Full Story of Relpax Patent Protection Not Told by Orange Book?

Pfizer’s oral anti-migraine medicine Relpax, (Eletriptan hydrobromide) appears to have more patent protection than meets the eye.    A report by GenericsWeb has uncovered an array of patent protection in terms of molecular form, active ingredient synthesis, formulations and medical use on not only the commercial product but also on potential commercial alternatives for generic competitors.

SYDNEY, N.S.W., May 23, 2006 – Pfizer’s oral anti-migraine medicine Relpax, (Eletriptan hydrobromide) appears to have more patent protection than meets the eye, according to an analysis of GenericsWeb Pipeline Patent Intelligence.

Patent term extensions on the Eletriptan active ingredient are set to expire in Australia, Germany and the U.K. in 2015; and 2013 in the U.S. However, based on a comprehensive search for patents protecting the Relpax product from generic competition, the GenericsWeb Pipeline Developer report for Eletriptan exposes significant patent protection in addition to that afforded by the molecule patent.  “This could deter generic competition until 2017 in most countries” commented Mr Leighton Howard, Managing Director of GenericsWeb.

Although the U.S. Orange Book lists only one patent protecting the Eletriptan chemical compound per se, analysis of the Pipeline Patent Intelligence has identified another significant patent that seemingly protects the specific ‘alpha’ crystalline polymorph of Eletriptan hydrobromide used in the Relpax product.  The FDA considers statutory provisions to be in place for an NDA holder to disclose patents that claim the active ingredient contained in its product, for inclusion in the Orange Book publication.  However, information found in the GenericsWeb report suggests that some key patents are missing from the Orange Book listing for Relpax.

This emphasises the importance that all generic manufacturers rely only on comprehensive patent searching using professional techniques such as that found in Pipeline Patent Intelligence, rather than relying solely on the Orange Book publication to drive the timing and focus of their developments.

Beyond this, patent filing data demonstrates that Pfizer has conducted significant research and development before market launch at the end of 2000.  This has afforded Pfizer an array of patent protection in terms of molecular form, active ingredient synthesis, formulations and medical use of not only the commercial product but also of potential commercial alternatives for generic competitors.

“A prominent aspect of the Eletriptan Pipeline Developer report is the high proportion of formulation patents,” continued Mr Howard.  “This is predominantly due to the cross-patenting of other triptan drugs, compounded by the typical response by generic competitors to circumvent patents later in the lifecycle of the drug”.  Patent filings also indicate that Pfizer are considering alternative oral solution formulations for Eletriptan.

“Process patents in particular should be studied closely” added Mr Howard, “as Pfizer developed lower cost routes of synthesis for the active ingredient, it patented them to
prevent use by generics who strive for a low cost base”.

GenericsWeb Pipeline Patent Intelligence provides the unrivalled patent knowledge you require at the click of a button to navigate your generic drug development with confidence.  For further information about GenericsWeb Pipeline Patent Intelligence, contact Jesse Tale at This e-mail address is being protected from spam bots, you need JavaScript enabled to view it or call +61-2-98186111.

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