## Facts

- Photocure ASA owned a patent covering Metvixia®, a topical photochemotherapy drug whose active ingredient is methyl aminolevulinate hydrochloride (MAL hydrochloride).
- Photocure sought a patent term extension under 35 U.S.C. § 156 based on FDA regulatory review preceding Metvixia®’s first permitted commercial marketing.
- The PTO denied the extension, reasoning that an earlier FDA-approved drug contained aminolevulinic acid hydrochloride (ALA hydrochloride), which the PTO viewed as sharing the same “active moiety” as MAL; thus, Metvixia® was not the first permitted commercial marketing of the relevant product.
- Photocure sued under the Administrative Procedure Act in the Eastern District of Virginia, challenging the denial as contrary to law.
- The district court set aside the PTO decision and held the patent eligible for term extension.
- The PTO Director appealed to the Federal Circuit.

## Issues

1. Whether, for 35 U.S.C. § 156, “drug product” and “active ingredient” refer to the specific FDA-approved chemical compound (including salts or esters), or instead to a broader “active moiety” concept.
2. Whether MAL hydrochloride constitutes a distinct “drug product” from previously approved ALA hydrochloride such that Metvixia® represents the first permitted commercial marketing of that product under § 156.
3. Whether deference is owed to the PTO’s interpretation when it conflicts with the statute’s text.

## Decision

- The Federal Circuit affirmed the district court.
- The court held that MAL hydrochloride is a different “active ingredient” and therefore a different “drug product” from ALA hydrochloride for § 156 purposes.
- The court rejected the PTO’s reliance on “active moiety,” concluding the statute’s language controls and does not adopt that FDA regulatory concept.
- The court declined to defer to the PTO because the statutory definition was clear and the agency’s interpretation was inconsistent with the text.
- Metvixia®’s patent was eligible for a patent term extension under § 156.

## Legal Principles

- Under 35 U.S.C. § 156, “drug product” means “the active ingredient of a new drug, including any salt or ester of the active ingredient,” focusing on the specific chemical compound present in the approved product.
- The statute’s “first permitted commercial marketing or use” requirement is assessed by reference to the approved active ingredient (including its salts or esters), not by collapsing different compounds into a shared “active moiety.”
- Statutory language that expressly includes salts and esters cannot be read in a way that effectively eliminates that inclusion.
- Courts will not defer to an agency construction that contradicts unambiguous statutory text, even in technically specialized regulatory contexts.

## Conclusion

The Federal Circuit held that § 156 patent term extension eligibility turns on whether the FDA approval was the first permitted commercial marketing of the specific approved active ingredient (including salts or esters), and because MAL hydrochloride is distinct from previously approved ALA hydrochloride, Photocure’s patent qualified for an extension.


Photocure ASA v. Kappos, 603 F.3d 1372 (Fed. Cir. 2010)