiry of the molecule. The CPC tags here - A61K 39/3955 (antibody medicinal preparations), A61K 45/06 (combinations), C07K 16/22 (anti-VEGF antibody) - describe a combination-of-actives claim, the kind that accumulates around a durable biologic over a decade.

The litigation-relevant caveat, in editorial discipline, is that an allegation of infringing a use patent is not a holding, and the scope of a combination claim is exactly what gets contested. Whether a competitor's regimen reads on the claimed combination turns on the specific partners and the indication, not on the franchise name. None of that is decided until a court construes the claim.

For exclusivity math, the practical takeaway is to never read a biologic's protection off a single composition-patent expiry date. The effective runway is the envelope of composition plus formulation plus use grants, and combination patents like this one are a recurring way that envelope extends beyond what the molecule patent alone would suggest.