Amgen v. Sanofi: antibody breadth needs enabling evidence

Clarus Biotech Review

The 2023 decision puts a measurable boundary around a broad molecular-platform narrative.

Amgen v. Sanofi makes an intellectual-property milestone concrete. On May 18, 2023, the U.S. Supreme Court affirmed the judgment against the challenged antibody claims for lack of enablement. The dispute concerned antibodies that bind PCSK9 and block its interaction with LDL receptors. [1]

## Count examples without confusing them with claim scope

The opinion describes disclosure of amino-acid sequences for 26 antibodies. The challenged claims reached a broader functional class. The Court's reasoning connected claim breadth with the extent of teaching needed to make and use the claimed invention. A count of disclosed examples was not, by itself, the scope of commercially durable protection. [1]

## A patent milestone is different from a drug milestone

The opinion discusses the competing cholesterol therapies Repatha and Praluent, but the legal outcome is not a finding that either drug failed clinically. It concerns the validity of particular claims. A diligence narrative should keep regulatory authorization, therapeutic evidence, claim validity, ownership, and freedom to operate on separate lines.

## Put the uncertainty into the investment brief

For an emerging antibody company, map which claims support the planned product, which data enable their proposed breadth, which markets and activities are covered, and which challenges could alter the protection thesis. Qualified counsel should evaluate the actual record. A search hit, an AI summary, or a pending filing is not a legal opinion.

## Measure the readiness of the factual package

Useful operating measures include the completeness of claim-to-example mapping, unresolved evidence gaps, scope changes requiring re-review, and the elapsed time since the last product-specific assessment. Legal expenditure should be budgeted as a dependency, but this decision does not supply a transferable litigation-cost figure. The milestone is a reviewable protection thesis with explicit boundaries, rather than a headline count of patents.

Source adaptation: the stored freedom-to-operate paper informed the commercialization-scope brief. The distinct case here is the Supreme Court's enablement ruling.

Sources

https://www.supremecourt.gov/opinions/22pdf/21-757_k5g1.pdf

Original article: https://www.clarusreview.bio/articles/patent-readiness-commercialization-brief