The FDA's Oncologic Drugs Advisory Committee granted a limited endorsement for Celltech Group plc's antibody-targeted chemotherapy, Mylotarg, for the treatment of patients with CD33-positive relapsed acute myeloid leukemia (AML).

The Slough, UK-based Celltech's marketing and development partner, American Home Products Corp., of Madison, N.J., was seeking a wide indication for patients with CD33-positive relapsed AML, but the committee recommended late Friday the product should be approved only for patients who are over the age of 60.

"Achieving the advisory committee's overwhelming recommendation that the product be approved in patients over the age of 60, which covers the largest portion of patients, is obviously very encouraging news," said Celltech media spokesman Jon Coles.

Mylotarg is a humanized recombinant antibody linked with a potent antitumor antibiotic called calicheamicin. The antibody portion of Mylotarg is directed against the CD33 antigen, a glycoprotein commonly expressed by myeloid leukemia cells.

The FDA usually follows the recommendations of its advisory committees, but isn't bound to do so.

Celltech's stock (NYSE:CLL) closed Monday at $40.50, up $4.125. - Lisa Seachrist