Hi there, folks. It has been a while since I blogged. I decided that I would continue once again and share some of the references that I came across while perusing the journals, while using the free blog-hosting services that are available. This particular post was something I came across while looking at some stocks online. I was searching taking a look at Celgene (CELG) stock and came across this discussion regarding the tricky world of patent litigation and more specifically, its application to matters concerning crystal form and polymorphism. Having worked both sides of generic and brand-name pharma, I am interested in how this case will work out.
I know that this article’s subject matter is on the periphery of what is involved in developing a process. I have worked on crystallizations and been concerned with polymorph control, so this is a textbook case, that is current, about patent coverage, polymorphs and generic competition.
Revlimid is a thalidomide analog that is used for the treatment of multiple myeloma. Apparently, as commonly occurs in the pharmaceutical industry, one tries to write the patents to cover as many crystal forms as you can and hope this delays the generic pharmaceutical companies from swooping in with a patent submission for a form you forgot to cover. Apparently, with Atoravastatin (Lipitor), the patent coverage for the amorphous form was not covered and this was exploited to bring a generic version to market quicker, circumventing the existing patent.
The issue is that patent US Patent 7,465,800 describes 8 polymorphs, A-H which include which include three unsolvated forms, the hemihydrate, a dihydrate, an acetone hemisolvate, an acetonitrile solvate, and a dehydrated form of the dihydrate. The hemihydrate is the only one covered by the patent. The patent covering composition of matter describes an anhydrous preparation of the drug substance.
Natco and Activis are taking a shot at challenging Celgene’s patents on Revlimid. It is important to note that Revlimid is providing Celgene with 67 % of its 2013 revenue, so this is a fight worth fighting for. Celgene has 11 patents covering Revlimid, so it will not be an easy task for a generic company to navigate around them.
It is a really well-written article and I thought I would share. Stay tuned for more.
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Feel free to comment on this interesting story.
Update: Celgene won its case in court. Found this morning on Barron’s.