Pharma In Brief - Canada: Federal Court Dismisses Prohibition Application For Valganciclovir Hydrochloride Tablets [VALCYTE®]

Case: Hoffmann-La Roche Limited v. Apotex Inc. et al. Drug: Valganciclovir hydrochloride (VALCYTE®) Nature of case: Prohibition application pursuant to PM(NOC) Regulations Successful party: Apotex Inc. Date of decision: July 12, 2013

Summary

Hoffmann-La Roche Limited ("Roche") brought an application pursuant to section 6 of the Patented Medicines (Notice of Compliance) Regulations for an order prohibiting the Minister of Health from issuing a Notice of Compliance to Apotex Inc. ("Apotex") in respect of its valganciclovir hydrochloride tablets (the "Apotex Product") until the expiry of Canadian Patent No. 2,154,721 (the "'721 Patent").

The '721 Patent relates to a novel antiviral drug, valganciclovir, described as the mono-L-valine ester of ganciclovir, a leading drug for the treatment of certain herpes viruses, particularly cytomegalovirus. Ganciclovir itself exhibits low oral bioavailability, requiring slow daily intravenous infusion of the drug.

Apotex alleged that the '721 Patent was invalid on the basis of anticipation, obviousness and overbreadth, and that its Apotex Product would not infringe certain claims of the '721 Patent. In its analysis, the Court expanded the disclosure component of the anticipation test, departing from the more stringent test set forth by the Supreme Court of Canada in Apotex Inc. v. Sanofi-Synthelabo Canada Inc. (2008 SCC 61) ("Sanofi"). The Court held that Apotex's invalidity allegations with respect to anticipation and obviousness were justified. The Court also found that Apotex's allegation of non-infringement was justified in respect of one of the '721 Patent's claims. As such, the Court dismissed Roche's prohibition application.

The inventive concept of the '721 Patent

The parties disagreed as to whether the '721 Patent claims that the mono-L-valine ester of ganciclovir, valganciclovir, has better oral bioavailability than other esters of ganciclovir, including the bis-valine ester, disclosed in EP '329 (European Patent) or whether it only claims that valganciclovir is better than ganciclovir itself.

The Court found that the '721 Patent does not assert that the invention is an improvement over the esters disclosed in a prior application (EP '329), but rather only asserts that the invention is an improvement over the parent compound, ganciclovir. The Court also rejected Apotex's argument that the invention of the '721 Patent is crystalline valganciclovir and its salts, finding that crystallinity should be...