Thursday, 5 September 2013



The Drug Price Competition and Patent Term Restoration Act (Hatch-Waxman act) of 1984  streamlined  generic drug approval process in US. HWA created an abbreviated process for generic drug approval without conducting costly and duplicative clinical trials. (Under the new legislation, generic entrants needs to establish the bio equivalence of its drugs to the original).The rules created processes and incentives for both branded and generic companies involving challenges to patents.

An important section of Hatch-Waxman Act actually encourages generic companies to challenge weak patents. If a generic company is the first to file its Abbreviated New Drug Application (ANDA) with a Paragraph IV certification and prevails in the subsequent lawsuit, that generic company is granted a period of market exclusivity of 180 days.

The 180-day exclusivity incentive can be significant for a generic company as it would be the only generic version on the market. So, it can price its product slightly below the branded version for six months, take market share from the branded product, and maintain its price point before other generics enter the market and erode the price and segment margins. The additional profit for a generic firm can be enormous if the product it challenges is a so-called blockbuster or megabrand.

The HWA added two provisions to the  
Federal Food, Drug and Cosmetics Act namely Section 505(b)(2) and Section 505(j). Section 505(b)(2) was added with respect to Hybrid New Drug Application and Section 505 (j) was added with respect to ANDA. ANDA has four types of submissions. 

Para I: A Para I filing for the launch of generic drug is made when the innovator has not made the required information in the Orange book.

Para II: A Para II filing is made when the drug is already off patent.

Para III: A Para III filing is made when the applicant does not have any plans to sell the generic drug until the original drug is off patent.

Para IV: A Para IV filing for the launch of generic drug is made when the applicant believes its product or the use of its product does not infringe on the innovator's patents or where the applicant believes such patents are not valid or enforceable.

PARA – IV Filing &  180 days exclusivity

By making a Paragraph IV filing, the generic drug maker says the patent is at least one of the following: (1) invalid; (2) not infringed; or (3) unenforceable.

An ANDA applicant filing a paragraph IV certification must notify the proprietor of the
patent. The patent holder may bring a patent infringement suit within 45 days of receiving such notification. If the patent owner timely brings a patent infringement charge against the ANDA applicant, then the 30 month stay would be given to the FDA by the court.

·      FDA is banded from approving the application for 30 months.

·      Or until court holds that the patent is invalid or would not be infringed, FDA can approve the ANDA application.

·      If the court gives decision in favour of patentee, FDA will not approve ANDA.

Once 30 months have passed, allows the FDA to approve the ANDA application, even though litigation is ongoing and after approval both parties can market their product until the decision would be given by the court within the patent expiration period.

Basic Structure of PARA –IV Filing

        CTD submission to USFDA by generic drug manufacturer.

        Notice Letter to Patent Owner - Applicant has to notify the patent holder within 20 days of ANDA application.

        45-Days for Patent Owner to Sue - If patentee files infringement suit against ANDA applicant with 45 days from receiving of notification in the court, litigation starts in court.

        30-Month Stay of FDA Approval of ANDA - When court gets the infringement suit, gives 30 months stay to FDA for approval of the ANDA application, otherwise FDA can approve or dis approve the application; no stay would be given to the FDA.

        180-Day Marketing Exclusivity for Successful First-Filer – If Court decision in respect to ANDA applicant, applicant gets the 180 days market exclusivity, or if not, then ANDA can submit application in Para-II/III.

180-day Exclusivity

        180-day Marketing Exclusivity created to encourage Paragraph IV challenges by rewarding First Filers for undertaking the costs and risks of patent litigation, to challenge weak or improperly obtained patents, or to defend non-infringing generic products.

        At one time, “very valuable to generic manufacturers, as they can sell product at a price significantly higher than they could if multiple generics were on the market.”

·      The 180 day exclusivity provides leverage for the branded manufacturer to block multiple generics while negotiating with only one

·      The 30 month stay allows for creative delaying tactics

·      By negotiating to delay the entry of the first filer, the brand effectively delays entry by all filers.

Paragraph IV Certifications under Hatch-Waxman have spawned a tremendous number of legal conflicts between the generic drug makers and the owners of those patented drugs.


  1. Can you share some case studies related to this for further understanding..?
    Suggest any source from where we can get the information about this.