GSK India Saves Tykerb Main Patent But Loses Claims On Salt Patent To Fresenius Kabi
This article was originally published in PharmAsia News
Executive Summary
Amid a series of patent related setbacks faced by global drug firms, GSK has safeguarded Tykerb against Fresenius Kabi.
MUMBAI – British drug maker GlaxoSmithKline PLC managed to ward off generic competition to its flagship breast cancer drug Tykerb (lapatinib) in India. An India patent court delivered a mixed judgment July 27, upholding its main compound patent but rejecting claims on a salt patent on grounds of obviousness and lack of enhanced efficacy.
The validity of GSK’s drug patents was questioned by infusion and injectables company Fresenius Kabi Oncology Ltd. but the ruling by the Chennai-based Intellectual Property Appellate Board helps Tykerb to be free from potential generic threats till early 2019.
The Power Of 3(d)
In two separate orders, Justice Prabha Sridevan and Justice D.P.S. Parmar broke down the case drawing in comprehensive examples from earlier decisions both for and against their mixed verdict.
In supporting GSK’s main compound patent and in effectively disallowing the statutes of Section 3(d) of the Indian Patent Act, which deal with incremental innovations and significantly enhanced efficacy, the court said that under Section 3(d) an applicant must prove it has the same therapeutic efficacy as the known substance. The jury in one instance said, “In this case there are too many choices and too many mays and too many surmises.” It specifically pointed out that Fresenius was unable to justify its obviousness attack.
What came as a boost for GSK was the court’s point about substantial pleadings necessary to invoke Section 3(d). “It is only when the pleadings show how the invention is one kind of a derivative of known substance, the patentee will have to explain how the grant of patent is justified because of the enhancement of therapeutic efficacy. In this case, the pleadings are not adequate. We hold that Section 3(d) ground has not been proved,” the order noted.
The order dealt with arguments of obviousness for which the court backed its decision with examples cited from previous cases like Novartis AG Vs. Union of India over imatinib and Roche Vs. Cipla Ltd. on erlotinib (Also see "India’s Supreme Court Dismisses Novartis’ Glivec Patent; Upholds Section 3(d) Of India Patent Act" - Scrip, 1 Apr, 2013.).
Fresenius Kabi did manage to get the salt patent revoked. Legal experts have mostly held the view that to maintain or enforce patents on salts or similar derivatives is becoming increasingly tough (See: GSK Fresenius Aug. 1 IPAB Order 1 and GSK Fresenius Aug. 1 IPAB Order 2 ).
The claims on the ditosylate salt of lapatinib were found obvious in view of the documents cited by Fresenius, but that apart, the claims were also hit by Section 3(d) of the Indian Patents Act, according to the order. The court noted that since the later expiring ditosylate salt patent was revoked, an argument of ever-greening could not stand.
Discounted Pricing
GSK is undeterred by the mixed decision – one upholding its patent claim on the main compound and the other revoking it. It said it is pleased that the Intellectual Property Appellate Board in India has upheld its basic patent for the lapatinib compound, which is the active ingredient in Tykerb. The patent has an expiry date in January 2019.
Tykerb has provided significant benefit to women with HER-2 positive breast cancer in India over the four years it has been available, GSK said, noting that as part of its access strategy, the company offers significantly discounted prices for Tykerb in India (Also see "In India, GSK Takes A Deep Dive To Launch Revolade, Votrient At 75% Price Cut" - Scrip, 25 Jul, 2011.).
“We will continue to take steps to ensure that Tykerb is available to women with breast cancer in India who need it,” the spokesperson said in an e-mailed response.
GSK said it is disappointed that the IPAB revoked its 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,” the company clarified.
An appeal against the IPAB decision may not be far off. The company said it is studying the decision but maintained it believes in the inventiveness of the lapatinib ditosylate salt and “will consider the possibility of taking further steps before the appropriate authorities to validate this.”
“Intellectual property protection is an important aspect in ensuring that innovation is encouraged and appropriately rewarded. It underpins the continued commitment from research-based pharmaceutical companies to invest in developing new medicines,” it maintained.
Large global companies have been clamoring against a spate of adverse court decisions in India. The charge came most strongly from Pfizer Inc.’s Chief Intellectual Property Counsel Roy Waldron, who alleged India followed protectionist laws for its generic drug industry. Waldron said the revocation of a Pfizer patent on Sutent (sunitinib)constituted a fundamental breakdown of an incentive‐based IP system (Also see "Pfizer Urges U.S. Congress To Address Threats Posed By Indian Patent System" - Scrip, 14 Mar, 2013.).