Pfizer takes Alembic to US court on drug patent

Pfizer, the pharmaceutical giant, has gone to a US court to stop or at least delay Gujarat-based Alembic Pharmaceuticals from trying to sell a generic version of the former’s anti-depressant drug, branded Pristiq.

Vadodara-based Alembic and US-based Breckenridge Pharmaceutical have been named co-defendants in a suit filed by Pfizer in response to their separate Abbreviated New Drug Application (ANDA) to market desvenlafaxine succinate extended-release tablets in 50mg and 100mg strength. These are sold by Pfizer as Pristiq and it holds a US patent on it. The suit alleges patent infringement.

Any company wishing to sell the generic version of a patented drug in the US market must make an ANDA to the sector regulator. Those first in the queue to get an approval receive what is called a 180-day exclusivity period to sell their version of the drug.

"Any innovative pharma company would immediately react to such ANDA filings and their first argument would be of a possible infringement of patent. Now, whichever company wins the legal battle would have the rights to market the drug in the US," explained R K Baheti, director, finance for Alembic.

Adding: “The market for the drug is around $1 billion. Once the patent is gone (in this case, some years down the line), there would be some price erosion when multiple players start selling the generic product. Even then, there would be huge demand for the drug.”

Alembic said it had filed an ANDA for desvenlafaxine succinate on the first possible date under US law and expected to share the 180-day exclusivity period with other companies which had filed similar ANDAs. Alembic is the sponsor and manufacturer of the ANDA and the drug is to be marketed exclusively by Breckenridge.

Alembic expects at least two to three companies would get permission to market the drug. The subsequent price would depend on the number which do so. The launch of the generic versions of the drug would, however, be not before 2015, said Baheti.

Earlier this month, Pfizer had filed a suit against Zydus USA’s ANDA; it, too, sought approval to market a generic version of Pfizer’s Pristiq before expiration of the US patent. A similar suit has been filed against Florida based Watson Laboratories, subsidiary of a speciality pharmaceuticals company, Watson Pharmaceuticals.

Incidentally, earlier this month, Alembic and Breckenridge had settled a patent case with Novartis for Rivastigmine Tartrate capsules, used for treating dementia. Novartis granted the two companies a licence to market their generic drug in the US market before the date of expiry of the patent. Alembic has said it would launch the drug immediately.

Stocks of both Alembic and Zydus gained on the Bombay Stock Exchange during the day's trade. While Alembic's stocks were up 2.1 per cent to Rs 55.60, Cadila Healthcare (Zydus Cadila) stocks had gained 056 per cent to end at Rs 769.20.