Endo sues Zydus to block generic version of Pfizer's Chantix

Endo International

09/08/2023 22:27

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      Endo still sells anti-smoking drug following Chantix
recall
    

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      Endo said Zydus competitor infringes patent it received on
Tuesday
    

  
    By Blake Brittain
       Aug 9 (Reuters) - Endo International  ENDPQ.PK  has sued
Zydus Pharmaceuticals  ZYDU.NS  in Delaware federal court,
claiming Zydus violated its patent rights with a generic version
of Pfizer's  PFE.N  recalled smoking-cessation drug Chantix.
    Endo's generic drugmaking subsidiary Par Pharmaceutical said
in a complaint made public on Wednesday that Zydus' generic
infringes a newly issued U.S. patent covering Endo's process for
making its version of the drug.
        Endo received the patent on Tuesday, covering a method
of manufacturing Chantix's active ingredient varenicline with
safe levels of the impurities that caused Pfizer to take Chantix
off the market. Endo asked the court to block Zydus' U.S. sales
of its generic and requested an unspecified amount of money
damages.
    Representatives for Endo, Zydus and Pfizer did not
immediately respond to requests for comment on Wednesday.
    Chantix earned Pfizer more than $1 billion in sales in 2019.
Pfizer recalled the drug in 2021 after finding it contained high
levels of impurities that increase cancer risks.
    Endo launched a generic version of the anti-smoking drug
with fewer impurities later that year. It said making the
FDA-approved tablets is "difficult to do, as evidenced by the
fact that Pfizer has been unable to reformulate its Chantix
product to meet those requirements despite the huge incentive it
has had to do so."
    The FDA approved India-based Zydus' generic-drug application
for its version of Chantix in June. Endo said Zydus has since
launched the generic in the United States.
    The case is Par Pharmaceutical Inc v. Zydus Pharmaceuticals
(USA) Inc, U.S. District Court for the District of Delaware, No.
1:23-cv-00866.
    For Endo: Martin Black of Dechert
    For Zydus: Not yet available

 (Reporting by Blake Brittain in Washington)