In this final instalment, we address common questions relating to requirements and rights during the (pharmaceutical) extension of term.
Can an extension of term be sought for patents containing a combination of pharmaceutical products?
In Australia, the case of Merck Sharp & Dohme Corp v Sandoz Pty Ltd  FCA 947, has been significant in discussing this question in some detail. The case itself was discussed in an earlier article, written by our Senior Associate, David Tso. To briefly summarize, the claims of the pharmaceutical patent issued to Merck were directed to a compound sitagliptin, and a composition containing a combination of sitagliptin and metformin. A patent term extension was granted to Merck on the combination of sitagliptin and metformin, since it received regulatory approval 5 years after grant of the patent, whereas sitagliptin on its own would have received regulatory approval less than 5 years after grant of the patent. However, when challenged by Sandoz, it was found that an error had occurred in calculating the extension of term, since the patent term extension was not based on sitagliptin alone. In other words, the patent term extension was not based on the pharmaceutical substance with the first regulatory approval date. The Federal Court ruled that if Merck was allowed to retain the current patent term of extension, they could obtain “a monopoly over sitagliptin for more than 20 years in circumstance where it never suffered an unacceptable delay in its capacity to exploit sitagliptin” (at para ). Thus, the Register of Patents was subsequently rectified, and the extension of term reduced to zero.
In light of this decision, where a patent claims a combination of pharmaceutical substances, it has become preferable in Australia to have separate patents for each pharmaceutical substance that has or will receive regulatory approval, so that each patent can receive an extension of term to which they are entitled to, based on their eligibility for such.
As discussed earlier, the US considers the first regulatory approval of the “active ingredient”. Where a US patent claims a combination product that contains one or more active ingredients, whereby one or more of these active ingredients previously received regulatory approval, at least one of the claimed active ingredients must be new in order to qualify for a patent term extension. This concept was discussed in the case of Arnold Partnership v. Dudas, 362 F.3d 1338, 1341 (Fed. Cir. 2004), whereby a pharmaceutical product encompassed the combination of hydrocodone and ibuprofen, both of which previously received separate FDA approval. The Court held that a patent term extension for a combination therapy is only available where the active ingredients, when considered separately, have not been previously marketed. In other words, if at least one of the claimed active ingredients was new, and had not received prior FDA approval, then the patent would have been eligible for a patent term extension, even if there is a new synergistic effect from using the combination of the previously approved active ingredients.
Considering a similar scenario in Europe, for patents claiming products that contain two or more active ingredients that together deliver a combined effect, there is case law in Europe that points towards the fact that for a valid SPC application, the patent claims do not necessarily need to explicitly mention the combination of active ingredients (Teva UK Ltd & Others v Gilead Sciences Inc.  C-121/17). Instead, it should be possible for the skilled addressee to determine the combination of active ingredients of the product based on the prior art at the date of filing the patent in question. Thus, where a patent utilises broad claims wherein at least one active ingredient is unknown is sufficient to invalidate a SPC application.
Patent rights during the extension of term
If an extension of term has been granted, it is important to note that the rights of the patentee are limited, in the sense that it is not considered an infringement if there is exploitation of the pharmaceutical substance for any purpose other than a therapeutic use. Furthermore, it is not an infringement of the pharmaceutical patent if there is exploitation of the pharmaceutical substance in another form, meaning that only the pharmaceutical substance per se is protected.
This concept of limited extended protection is similar in the United States and in Europe.
Patent term extensions in the US only extend the exclusive patent rights to any regulatory approved use of the product. In other words, if the patent claims several products, in addition to the regulatory approved product, only the product that has received FDA approval will receive extended patent rights, whilst the exclusive rights of the remaining non-approved products in the patent will expire when the original patent term ends.
Likewise, in Europe, SPCs extended protection covers the same protection that was offered by the patent, in that if the patent claims covered only use of the product for a particular purpose, then the SPC will offer the same protection, covering only use of the product for that stated purpose.
When to apply for a patent term extension
In Australia, the application for an extension of term must be made within 6 months of the date of grant of the patent, or the date from when the pharmaceutical substance was first included in the ARTG, whichever is later.
Along similar lines, the deadline for applying for a SPC is 6 months from the time the product received marketing authorisation for most European countries.
Crucially however, the deadline to apply for a patent term extension in the US is much shorter, with the deadline falling within 60 days of the product receiving approval from the FDA. This deadline is non extendable.
Extension of time to apply for an extension of term
As mentioned above, the deadline to apply for a patent term extension in the US is non-extendible. However, in Australia there are generous provisions under 223 of the Patents Act that allow for an extension of time to apply for an extension of term.
The relevant provisions in Australia states the patentee must be able to demonstrate that an error or omission has occurred, or there has been circumstances beyond their control that led to the error or omission for doing the relevant act.
There have been some cases that have discussed the concept of an extension of time to apply for an extension of term, in Australia. These include:
Alphapharm Pty Ltd v H Lundbeck A/S  HCA 42, wherein it was discussed that where an extension of term is applied for during the term of the patent, section 223 of the Patents Act can be applied to extend the time in which to apply for said extension of term.
Secondly, in Boehringer Ingelheim International GmbH  APO 60, it was discussed that where a patent has already been expired, an application for an extension of time cannot be filed. Thus, emphasizing the need to file for an extension of time during, and not outside of, the term of a patent.
In Europe, as mentioned above, SPCs are national rights. Thus, extension requests must be made before each national patent office, although the process for doing so in most European countries is similar. This is also true for paediatric SPCs, the application deadline for which is no later than two years prior to the expiration of the SPC.
Specifically, most European countries require that the SPC holder, when applying for a paediatric SPC extension, provides evidence that the deadline was missed despite “all due care” being undertaken, which carries a much higher proof burden, in comparison to that required in the UK. This typically requires a thorough explanation of how the patent records are maintained, how the record system generates reminders for upcoming deadlines, and in light of all those factors, explaining how in that particular instance, the deadline for applying for the SPC was overlooked.
In the UK, an extension of time can be sought to apply for the extension of term, if evidence is provided to demonstrate that it has always been the applicant’s intention to apply for the paediatric extension. In other words, the burden of proof is much lower, requiring only demonstration of intention, and that once the error was known, the applicant had acted diligently to resolve the error. This requirement is noticeably similar to section 223 of the Australian Patents Act.
Key takeaway points
For patentees of pharmaceutical products seeking to obtain patent term extensions in overseas jurisdictions, we advise that claims in a single patent application should be directed to a single pharmaceutical substance. Even though this would likely cost more than having a single patent application covering two separate pharmaceutical substances, separate applications allow applicants to take full advantage of any patent term extensions that may be granted, at least in Australia. We also advise that care should be taken with respect to use of Swiss style claims in Australia, since use of these claims could affect validity of a patent term extension. It is advisable for pharmaceutical patentees seeking a patent term extension on a global pharmaceutical patent portfolio to work towards the US deadline, not least because the deadline for applying is much shorter than in Australia and Europe, but also because the deadline is not extendible. This is particularly important to consider if the US is a market of interest.
At Michael Buck IP, we have highly experienced attorneys who can assist in navigating this complex area. For additional information or advice relating to your pharmaceutical patent/s, please don’t hesitate to contact us.