Indian authorities have revoked the patent granted to GlaxoSmithKline Plc's breast cancer drug `Tykerb' as the drug represented only a modified form of the original compound `lapatinib', which already has a patent.
The Intellectual Property Appellate Board (IPAB), however, upheld the patent granted to the drug's active pharmaceutical ingredient, lapatinib, which was GSK's original innovative drug product.
Tykerb is the salt form of lapatinib that is sold in India.
The move is in tune with the government's policy of not encouraging patents to new drug formulations with cosmetic changes to original drug forms.
The IPAB ruling comes on a petition filed by Fresenius Kabi Oncology, the Indian unit of German healthcare group Fresenius SE, challenging the patents granted to both the original molecule `lapatinib' and its salt version 'Tykerb'.
According to Fresenius Kabi, there was nothing innovative in both the original molecule `lapatinib' as well as its marketed version 'Tykerb'.
"This decision is just like the landmark Glivec ruling. The IPAB has said that the salt version of lapatinib cannot hold a patent," said lawyer Dominic Alvares of S Majumdar & Co, which represented Fresenius Kabi in the case.
A strip of 10 Tykerb tablets costs about Rs4,160 ($69) in India and a patient in an advanced stage of cancer is expected to take five tablets a day for 21 days.
Multinational drug firms use cosmetic changes or `incremental innovations' to patented drugs to stay patented beyond the expiry date.
The government had earlier also revoked patents of some key drug formulations produced by pharma MNCs in a bid to make life-saving drugs more affordable to patients.
In April, this year, the Supreme Court had rejected a patent for Novartis AG's cancer drug `Glivec', saying it was an amended version of a known molecule called `imatinib'.
The IPAB had, last year, revoked patents granted to Pfizer Inc's cancer drug `Sutent', Roche Holding AG's hepatitis C drug `Pegasys', and Merck & Co's asthma treatment aerosol suspension formulation, in a bid to make medicines affordable to the common man.
The IPAB ruling comes as a blow to GSK, which had cut prices of Tykerb by a third in order to push sales of the product even as it remained a part of the government's flexible pricing programme.
India's $13 billion drugs market, which is also fast expanding, is under siege by Western drugmakers who use intellectual property rights to covet a bigger share of the market.
GSK said it is still studying the IPAB's decision but maintained that it would consider the possibility of taking further steps before the appropriate authorities to validate its claims.
However, GSK added: "We are pleased that the IPAB in India has upheld our basic patent for the lapatinib compound, the active ingredient in Tykerb."