A special court on intellectual property in India has revoked a patent granted to drug-maker GlaxoSmithKline for breast cancer drug Tykerb.

In line with earlier judgments that disallowed incremental innovations, the latest patent revocation comes on a challenge by Fresenius Kabi Oncology, the Indian unit of German healthcare group Fresenius SE.

The patent on lapatinib ditosylate salt marketed by GlaxoSmithKline as Tykerb was revoked as the product was merely a new form of a known substance, said Dominic Alvares, lawyer with S. Majumdar & Co, representing Fresenius.

The patent-protected period on this revoked salt was to expire in mid-2021, a Fresenius official said.

Fresenius had challenged both GSK’s patents on lapatinib and its salt before the Intellectual Property Appellate Board. But the challenge on GSK’s base compound, lapatinib, was unsuccessful and so its patent protection continues till it expires in January 2019.

Explaining the significance of the development, R. Sankaran, Fresenius Kabi’s Vice-President (Intellectual Property Management), said interested generic companies are free to manufacture and distribute this product, but after the patent protection on the basic salt expires in 2019.

Unlike other patent battles in the country between foreign and domestic companies, this case involves multinationals.

Disappointed

Meanwhile, GSK said it was studying the IPAB’s decision. Maintaining the inventiveness of lapatinib ditosylate salt, GSK said it would consider taking further steps before the appropriate authorities to validate its product. Shamnad Basheer, an intellectual property expert, said that the decision was fair, and in line with earlier decisions where genuine innovations are protected.

The Tykerb case is the latest in a string of patent-related cases in India.

The most high-profile of these, involving Novartis’s blood cancer drug Glivec, ended earlier this year, when the Supreme Court rejected the company’s plea for patent protection on its drug.

>jyothi.datta@thehindu.co.in