Medicinal chemists have always looked to the nature as a source for new therapeutic agents. Examples of such agents include digitoxin, a drug used to treat congestive heart failure, isolated from the common foxglove, Digitalis purpurea, and taxol and vincristine, anticancer agents isolated from Taxus breifolia and Vinca rosea Linn, respectively.
Historically, the United States Patent and Trademark Office (USPTO) has granted patents on such naturally occurring agents. However, when the United Supreme Court issued an opinion that isolated DNA molecules are not eligible for patenting, in Association for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. __, 132 S. Ct. 2107 (2013), much disappointment was created among medicinal chemists and other interested public since it could potentially mean that research and development on natural products could be severely curtailed.
The above opinion, as well as other opinions from the high court on what would not be patent eligible subject matter, prompted the USPTO to issue guidelines on patent eligible subject matter. The guidelines issued in March 2014, however, were not well received by the public due to the complex steps that the examiners and the public must undertake in determining what would be patent eligible subject matter. Based on the comments received from the public on the guidelines, the USPTO, on December 16, 2014, issued what is known as the “2014 Interim Guidance on Patent Subject Matter Eligibility,” which is a significant improvement over the prior guidelines.
The USPTO Interim Guidance is premised on the concept developed over the years that laws of nature, natural phenomena, and abstract ideas are not eligible to be patented. Accordingly, the first step in determining whether a patent claim is eligible to be patented is determining whether the claim is directed to a law of nature, natural phenomenon, or an abstract idea. If the answer is yes, for example, the claim recites a nature-based product, then the second step would be to determine whether the nature-based product has markedly different characteristics, such as a structure, function or other properties than its naturally occurring counterpart. If there is no markedly different characteristic, then the claim would not be patent eligible.
The USPTO, in its Interim Guidance, provides many examples to illustrate nature-based products which are patent eligible. For example, gunpowder, made up of a mixture containing 75% potassium nitrate, 15% charcoal, and 10% sulfur, would be patent eligible even though potassium nitrate, charcoal, and sulfur are naturally occurring materials. When the three components are present in a mixture, the mixture has the new explosive property, which is the “markedly different” characteristic.
The USPTO clarified that a naturally occurring product called “Amazonic acid” isolated from an Amazonian tree, whose leaves were known to contain a chemical useful for treating breast and colon cancers, would not be patent eligible, whereas derivatives of the isolated compound such as 5-methyl amazonic acid and deoxyamazonic acid would be patent eligible in view of the difference in structure and the fact that the 5-methyl group contributed to a new property, i.e., promoting hair growth, in addition to its anticancer property. A patent claiming a pharmaceutical composition comprising a core comprising amazonic acid and a layer of natural polymeric material enveloping the core would also be patentable according to the Interim Guidance although the claim recites two naturally occurring products. The pharmaceutical composition has the advantage that amazonic acid is not released until the composition reaches the colon due to the relative insolubility of the natural polymeric coating, thus increasing the bioavailability of amazonic acid. In addition, since amazonic acid is insoluble in water, a stable aqueous composition comprising amazonic acid and a solubilizing agent (such as sugar or polyol) would be patent eligible. Claims directed to methods of treating colon cancer or breast cancer employing the use of purified amazonic acid would be patent eligible according to the USPTO.
Antibiotic L, naturally produced by Streptomyces arizoneus, and having a hexagonal pyramidal structure, would not be patent eligible, whereas, laboratory-produced Antibiotic L having tetrahedral structure is patent eligible. Similarly, naturally occurring energy-generating plasmids which are capable of degrading a single hydrocarbon, such as those of Pseudomonas bacteria, would not be patent eligible according to the USPTO, whereas, man-made bacterium from the genus of Pseudomonas containing at least two stable energy-generating plasmids, each plasmid providing a separate hydrocarbon degradative pathway would be patent eligible.
According to the USPTO, an isolated nucleic acid having a SEQ ID NO:1, obtained from a Virginia night shade plant, would not be patent eligible whereas an isolated nucleic acid comprising a sequence that has at least 90% identity to SEQ ID NO:1 and containing at least one substitution modification relative to SEQ ID NO:1 would be patent eligible, as are an isolated nucleic acid also containing an attached fluorescent label and a vector comprising the naturally occurring nucleic acid and a heterologous nucleic acid sequence which is a viral promoter sequence causing the night shade plant to produce the gene containing the nucleic acid all the time rather than only when damaged by insects.
While the USPTO is not likely to grant patents to naturally occurring products without a markedly different characteristic, which is a significant departure from the past practice, granting of patents on nature-based products has not been completely foreclosed. Opportunities still exist for patenting nature-based products having a markedly different characteristic.