PTAB Doubles Down on Natural Products Doctrine in Human Milk Case
The Patent Trial and Appeal Board recently affirmed the §101 rejection of claims directed to a nutritional human milk product, finding the claims to be ineligible for patenting.1 The decision offers some interesting insights into how the Board analyzes patent eligibility for biotech inventions, particularly those involving purified or modified natural products.
The Technology: Not Your Average Milk
The case involved BIOMILQ’s technology for an isolated nutritional human milk product. The key claimed features were that the milk product included:
- a human milk protein
- a human lipid
- a human polysaccharide
The claimed milk product was also required to be:
- sterile (free of microorganisms)
- free of cell culture medium
- free of environmental contaminants or certain food allergens
The § 101 Analysis: A Natural Products Deep Dive
As an initial matter, the Board agreed with the Examiner that the primary components recited in the claims (i.e. protein, lipid, and polysaccharide) are found in a naturally occurring product, namely human breast milk.
In determining whether the claims recited a judicial exception to §101, the Board’s analysis focused heavily on whether the claimed milk product was “markedly different” from naturally occurring breast milk. Here’s where things got interesting:
Environmental Contaminants & Allergens
The Board wasn’t convinced that being free of contaminants and allergens distinguished the product from nature. They cited evidence that breast milk from women in non-industrialized areas often lacks environmental contaminants, and milk from women avoiding certain foods naturally lacks those allergens.
The Sterility Question
The most fascinating part of the analysis centered on sterility. While the applicant provided expert declarations stating that natural breast milk contains beneficial bacteria, the examiner cited a scientific journal that found some breast milk samples to be sterile.
The Board applied a preponderance of the evidence test, and refused to agree with the applicant that sterile human milk is not naturally occurring. The Board went on to say that even if sterile human milk does not occur naturally, the absence of naturally occurring bacteria from the claimed milk product is insufficient to make the milk product markedly different from natural human milk. They analogized to Myriad, in essence saying that just as isolating DNA doesn’t make it patent-eligible, removing naturally occurring bacteria from milk doesn’t create marked differences.
Key Takeaways for Practitioners
- Natural Products Strategy: When claiming a modified natural product that lack certain natural components, ensure that the absence of those natural components makes the modified product markedly different from the product as it occurs in nature.
- Evidence Can Be Helpful: The Board considered both published evidence and expert declarations when evaluating whether the claimed product was naturally occurring. Having publications and/or declarations supporting your position on natural occurrence can be useful.
- The Myriad Shadow: The decision shows how Myriad’s principles continue to be applied broadly – mere isolation or purification of natural products, even with beneficial results, may not be enough for patent eligibility.
This decision highlights certain challenges which may be encountered when pursuing patents on purified or modified natural products.
PERA Implications
Under the currently proposed language of the Patent Eligibility Restoration Act (PERA, Senate Bill 2140), the human milk product claims that were found ineligible by the Board would likely have been found to meet the patent eligibility requirement (e.g. pursuant to §§101(a), (b)(2)(A)).
1 Ex parte Strickland (Appeal 2024-002927; December 10, 2024) [PDF]