Allergan v. Sandoz@Bimatoprost: CAFC

On August 04, 2015 before Circuit Judges LOURIE, LINN, and HUGHES, United States Court of Appeals for the Federal Circuit Affirm the decision of District Court of Eastern District of Texas, which held that the asserted claims of Allergan’s US ’504, ’605, and ’479 are not invalid for obviousness or for lack of an adequate written description and enablement. The decision can be find here.


Sandoz, Lupin, Hi-Tech, and Watson each submitted an Abbreviated New Drug Application (“ANDA”) to the FDA, seeking approval to engage in the commercial manufacture, use, importation, sale, or offer for sale of generic versions of Lumigan (Bimatoprost) 0.01% prior to the expiration of the US 7,851,504, 8,278,353, 8,299,118, 8,309,605, and 8,338,479 patents. In response, Allergan sued each of the ANDA applicants in the United States District Court for the Eastern District of Texas, asserting that their ANDA filings infringed those patents. The district court consolidated those actions into one case.

About Lumigan:
In 2001, the FDA approved Lumigan® 0.03%, a once daily topical solution developed by Allergan, for treating open angle glaucoma and ocular hypertension. Lumigan 0.03% contains 0.03% by weight of Bimatoprost and 50 parts per million (“ppm”) benzalkonium chloride (“BAK”), among other ingredients.

Although Lumigan 0.03% was effective at lowering IOP, it also caused frequent and severe hyperemia. Many patients thus stopped using it without consulting their physicians, which led to gradual vision loss. To address that problem, Allergan explored a number of alternative formulations of Bimatoprost and surprisingly discovered that increasing the concentration of BAK from 50 ppm to 200 ppm significantly increased the corneal permeability of Bimatoprost. After further research, Allergan developed Lumigan® 0.01% (“Lumigan 0.01%”).

Lumigan® 0.01% contains 0.1 mg/mL of Bimatoprost and benzalkonium chloride 0.2 mg/mL with other excipients. Lumigan is a prostaglandin analog indicated for the reduction of elevated intraocular pressure in patients with open angle glaucoma or ocular hypertension. Lumigan 0.01% is approved (NDA: N022184) to Allergan on Aug 31, 2010. Allergan expects net sales of Lumigan between $590 million and $620 million.

There are several patents listed in Orange Book for Bimatoprost. The patents in lawsuit are US 7,851,504 (Jun 13, 2027), US 8,278,353, US 8,299,118, US 8,309,605 and US 8,338,479 which all are OB listed for Bimatoprost. The above said patents claims various compositions of Bimatoprost.

Allergan (plaintiff) v. Sandoz, Lupin, Hi-Tech Pharmacal CO (Defendants) @Texas:
After Allergan sued Sandoz and others in the district court, the  district court held a five-day bench trial in July 2013 on the issues of obviousness and infringement. The defendants argued that the claims were invalid for lack of written description and enablement in pre- and post-trial briefings.

The defendants argued that Woodward disclosed a formulation comprising 0.001%–1% Bimatoprost and 0–1000 ppm BAK for treating glaucoma, and that the amounts of Bimatoprost and BAK in the claimed formulation fall within those prior art ranges, thus rendering the claims obvious.

The cited prior art is:

1) Woodward’s US 5,688,819; and
2) Lyons’s US 6,933,289.

After going through the factual findings, the district court concluded that the asserted claims would not have been obvious. In reaching that conclusion, the court emphasized that the prior art taught away from the claimed invention because it taught:

1) that Bimatoprost lost efficacy as its concentration decreased;
2) that BAK had no impact on Bimatoprost’s permeability; and
3) that BAK was cytotoxic and could cause corneal disorders.

The district court also rejected the defendants’ invalidity challenges based on the written description and enablement requirements and it states that each of the ANDA products infringed each of the asserted claims.

Further, the defendants timely appealed (2014-1275) the decision to Federal Circuit and Hi-Tech also challenges the district court’s finding that it infringed the claims of the ’504, ’605, and ’479 patents literally and under the doctrine of equivalents.

Hi-Tech argued that it’s ANDA specifies that the proposed product has a pH of 6.8–7.2 during the product’s shelf life. And it also argues that the district court erred in construing a “pH of about 7.3 and also erred in finding that Hi-Tech literally infringed the Group I claims and that prosecution history estoppel did not bar Allergan from relying on the doctrine of equivalents to prove infringement.

Finally, the judges of CAFC reviewed the district court’s decision and its findings, after considering the arguments the Federal Circuit made the following points:

i) Rejected the Appellants’ argument that the unexpected results do not support nonobviousness because they are merely the inherent properties of an otherwise obvious formulation;
ii) The specifications of the asserted patents provide an adequate written description of the invention;
iii) The asserted claims are not invalid for lack of enablement;
iv) The district court did not clearly err in finding that Hi-Tech literally infringed the Group I claims and that Hi-Tech infringed the claims of the US ’504, ’605, and ’479 patents.

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