Patenting New Methods of Treatment Using Known Compositions
One question that comes up from time to time is whether you can get apatent on a new method of treatment (sometimes called a new “indication”) using an existing chemical composition. The answer is “possibly.”
If a chemical composition is known, you cannot obtain a patent to the chemical composition itself. The US Court of Appeals for the Federal Circuit has held that “[t]he discovery of a new property or use of a previously known composition, even when that property and use are unobvious from the prior art, cannot impart patentability to claims to the known composition.” In re Gleave, 560 F.3d 1331, 1338 (Fed. Cir. 2009), citing In re Spada, 911 F.2d 705, 708 (Fed. Cir. 1990). This means that you cannot get a patent claim that simply covers the composition because you have discovered it has properties that were not previously known. A composition claim requires a novel and non-obvious composition, regardless of its properties. You may be able to get a patent for a method of using the known composition. However, to do so, you must be able to identify steps in the use of the composition that are not known or obvious from the prior art.
In some cases, the composition may actually be different relative to the prior art because you have combined different inactive ingredients with the active ingredient. In that case, if the combination of the active ingredient and the different inactive ingredients is novel and non-obvious, the new composition would be patentable as would methods of using it. In Endo Pharms. Sols., Inc. v. Custopharm Inc., 894 F.3d 1374 (Fed. Cir. 2018), the Federal Circuit affirmed a district court’s verdict that a patent with claims that combined the known compound testosterone undecanoate with a vehicle that was not used in the prior art. In addition, however, the patent included method claims with a dosing schedule and a dosage that were not disclosed in the prior art. This combination led the Court to uphold the validity of claims to the method of use of the composition.
The situation in Endo is different from one in which the full composition and method of use are known in the prior art but a new effect or benefit is discovered. In that situation, the newly discovered effect would have already been taking place when the composition was used in the known manner. Simply identifying a new benefit of a composition is not enough to get a patent if that benefit would already have been achieved by using the composition in the manner described by the prior art.
So, if you are looking to patent a new use of an existing composition, you will need to claim something different in the way it is used. This can be done by claiming new dosages, routes of delivery (e.g., topical versus oral versus injected), and dosing schedules. You should be prepared to demonstrate that the manner in which you use the composition achieves some sort of unexpected benefits relative to what happened when the composition was used in the prior art. Such evidence can be critical when responding to an obviousness rejection.