Teva UK Ltd v Merck & Co, Inc

For obviousness, the question is whether the claimed invention, considered as claimed, would have been obvious to the skilled person. A product or formulation may be inventive because of an asserted technical effect even if making it would itself be obvious. In an “obvious to try” case, there must be a fair expectation of success, assessed in the light of all the circumstances. Relevant factors include motivation, available research avenues, the effort involved and the expectation of success. A second medical use claim requires a discernible therapeutic effect in the specified patient class. Where a patent discloses both co-administration and co-formulation, limiting a claim to the preferred co-formulation does not necessarily add matter. However, an amendment may add matter if it claims combinations or ranges not directly and unambiguously disclosed in the application as filed.

Teva sought revocation of Teva UK Ltd v Merck & Co, Inc’s European patent for ophthalmic formulations combining dorzolamide and timolol for glaucoma treatment. Merck applied to amend the patent. Teva challenged the patent and the amendments for lack of novelty, lack of inventive step, added matter and insufficiency.

The principal prior art was the Nardin abstract, which disclosed concomitant administration of topical MK-507 and timolol and an additive reduction in intra-ocular pressure. The issues included whether the claims covered concomitant administration, whether the proposed amendments added matter, and whether a skilled team would have found co-formulation obvious in light of Nardin and common general knowledge.

1. Construction and effectiveness. Claim 1 covered co-administration as well as co-formulation. The reference to a single “medicament” did not prevent it covering two drugs prepared for separate administration. The treatment claims required the formulation to produce some discernible effect in the relevant patient class, although no particular degree of effectiveness was specified (paras 48–59).
2. Added matter. The amendment to claim 1, limiting it to a topical co-formulation, was directly and unambiguously disclosed in the application as filed. Co-formulation was disclosed as the preferred use, and its advantages for patient compliance were technically apparent to the skilled person. The amendment to claim 18, limiting the pH range to 5.5–6.0, added matter. The amended claim covered combinations and ratios outside the ranges disclosed in the application as filed, and the amendment was therefore refused (paras 60–76).
3. Novelty and inventive step. The unamended use claims were not limited to co-formulation. The skilled person could identify MK-507 as dorzolamide by routine investigation. The claims therefore could not survive Nardin. Applying the structured approach in Pozzoli v BDMO, the inventive concept of claim 6 was the use of a co-formulated dorzolamide and timolol solution for patients insufficiently responsive to timolol. The only material difference from Nardin was co-formulation.
4. The skilled team, comprising a clinical ophthalmologist and an ocular pharmacologist, would have been highly motivated to investigate co-formulation. The additive effect at timolol’s established dosing interval, the compliance advantage of one-drop treatment and the absence of any concrete obstacle would have produced a fair expectation of success. The pH and solubility problem would not have caused abandonment. Viscosity modifiers were common general knowledge, and the project could be taken through pre-clinical testing without invention (paras 100–161).
5. The patent as proposed to be amended was invalid for lack of inventive step. Unamended claims 1–6 and 8–9 also lacked inventive step. The insufficiency objection did not arise, although it would have succeeded against at least the use claims if the court had found that the skilled team could not demonstrate the necessary pre-clinical effect (paras 162–164).

Not stated in the judgment.