Clinical trials and obviousness

25.07.2016

On 10 June 2016 Henry Carr J handed down a lengthy judgment in the Hospira v Cubist case. The case related to three patents concerning to the antibiotic daptomycin. The patents fell into two categories: one patent was a dosage regime patent claiming a dosage regimen of between 3-10mg/kg of daptomycin administered once every 24 hours; the other two patents (the “purity patents”) concerned purification processes for daptomycin.
One of the main points of interest in the decision concerned Cubist’s report of upcoming clinical trials and obviousness. Henry Carr J held that the dosage regime patent was not entitled to claim its first priority date. As such a press release from Cubist reporting on some forthcoming clinical trials was relied upon by Hospira to allege lack of novelty and lack of inventive step of the dosage regime patent. The press release notably stated that Cubist would be conducting phase III trials in which patients would receive 4mg/kg once every 24 hours for up to 14 days. The press release was held not to anticipate the patent as the trials themselves had not yet taken place and so there was no disclosure that the treatment was efficacious. However, Henry Carr J held that the press release did render the patent obvious. This was based on a number of facts, in particular that phase II trials must have shown that the doses were sufficiently safe and efficacious to proceed to phase III trials and there was expert evidence that the skilled person would assume this. There was further evidence that phase III trials are costly and a company would not have entered into these without a very good prospect of success. Previous reports of trials into the drug performed by Eli Lilly would also have increased the team’s expectation of success. The judge did not accept Cubist’s argument that the skilled team would have awaited the outcome of the Cubist trials and would not be motivated to carry out his own work. This was said to be irrelevant to technical obviousness and in any event was wrong on the basis of expert evidence that the skilled team would be interested to participate in such trials.
Despite finding the dosage regime patent obvious over the press release, in case he was wrong on that issue Henry Carr J considered another piece of prior art, which did not require any loss of entitlement to priority. This document reported on a phase I study in 12 healthy volunteers. As there were no phase II or phase III trial results, there was held to be no anticipation over this further document. However, the judge held that the patent was also obvious over it.
The purity patents were both also found to lack inventive step on the facts. Henry Carr J noted in the judgment that hearing the case of all three patents at same time was not easy for the court or the parties, and noted that generally three patents with different subject matter is too much for one trial. It would have been better to hear the case on the dosage regime patent and then the purity patent cases a shortly afterwards.
A final note of interest is that in several places Henry Carr J referred to the decision of the EPO Opposition Division (OD) relating to the dosage regime patent and noted that his judgment agrees with this decision. The OD decision is currently under appeal to the EPO Technical Board of Appeal.

Katie Cambrook

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