AMAG Pharmaceuticals shares hit year low

Shares of biotechnology company AMAG Pharmaceuticals Inc. plunged today after the company said it may have to conduct additional studies in order to gain approval for its experimental cancer imaging agent Combidex.

The stock fell $3.18, or 6.8 percent, to $44 in morning trading. They earlier traded as low as $42.70, after trading in a 52-week range of $43.59 to $72.95.

The Food and Drug Administration's review of Combidex has been ongoing since March 2005, when it asked for additional clinical data. In December, AMAG's European marketing partner Guerbet S.A. withdrew its application for the drug with regulators there after they indicated it was not effective.

Combidex, known as Sinerem in Europe, designed to help detect cancerous lymph nodes in conjunction with magnetic resonance imaging.

"Based on our review of the data from the Guerbet trial, it appears unlikely that the data from that trial will be sufficient to address the concerns raised by the FDA, which means we may have to sponsor one or more additional clinical trials to obtain approval for Combidex," AMAG said in a Securities and Exchange Commission filing Wednesday. "We cannot at this time predict with certainty the timing or likelihood of our ability to satisfy the conditions specified by the FDA for approval of Combidex, if at all."

The company is also waiting for FDA approval on its lead product candidate, Ferumoxytol, an intravenous iron replacement therapy for iron deficiency anemia in chronic kidney disease patients. Earlier in February, the FDA rejected a rival drug candidate, made by Daiichi Sankyo Co., sparking some investor concern that Ferumoxytol could face a tougher review process.

The FDA is expected to make a decision on Fermuxytol by Oct. 19. (AP)