(Updates with closing stock price in third paragraph.)

Oct. 10 (Bloomberg) -- Allos Therapeutics Inc., a cancer drugmaker that received a takeover offer from AMAG Pharmaceuticals Inc., dropped to a record low after saying a second bid by a rival company was withdrawn.

Allos, based in Westminster, Colorado, fell 18 percent to $1.43 in New York, the lowest price since the stock began trading in March 2000. The shares have fallen 69 percent in the past year.

Allos is working with Lexington, Massachusetts-based AMAG to complete the all-stock acquisition valued at $686 million, or $2.44 a share, when the deal was announced in July, the company said in a statement today. It’s now valued at about $1.73 after declines in AMAG’s share price.

A rival pharmaceutical company that originally offered $2 a share, and boosted the bid to $2.20 a share in cash and stock on Sept. 21, sent a letter to Allos on Oct. 7 withdrawing the revised offer.

Allos is no longer in discussions or negotiations with the company, it said in the statement. Allos’s only product, Folotyn, is an intravenous treatment for T-cell lymphoma, a type of blood cancer. Allos sold $35.2 million of Folotyn in 2010, less than analyst forecasts of about $49.6 million, said Carol Werther, an analyst at Summer Street Research in Boston, in a July 21 note to clients.

Under the terms of AMAG’s offer, Allos investors are slated to receive 0.1282 share of AMAG for each Allos share they own.

--Editors: Chris Staiti, John Lear

To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net

To contact the editor responsible for this story: Reg Gale at rgale5@bloomberg.net