Obviousness And Discoveries From Routine Testing: UK Supreme Court Decides Correct Approach

The UK Supreme Court has handed down its judgement in Actavis v ICOS [2019] UKSC 15 unanimously upholding the earlier decision of the Court of Appeal that the patent to a specific dosage regimen of tadalafil was obvious. However, in doing so the UK Supreme Court has allayed the concerns of innovators and big pharma by confirming there is no automatic bar to dosage claim discoveries, made through well-established or routine procedures provided they involve an inventive step.

Background to the dispute

This case concerned the dosage patent EP(UK) 1,173,181 (the '181 Patent') and in particular claims relating to a specific low 5mg dose of the drug tadalafil marketed under the brand name CIALIS and used to treat erectile dysfunction or 'ED'. The CIALIS drug is a competitor (second in class) of the well-known branded drug VIAGRA. However, VIAGRA had certain side effects. Both tadalafil and sildenafil, the active ingredients in VIAGRA, are inhibitors and work by blocking phosphodiestaerase, which otherwise would lead to failure of the dilation of blood vessels.

The 181 Patent is owned by ICOS and is exclusively licensed to Eli Lilly. During pre-clinical and clinical studies, Eli Lilly found that a daily low oral dose of 5mg was therapeutically effective, and minimised the adverse reactions of using the VIAGRA drug.

The decisions of the lower courts

Actavis and others (being generic companies) sought to revoke the 181 Patent to clear the way before their own generic product launches. The main attack was lack of novelty and inventive step (with priority, added matter and insufficiency included in the attack) over the nearest prior art (the 'Daugan Patent'), which disclosed a class of compounds including tadalafil for treating ED. The Daugan Patent had disclosed doses of tadalafil in the range of 0.5 to 800mg but only provided data for a 50mg dose and not a 5mg dose. A key issue was whether routine dose-ranging studies required for clinical development and regulatory approval would have ordinarily extended to the 5mg dose, and so involved an inventive step.

ICOS argued that the low dose would not have been obvious before conducting the Phase II trials, and counterclaimed for infringement.

In the High Court, Mr. Justice Birss considered that the results of the clinical studies were not predictable in advance. He accepted expert evidence that it was not established that the skilled team would always seek to identify the minimum effective dose of a...