FDA Misses Review Deadline for Nplate

The FDA failed to act on Amgen’s investigational chronic immune thrombocytopenia purpura (ITP) treatment Nplate by its July 23 action date — even after it extended the review time for the product by three months.

ITP is a disorder in which blood does not clot appropriately due to a low number of platelets.

“We remain optimistic that a final decision will be made soon, but Amgen cannot speculate on the timing of the FDA’s response,” Amgen said. The original action date on the Nplate (romiplostim) application, which is under priority review, was April 23.

Earlier this year, the FDA’s Oncologic Drugs Advisory Committee voted unanimously that the product had a favorable risk-benefit profile. The agency had expressed concern over the biologic’s limited clinical data given its safety concerns, including reticulin fibrosis in bone marrow, which is associated with benign and malignant conditions.

The committee said the product should be limited to patients with chronic ITP and be marketed under a patient-registry program.

The drug’s proposed indication is to treat chronic ITP in adults who have not had their spleens removed and have not responded to or are intolerant of corticosteroids or immunoglobulins. The indication also would include patients who have not adequately responded to therapy after their spleen was removed.