* Royalty has not received response from Elan
* Biggest shareholder is Johnson & Johnson
By Jessica Toonkel
NEW YORK, Feb 26 (Reuters) - New York-based investment firm Royalty Pharma does not want to take "no" for an answer to its $6.6 billion offer for Irish drugmaker Elan Corp.
The company plans to spend the next few weeks calling Elan shareholders about its offer that was made Feb. 18, according to a source familiar with the situation.
Royalty Pharma, which buys royalty streams of patented drugs and whose portfolio includes rheumatoid arthritis drugs Humira and Remicade, is turning to Elan's investors, because it has not gotten a formal response from the company about its offer, said the source, who wished to remain anonymous because they are not allowed to speak to the press.
Elan's biggest shareholder is Johnson & Johnson with an 18 percent stake.
An Elan spokesman declined to comment beyond Monday's statement. Johnson & Johnson declined to comment.
Royalty Pharma's offer, which was worth $11 per Elan share, came just days after Elan announced it had sold its 50 percent interest in multiple sclerosis drug Tysabri for $3.25 billion plus future royalty payments to U.S. partner Biogen Idec, and then reinvent itself.
As a result of the Tysabri sale, Elan announced Friday that it would return $1 billion to shareholders and make acquisitions with the rest of the $3.25 billion raised from the deal . Elan did not disclose the Royalty Pharma offer, which was indicative, and not a formal bid.
Elan, in a statement Monday, said Royalty Pharma's bid was "indicative, conditional, proposal which may or may not lead to an offer being made for the entire issued share capital of the Company."
Elan also called the Royalty Pharma bid "highly opportunistic," given that shareholders had not had the opportunity to assess the full benefits of the Tysabri sale.
However, Royalty Pharma does not think that Elan's management had the experience to make acquisitions, the firm said in its statement announcing its proposed offer Monday.
In afternoon trading, Elan's stock was trading above the offer price at $11.03, a 7 percent increase from Friday's close on the New York Stock Exchange.