Teva and Sandoz brought claims against Astellas for its patent relating to a compound 'mirabegron', sold under the brand name Betmiga, that is used to treat overactive bladder (OAB).
The judgement in the Australian court deals with the allegations by the claimant that the patent is invalid due to obviousness and insufficiency. The grounds also include disputes over the witness, characteristics of a skilled person in question and the scope of their common general knowledge.
The first ground, that is the expert witness is the argument made by Astellas criticizing the Claimants’ pharmacology expert, Dr Argentieri. They criticized the approach the doctor took when deciding characteristics of a skilled person. They also alleged that the doctor had read prior art through the eyes of a skilled person who was “smarter than everyone else”.
The judge noted that the criticisms were based on the witness not asking the right questions and not on his integrity or independence. Astellas brought forward two more criticisms related to therapeutic pathways under consideration and the expert’s assessment of the data. The judge acknowledged that the list of pathways made by the expert was from memory, but it could be concluded that the Claimant’s lawyers had some influence in the making of the list.
In regards with the matter of who constitutes a skilled team and the extent of specialization. The claimants argued that the skill set of the team would be more focused and narrower to the matter at hand, while the court rules that the skill team would be broader than the given drug type and would include all novel treatments for OAB.
A case of obviousness was also argued for by the claimants, they claimed that the “possible avenues of research” are only those that are from a prior patent. Th judge however held that the claimants were oversimplifying the situation and rejected the obviousness argument.
The declaration of principle in Brugger v. Medic-Aid Ltd that an obvious path is not made less clear by the existence of additional obvious routes was approved by the Supreme Court in Actavis v. ICOS.
However, the Supreme Court accepted "the quantity and range of viable lines of investigation" as a relevant consideration in the assessment of obviousness, thus that does not mean the availability of multiple potential paths forward is meaningless.
In this instance, the claimants asserted that only "potential lines of inquiry" originating from the identified prior art are pertinent, and that the possibility of an entirely different strategy emanating from a different starting point will not exclude the claim from being evident.
Justice Meade ruled that the Claimants had oversimplified the matter and inflated the skilled person's confidence in relation to treating OAB with 3-AR agonists. Clinical trials would have been conducted in the hopes of discovering a potential new treatment, not as a routine test with a clear expectation of a positive result, despite the fact that at the time, review papers stated that they would be necessary to determine whether or not 3-AR agonists were a viable option for treating OAB. Because there are so many other opportunities to enhance current treatments, the knowledgeable individual would have exercised the proper prudence. Furthermore, it could not be assumed that any agonist of the 3-AR would be effective. As a result, the knowledgeable person would have recognised that there was a degree of ambiguity around the viability of using β3-AR agonists, including mirabegron specifically, following the teaching in ‘288. Therefore, Justice Meade rejected the Claimants’ obviousness attack.
Justice Meade rejected the claimants' "squeeze" argument, according to which the patent was no more enabling than the teaching of the "prior art," finding that the patent's disclosure was significantly different from that of "288.
The patent was determined to be valid and infringed as a result of all of the Claimants' invalidity defences failing.