Product-by-process claims

With population growth, an aging demographic and the development of innovative drugs, the Hong Kong pharmaceutical market is forecasted to grow to over US$2 billion by 2019. Hong Kong is therefore one of Asia’s most popular jurisdictions for extending patent protection for new drugs. However, as is sometimes common, the exact molecular structure and mechanisms of drug pharmacology are not always known at the time of patent application. Instead, products are described using process methodology, also know as 'product by process'. In general, these claims may be in the form of 'X obtained by process Y' or 'X obtainable by process Y', defining product X in terms of process Y.

In Hong Kong, no specific provisions or regulations concern product-by-process claims under the Patent Ordinance. There are two types of patent in Hong Kong: standard patents and short-term patents. There is no substantive examination for either type. A Hong Kong standard patent is obtained through a two-stage re-registration of a designated patent application granted by the Chinese State Intellectual Property Office (SIPO), the UK Intellectual Property Office (UKIPO) or the European Patent Office (EPO) (designating the United Kingdom). A short-term patent is obtained through direct filing in Hong Kong with submission of a search report issued by SIPO, the EPO, the UKIPO or an international search authority under Article 16 of the Patent Cooperation Treaty.

Although no substantive examination is conducted, the patentability of a Hong Kong standard patent depends on its parent patent application, on which substantive examination should have been conducted by the designated patent office. For a short-term patent, although a favourable search report is not a prerequisite for the grant of a patent right, it might be required to prove the validity of a short-term patent in any enforcement proceedings before a court.

Therefore, to answer the question of whether product-by-process claims are allowed and how infringement is assessed in Hong Kong, the practices of SIPO, the UKIPO and the EPO must be considered.

In China, the Examination Guidelines state that for chemical products which cannot be sufficiently characterised by features other than their manufacturing process, their manufacturing process may be used to characterise the claims. Therefore, product-by-process claims are allowed. During examination on a product-by-process claim, consideration will be given to whether the person skilled in the art can infer that the manufacturing process is necessary for a particular structure or composition of the product which is different from prior products – that is, the product defined in a product-by-process claim should be novel and inventive. Otherwise, the claim will not be allowed even if the manufacturing process is different from its prior art. In practice, the language ‘obtained by’ is often used in this type of claim. However, this language may be considered too vague and is likely to be rejected by an examiner as it may be virtually impossible to define the scope of protection of the claim. In order to assess infringement, the process features are considered limiting in this type of claim. In other words, such claims will be infringed only if the product is produced by the process defined in the claims. Further, it is unclear whether the doctrine of equivalency can be applied in determining infringement of product-by-process claims.

Before the EPO and the UKIPO, similar to SIPO, product-by-process claims will be admissible only if the products themselves fulfil the requirements for novelty and there is no other information available which could enable the applicant to define the product satisfactorily by reference to its composition, structure or another testable parameter.

Considering that the grant of a Hong Kong standard patent relies on examination of the designated patent applications by SIPO, the EPO or the UKIPO, it is obvious that product-by-process claims will be allowed in Hong Kong. Regarding the determination of infringement, there have been no court rulings in Hong Kong for reference. However, it can be reasonably deduced that the Hong Kong courts would refer to practices in China and the United Kingdom – that is, the claimed process steps would need to be performed in order to infringe this type of claim in Hong Kong.