28 April 2015Americas

US court hands down Absorica claim construction

A US court has ruled on how five claims in two patents related to acne drug Absorica (isotretinoin) should be construed, in a patent infringement case between Canada-based Cipher Pharmaceuticals and Actavis.

Assessing a so-called Markman hearing, the US District Court for the District of New Jersey was determining precisely what the disputed patents claim in their construction.

The case started after Actavis, then Watson Laboratories, filed an Abbreviated New Drug Application with the US Food and Drug Administration seeking approval to make and sell a generic version of Absorica in September 2013.

Cipher sued Actavis at the New Jersey court for patent infringement the following month with co-plaintiffs Galephar Pharmaceutical Research, which owns the patents and licenses them to Cipher, and Ranbaxy Laboratories, now owned by Sun Pharma, which markets Absorica in the US.

The five disputed claims appeared in US patent numbers 7,435,427 and 8,367,102, which cover a “pharmaceutical semi-solid composition of isotretinoin”.

Actavis argued that four of the five disputed claims were indefinite.

Among the disputed terms within the claims was “semi-solid suspension”. Cipher argued that the term is a “term of art” and that it should not be replaced with any other words.

The court held a hearing on the meaning of the disputed claims on April 2 and gave its own construction of the disputed terms on April 20.

“‘Suspension’ has a plain meaning to a person of ordinary skill in the art,” the opinion said. “The patent and the prosecution history support this plain meaning.”

However, Actavis asked the court for an explanation of the claim language “as it would have been understood by a person of ordinary skill”.

The court said that the issue is whether the word “suspension” should apply only to suspensions that the active ingredient is “predominantly undissolved”, or where more than 50% of the isotretinoin particles are in suspension, rather than just in the solution.

The court decided that the term “semi-solid suspension” means “a semi-solid composition wherein the isotretinoin is not 100% in solution”.

It also corrected a typographical error in one of the disputed claims, so that instead of reading “hydrophobic lipidic balance (HLB) value”, it read “hydrophilic lipophilic balance (HLB) value”.

In a statement, Cipher said that the court had not yet determined whether the patents at suit were infringed or invalid.

Shawn O’Brien, the company’s president and chief executive, said: “We are pleased with the outcome of the Markman hearing, which ultimately has bearing on the determination of infringement and validity when the matter goes to trial.

“With the hearing completed, we look forward to the scheduling of a trial date as Cipher and Ranbaxy continue our vigorous defence of Absorica’s IP rights.”

Actavis did not respond to a request for comment.