* Will follow drug needs, no matter for how many patients - CEO
* Says Roche portfolio already addresses some rare diseases
* No comment on interest in U.S. biotechs Alexion, Biomarin
By Natalie Huet
PARIS, Oct 23 (Reuters) - The chief executive of Roche did not rule out a move into treatments for rare diseases on Wednesday, saying the Swiss drugmaker would go where it could address unmet medical needs, even for very small numbers of patients.
There has been speculation that Roche might branch out into the lucrative area of rare or so-called orphan diseases, which affect only a small number of people, after reports it was considering bids for two U.S.-based companies, Alexion Pharmaceuticals and BioMarin Pharmaceuticals.
Chief Executive Severin Schwan told a news conference in Paris that Roche's main criteria when looking at which diseases to go after was not the size of the patient population but how much additional value and medical benefit could be generated for the individual patient.
Asked if that meant he did not exclude a move into rare diseases, he said: "We go where the science takes us, wherever it is, independent from the size of the patient population."
Schwan said that Roche's portfolio already included treatments for rare diseases such as cystic fibrosis and chronic lymphocytic leukaemia (CLL).
"The reasons we went into those areas was because there was a medical need ... and we felt we could make a difference for those patients concerned," he said.
But he declined to comment specifically on whether Roche was interested in buying Alexion or BioMarin.
His broader comments on the topic contrast with those of the group head of pharmaceuticals, who said in an interview last month that treating ultra-rare diseases was a business that was distinct from Roche's current area of expertise.
Shares in Roche were up 0.7 percent at 248 Swiss francs at 1500 GMT, when the STOXX Europe 600 Healthcare sector index was up 0.1 percent.
Shares in Alexion were down 0.2 percent at $107.52 while Biomarin was down 0.1 percent at $67.28, while the Nasdaq Biotech Index was down 0.7 percent.
High prices and lower development and marketing costs of treatments for orphan diseases are drawing the attention of big pharmaceutical companies as older drugs lose patent protection.
Shares in biotechnology group Alexion jumped in July after people familiar with the matter said Roche was seeking financing for a possible bid. No offer has emerged.
Roche has also been linked to BioMarin Pharmaceuticals, although the company denied last month it was raising financing for a bid on the company.
The Basel-based firm is looking to branch out beyond its core cancer drugs and Schwan highlighted the group's focus on autoimmune and inflammatory diseases as well as neuroscience.
"So in those three areas naturally we are a partner of choice for many companies. But again, if there was an interesting opportunity outside of those established areas, I would be very open to look at it," he said.
Schwan last week knocked down speculation that Roche could merge with rival Novartis, saying it preferred bolt-on acquisitions.
He declined on Wednesday to give a price range for such deals, saying he wanted to stay flexible and see what opportunities come up.
"We will always go where we think we have a chance to put a progress of science into medical applications. The price is then a consequence of the opportunity," he said.