Obviousness Of Lilly’s Tadalafil (CIALIS) Dosage Form Patent Stands – Patent

The Federal Court of Appeal has dismissed Lilly’s appeals of
judgments that held Ca،ian Patent No. 2,371,684 (the 684
patent) claims invalid. The decision, Eli Lilly v A،ex,
2023 FCA 125, was
issued on June 2, 2023.

The 684 patent relates to the use of ، pharmaceutical unit
dosage forms containing tadalafil (2-20 mg, 2.5
mg, 5 mg, 10 mg, 20 mg, 5-20 mg) for the treatment of ،ile
dysfunction (ED). Lilly markets tadalafil as
CIALIS. Lilly brought four infringement actions
– a،nst A،ex, Pharmascience/Riva, Mylan, and Teva; the
defendants counterclaimed for a declaration of invalidity. In a
single set of reasons, the Trial Judge found Lilly would have been
en،led to relief due to infringement by each defendant if the
،erted claims were valid, but held the claims were invalid for
anti،tion and obviousness (see our Rx IP Update
report).

On the appeal, there was no issue as to the Trial Judge’s
construction of the claims or factual findings.

Lilly argued that the Trial Judge erred in law in her approach
to construing the inventive concept in the obviousness ،ysis.
Applying the Trial Judge’s factual findings, ،wever, the FCA
concluded that even if the new inventive concept proposed by Lilly
was accepted, the finding on obviousness must stand. The prior
findings – including that dose range studies would be routine
steps – applied to the proposed inventive concept that
“the claimed dosages of tadalafil, ،ly administered,
provide efficacy to treat male ED, including the minimization or
elimination of flu،ng as compared to larger doses of
tadalafil”.

While agreeing with the Trial Judge’s findings that drug
dosing of tadalafil for the treatment of ED was routine work having
regard to the prior art, the FCA declined to endorse this statement
at large: “There may be cases where dosage selection is not
routine.”

It was unnecessary for the FCA to address the arguments on the
issues of anti،tion and whether the 648 patent is a selection
patent.

S،uld you have any questions, please do not hesitate to contact
a member of the Pharmaceutical Litigation Group.

The preceding is intended as a timely update on Ca،ian
intellectual property and technology law. The content is
informational only and does not cons،ute legal or professional
advice. To obtain such advice, please communicate with our offices
directly.