API and IP Newsletter
Contents
DMFs filed in February 2022
We analyse DMF filings by Indian companies. Some of the DMFs filed by the Indian companies and our analysis is as below.
General information
FDA finishes veterinary drug compounding guidance at last
The agency's challenge was to enable veterinarians to meet the widely varying needs of their animal patients without providing a loophole through which businesses could sidestep the government's rigorous drug-approval process.
The result, Guidance For Industry #256 - Compounding Animal Drugs from Bulk Drug Substances, released on April 13, seems to have achieved the desired balance, judging from early positive reviews from veterinary pharmacy experts.
News here.
Russian pharma pipeline dominated by private entities, but no clear source of capital
Russia’s active pipeline covers drugs in all active novel clinical and preclinical stages of development, including the pre-registration stage of development, and excludes drugs considered to be inactive or discontinued. The pipeline is dominated by private companies, which account for 70% of all companies involved.
News here.
Intellectual Property
Merck Sharp & Dohme Corp (MSD) V. Pharmascience Inc.(PMS)
In US there is Orange Book, in Canada there is patent registry (here). In Canada litigation/generic approval process is similar to ANDA litigation/approval, but there are many differences.
Health Canada approval of generic drugs and biosimilars is stayed for up to 24 months from the date that the innovator commences proceedings under the Patented Medicines (Notice of Compliance) Regulations, in contrast to the 30-month stay on the FDA under Hatch-Waxman from a generic’s notice of an ANDA filing and the absence of a stay under the Biologics Price Competition and Innovation Act.
Unlike US, patent is not automatically invalidated in PMNOC litigations.
But today we are not covering these differences. We will cover inventive step discussion in MSD vs Pharmascience and Sitagliptin patents.
The patents in register (OB equivalent in Canada) are as below.
This action initially alleged infringement of three patents - the 400 Patent, as well as two other patents listed on the Patent Register in association with Sitagliptin phosphate monohydrate – Canadian Patent Nos. 2,536,251 [251 Patent] and 2,450,740 [740 Patent], see above table. However, the allegations in respect of the 251 Patent and 740 Patent were discontinued prior to the trial.
The 400 Patent is directed to the dihydrogenphosphate [DHP] salt of sitagliptin and its crystalline monohydrate form, a process for making the DHP salt of sitagliptin as a crystalline monohydrate, its formulation as a pharmaceutical composition and its use to treat diseases affected by the inhibition of DPP-4, such as type 2 diabetes.
In areas of endeavour where advances are often won by experimentation, an “obvious to try” analysis. The critical question is whether it “was more or less self-evident to try to obtain the invention” having regard to the following factors, while noting that “mere possibility that something might turn up is not enough”
Is it more or less self-evident that what is being tried ought to work? Are there a finite number of identified predictable solutions known to persons skilled in the art (PSA)?
What is the extent, nature and amount of effort required to achieve the invention? Are routine trials carried out or is the experimentation prolonged and arduous, such that the trials would not be considered routine?
Is there a motive provided in the prior art to find the solution the patent addresses?
Applying this to the obviousness analysis, the question to be answered is whether bridging the gap between prior art WO498 (which discloses sitagliptin and its hydrochloride salt, amongst other compounds) and the inventive concept of the claims of the 400 Patent would have been obvious to the PSA having regarding to common general knowledge and prior art.
As was acknowledged by PMS in oral argument, if the patent is a selection patent, the Court may have regard to the inventive concept and may look to the disclosure to nourish what it is about the species that is claimed that is selective over the genus. However, PMS asserts that the 400 Patent is not a selection patent and there is no advantage explicitly disclosed with respect to the crystalline monohydrate claimed in the 400 Patent.
The 400 Patent is a selection patent whose prior genus application (WO498) discloses a large class of compounds with some recognized utility, in this case, for treating type 2 diabetes. WO498 identifies 33 specific compounds in its examples that come within its scope, one of which is the compound now known as sitagliptin (example 7). As acknowledged by all of the experts, WO498 does not point directly or indirectly to sitagliptin as being a preferred compound of the compounds disclosed. Nor does it provide any data or scientific justification for selecting any of the compounds it discloses over any of the others as a lead compound.
PMS highlights that only seven detailed examples exist within WO498 and of those seven examples only two (examples 6 and 7) resulted in the formation of a solid compound (the others are described as being either foamy solids or an oil). PMS argues that this would narrow the compounds of interest for the PSA to those of examples 6 and 7.
However, the Court disagreed, said there is no evidence to support this argument and found patent is valid and infringed by PMS.
Decision here
