Section 3(d) strikes again in GSK India patent defeat
India’s Intellectual Property Appeal Board (IPAB) has revoked a patent covering GlaxoSmithKline’s (GSK) breast cancer drug Tykerb, in the latest blow to western pharmaceutical companies in India.
The IPAB upheld GSK’s basic patent for lapatinib, a compound which blocks signals within cancer cells that make them grow and divide, but rejected a second patent directed to the salt form of the original compound.
GSK markets lapatinib as Tykerb in countries including the US and India, but as Tyverb in Europe.
Generic drug company Fresenius Kabi Oncology challenged the patents, prompting two separate IPAB rulings on July 27, published on August 1.
Fresenius tried to revoke both patents by citing obviousness, non-disclosure and section 3(d), a provision in Indian patent law preventing the patenting of new forms of known substances that fail to enhance the substance’s efficacy.
The section was used by the Indian Supreme Court decision this year to reject a patent directed to Glivec, a leukaemia drug marketed by pharmaceutical company Novartis.
In the GSK case, the IPAB rejected all parts of the challenge to the basic patent, which contains lapatinib as its active ingredient and is set to expire in 2019.
Addressing the patent directed to lapatinib ditosylate, due to expire in 2021, the IPAB first assessed the section 3(d) provision, saying if the salt “fails this test, it is not an invention”.
GSK had claimed the salt absorbs much lower amounts of water “when exposed to a broad range of humilities, and can be prepared in a stable crystal form”, and therefore had greater therapeutic efficiency.
But the IPAB said that while the properties of the salt may have more advantages over those in the original compound, they “do not result in therapeutic efficacy”.
“Applying s.3(d) and the decision of the Supreme Court in the Novartis case we find that this is not an invention. The patent deserves to be revoked,” it said of the patent.
The IPAB did press ahead and assess the remaining objections, finding the patent obvious but rejecting the complaint about non-disclosure.
A GSK spokesman said it was pleased the IPAB had upheld the basic patent for the lapatinib compound.
“This means that Tykerb remains subject to patent protection until the expiry of the basic patent in 2019. The patent directed to the specific lapatinib ditosylate salt had an expiry date in June 2021.”
He added: “We are disappointed that the IPAB has revoked our later expiring patent for the lapatinib ditosylate salt. This latter ruling only relates to the lapatinib ditosylate salt patent in India and does not affect our basic patent for Tykerb or corresponding patents in other countries. We are studying the IPAB’s decision but maintain our belief in the inventiveness of the lapatinib ditosylate salt and will consider the possibility of taking further steps before the appropriate authorities to validate this.”
The ruling is another high-profile application of section 3(d), which has caused some Western pharmaceutical companies to worry about the strength of IP protection in India.
Michael Pears, senior associate at Potter Clarkson LLP, said innovative companies will consider the interpretation of section 3(d) as a further bar to protecting medicines in India.
While it is fair that there must be an enhancement in efficacy, he said, and that other countries set similar rules, there seems to be a higher inventive step standard in India for pharmaceutical products.
“The equivalent European patent was granted by the EPO, which acknowledged that the ditosylate salt absorbed significantly lower amounts of water when exposed to humidity, and that this could not have been predicted by the skilled person. So, the salt was non-obvious. By not recognising incremental, but genuine, innovation, the decision may well stifle research and development in India.”
Local lawyers and patient groups, however, have argued that section 3(d) encourages companies to innovate instead of focussing on patenting minor variations of existing drugs.
