Novartis challenges the entitlement of the Patents to priority. Attention has focussed on the entitlement of the Patents to priority from the third of the priority documents listed above (“PD3”) since (a) MedImmune accepts that the Patents are invalid if they are not entitled to priority from that document and (b) Novartis does not rely upon any prior art which was made available to the public in the interval between the filing dates of the first and third priority documents. Novartis disputes both that the claimed inventions are disclosed by PD3 and that the Patentees have the right to claim priority from PD3. It became clear at an early stage of the trial, however, that the parties were not ready to contest the latter issue. Accordingly, it was agreed that that issue will be tried separately at a later date.