Natural Product Patentability in view of Association for Molecular Pathology v. Myriad

After the Supreme Court announced that isolated gene is a product of nature and therefore no longer patentable, the first question that popped into my mind is—what about natural products?

Natural products, as its name dictated, are products of nature.  The most famous natural product is probably salicylic acid, a natural product isolated from willow tree bark, which is now used for various medicinal uses under the well-known trade name Aspirin.  Other well-known natural products include paclitaxel, an anticancer drug isolated from Pacific Yew tree, which is now known under the trade name Taxol; and artemisinin, an antimalarial drug isolated from sweet wormwood. 

Natural products are isolated from plant, animal, or microorganism sources. The chemistry discipline that specializes in studying natural product is unimaginatively named “natural product chemistry.”  Natural product chemists work to find from nature new chemical entities with novel pharmacological mechanism to combat diseases.  Finding any new chemical entity is a creative and time consuming effort.   Government grant agencies as well as pharmaceutical companies have invested heavily into the discipline. 

Natural products tend to lead the way in directing the new drug development.  Novel natural products with good bioactivities are usually immediately patented.  Investments into the discipline are made under the assumption that natural product are patentable.  However, are they still patentable under the Association for Molecular Pathology v. Myriad, 569 U.S.____ (June 13, 2013)?

My belief is yes—the natural product is still patentable.  The reason is that the Supreme Court’s analysis on the patentability of an isolated gene focuses on the informational function of the gene rather than the chemistry structures of DNA.  The Court recognizes that DNA is really about the information and that Myriad’s claims are not “saved by the fact that isolated DNA from the human genome severs chemical bonds and thereby creates a nonnaturally occurring molecule.” Slip op. page 14.  The Court notes that

“Myriad’s claims are simply not expressed in terms of chemical composition, nor do they rely in any way on the chemical changes that result from the isolated of a particular section of DNA.  Instead, the claims understandably focus on the genetic information encoded in the BRCA1 and BRCA2 genes.  If the patents depended upon the creation of a unique molecule, then a would-be infringer could arguable avoid at least Myriad’s patent claims on entire genes … by isolating a DNA sequences that included both the BRCA1 or BRCA2 gene and one additional nucleotide pair.  Such a molecule would not be chemically identical to the molecule “invented” by Myriad.”

Slip op. page 15.

Patent claims on natural products are all about chemical structure.  In fact, I have yet to seen a patent claiming only a natural product chemical structure.  Using paclitaxel as an example, as of today, there are 8310 paclitaxel related patent families.  The following outlines some example strategies for patenting this natural product:

      1. Claiming paclitaxel with various substitutions

      2. Claiming various salts of paclitaxel 

      3. Claiming specific paclitaxel derivatives (for example, benzoate derivatives, water soluble derivatives)

      4. Claiming paclitaxel conjugates (for example, paclitaxel connected to a large molecule such as a polymer, fatty acids, etc.)

      5. Claiming a pharmaceutical composition of paclitaxel

      6.  Claiming various specialized formulation containing paclitaxel and its derivatives (for example, controlled release, aerosol, eyedrop formulation, injection formulation, etc.)

      7.  Claiming paclitaxel in combination with other active ingredients (for example, drug cocktail)

      8.  Claiming devices containing paclitaxel (for example, implantable device with paclitaxel and hydrogel coating)

      9.  Claiming methods of isolating paclitaxel and its derivative from natural resources

     10. Claiming methods of synthesizing or semi-synthesizing paclitaxel and its derivatives

     11 .  Claiming methods for making compositions and formulations containing paclitaxel and its derivatives

     12.  Claiming methods for treating a disease using paclitaxel and its derivatives.

The above patent strategies focus on the chemical structure of paclitaxel and its biological utilities.  In addition, by focusing on the chemical structure, the patent strategies on protecting a natural product have the flexibility of covering various aspects derived from potentially unlimited combination of substitutions, derivatizing groups and formulation chemicals.  Therefore, I believe that natural products will remain patent eligible in view of the Supreme Court’s ruling on the gene patentability.  In an unlikely event that the Supreme Court someday decides that natural products per se are not patent eligible, I believe that the nature of chemistry art provides such an enormous leeway for a potential patentee to claim a natural product derivatives and compositions that an impact of such an unlikely event can be significantly limited with smart patenting strategy.

Thanks for reading.

Connie

cwan@patentonomy.com