Pharmaceuticals. New drugs and medicines are typically protected by utility patents in the form of processes or compositions of matter.  This is consistent with United States patent law,  which allows anyone who  “invents or discovers any new and useful process.  .  .  or any composition of matter” to file for patent protection.

How Claimed.  Patent claims for a composition of matter are constructed in terms of the drug’s constituent elements.  Process claims are either a “method of using” the drug to treat a particular ailment, or a “method of making” the drug, which detail the steps used to make the chemical composition.


New Use for an Old Compound. United States patent law permits one to obtain a patent for a new and unobvious use of an existing chemical compound.  For example, if a chemical used for cleaning metals was discovered to be beneficial in treating Parkinson’s disease, the process of using that chemical for medical treatment would be patentable even though the chemical already exists and is well known in other applications. This is a new use of an existing compound.  However, what is unobvious is a matter of judgment.

Generally, an invention is not obvious if the invention is beyond the ordinary abilities of a person of ordinary skill in the art in the appropriate field. In the example cited, if there is no suggestion anywhere in the medical field that the chemical is useful for treating Parkinson’s disease, this is probably a good indicator that such use is not obvious.


An April 8, 2005 decision of the Court of Appeals for the Federal Circuit essentially holds that a compound is not new if a method of making it has been previously disclosed, even if the compound has never been produced.  The legal theory is called inherent anticipation, which essentially says that a drug is not patentable if it could have been made by methods disclosed before the application was filed.  SmithKline Beecham Corp. v. Apotex Corp., 03-1285, -1313, 2005 U.S. App. LEXIS 5675, 2005 WL 788426 (Fed. Cir. 2005).  The Supreme Court on June 19, 2006 declined to review the SmithKline decision, leaving it as the current law on inherent anticipation.

For example, if a new drug were found to be created (even in trace quantities) in the manufacture of another old drug, then the new drug would not be patentable.  All an infringer would have to show to invalidate a patent is that “‘the disclosure [of the prior art] is sufficient to show that the natural result flowing from the operation as taught [in the prior art] would result in’ the claimed product.”  The court also comments, “SmithKline’s allegations of contributory infringement based upon the theory that PHC anhydrate converts into PHC hemihydrate upon ingestion further supports this court’s finding of inherent anticipation.”  These comments suggest that if a new drug were found to be created as a metabolite within the body as a reaction to another drug, then the new drug would be unpatentable.


The SmithKline decision has implications not only for patent applications, but it also could affect the validity of existing drug patents.  On the one hand, the decision makes sense because one practicing prior art techniques should not be held to infringe a new drug patent merely because the old art creates the new drug.  So if one can’t be held to infringe, then how can there be a patent on the drug.  However, on the other hand, if no one discovered that new drug prior to its patenting, then the discoverer should be entitled to patent that newly discovered drug.  Yet, for drugs, such newly discovered compounds are not “new” for purposes of patent law if they were inherently in existence from using prior art.  Thus, patenting them will no longer be possible.  This dilemma of inconsistency was noted in the order accompanying the decision on the petition for en banc rehearing by Circuit Judge Newman, who observed that the decision calls into question “[t]he patentability of antibiotics, hormones, antibodies, and myriad other previously unknown or unisolated products.  .  .  .”


Extending a Drug Patent By a New Application Claiming Metabolites. At one time, a drug patent could be effectively extended by filing a separate patent application on the active form of the drug converted in vivo in the body of the person taking the drug.  This active form of the drug is a metabolite and has a different chemical composition than the drug.  A  metabolite, formed in vivo, is often not known prior to filing for a patent on the drug in question, and may only be identified years after the filing.  Since the metabolite is a new substance, a patent on it would effectively prevent anyone from using the drug that causes it to be made in the body.

The case law is now very clear that if the drug patent inherently produces a metabolite, then that metabolite is effectively published to the world at the same time the drug patent application is published.  That being the case, the metabolite may only be claimed in a new patent application by the drug inventor within 12 months of publication of the drug patent application or upon patent issuance if the application is not published.  That new patent application may be a provisional patent application.


Other Legal Considerations?  Before a patent may lawfully issue on a new composition of matter, the compound must be shown to have some usefulness, that is, in the words of the Supreme Court, the applicant must be able to show that a “specific benefit exists” to the compound.   Brenner v. Manson, 385 U.S. 419 (1966).  In that case, the applicant had a composition of matter ( a steroid), and a process that worked to produce the steroid.  However, that was not enough for patentability.  The finding was that there must be some identified specific usefulness to the steroid.  

Practical Considerations. Usefulness is more than an academic determination.  The absence of proof of usefulness can have real consequences if a patent application is filed too soon on a new drug undergoing testing.  The quotation from the Supreme Court decision mentioned above involved an new steroid drug and a claim for the process of making the steroid.  Just because the process of making the steroid actually produced the steroid, was no substitution for a showing a usefulness of the steroid.  Ultimately, the patent application was rejected because testing hadn’t proceeded sufficiently to show a useful application.   How much testing is needed?  The Federal Circuit says that there must at least be “acceptable evidence of medical effects in a standard experimental animal.” In re Brana, 3051 F.3d 1560 (Fed. Cir. 1995).  It is generally held that there must be a reasonable correlation between the pharmacological activity and the asserted utility.

Establishing Reasonable Correlation. An applicant can establish this reasonable correlation between the pharmacological activity and the asserted utility by relying on statistically relevant data, which documents the pharmacological activity of a composition, the reasoning for such correlation, and the scholarly articles or other documentary evidence.   As a practical matter, evidence of structural similarity to a compound known to have a particular pharmacological utility coupled with reasoning to explain why that structural similarity is believed to be relevant, is helpful to establishing a correlation.  The applicant does not have to prove that a correlation exists as a matter of statistical certainty, nor does the applicant have to provide actual evidence of success in treating humans where such a utility is asserted.


Implying Clinical Results, Fatal. In one recent infringement case, the patent application and the patent prosecution was reviewed by the court and found to have been misleading by omission.  The court found that the applicant had by implication (not a direct mis-statement) led the examiner to believe that the patentable discovery was based on clinical results on a drug, but it really only had been based on medical insight.  Even though patentability is not affected by whether or not a discovery is by insight or experiment, even though the medical insight was ultimately proved correct, and even though the applicant had a good faith belief in the novelty of the invention, the implication of clinical results by the applicant was cause for invalidating the patent!  Purdue Pharma v. Endo Pharmaceuticals, Inc., 04-1189, -1347, -1357 (Fed. Cir. 2005).


Patent Term Extension for Drugs? Because drugs and other medical inventions (drug product, a medical device, food additive, color additive or related process) can be the subject of prolonged testing before they can be introduced into the market, Congress passed the Drug Price Competition and Patent Term Restoration Act of 1984.  This law permits extending the patent term for inventions that are subject to pre-market approval process under the Federal Food, Drug and Cosmetic Act.  Calculation of the extension is a complicated determination.  Essentially, the regulatory delay is added to the life of the patent so that the remaining time in the patent life can be up to 14 years. See section 156 of Title 35 of the Untied States Code for these provisions on patent term extension.


How to Proceed. Telephone (703-242-1247) or email Attorney Louis Ventre, Jr. with a short description of the drug you want in your application. If the Law Firm of Louis Ventre, Jr. has no conflicts and Attorney Louis Ventre, Jr. agrees to represent you, he will send you a retainer agreement with additional instructions on what information is needed.  As with other utility patent applications, Attorney Louis Ventre, Jr. does a preliminary search of U.S. patents and U.S. applications to make a judgment on patentability. After you receive a preliminary patentability determination, if you then decide not to submit an application, your retainer will be refunded, except for inventions in areas of high failure risk, typically defined as abstract inventions. For the high failure risk areas, all but $1,000 is refundable. These high risk areas will be identified in advance so that there should be no confusion on your part.


More Answers on Patents. See the FAQ page for more questions answered on patents, the utility patent application page for general patenting details, the plant patent page for information on new flowers and other plants, the provisional patents applications page for information on one-year patent applications, the software patent applications page for information on protecting computer programs, and the business method applications page for information on patenting business methods.


Potential Infringement for Importing Drugs. A number of State and local governments in the United States have openly encouraged the importation of drugs from Canada and this may, unwittingly subject them to patent infringement liability.  Since Canada has price controls on drugs, U.S. drug manufacturers may only sell to Canadian pharmacies at greatly reduced prices.  Selling at such reduced prices helps to cover manufacturing costs, so it is beneficial to U.S. drug companies and ultimately to consumers.  However, the benefit at least to the drug companies may disappear if their product is re-sold by Canadian retailers in the United States.  Canadian pharmacies that re-sell back to U.S. consumers in what is called a “gray market” are probably infringing the U.S. drug manufacturers patent rights.   U.S. States and local governments that openly advocate and use such imported drugs for their employees are very likely equally subject to liability for patent infringement.  See the drug infringement discussion of this issue.

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