For the patent classification task of the 2010 CLEF-IP evaluation we have used three different approaches combining semantics and statistics-driven techniques: first approach is based on an indexing-retrieval method using the Lemur system enhanced with a class calculation algorithm; the second approach combined a semantics-driven technique for class model building and the use of an advanced statistical classifier; the third approach combined the two previous methods, attempting to exploit their complementarity for results quality improvement. The results obtained for our system are encouraging: we ranked second in terms of precision on first candidate, which is, from an application point of view, the most pertinent score.