Millennium Pharmaceuticals of the USA said yesterday it had rejected an unsolicited takeover offer from an undisclosed suitor, after a televised report said the firm had put itself up for sale.

The biopharmaceutical firm said it had looked into the takeover offer, but decided to remain independent, focusing on “on its stated strategy by growing sales of its market-leading cancer product Velcade (bortezomib) for Injection, progressing a pipeline of seven novel product candidates and achieving profitable growth long-term.”

The rumour of the sale forced Millennium’s share price up 7.7% yesterday to $10.09, after briefly setting a new 52-week high of $11.46, although analysts said the stock was likely to slip back now the real story had been divulged.

Last week, Millennium filed for approval of a new indication for Velcade, the treatment of relapsed or refractory mantle cell lymphoma, to add to its current role as a treatment for multiple myeloma. The filing was based on the results of the PINNACLE study, which found an overall response rate of 33% and a complete response rate of 8% with Velcade in this aggressive form of non-Hodgkin’s lymphoma.

First-quarter sales of Velcade were $53 million, up 19%, and Millennium is predicting full-year sales of $225 to $250 million for the drug.