Anti-Climax or a Win-Win for All: FDA Approves Olmesartan Generics

 

 

We are pleased to bring to our readers a guest post by Mayank Dixit. Mayank works in the IP cell of a multinational pharma company in Mumbai.

 

 

Anti-Climax or a Win-Win for All: FDA Approves Olmesartan Generics

Mayank Dixit

Last week, the FDA approved generic versions of Olmesartan and its combinations with amlodipine and/or hydrochlorothiazide. The development would have been quite a ho-hum affair but for the 180-day exclusivity granted to Mylan for its generic equivalents of Benicar® and Benicar® HCT drug products.

As readers with even the most fleeting attachment to lawsuits on intersection of patent and FDA law would know that this drug product had been a subject of herculean tug o’ war between generic rivals- Mylan and Apotex, a brief background is still in order. Mylan was the first generic to file an ANDA with a paragraph IV certification to the two orange book listed patents for both Benicar® as well as Benicar® HCT. US 5,616,599 (US’599), the patent which expired with paediatric exclusivity on Oct 25, 2016, was held valid by the federal circuit forcing Mylan to convert its certification to para III. US 6,878,703 (US’703), the second patent to which Mylan filed a para IV was therefore the only patent on which its 180-day exclusivity rested and consequently was fiercely litigated by Apotex in an attempt that almost reached fruition, to strip Mylan of the prized exclusivity to the blockbuster drug product.

The district court held that since US‘703 patent was formally disclaimed by Daichii, it did not give rise to any dispute between the generic filer and the NDA or patent holder. Apotex, living up to its reputation of a barnacle litigant, succeeded in overturning the verdict at the appellate level. In addition to acknowledging the existence of substantial controversy that requires issuance of declaratory judgment the federal circuit also stated that the 75 day clock under the failure-to-market forfeiture provisions will begin to run for Mylan when Apotex has a tentatively approved ANDA as well as a non-appealable judgment of non-infringement. Though Apotex obtained a judgment of non-infringement in Jan 2016, in a bizarre turn of events, Apotex moved to vacate the district court’s non-infringement decision. The move which obviously reeks of a favourable settlement, perhaps also points to the intractable nature of deficiencies that bridled approval of Apotex’s ANDA.

In all probability, Apotex’s game plan would have been to obtain both the tentative approval and the non-appealable judgment of non-infringement about 75 days before the expiry date of US’599 patent so as to cause forfeiture of Mylan’s 180-day exclusivity unless it finds a saviour in Daichii, allowing it a waiver of paediatric exclusivity attached to the US’599 patent, of course at a price.

Fast forward to Oct 26, 2016, when FDA granted final approval to Mylan for olmesartan and olmesartan hydrochlorothiazide as well as conferred 180-day exclusivities for these products. We anticipate updation of orange book with “PC” flagging specifying exclusivity expiry dates very soon. Though there is still no visibility on the fate of Apotex’s ANDA, we have a strong hunch that Apotex made a killing quietly.

As for the generic approvals for olmesartan and amlodipine combinations, any associated 180-day exclusivities would have evaporated when the only orange book listed patent (US’599) was held valid by federal circuit. Since the first filers’ exclusivity would have rested only upon the US‘599 patent, certification amendment to para III sounded a death knell to the associated exclusivities and consequently paved way for approval of all the eligible ANDAs. Lastly, the triple combination product with hydrochlorothiazide (Tribenzor®) was never a subject of para IV certification and thus eligible ANDAs such as Torrent and Par obtained final approval post patent expiry on Oct 26, 2016.

All in all, the litigation maelstrom and FDA’s actions and responses provided for intensely absorbing read, not to forget, how it also forged landmark precedents.

Image from here