Cipla & BMS may settle patent dispute over Entecavir in India

US-based pharma major Bristol-Myers Squibb (BMS) and Indian pharma company Cipla Ltd. are heading towards an amicable settlement on a long-stretched patent dispute concerning BMS’ hepatitis B drug Entecavir, a leading anti-viral drug for Hepatitis B patients that brings in more than a billion dollars each year globally for BMS.

Entecavir, being a pre-1995 molecule, was not patented in India as the Indian patent law did not provide patent protection for “products” till 1995. However, BMS filed a patent application for its once-daily composition comprising Entecavir and got a patent in India for the same. The patent application (IN/PCT/2002/00891/MUM) was filed at the Mumbai patent office by BMS in 2001 and it was granted (IN213457) in the year 2008.

Claim 1 of IN ‘457 read as:

1. A pharmaceutical composition effective for once a day oral administration to treat Hepatitis B virus infection in a human adult patient comprising up to 1 % of entecavir, adhered to a carrier substrate of a kind such as herein described, and pharmaceutically acceptable excipients such as herein described in an amount as herein described, wherein the said percentage is based on a total composition weight of 100 mg.

Claim 12 of IN ‘457 read as:

12. A method of preparing a pharmaceutical composition of entecavir as claimed in claim 1 comprising (a) dissolving said entecavir and an adhesive substance in a solvent wherein said solvent is water or water having an acidic or basic pH, (b) spraying said solution obtained in step (a) onto a carrier substrate while said carrier substrate is in motion, (c) drying said coated carrier substrate from step (b) to remove said solvent, and (d) combining said dried coated carrier substrate from step (c) with other excipients as claimed hereinabove to form said pharmaceutical composition.

In 2010, Cipla had filed a revocation application with India’s Intellectual Property Appellate Board (IPAB) against BMS’ patent IN ‘457 covering a pharmaceutical composition comprising up to 1% of Entecavir effective for once a day oral administration to treat Hepatitis B virus infection in a human adult patient.

When the case came up before the IPAB, the counsel representing Bristol-Myers Squibb informed the patent tribunal that both the drug makers are in negotiations to settle the patent dispute. The IPAB bench comprising chairman justice KN Basha and DPS Parmar, technical member, patents, adjourned the matter since both the parties were exploring the possibilities of an amicable settlement.

BMS previously reached a settlement with Indian generic firm Natco Pharma concerning the drug. Natco and BMS had entered into a similar settlement over the Entecavir composition patent after Natco had applied for revocation of the patent at the IPAB.

Generic drug producers such as Dr. Reddy’s and Cadila launched their generic versions of Entecavir (Baraclude) in India earlier in 2010 by designing around the once-daily composition patent. Ranbaxy had also launched a generic product of the drug earlier in the Indian market.

US scenario of Entecavir: (Patent dispute between BMS & Teva)

Entecavir is protected by two patents in the United States viz. US 5206244, product patent which covers the Entecavir molecule, and US 6627224 which covers Entecavir compositions effective for once a day oral administration. Teva Pharmaceutical, an Isreal based generics major, challenged the Entecavir product patent in a US court and launched its generic version of Entecavir in the US market. Teva successfully invalidated the Entecavir product patent based on obviousness ground and an appeal by BMS was denied by the US Court of Appeals for the Federal Circuit, in 2014.

About the Author: Antony David, Senior Patent Associate at Khurana & Khurana, Advocates and IP Attorneys and can be reached at [email protected]