A recent High Court decision, [2022] EWHC 2847 (Pat), between claimants Teva and defendants Novartis provides clarity on how the inventive concept of a patent is to be interpreted under UK law.

Hacon HHJ, who heard the case, ruled that the invention of a patent is defined specifically by the claims, thus any features present in the claims must contribute to or embody the inventive concept of the invention and any features not present within the claims correspondingly cannot.

Background

The dispute revolves around Novartis’ product, Exjade, which is the company’s branded form of iron treatment drug deferasirox as described in two formulation patents, EP2964202 and EP3124018. Both of these patents disclose a film covered dose of deferasirox; a drug used in the removal of iron from a patient’s blood. Patients are treated with this drug as they suffer with iron overload which may arise from blood transfusions, themselves often a treatment for genetic disorders such as sickle cell disease or blood cancers. Surplus iron present in the body accumulates in the liver, spleen, bone marrow and other organs and if left untreated can lead to organ failure and ultimately death.

Previous drugs designed to treat this condition have either required that the patient wear a pump and accommodate a subcutaneous infusion for upwards of 8 hours, or consume a solution which some patients find unpalatable and can cause unpleasant side effects. A film coated tablet, which the patient need not taste nor infuse via lengthy injection, is clearly a significant improvement on that which has come before and is clearly motivated by the need to address these disadvantages.

Generics manufacturer Teva has also produced its own version of an orally consumable form of deferasirox under the name Teva DFX.

The complaint

Teva applied to revoke* Novartis’ two patents ‘202 and ‘018, and also sought a declaration of non-infringement of their product Teva DFX, also used for iron chelation. Novartis counterclaimed with an allegation of infringement of both patents by the product Teva DFX.

The claims of Novartis’ patents

Claim 1 of both patents, ‘018 and ‘202, are shown below respectively:

“1. A swallowable film coated tablet which contains deferasirox or a pharmaceutically acceptable salt thereof present in an amount of from 45% to 60% by weight based on the total weight of the tablet, and wherein the tablet contains 90 mg, 180 mg or 360 mg of deferasirox,

wherein the tablet further comprises,

1. at least one filler in a total amount of 10% to 40 % by weight based on total weight of the tablet, wherein the filler is microcrystalline cellulose;
2. at least one disintegrant in a total amount of 1% to 10% by weight based on the total weight of the tablet, wherein the disintegrant is cross-linked polyvinylpyrrolidone (crospovidone);
3. at least one binder in a total amount of 1% to 5% by weight based on the total weight of the tablet, wherein the binder is polyvinylpyrrolidone (PVP);
4. at least one surfactant in a total amount of up to 2% by weight based on the total weight of the tablet, wherein the surfactant is poloxamer;
5. at least one glidant in a total amount of 0.1% to 1% by weight based on the total weight of the tablet, wherein the glidant is colloidal silicon dioxide;
6. at least one lubricant in a total amount of less than 0.1% to 2% by weight based on the total weight of the tablet, wherein the lubricant is magnesium stearate; and
7. a coating.

and wherein the tablet does not contain sodium lauryl sulfate and does not contain lactose.”

“1. A swallowable film coated tablet comprising deferasirox or a pharmaceutically acceptable salt thereof present in an amount from 45% to 60% by weight based on the total weight of the tablet, wherein the tablet is without sodium lauryl sulfate and lactose and comprises

1. microcrystalline cellulose;
2. crospovidone;
3. povidone;
4. poloxamer 188;
5. colloidal silicon dioxide;
6. magnesium stearate.”

The Arguments

Novartis characterised the inventive concept of their patents by stating that the film coated tablets of their applications, having specific non-active mediums (explicitly not sodium lauryl sulfate and lactose) had a higher bioavailability compared to the prior art: non-film covered tablets dissolvable in water for consumption. They also stated that the tablet of their applications could be taken with a small amount of food in contrast to the solution of the prior art, which must be taken on an empty stomach. Conspicuously absent from their characterisation was the range, 45-60%, of the total amount of defeasirox by weight within the tablet.

Teva argued that the inventive concept was entirely concerned with the 45-60% range of concentration of deferasirox as stated in claim 1 of Novartis’ applications and also that the tablet was film coated.

The judgement

It was seen that, as in established case law, the invention is specified in the claim, and that the inventive concept of a claim cannot be present in matter which does not contribute to the invention. Hacon HHJ noted that neither of the inventive concepts put forward by Novartis are present within either claim of their two patents, thus their characterisation of the inventive concept cannot be valid. The concept that the tablets offer higher bioavailability and that they can be taken with a small amount of food may well be discussed within the description, but since they are not provided as features of the claim, they cannot be said to form part of the inventive concept of the claimed invention.

In fact, in suggesting that features from the description are so important to the inventive concept, Novartis somewhat bolstered Teva’s interpretation of the inventive concept that the range of 45-60% is key, especially since it is specified within the description that a target of 56% is preferred and that this feature is repeated within the claims.

The independent claims of both patents were considered under the characterisation of Teva, and were found not to show inventiveness over the art.

In addition, Hacon HHJ found that the concentration of deferasirox within Teva DFX lies outside the range as specified within claim 1 of the patents of Novartis. Since a range implies strict adherence of a given feature between the particular stated limits, a value hat falls substantially outside the given range is considered not to infringe.  

Summary

This judgement shows the establishment of an approach to assessing inventive step in which the features present in the claim alone are considered. Despite expansion of those features within the specification, or a discussion of the benefits of certain features elsewhere within the description, any defence of the inventive concept is limited to the features that can unambiguously and directly be found within the claim. Following this judgement, it is unlikely that a creative construction of the benefit of these features can represent a convincing foundation upon which to build a defence of inventiveness, thus one must be careful to ensure that one does not rely on including novel features in a claim upon which an inventive step may be argued, but that inventive features are explicitly recited within the independent claims of a claim set.