In the latest chapter of the dispute between Bayer New Zealand Limited (Bayer) and Norbrook Laboratories Limited (Norbrook), Bayer has successfully defended an opposition to its Australian patent application for a teat-seal formulation used to prevent mastitis in cows
Norbrook opposed Bayer’s patent application on the grounds of lack of clarity, lack of sufficiency, lack of support, lack of utility and lack of inventive step. The opposition was determined under the provisions of the Raising the Bar Act.
Invention and Claims
The patent application related to formulations addressing the problem of mastitis during the period when cows are not producing milk, and where pathogens can access the teat.
The claims were for a formulation for the prevention of mastitis in animals, comprising an oil-based barrier material including barium or bismuth, mixed with povidone-iodine (PVP-I), an antiseptic which kills or prevents the spread of mastitis-causing organisms in the animal’s teat.
Clarity
Norbrook argued that the claims lacked clarity because a third party could not ascertain, without difficulty, whether or not the antiseptic was killing or preventing the spread of mastitis producing organisms in vivo, particularly because the barrier itself had a prophylactic effect by preventing pathogens from entering the teat. However, the examples demonstrated in vitro tests that could be used to assess this factor, which was shown to translate into in vivo activity. The claims were therefore clear.
Support
All of the examples in the specification used chlorhexidine as the antiseptic (not PVP-I). Norbrook argued that the claims did not encompass the examples, that PVP-I was only merely mentioned in the specification, and that the real technical contribution was the use of chlorhexidine as the antiseptic. The Hearing Officer rejected these arguments, deciding that the technical contribution was the use of a class of antiseptics (including PVP-I) that have specific properties. It was not necessary to have a worked example on every member of that class.
Sufficiency
Norbrook argued that there would be an undue burden to develop a working formulation with PVP-I instead of chlorohexidine because of the variables and costs in formulation development. This argument failed because the specification provided examples of in vitro and in vivo assays to assess the formulations, and there was not enough evidence that the formulation of PVP-I into the teat-seal was difficult or required significant experimentation.
Utility
The claims were limited by function, so this ground could only succeed if there were no working embodiments in the claims. There was evidence that one PVP-I containing formulation prepared by Norbrook’s expert was ineffective, but this was insufficient to demonstrate that no useful formulations exist.
Inventive Step
Norbrook raised 18 prior art documents that disclosed either teat-seals with oil-based bismuth barriers with other active ingredients or teat-seals/teat dips comprising PVP-I but without a barium or bismuth-containing oil-based carrier.
The Hearing Officer was not satisfied on the evidence that it was obvious to substitute in PVP-I or barium or bismuth-containing oil-based carrier in the formulations disclosed in these prior art documents, when the teaching of the documents, and what was known about PVP-I at the priority date was taken into account. Norbrook was criticised for not providing any specific reasoning for why the differences between the prior art and the claimed invention were obvious.
Key Takeaways
- The claims do not need to encompass or reflect the worked examples in a specification in order to be adequately supported. However, explanations in the specification of a principle of general application that covers the scope of the claim (beyond a mere mention) will be required.
- Examples in the specification of how the skilled person can design and test additional embodiments can be useful for refuting that there would be an “undue burden” for the sufficiency ground.
- When relying on the lack of inventive step ground, evidence and submissions demonstrating why the gap between the prior art and the claimed invention would be obvious to the skilled addressee to overcome should be provided.