Pregabalin (Lyrica) 25, 50, 75, 100, 150, 200, 225, 300 mg/capsule: Pfizer asserted another patent against Sun Pharma

Innovator Pfizer has sued Sun pharma for the infrigement of US5563175 patent, which covers method of use of Pregabalin. Earlier, innovator has sued Sun for the infringement of US6197819 patent.

Background of litigation
Innovator Pfizer in a bid to protect it’s blockbuster neuropathic pain treatment Pregabalin (Lyrica) against generic challenge has filed patent infringement suit against various generic players in April 29, 2009 in Delaware District Court.

The said lawsuit was filed in response to ANDA filed by various generic players on this product for Pregabalin (Lyrica) 25, 50, 75, 100, 150, 200, 225, 300 mg/capsule.
The generic players have filed Para IV against following Orange Book listed patent:

US5563175 (Expiry: Oct 8, 2013): Which covers A method of treating a patient having seizure disorders which comprises administering to said patient an effective amount of a substantially pure compound of the formula S-(+)-4-amino-3-(2-methylpropyl)butanoic acid.

US6001876 (Expiry: Dec 30, 2018): Which covers method of treatment of pain using (S)-3-(aminomethyl)-5-methylhexanoic acid and 3-aminomethyl-5-methyl-hexanoic acid.

US6197819 (Expiry: Dec 30, 2018): Which covers S-(+)-4-amino-3-(2-methylpropyl) butanoic acid as a single optical isomer as product.

Subsequently, innovator sued following 7 generic players for patent infringement:

1. Sun Pharma
2. Lupin
3. Wockhardt
4. Cobalt
5. Actavis
6. Sandoz
7. Alpharma (Mylan)

The above generic players have filed their ANDA on Dec 30, 2008, i.e earliest ANDA filing date, accordingly, these generic players will be eligible for lucrative 180 days generic exclusivity as per Hatch-Waxman provisions.

Possibly, generic players have filed ANDA with invalidation grounds against Orange Book listed patent.

Importantly, innovator has sued all generic players for the infringement of ‘819 patent (product patent). Additionally, innovator has sued Lupin for ‘175 and ‘876 patent. Earlier, innovator got USFDA approval to market this product in 25, 50, 75, 100, 150, 200, 225, 300 mg/capsule on Dec 30, 2004.

Pregabalin is indicated for management of neuropathy pain associated with diabetic peripheral neuropathy, postherpetic neuralgia, adjunctive therapy for adult patients with partial onset seizures and management of fibromyalgiaThis product has achieved approximately 2.0 billion USD global sales in the year 2007 and future sale forecast for this product is quite bright.