Mayne Group will book a AUD$5 million one-off charge in its first-half results after a UK appeal court ruled its version of the cancer drug epirubicin infringed a patent on the original drug.

Mayne had been looking to win approval to sell its formulation of epirubicin, used in breast cancer chemotherapy, before the patent held by Pharmacia Italia, a unit of Pfizer, expired in June 2006.

The English High Court had ruled in favour of Mayne last October, but the Court of Appeal overturned the ruling on a point of law.

Mayne said the AUD$5 million charge it will record reflects the top end of estimated legal and other costs associated with the UK litigation. Analysts expect Mayne to report a net profit of around AUD$35 million before one-offs for the first-half when it releases its results on February 23.