|The Patent Term of an Obesity Drug – good news for patent owners and bad news for generic drug manufacturer?|
With a population of over 7 million and a GDP of over US$220 billion, Hong Kong is an attractive market for pharmaceuticals. For example, the Hospital Authority, Hong Kong’s administration of the network of public hospitals, alone has an anticipated expenditure on pharmaceuticals of about US$33 million for the first 6 months in 2011.
While the term of a Hong Kong standard patent is set by the Patents Ordinance as 20 years from the filing date, a recent patent infringement case demonstrated that the term of a patent could be extended beyond the 20 year term.
The patent infringement case was in relation to Hong Kong standard patent No.1006002 (the ‘Hong Kong Patent’), which is identical in scope to European Patent No. EP 0,397,831. The Hong Kong Patent claims the use of a chemical compound commonly known as Sibutramine in the manufacture of medicaments for the treatment of obesity. The filing date of the Hong Kong Patent was 21 November 1989 and therefore has an expiry date of 21 November 2009 under the Patents Ordinance.
The patented medicament was launched in Hong Kong in 2002 under the brand name ‘REDUCTIL’, and the sales have grown from US$2,706,000 in 2002 to US$ 6,433,000 in 2008.
Brief facts of the case are as follows:
In late 2005, the 1st Defendant, a Hong Kong company, applied to register in Hong Kong ‘OBIRAX’, a drug containing Sibutramine manufactured by Micro Labs Limited of India. The 1st Defendant imported the drug to Hong Kong and applied to register the generic drug with the Department of Health (the government authority of Hong Kong responsible for drug registration) as a drug for weight management.
The 2nd Defendant, also a Hong Kong company, had been distributing and selling ORIBAX since registration.
Both the 1st and 2nd Defendants are closely related and have a pharmacist shareholder and director.
On 20 January 2009, about 10 months before the anticipated expiry of the Hong Kong patent, the Plaintiff applied for an interlocutory injunction to prevent the Defendants from further dealing with the generic drug. An interlocutory injunction was granted on 27 March 2009 and up to 21 November 2009, the anticipated expiry date of the Hong Kong patent.
Shortly before the expiry of the interlocutory injunction and on 18 November 2009, the Plaintiff applied for an extension of the interlocutory injunction for nine months. The extension was granted, thereby extending the effective term of the Hong Kong patent to 20 years 9 months!
Some interesting indications of this case:
1. This is the first Hong Kong patent case effectively extending the term of a Hong Kong patent beyond 20 years. The UK cases Dyson Appliances Ltd v Hoover Ltd (No.2)  RPC 544 and Generics v Smith Kline & French Laboratories Ltd  RPC 801 were cited.
2. The request of the nine-month extension was related to the undisputed term of nine months needed for registration with the DOH to compensate for ‘the attempt to steal a headstart’ to register the drug before patent expiry.
3. This case applies the UK case of Smith Kline & French Laboratory Ltd & another v Douglas Pharmaceuticals Ltd  FSR 522 also confirms that there is NO Bolar exemption in Hong Kong.
4. The validity of the Swiss type claims or second medical use claims was affirmed by the Court.
5. The Defence that curing of obesity does not cover management of weight was rejected.
6. This case also sets a precedent in Hong Kong that where it is not possible to hold a trial before patent expiry, the Plaintiff must ‘at least show a good prospect of success at trial’ in order to be considered for an interlocutory injunction beyond the term of patent.
The law and procedure on this subject are very specialized and complicated. This article is just a very general outline for reference and cannot be relied upon as legal advice in any individual case. If any advice or assistance is needed, please contact our solicitors.
Please contact our Intellectual Property & Technology Practice Group – Patent:
+(852) 2107 0329
Published by ONC Lawyers © 2010