Judge invalidates Allergan’s key patents for dry-eye treatment Restasis

A federal judge in Texas invalidated four key patents for the dry-eye treatment Restasis yesterday, in a blow to drugmaker, Allergan. The company had earlier transferred its patents to a Native American tribe as a protective measure. (See: Allergan transfers drug patent to Mohawk tribe to sidestep lawsuits)

According to commentators, the ruling by United States Circuit judge William C Bryson of the Eastern District of Texas, does not mean generic versions of the drug will be available soon.

Allergan said it planned to appeal the decision. The FDA has not approved any copycat versions of the drug.

The decision, however, comes as a setback for the company, whose stock fell over 5 per cent on the news. Restasis is the drugmaker's second best-selling product, which racked up $1.5 billion in sales in 2016.

In September, Allergan resorted to an unusual tactic of paying the Saint Regis Mohawk Tribe in upstate New York to take possession of the patents, which were then leased back to the company. The measure was aimed to ward off a patent challenge different from the federal court case - that is underway in an administrative proceeding before a unit of the United States Patent and Trademark Office.

According to the Mohawk tribe, sovereign immunity allows shielding of the patents.

The FDA granted approval to Restasis in 2002, three years after the company initiated the drug-approval process. The company held an original patent on the formulation, known in the case as the Ding I patent, US Patent No 5,474,979, filed in 1994 which expired in 2014.

Judge Bryson ruled that Allergan's patents on later formulations were obvious in light of the Ding I patent, as also the two other patents known as the Sall patent and the Ding II patent.

While a doctor testifying for Allergran claimed a particular formulation of 0.05 per cent cyclosporin and 1.25 per cent castor oil was especially effective in the treatment of dry eye, according to the judge, the .05 per cent cyclosporin/1.25 per cent castor oil formulation "did not perform significantly better than other formulations known in 2003," when Allergan patented its later formulation, which became Restasis.