* Data on cancer drugs from European companies

* Includes Novartis, Merck MGaA, Roche, Glaxo

* Some data available Friday, May 16, 0100 GMT, ahead of May

30 meeting of American Society of Clinical Oncology (ASCO)

By Sam Cage

ZURICH (Reuters) - Investors will assess clinical data this week on cancer drugs from several European companies, who are increasingly keen to develop their oncology portfolios as fierce generic competition erodes business in other areas.

Swiss-based Novartis AG (NOVN.VX: Quote, Profile, Research) will present two sets of kidney cancer data on RAD001, seen as one of its most important new drugs, at the American Society of Clinical Oncology (ASCO) annual meeting, which starts May 30 in Chicago.

Data on RAD001 -- and other important drugs from European companies, including Roche Holding AG (ROG.VX: Quote, Profile, Research) and Merck KGaA (MRCG.DE: Quote, Profile, Research) -- will be presented at the ASCO meeting, but much of the information will be available from early on Friday.

Cancer drugs are a popular target for drugmakers, as they are less vulnerable to competition than other franchises and tend to command higher prices, and RAD001 could be a possible billion-dollar seller.