FDA Delays Approval of Amag's Ferumoxytol

Unresolved manufacturing issues have contributed to a delay in the approval of Amag Pharmaceuticals'(AMAG Quote) injectable iron replacement therapy, the company announced Monday night.

Amag said it received a second complete response letter from the Food and Drug Administration, ahead of the agency's expected approval decision date of Dec. 30.

The company is seeking FDA approval for ferumoxytol, now known by its brand name Feraheme, as a treatment for iron-deficiency anemia in patients with chronic kidney disease.

Amag, in its announcement Monday, doesn't specify how long it believes Feraheme's approval will be delayed, although the company doesn't believe new clinical trials will be required for approval.

The FDA, in its complete response letter, requested additional information to resolve three issues prior to granting Feraheme's approval, according to the company.

The three issues are: data to clarify a specific chemistry, manufacturing and controls question; resolution of the deficiencies observed during the pre-approval inspection of the company's manufacturing facility; and finalization of labeling discussions for Feraheme with the FDA.

The first and second requirements, both related to the manufacturing of Feraheme, most likely are responsible for the approval delay. Amag previously disclosed that an FDA inspection of its Feraheme manufacturing plant in Cambridge, Mass., uncovered problems that needed to be corrected prior to approval.

The FDA inspection report listed 11 manufacturing items that required fixing, some or all of which Amag reportedly addressed in the company's response to the agency filed in late October.