Chinta & Fratangelo LLP

Judge Hochberg Finds Actavis’ ATELVIA® Patents Obvious

In a decision issued on March 4, 2015, Judge Faith Hochberg of the New Jersey District Court found two Warner Chilcott patents covering risedronate sodium delayed release tablets, US7645459 and US7645460, obvious in a Hatch-Waxman paragraph IV action against Teva Pharmaceuticals USA. Warner Chilcott is now owned by Actavis.

The patents describe 35 mg of risedronate sodium in combination with ethylene diamine tetraacetic acid (EDTA). The EDTA is said to chelate calcium in the digestive tract which can bind to bisphosphonates, such as risedronate, and prevent absorption of the drug in the gut when oral dosage forms are swallowed.

After Teva filed an abbreviated new drug application (ANDA) with a “Paragraph IV” certification, Warner sued Teva for patent infringement. Teva responded that the patents were anticipated or obvious. Teva primarily relied on a Brazilian patent application, published in 2003, which disclosed several bisphosphonate oral dosage forms in combination with EDTA.

With regard to the anticipation argument, the court found that all elements of the asserted claims were present in the Brazilian patent application except for a limitation of “pharmaceutically acceptable absorption” of the drug. The court concluded that under the clear and convincing standard required for a holding of anticipation, there was “insufficient evidence to clearly and convincingly find that any embodiment would necessarily produce the claimed element.” Slip op. at 25. Thus, the Brazilian application was not anticipatory.

However, in the obviousness prong, the court found that EDTA was a well known chelator of calcium, and that none of the secondary considerations reviewed by the court could save the patents. The court looked at teaching away, long-felt unmet need, unexpected results, simultaneous invention, skepticism, and failure of others.

In the analysis of the differences between the claims and the prior art, the key holding was in the discussion of “pharmaceutically acceptable absorption.” The court looked at whether the prior art suggested the claimed combination, and whether there was a reasonable expectation of success. Slip op. at 54. The court found that there was a motivation to improve the oral absorption of bisphosphonates, to use EDTA to bind calcium in the digestive tract, and to limit the amount of EDTA to spread tight junctions in the intestine (an undesirable outcome of high doses of EDTA). Slip op. at 58. The court also found there would be a reasonable expectation of success that EDTA would solve the problem. “A person of ordinary skill in the art would have had a reasonable expectation of success that a dose of EDTA could reliably chelate the expected amount of calcium in the small intestine after a meal without separating the tight junctions and substantially increasing absorption. The expected result of such a formulation would be ‘absorption [that] is similar with or without food.’” Slip op. at 61.

The court therefore found clear and convincing evidence that a person of ordinary skill at the time of the invention (in 2005) would have been motivated to use EDTA in the claimed amounts with a reasonable expectation of success. Slip op. 65–66.

The asserted claims were accordingly found to be obvious.

Citation: Warner Chilcott Co. LLC v. Teva Pharms. USA, Inc., No. 11-6936 (D.N.J. 3/4/2015)