Pharmikos Pharmacology Consulting                                    John Lehmann PhD Scientific analysis of therapeutic and side effects of drugs, data interpretation, causation, patent claims, NDAs








Pharmikos > Focus Areas > Patents & Infringement

pharmaceutical patents prior art  obviousness

Prior Art, the Person of Average Skill in the Art, and Obviousness. Pharmacologists with a reasonable command of chemistry play an important role in patent activities.

Prior Art refers to previously known subject matter relating to the present invention and includes publications, prior patents, prior use, prior public and general knowledge or a prior invention. As a rule, patent applications coming from academic institutions tend to be relatively weak in researching Prior Art.

Person Skilled in the Art: Person of Average Skill in the Art or Person Having Ordinary Skill in the Art (often abbreviated Phosita in the United States) is a term of the art of patent lawyers. If it would have been obvious for this fictional person to come up with the invention while starting from the prior art, then the particular invention is considered not patentable.

The Person Skilled in the Art is also used as a reference for determining when Infringement occurs or when a patent is sufficiently disclosed.

In the golden age of drug discovery recognized by the Nobel Prize in Medicine (1988) awarded to Sir James W. Black, Gertrude B. Elion and George H. Hitchings, relative few properties of a drug were eligible for patenting:

· Primary uses
· Processes and intermediates
· Bulk forms
· Simple formulations
· Composition of matter

This list has since grown to include:

· Expansive numbers of uses
· Methods of treatment
· Mechanism of action
· Packaging
· Delivery profiles
· Dosing regimen
· Dosing range
· Dosing route
· Combinations
· Screening Methods
· Chemistry Methods
· Biological Target
· Field of use

Stereoisomers: A fertile field for gaining extended patent life on drugs is to separately patent the active enantiomer when patent life runs out on the racemic mixture. Many differential pharmacological properties of Stereoisomers are underexploited in such patents. For instance, the agonist S-apormorphine differs from R-apomorphine not just in terms of one being 'active' and the other 'inactive'; but potency and intrinsic activity are different, also.

Lehmann J, Smith RV, Langer SZ.
Stereoisomers of apomorphine differ in affinity and intrinsic activity at presynaptic dopamine receptors modulating [3H]dopamine and [3H]acetylcholine release in slices of cat caudate. Eur J Pharmacol. 1983 Mar 18;88(1):81-8

pharmaceutical patents doctrine of equivalence stereoisomers

Doctrine of Equivalents. Even when elements of a patent are not identical to elements of an allegedly infringing use, the patent holder may assert that the infringement is equivalent. For instance, the patent for zowatelol may have described only zowatelol hydrochloride, and a competitor might assert that zowatelol bitartrate is novel. In this case, in all likelihood a reasonable PHOSITA would find that the two drugs were equivalent, and the maker of zowatelol would be infringing.

In the USA, the Doctrine of Equivalence is defined in two ways. First, the triple identity test states that something is deemed equivalent if:

1. It performs substantially the same function
2. in substantially the same way
3. to yield substantially the same result.
Graver Tank & Mfg. Co. v. Linde Air Products Co., 339 U. S. 605 (1950)

Under the second test a New Active Substance is deemed equivalent if there is only an "insubstantial change" between each of the elements of the accused New Active Substance and each of the elements of the patent claim. (Warner-Jenkinson Co. v. Hilton Davis Chem. Co. (1997))

New Active Substance (NAS) is a term of the art that generally has replaced the older term, New Chemical Entity (NCE), reflecting the increased role of biotechnology in pharmaceuticals. The regulatory (FDA) definitions for the terms New Chemical Entity and New Molecular Entity are different from their meaning in patent law.

Strategic Patenting. "Picket fences” or families of many patents around a single product bolster the amount of protection offered to financially crucial products:
· basic composition elaborated to include new and alternative compounds
· use patents including method of treatment involving new use of known compounds
· therapies in combination with other drugs;
· synthetic production
· formulation and drug delivery
· prodrugs and delivery methods
· active metabolites
· research applications
· gene-markers showing response to drug therapy or toxic events

Pharmacology Patent Consultant. The role of the Pharmacologist as Patent Consultant is fortunately not to understand the intricacies of patent law (that's the Patent Attorney's job), but rather to act as a Person of Average Skill in the Art to apply the criteria of the Doctrine of Equivalents.

Pharmacology Consultant Pharmaceutical Patents & Infringement Pharmacologist

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