In a bid to delay the launching of generic drugs, the multinational drug manufacturers have recently asked the Indian government to develop a registry which will have all the collated information regarding drug applications pending manufacturing and marketing approval. This is not the first time that these pharma giants have tried hindering the process of generic drug development. Previously, there was an attempt to prevent generic drug players from conducting research and development during the life of the patent. This would in-turn lead to a delay in the marketing of the generic drug after the patent expiry of the brand company's drug. In the US, this is not possible because of the Hatch-Waxman provision which encourages competition and lower prices and allows generic companies to conduct experiments using safety and effectiveness studies of the innovator during the life of the patent. Furthermore, in the US there is an on-going effort to pass CREATES Act, which proposed that a generic drug manufacturer would be entitled to file a civil action against an innovator drug company if the latter refuses to make available enough samples of a product for testing. However, no such legislation protecting generic players has been passed as of yet in India.
Some other tactics which have been employed as aforesaid by innovator companies across various jurisdictions are:-
1) Filing multiple divisional patent applications with trivial modifications to the parent patent application
Since extending the sales and protection of blockbuster drugs as much as possible is of paramount importance, innovator companies may file multiple divisional applications of the parent application so as to hinder generic entry for a long time. Such patent clusters also cause uncertainty and obscurities with regards to the patent status of a drug product. Generic companies could initiate invalidation proceedings of such patents, but refrain from doing so taking into consideration the time and money to be invested. Patent ever-greening is a prevalent practice adopted by innovator companies in the US since second use, new dosage form or route of administration, polymorph, salt etc. of an active ingredient can be patented to extend the life of a patent family. An example of second medical use patenting can be that of duloxetine (marketed by Eli Lilly) which initially received protection for treatment of major depressive disorder, but eventually went on to receive patents for other uses like fibromyalgia, neuropathic pain, eating disorders etc.
A classic example of patent ever-greening can be that of atorvastatin, a block buster drug sold by Pfizer Inc. under the brand name Lipitor. The first generic patent for the class of HMG-CoA inhibitors filed in 1986 expired in 2010. A specific patent US5273995 for atorvastatin calcium filed in 1991 expired in 2011 giving an additional year of exclusive rights to market the drug. To further extend market rights, another patent US5969156 was filed in 1996, disclosing atorvastatin polymorphic forms I, II and IV which expired recently in 2017. Therefore, a total of six additional years of protection over the original patent expiry was obtained by this ever-greening strategy. In India, section 3 (d) prevents patenting of salts, esters, ethers and other few forms of a known substance unless enhanced therapeutic efficacy is proven. However, pharma companies are at times able to find loopholes even in this provision.
2) FDA Citizen petitions
It is a common practice for pharmaceutical companies in the US to file citizen petitions impeding approval of ANDAs (Abbreviated New Drug Application) and 505 (b) (2) applications. A citizen petition is usually submitted to the FDA requesting changes in health policy or in genuine cases like amending or revoking an order or regulation and any other administrative action. This provision has been widely misused by innovator companies in cases like:-
(i) determining if a generic drug is the same as the reference listed drug (RLD)
(ii) designation of an additional reference standard (RS) for a drug if the current RLD/ RS are not available in the market for testing purposes
(iii) assigning schedule V to a particular drug product
(iv) requesting the FDA to refrain from receiving or approving any ANDA that references the NDA of the innovator, unless the ANDA sponsor provides data consistent with the requirements set forth in the petition for establishing bioequivalence
(v) determining if an RLD was withdrawn from the market for safety and efficacy reasons.
(vi) whether a drug is suitable for submission in an ANDA
However, section 505 (q) of the FD&C Act provides that citizen petition may not delay the approval of a generic drug, unless it is observed that such delay is necessary to protect the public health. In the US, 179 CPs were filed in the year 2018 and a gradual increase in its filings has been observed over the previous years.
An example of such a case is the citizen petition filed by TherapeuticsMD, Inc. on December 11, 2018 requesting the FDA to refrain from receiving or approving any ANDA that references Imvexxy" (estradiol vaginal inserts), NDA #208564, unless the ANDA sponsor provides data consistent with the requirements set forth in this petition for establishing bioequivalence ("BE"). TherapeuticsMD submits this petition seeking issuance of an appropriate BE guidance for Imvexxy.
3) Weakness in the opposition procedure
This is mostly to do with the time taken by the Controller in reaching a decision with respect to the opposition proceedings.
4) Compulsory licensing
The only ever case of compulsory license being granted in India was to Natco Pharma. Innovator companies walk away scot-free without making life-saving drugs available in sufficient quantities and at reasonable prices to the public as also evidenced by the fact that there is no timely filing of Form 27 as per the working requirement of the Indian Patent Act. If compulsory licenses are not granted to remedy such wrong-doings, how will generic companies be able to bring out generic versions to help the public at large?
5) Litigation settlements between innovator and generic companies
Distribution of authorized generics by an innovator company, its affiliate or a generic distributor after patent term expiry reduces market share which should ideally be covered by generic companies. An interesting case of the aforementioned has been by Valeant Pharma which launched authorized generic of diabetes drug Glumetza (Metformin) in the US. Lupin had already enjoyed a 180-day exclusivity pursuant to a P-IV filing. The launch of the authorized generic by Valeant not only ate into Lupin's market share for the drug but also ended up increasing competition and prices. It is not uncommon to hear of settlements in the form of reverse payments or potential licenses between P-IV filers and innovators which tactfully averts the launch of generics to a later date. The Restasis case is an epitome of a controversial license tactic gone sourly wrong, otherwise known as the sovereign immunity case. Allergan licensed its patent to the St. Regis Mohawk Indian Tribe and tried to shield its patents from IPR challenges filed by Mylan, Teva and Akorn using tribal sovereign immunity. However, Allergan did not succeed and its patents stand invalidated.
In view of the above, it can be inferred that innovator companies can go to any extent to protect their patents. Who is to say what will happen if the pending drug application registry is made available to innovator companies and what strategies they will employ to quash attempts by the generic manufacturers to launch their version. The government will have to take efforts to ensure that it does not encourage its use for unnecessary litigation.
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