Cinacalcet (Sensipar): Barr confirms Para IV Challenge to innovator's patents

Barr Pharma has challenged four orange book listed patents held by Amgen Inc. for its Cinacalcet or Sensipar (30, 60 and 90 mg tablets), used by dialysis patients to treat side-effects of the treatment. Innovator Amgen got approval on this product on Mar 8, 2004. Following are the Orange Book listed patents on this product:
US6011068 (Expiry: Dec 14, 2016)- Link
US6031003 (Expiry: Dec 14, 2016) Link
US6211244 (Expiry: Oct 23, 2015) Link
US6313146 (Expiry: Dec 14, 2016) Link
Sensipar or Cinacalcet (N-[(1R)-1-(1-naphthyl)ethyl]-3-[3-(trifluoromethyl)phenyl]propan-1-amine) acts as a calcimimetic by allosteric activation of the calcium-sensing receptor that is expressed in various human organ tissues. It is sold by Amgen under the trade name Sensipar in North America and Australia and as Mimpara in Europe. Cinacalcet is used to treat hyperparathyroidism (elevated parathyroid hormone levels), a consequence of parathyroid tumors and chronic renal failure.
Barr said it filed ANDA with Para IV certification against Orange Book listed patents on Cinacalcet on March 10, 2008.
Sensipar recorded $377 million in U.S. sales during the 12 months ending May, Barr said.

Cinacalcet (Sensipar): Teva sued innovator for process patent infringement

Teva has filed patent infringement lawsuit against Innovator Company Amgen w.r.t Cinacalcet process patent infringement in Distric court for Eastern district of Pennsylvania. Generic pharma giant Teva got following process patent:

US7449603 (assignee: Teva, Date of Grant: November 11, 2008): Which covers process and intermediates for the synthesis of Cincalcet

Earlier, innovator sued Barr (Now, subsidiary of Teva) for filing Para IV on Cinacalcet (Sensipar) 30, 60 and 90 mg tablets in March, 2008 as reported by us Here . Subsequently, innovator sued Teva and Barr in Delaware district court in July, 2008.

Now, it will be interesting to monitor counter litigation strategy of Teva against innovator.

Also, Teva has asserted it’s API process patents on Carvedilol (Coreg) like US7,056,942, US6,710,184, US6,699,997, and US7,126,008 against various generic players and later on settled with some players like Ranbaxy Laboratories, Dr Reddy's Laboratories and USV Ltd , Glenmark (as reported by us on this product Here ) and recently with Cadilla . The product patent on Carvedilol has already expired but API process patents of Teva are blocking for other generic players.