Patents are the most important form of intellectual property protection in the field of life sciences products. This is because, in exchange for disclosing the patented technology to the wider world, they provide market exclusivity for the patent owner's product – the same product entering the market from a competitor would be at risk of patent infringement proceedings. In the medicinal products business, in which the cost of bringing a drug to market is notoriously expensive, that exclusivity is important.

The criticism is sometimes made that the number of patents that protect some drugs unjustifiably prevents competing third party products entering the market for too long. This can be a particular problem for biological drugs and competing 'biosimilars', especially when a number of the patents are still at the application stage and cannot, therefore, be challenged in invalidity proceedings. A rarely seen form of court relief has now been approved in principle by the Court of Appeal which may assist in striking the right balance in these situations.

This was the situation in the Fujifilm Kyowa Kirin Biologics Co. Ltd & Anor (FKB) v Abbvie Biotechnology Ltd litigation, in which FKB is seeking to bring to market its own biosimilar version of adalimumab (a drug prescribed for certain forms of arthritis). In this action, FKB has sought to solve the problem of avoiding pending patent applications on adalimumab by filing two claims to obtain so-called 'Arrow declarations'. This is a rare form of relief and it is designed to effectively 'clear the way' of patent applications in prosecution for an indefinite or prolonged period of time, without waiting for them to grant.

The Arrow declarations sought are that FKB's own product is anticipated or obvious at the priority dates of several patent applications for particular dosages and indications of adalimumab that are still in prosecution. A successful Arrow declaration would imply that any patent that is infringed by the adalimumab product must also be invalid by anticipation or obviousness, requiring it to be removed from the patents register.

In the FKB case, in November 2016, this form of relief was tested in the Court of Appeal for the first time. The key objection raised against Arrow declarations before the Court of Appeal was that they are effectively a decision on validity. This is important, because section 74 Patents Act 1977 limits those actions in which validity can be raised, and does not include declarations of this type. Despite the practical implications of an Arrow declaration for patent validity, the Court of Appeal held that such a declaration is available in principle. The Court stated that it "does not necessarily offend against" section 74, but may do so "where it is a disguised attack on the validity of a granted patent". However, and importantly in the context of this case, where the declaration is sought for the purpose of clearing the way of patent applications, the Court adds that "such declarations do not offend against the scheme of the [European Patent Convention] or the [Patents] Act simply because the declaration is sought against the background of pending divisional applications by the counter-party". Nonetheless, the Court of Appeal also states that "the existence of pending applications cannot itself be a sufficient justification for granting a declaration…". Instead, whether such a declaration is justified depends on whether a sufficient case can be made for the exercise of the court's discretion.

The Court of Appeal has thus established that Arrow declarations are available in principle. Attention now turns to whether the Patents Court will exercise its discretion to award the declarations sought after having heard trials on the merits of the claims. We will then know more about the factors that are relevant to the court when deciding whether to grant this form of relief, enabling third party product entry despite pending patent protection.