Natural products (i.e. products produced by living organisms such as plants, animals and microbes) have historically been a major contributor to treatments and drug discoveries for various illnesses and diseases. According to a 2004 paper[1], 60% of cancer drugs and 75% of infectious disease drugs are derived from natural products. Furthermore, a significant number of natural product drugs have come from microbes and/or microbial interactions with hosts[2]. 

A new project - the AnoxyGen Project - is planned over the next 5 years to investigate the biosynthetic pathways and active compounds of anaerobic bacteria and any benefits they may offer in the fields of medicine, ecology and biotechnology[3]. The project may also provide further information on how some of these bacteria operate as pathogens.

Anaerobic bacteria have different metabolic pathways to those of plants, animals and humans given they evolved in an oxygen free environment. However, there is still much which is unknown about these pathways and the active compounds produced by these bacteria. This is because many of their biosynthetic genes are inactive in laboratory conditions. The AnoxyGen Project aims to overcome this by using newly developed molecular and synthetic biology tools.

This project could very well lead to the discovery of new active compounds with medical or other useful application.

Whilst natural products still have potential to lead to new developments in drug discovery, biotechnology and various other areas, care is required when considering patentability.

Under English law, an invention is patentable if: (i) it is new (i.e. has not been made available to the public anywhere in the world by written or oral description, by use or in any other way before the priority date of the application); (ii) it involves an inventive step (not obvious to the person skilled in the art based on the prior art); (iii) it is capable of industrial application; and (iv) there is no specific exclusion to patent protection being granted.

One of the main hurdles for inventions based on natural products is around novelty and obviousness given these products by their very nature already exist and are present in nature. Furthermore, simply finding a natural product or biological material would be considered a mere discovery and therefore excluded from patentability. However, this does not necessarily mean it is not possible to patent these products. As mentioned in paragraph 2, Schedule A2 of the Patents Act ("PA") 1977, "biological material which is isolated from its natural environment or produced by means of a technical process may be the subject of an invention even if it previously occurred in nature".  

Even if the compound itself is not novel, new uses for existing compounds can qualify for a patent. That being said, a method of treatment does not and therefore, where the new use is therapeutic, care is required to ensure the claim does not fall foul of this exclusion. Case law has confirmed that a purpose limited product claim in the form "product X for treating disease Y" is acceptable. One issue with these 'second medical use' claims is that they are potentially more difficult to enforce. This is because the patent owner would need to show that the product is being used or sold for the patented purpose rather than a legitimate purpose which is outside the scope of the patent in question. 

A new formulation might also be patentable e.g. the same ingredients but in a different ratio.  Unlike the example above, this type of claim would not be limited to use and might therefore be easier to enforce. However, it may be difficult to argue that the specific formulation is inventive, particularly if using different ratios would have been obvious to try.

Similarly, it may be possible to patent a combination of known natural products if the combination creates a previously unknown synergistic effect (i.e. an effect greater than the sum of the individual products). Again, it would be important to show that this effect is not obvious.

Furthermore, it is increasingly important to keep in mind the requirements around sufficiency. A patent will be invalid if it does not disclose the invention in sufficient detail to enable the person skilled in the art to work the invention without undue burden. A key requirement of sufficiency (particularly for second medical use claims) is plausibility which requires the specification of the patent application to show it is plausible that the claimed technical effect or treatment works. This is to prevent a patentee making speculative patent applications for use of a known substance to treat various diseases before having any evidence they do. As a result, it is also important to include sufficient data in support of the claimed technical effect in the patent and at the time of filing (following Sandoz Ltd v Bristol-Myers Squibb [2023] EWCA Civ 472).

In light of the above, it is clear that inventions based on natural products can be patentable. However, care is required when drafting and considering the basis on which they satisfy the requirements for patentability.

[1] Libraries from natural product-like scaffolds. Current Opinion in Chemical Biology, Volume 8, Issue 3, June 2004, Pages 281-286 (Libraries from natural product-like scaffolds - ScienceDirect)

[2] Natural Products as Sources of New Drugs over the Nearly Four Decades from 01/1981 to 09/2019, Journal of Natural Products Vol 83/Issue 3, March 12, 2020 (Natural Products as Sources of New Drugs over the Nearly Four Decades from 01/1981 to 09/2019 | Journal of Natural Products (acs.org))

[3] Synthetic biology reveals the secrets of life without oxygen (uni-jena.de)