List of APIs going Off-patent in 2006

Here is provided the list of important APIs going off-patent in 2006 with their latest updates.

Simvastatin: (Expiring on June 23, 2006)

U.S. Patent No. 4,444,784 (Hoffman Patent) titled “Antihypercholesterolemic compounds” discloses and claims Simvastatin and use thereof for treating hypercholesterolemia. The application for Hoffman Patent was filed on December 18, 1980 by Merck & Co. and issued on April 24, 1984. The term of Hoffman Patent will be 17 years calculated from the date of issuance of patent.

Hoffman Patent was eligible for patent term extension under 35 USC § 156 (Hatch-Waxman Act) and was granted extension of 1704 days, extending the patent validity period from April 24, 2001 to December 23, 2005. Later Hoffman Patent also received additional six months pediatric exclusivity, yet again extending the patent validity period till June 23, 2006.

Earlier Ranbaxy and Ivax filed Para IV certification challenging the validity and enforceability of two orange book listed patents – US RE36481 and US RE36520 – expiring in 2008 and 2009 respectively. Ranbaxy being the first to file Para IV certification was entitled for 180-days exclusivity period. In response, Merck de-listed both the US patents and thereby preventing Ranbaxy from getting 180-days exclusivity period. Recently, Merck has granted Dr. Reddy’s Laboratories exclusive rights to market generic version of Zocor (Simvastatin) as authorized generics once Simvastatin go off-patent.

Pravastatin: (Expiring on April 20, 2006)

U.S. Patent No. 4,346,227 (Terahara Patent) titled “ML-236B Derivatives and their preparation” discloses and claims pravastatin. The application for Terahara Patent was filed on June 05, 1981 by Sankyo Company Limited and issued on August 24, 1982. The term of Terahara Patent will be 20 years calculated from the date of US filing.

Terahara Patent was eligible for patent term extension under 35 USC § 156 and was granted extension of 1598 days, extending the patent validity period from June 05, 2001 to October 20, 2005. Later Terahara Patent also received additional six months pediatric exclusivity, yet again extending the patent validity period till April 20, 2006.

Earlier Teva filed ANDA seeking permission to sell generic pravastatin once Terahara Patent expires in April 2006 (Para III) and assertion that generic version would not violate three patents on the drug (Para IV certification). Teva being the first-to-file Para IV certification is entitled for 180-days exclusivity after favorable ruling from US District Court for the District of Columbia involving complex tussle with US FDA.

Sertraline Hydrochloride: (Expiring on June 30, 2006)

U.S. Patent No. 4,536,518 (Welch Patent) titled “Antidepressant derivatives of cis-4-phenyl-1, 2, 3, 4-tetrahydro-1-naphthaleamine” discloses and claims Sertraline hydrochloride and use thereof for combating mental depression in a mentally-depressed patient. The application for Welch Patent was filed on November 01, 1979 by Pfizer and issued on August 20, 1985. The term of Welch Patent will be 17 years calculated from the date of issuance.

Welch Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 1228 days, extending the patent validity period from August 20, 2002 to December 30, 2005. Later Terahara Patent also received additional six months pediatric exclusivity, yet again extending the patent validity period till June 30, 2006.

Earlier, Ivax filed ANDA seeking permission to sell generic sertraline HCl once Welch Patent expires in June 2006 (Para III) and assertion that generic version would not violate US Patent No. 5,248,699 (listed with orange book) on the drug (Para IV certification). Pfizer sued Ivax for patent infringement and latter settled their dispute out of the court. Ivax is, however, entitled for 180-days exclusivity once Welch Patent goes off-patent.

Finasteride: (Expiring on June 19, 2006)

U.S. Patent No. 4,760,071 (Rasmusson Patent) titled “17b-N-monosubstituted carbamoyl-4-aza-5a-androst-1-en-3-ones which are active as testosterone 5 a-reductase inhibitor” discloses and claims finasteride and use thereof for treating the hyperandrogenic condition of acne vulgaris, seborrhea, femal hirsutism, and benign prostatic hypertrophy and for inhibiting testosterone 5a-reductase. The application for Rasmusson Patent was filed on November 21, 1985 by Merck & Co. and issued on July 26, 1988. The term of Rasmusson Patent will be 17 years calculated from the date of issuance.

Rasmusson Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 328 days, extending the patent validity period from July 26, 2005 to June 19, 2006.

Earlier, Merck sued Dr. Reddy’s in response of Para IV certification filed with US FDA. Later Merck and Dr. Reddy’s settled patent dispute and Merck granted Dr. Reddy’s the exclusive right to market generic version of Proscar (Finasteride) after patent expiry as authorized generic.

Esomeprazole: (Expiring on October 19, 2006)

U.S. Patent No. 4,738,974 (Brandstrom Patent) titled “Base addition salts of Omeprazole” discloses and claims novel salts of the Omeprazole and use thereof for inhibiting gastric acid secretion and for treating gastrointestinal inflammatory diseases or cytoprotective effects. The application for Brandstrom Patent was filed on April 21, 1986 by Aktiebolaget Hassle and issued on April 19, 1988. The term of Brandstorm Patent will be 17 years calculated from the date of issuance.

Brandstorm Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 1 year, extending the patent validity period from April 19, 2005 to April 19, 2006. Later Brandstrom Patent also received additional six months pediatric exclusivity, yet again extending the patent validity period till October 19, 2006.

Earlier, AstraZeneca sued Ivax, Teva and Ranbaxy for patent infringement in the U.S. District Court for the District of New Jersey in response of Para IV certification filed with US FDA seeking permission to market generic versions of Nexium (Esomperazole).

Desloratadine: (Expiring on October 21, 2006)

U.S. Patent No. 4,659,716 (Villani Patent) titled “Antihistaminic 8-(halo)-substituted 6, 11-dihydro-11-(4-piperidylidene)-5H-benzo [5, 6] cyclohepta [1, 2-b] pyridines” discloses and claims desloratadine and pharmaceutical compositions thereof. Villani Patent also claims method of treating allergic reactions using desloratadine. The application for Villani Patent was filed on March 12, 1986 and issued on April 21, 1987. The term of Villani Patent will be 17 years calculated from the date of issuance.

Villani Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 2 year, extending the patent validity period from April 21, 2004 to April 21, 2006. Later Villani Patent also received additional six months pediatric exclusivity, yet again extending the patent validity period till October 21, 2006.

According to US FDA official website, there is no Para IV certification filed for desloratadine.

Terbinafine: (Expiring on December 30, 2006)

U.S. Patent No. 4,755,534 (Stuetz Patent) titled “Propenylamines, pharmaceutical compositions containing them and their use as pharmaceuticals” discloses and claims terbinafine and use thereof for treating diseases or infections caused by mycetes. The application for Stuetz Patent was filed on September 04, 1984 by Sandoz Ltd. and issued on July 05, 1988. The term of Stuetz Patent will be 17 years calculated from the date of issuance

Stuetz Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 543 days, extending the patent validity period from July 05, 2005 to December 30, 2006.

Earlier, Novartis sued Dr. Reddy’s for patent infringement in response of Para IV certification filed with USFDA but later patent challenge was withdrawn by Dr. Reddy’s.

Zolpidem Tartrate: (Expiring on October 21, 2006)

U.S. Patent No. 4,382,938 (Kaplan Patent) titled “Imidazo [1,2-a] pyridine derivatives and their application as pharmaceuticals” discloses and claims zolpidem tartrate and use thereof for providing anxiolytic effect. The application for Kaplan Patent was filed on October 21, 1981 by Synthelabo and issued on May 10, 1983. The term of Kaplan Patent will be 20 years calculated from the date of US filing.

Kaplan Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 5 years, extending the patent validity period from October 21, 2001 to October 21, 2006.

Balsalazide Disodium: (Expiring on July 08, 2006)

U.S. Patent No. 4,412,992 (Chan Patent) titled “2-hydroxy-5-phenylazobenzoic acid derivatives and method of treating ulcerative colitis therewith” discloses and claims balsalazide disodium and use thereof for treating ulcerative colitis. The application for Chan Patent was filed on July 08, 1981 by Biorex Laboratories Limited and issued on November 01, 1983. The term of Chan Patent will be 20 years calculated from the date of US filing.

Chan Patent was eligible for patent term extension under 35 USC §156 and was granted extension of 5 years, extending the patent validity period from July 08, 2001 to July 08, 2006.

According to US FDA official website, there is no Para IV certification filed for balsalazide disodium.

Nedocromil Sodium: (Expiring on October 02, 2006)

U.S. Patent No. 4,474,787 (Cairns Patent) titled “7,6 Dioxo-4H, 6H-pyrano [3,2-g] quinoline dicarboxylic acids and anti-allergic use thereof” discloses and claims Nedocromil sodium and use thereof for treating a condition involving an antibody antigen reaction or a reflex pathway. The application for Cairns Patent was filed on February 02, 1982 by Fisons Limited and issued on October 02, 1984. The term of Cairns Patent will be 17 years calculated from the date of issuance.

Cairns Patent eligible for patent term extension under 35 USC §156 and was granted extension of 5 years, extending the patent validity period from October 02, 2001 to October 02, 2006.

Perindopril Erbumine: (Expiring on August 21, 2006)

U.S. Patent No. 4,508,729 (Vincent Patent) titled “Substituted iminodiacids, their preparation and pharmaceutical compositions containing them” discloses and claims perindopril erbumine and use thereof for treating hypertension. The application for Vincent Patent was filed on October 02, 1981 by Adir and issued on April 02, 1985. The term of Vincent Patent will be 17 years calculated from the date of issuance of patent.

Vincent Patent eligible for patent term extension under 35 USC §156 and was granted extension of 1601 days, extending the patent validity period from April 02, 2002 to August 21, 2006.

According to US FDA official website, there is no Para IV certification filed for perindopril erbumine.

Lomefloxacin HCl: (Expired on February 21, 2006)

U.S. Patent No. 4,528,287 (Itoh Patent) titled “6-fluro-1, 4-dihydroxy-4-oxo-7-substituted piperazinylquinoline-3-carboxylic acids and method for preparing the same” discloses and claims Lomefloxacin HCl and use thereof for inhibiting bacteria and for increasing urinary excretion. The application for Itoh Patent was filed on September 17, 1984 by Hokuriku Pharmaceuticals Co. Ltd. and issued on July 09, 1985. The term of Itoh Patent will be 20 years calculated from the date of US filing.

Itoh Patent eligible for patent term extension under 35 USC §156 and was granted extension of 522 days, extending the patent validity period from September 17, 2004 to February 21, 2006.

Fulvestrant: (Expiring on October 01, 2006)

U.S. Patent No. 4,659,516 (Bowler Patent) titled “Steroid derivatives” discloses and claims fulvestrant and use thereof for producing an antiestrogenic effect. The application for Bowler Patent was filed on October 01, 1984 by Imperial Chemicals Industries Ltd. and issued on April 21, 1987. The term of Bowler Patent will be 20 years calculated from the date of US filing.

Bowler Patent eligible for patent term extension under 35 USC §156 and was granted extension of 2 year, extending the patent validity period from October 01, 2004 to October 01, 2006.

According to US FDA official website, there is no Para IV certification filed for fulvestrant.

Mivacurium Chloride: (Expired on January 22, 2006)

U.S. Patent No. 4,761,418 (Swaringen Patent) titled “Novel Compounds” discloses and claims Mivacurium chloride and use thereof for producing muscle relaxation. The application for Swaringen Patent was filed on July 17, 1985 by Burroughs Wellcome Co. and issued on August 02, 1988. The term of Swaringen Patent will be 17 years calculated from date of issuance.

Swaringen Patent eligible for patent term extension under 35 USC §156 and was granted extension of 173 days, extending the patent validity period from August 02, 2005 to January 22, 2006.