Merck predicts huge sales losses upon the expiry of protection for its blockbuster - Montelukast

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GenericsWeb, the leader in established pharmaceutical patent analysis and searching, recently published an article based on its proprietary Pipeline Patent Intelligence that analyses opportunities in launching generic versions of Merck’s blockbuster asthma treatment Montelukast (Singulair®). Montelukast products had global sales of USD $5bn in 2010.

The article by GenericsWeb highlights the following observations in relation to generic Montelukast:

  •     Patent protection for the Montelukast molecule expired in Canada in October 2011, protection extends to August 2012 in the US, and due to later authorisation of the product in Australia, the s70 extension on the molecule patent in this jurisdiction extends to April 2013.
  •     In Europe, many SPCs protecting the Montelukast molecule were granted with expiries in August 2012. However, Merck successfully complied with the agreed paediatric investigation plan (PIP) and successfully applied for 6 month extensions to the terms of several SPCs, giving a potential expiry of February 2013 in some of Western Europe’s largest markets, namely France, Germany and the UK, as well as in many of the region’s smaller markets.
  •     A later patent family claims crystalline Montelukast Sodium and processes for its preparation. Patents within this family are not considered to be a constraint to generic competition because the protected technology may possibly be circumvented by the synthesis and use of different molecular forms and/or salts.
  •     A second later patent family relates to the specific marketed oral granule formulation of Montelukast. Patents within this family are also not considered to be a constraint to generic competition because the protected technology is likely to be circumvented by generic re-formulation. Opposition against the European patent within this later family was filed by Hexal on the grounds of lack of novelty and inventive step which subsequently led to the decision to revoke the European patent, however this decision is currently under appeal.
  •     Data exclusivity has expired in all major territories.
  •     Amongst the US approvals, tentative FDA approvals have been identified for generic Montelukast Sodium, awarded to Endo, Glenmark, Mylan, Roxane, Sandoz, Teva and Torrent.
  •     The large number of generic authorisations awaiting launch in the UK is indicative of the likely competition the Singulair product will face across Europe upon SPC expiry.
  •     In total, over 90 individual applicants have been identified as filing patent applications relating to Montelukast, focusing primarily on molecular form and process patent applications. Generic players Chemagis, Dr Reddy’s, Synthon and Teva appear in the top five patent applicants identified for Montelukast.
  •     Since the initial approval of Montelukast in 1998, there has been consistent filing of molecular form and process patent applications confirming that the preferred strategy of generic manufacturers is to circumvent the crystalline form patent.

GenericsWeb notes that: “The API patents remain in force in most major territories and means there still exists a significant barrier to generic competition. The number of generics available in Canada, which were authorised just one day after Canadian molecule patent expiry, the large number of marketing authorisation holders identified in Australia and the UK and the number of Paragraph IV filings observed in the US is indicative of the critical interest shown by generic companies for Montelukast generics; indeed Merck predicts that it will lose substantially all US sales of its best-selling medication Singulair® in the first two years following expiry of the US patent, a prediction that will likely be mirrored in Europe following SPC expiry.”

You can read the entire article here at:

GenericsWeb, the leader in pharmaceutical patent analysis and searching holds an impeccable track record in providing quality patent information, and has allowed numerous pharmaceutical companies to successfully navigate intellectual property hazards. GenericsWeb is headquartered in Sydney, Australia, with offices in North America and Europe. All staff are highly skilled and experienced internationally and have extensive experience in pharmaceutical sciences and patent searching. For more information, visit the company's web site at


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