Pharmacapsules @ Gowlings: April 11, 2012 - Volume 11, Number 5

Edited by Jennifer Wilkie and Isabel Raasch

In this issue:

• The U.S. Prometheus Decision and Claims to Methods of Optimizing Dosing Regimens: Mayo Collaborative Services v. Prometheus Laboratories, Inc., U.S., No. 10-1150

The U.S. Prometheus Decision and Claims to Methods of Optimizing Dosing Regimens: Mayo Collaborative Services v. Prometheus Laboratories, Inc., U.S., No. 10-1150

By: Hélène D'Iorio

In a decision last month, the U.S. Supreme Court in a 9-0 ruling has held that the method claims of two patents directed to optimizing the dose of a specific drug for treating an autoimmune disease are not patentable because they merely recite laws of nature. 

The outcome of this decision brings Canada and the U.S. to the same end result for these types of patents (no enforceable patent), but how we get there differs.

The U.S. Supreme Court decision reverses the Federal Circuit's earlier rulings, which had upheld the validity of the claims.  Claim 1 of U.S. Patent 6,355,623 reads as follows:

"A method of optimizing therapeutic efficacy for treatment of an immune-mediated gastrointestinal disorder, comprising:

1. administering a drug providing 6-thioguanine to a subject having said immune-mediated gastrointestinal disorder, and
2. determining the level of 6-thioguanine in said subject having said immune-mediated gastrointestinal disorder,

wherein the level of 6-thioguanine less than about 230 pmol per 8 x 10⁸ red blood cells indicates a need to increase the amount of said drug subsequently administered to said subject and

wherein the level of 6-thioguanine greater than about 400 pmol per 8 x 10⁸ red blood cells indicates a need to decrease the amount of said drug subsequently administered to said subject."

The Court held that the claims did not do "significantly more" than describe the laws of nature and accordingly were not patentable.  The steps in the claimed methods (apart from the natural laws themselves) were found to involve "well-understood, routine, conventional activity previously engaged in by researchers in the field".  The Court expressed the view that upholding the patents at issue would "risk disproportionately tying up the use of the underlying natural laws, inhibiting their use in the making of further discoveries".

This decision, which is perceived as a blow to the protection of advances in personalized medicine in the U.S., is in line with more recent Canadian jurisprudence.

In Canada, claims directed to dosage regimens have been rejected as being directed to a method of medical treatment requiring the application of professional skill, thus falling outside an economic area related to trade, commerce or industry and outside of the definition of "invention". On the basis of a different legal reasoning, the U.S. and Canadian Courts have ultimately reached the same conclusion.

Also, watch for a more in depth article in the upcoming Life Sciences and Law:  Current Issues 2012-2013 book available in June 2012 online and at the BIO International  Convention in Boston.

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