The case of Les Laboratoires Servier v Apotex Pty Ltd  APO 11 (11 April 2008) provides a useful summary of the principles applied by the Commissioner of Patents in determining a request for dismissal of a patent opposition.
Following is an excerpt from the Abstract of the decision:
Some general principles that flow through to the dismissal of patent oppositions from recent changes to Section 31A of the Federal Court Rules and subsequent Federal Court decisions are discussed. Notably, an opposition need not be “clearly untenable” or “manifestly groundless” in order for it to be dismissed. An opposition may be dismissed if it is considered to have no reasonable prospects of success.
The claims as accepted defined a new polymorph of perindopril tert-butylamine salt which was characterised by X-ray crystallography. Uses of the compound in pharmaceutical formulations and methods were also defined. The proposed amendments sought to include claims to the compound and methods with the further characteristic that the polymorph was in the form of “individual needles”. The opponent opposed the amendments under section 104 and addressed all grounds of opposition available under section 102. The applicant requested dismissal of the opposition on the basis that it was manifestly groundless and could not possibly succeed.
A consideration of the case set out by the opponent shows that it has no reasonable prospects of success. The opponent has not established that there is a real issue to be determined, or the issues identified are in respect to matters that do not arise as a result of the amendments and would not be sustainable in an opposition under section 104. On that basis the opposition is dismissed.