حفاظت از حقوق مالکیت معنوی در SELEX و آپتامرها

In an earlier article, the author explained the technology of a particular field of combinatorial chemistry––using artificial DNA/RNA sequences––aptamers––as the screening ligand, and the SELEX protocol for exposing an aptamer library to the desired target. In the present article the author explores the types of claims currently being sought and granted for this technology. He considers the relevant legislation, and sets out his views on the validity of various approaches to seeking effective patent protection in this emerging technology, and the ways that protection may develop. He also investigates the potential value of seeking registered design rights in this area.

In my previous article, the science behind SELEX and aptamer technologies was explained [1]. I briefly considered how they were defined for the purposes of patent protection. It was readily apparent from that discussion that patents for those technologies have already been liberally applied for and only slightly less promiscuously granted, particularly by the USPTO. However, the desire to acquire patents in this field can be readily understood when the value of such rights is considered. For example Gilead Sciences Inc licensed its SELEX™ processes to Archemix Corp. for $17.5 million,1 in October 2001. The present article focuses on the form and wording of the patents applied for to date and then briefly considers the possibility of using design rights to protect the three-dimensional structure of aptamers.

Protecting patent rights in new technologies or even new applications of old technologies presents a number of challenges. The most serious being that until the wording of a particular form of claim is challenged and its validity thereby tested it may not prove adequate. The form of claims for SELEX/aptamers has begun to swing away from wide method type claims to ones which more specifically define the aptamer for which protection is sought. However, there are many granted method patents and only time will tell the extent to which they can be used to acquire rights (by way of Article 64(2) EPC) in any products generated by means of the protected protocol. The patents that claim aptamers with a specific function are less susceptible to invalidity on the grounds of insufficiency but instead suffer from the difficulties associated with how to draft the claims to give a meaningful scope of protection. Claims based upon sequences are easy to define but offer less than convincing protection for molecules whose true value lies in their three-dimensional form. As discussed above, simply adding a dependant claim for aptamers with substantial structural homology to one defined by way of sequence is unlikely to enhance the real scope of protection by itself, as it takes no account of the inherent structural pleiomorphism of oligonucleotides and structure claims of this type must be linked to aptamer function (as are the sequence claims). Alternatively, if structure based claims are accepted as a necessary part of any claim for an aptamer they could also be framed in terms of a defined binding footprint on the target molecule and thereby protect that which gives the aptamer its true value. The additional effort in defining this binding footprint will be more than offset by obtaining a potentially enforceable patent. Finally, the possibility of using the European Design Directive was considered as an additional means of protecting aptamers, which by their very nature might seem to fall within the scope of such design rights. However, the exclusions from registered designs of those which are either defined by function or necessity of fitting against another product severely limits its application to aptamers, although not to the point where they should not at least be considered, even after filing the patent.