Thursday 14 May, 2009

Risedronate Sodium Tablets (Actonel) 5mg, 30mg and 35 mg: Procter & Gamble Wins Patent Infringement Lawsuit; Generic version blocked till 2014

Innovator Procter & Gamble (P&G) announced (in a press release Here ) that United States Court of Appeals for the Federal Circuit (CAFC) has ruled in favor of P&G in the patent infringement lawsuit filed by P&G against Teva . The positive ruling protects P&G's rights in the U.S. to exclusively market the osteoporosis therapy Actonel(R) (risedronate sodium) tablets. Actonel is commercialized through collaboration between Procter & Gamble Pharmaceuticals and Sanofi-Aventis.
Following patents are listed in orange book w.r.t Risedronate tablets 5 mg, 30 mg and 35 mg:

US5583122 (Expiry: Jun 10, 2014)- Which covers Risedronate Sodium as product

US6096342 (Expiry: May 22, 2012)- Which covers a pharmaceutical composition comprising, from 0.15% to 40.00% by weight of a risedronate active ingredient and from 60.00% to 99.75% by weight of excipients comprising: lactose monohydrate, microcrystalline cellulose, crospovidone, and magnesium stearate

US6165513 (Expiry: Dec 10, 2018)- Which covers an oral dosage form comprising a safe and effective amount of a bisphosphonate wherein said oral dosage form is oval shaped, about 0.23 to about 0.85 inches in length, about 0.11 to about 0.4 inches in width, and about 0.075 to about 0.3 inches in thickness and said oral dosage form is film coated to facilitate rapid esophageal transit and avoid irritation in the mouth, buccal cavity, pharynx, and esophagus wherein said film coating allows for delivery of said bisphosphonate to the stomach


On August 13, 2004 P&G filed a patent infringement lawsuit against generic giant Teva to block generic version after Teva submitted ANDA with Para IV certification against Orange Book listed patents. Further, innovator alleged infringement of ‘122 patent against Teva. On February 28, 2008, the United States District Court of Delaware ruled in favor of P&G, expressly rejecting Teva's validity challenge. Subsequently, Teva filed an appeal of the decision. Oral arguments for the appeal were heard in December 2008.


Teva was seeking to market a generic version of Actonel in the United States under the assertion that the product patent ‘122 was not valid due to obviousness of the invention in the light of prior art disclosure in US4761406 (a prior patent by P&G on bisphosphonate).

The ‘406 patent disclosed (1-hydroxy-1-phosphono-2-pyridin-2-yl-ethyl)phosphonic acid compound (2-Pyrd-EHDP), however, Risedronate is chemically (1-hydroxy-1-phosphono-2-pyridin-3-yl-ethyl)phosphonic acid (3-Pyrd EHDP). The CAFC observed that patent is not obvious in the light of prior art disclosure.

Also, court observed a person having ordinary skill in the art at that time would not have selected 2-pyrd EHDP as lead compound for further structural modification to arrive at 2-pyrd EHDP (Risedronate). Also, court gave weightage to testimony by P&G expert and articles of Dr. Fleisch (Who had some published work to his credit on bisphosponate chemistry at that time). Dr. Fleisch wrote in 1984 that “every compound, while remaining a bisphosphonate, exhibit it’s own physical-chemical, biological and therapeutic characteristics, so that each Bisphosphonate to be considered of it’s own. To infer from one compound the effect in another is dangerous and misleading” Based on this published work, court rejected Teva’s structural similarity argument between 2-Pyrd EHDP and 3-Pyrd EHDP compounds. Additionally, court rejected obviousness type double patenting argument of Teva as claims of ‘406 patent and ‘122 were not same.


Teva has approved ANDA for Residronate tablets. As a result of CAFC's decision, Teva can market its generic version of Procter & Gamble's Risedronate Sodium Tablets, 5mg, 30mg and 35 mg after the expiry of ‘122 patent in June, 2014.


The U.S. Food and Drug Administration approved Actonel in 2000 for the prevention and treatment of osteoporosis in postmenopausal women. Actonel is the only oral osteoporosis therapy proven to reduce the risk of vertebral fractures with in a year


CAFC opinion Here

Earlier news of IPPharma Doc on this product Here

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Disclaimer: "IP Pharma Doc" blog is published for information purpose only. "IP Pharma Doc" blog contains no legal advice. I assume no legal responsibility for the views/information expressed here. “IP Pharma Doc” blog is my personal website and not edited by my employer, accordingly, no part of my blog should be attributed to my employer. All information on the present blog should be double checked for its accuracy and applicability. © Dr. Sarwal (2007)
 
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