Amgen Inc. announced that the United States Food and Drug Administration (FDA) has approved Nplate (romiplostim), the first and only platelet producer for the treatment of thrombocytopenia in splenectomized (spleen removed) and non-splenectomized adults with chronic immune thrombocytopenic purpura (ITP).

Nplate, the first FDA-approved peptibody protein, works by raising and sustaining platelet counts, representing a novel approach for the long-term treatment of this chronic disease.

Chronic ITP is a serious autoimmune disorder characterized by low platelet counts in the blood (thrombocytopenia), which can lead to serious bleeding events. Recognized as an orphan disease, chronic ITP affects an estimated 60,000 adult patients in the US and is considered an unmet need by the FDA.

Nplate, Amgen's first peptibody protein, is a novel engineered therapeutic fusion protein with attributes of both peptides and antibodies, but is distinct from each. Nplate works similarly to thrombopoietin (TPO), a natural protein in the body. Nplate stimulates the TPO receptor, which is necessary for growth and maturation of bone marrow cells that produce platelets.

"Until now, patients suffering from chronic ITP have had limited available treatment options, many of which are often unsuitable for long-term use due to side effects and tolerability issues," said David J. Kuter, M.D., chief of Haematology, Massachusetts General Hospital, Boston. "Nplate represents the first long-term treatment for adult chronic ITP patients, providing a new treatment approach for this chronic disease."

The FDA approval of Nplate was based on efficacy and safety results from two pivotal Phase 3 studies of adult patients with chronic ITP, including both splenectomized and non-splenectomized patients. The overall response rate for Nplate was 83 percent (n=69/83, p less than 0.0001) of treated splenectomized and non-splenectomized patients, and platelet counts were raised and sustained in these six month studies. Additionally, patients treated with Nplate were able to reduce or discontinue their use of concomitant ITP medications and emergency medications (i.e., corticosteroids, IVIG, Win-Rho, Anti-D therapy).

"For those suffering from ITP, the daily fear of experiencing a serious bleeding episode can be emotionally stressful and extremely difficult for both patients and their families. We welcome the addition of new treatment options which offer new hope for the treatment of this serious disease," said Craig Conway, executive director of the Platelet Disorder Support Association.

In addition to improved clinical benefits, described in the FDA labeling, Amgen believes Nplate offers patients a positive net health benefit with fewer hospitalizations from bleeding events, as well as reduced need for emergency medications (IVIG and Win-Rho). Amgen expects the total costs of care for chronic ITP patients managed with Nplate to be less than or comparable to the total costs of care with standard treatment regimens.

Amgen also announced it will launch the Nplate NEXUS (Network of EXperts Understanding and Supporting Nplate and Patients) programme, a multi-faceted program designed to provide comprehensive access, support and education for chronic ITP patients, their caregivers and healthcare providers. The Nplate NEXUS Program is part of the Risk Evaluation and Mitigation Strategy (REMS) developed by Amgen in partnership with the FDA to assure safe use of Nplate while minimizing risk. The program will facilitate appropriate use of Nplate, provide patient support through education and resources and help with ongoing follow up through safety data collection.

Through the Nplate NEXUS Programme, eligible patients who are uninsured, underinsured, or unable to afford their insurance co-payments may be able to receive reimbursement support and other assistance from Amgen. For example, one such program helps cover up to 50 percent of an eligible, commercially-insured patient's co-payments for Nplate. Recognizing that some patients may not have healthcare coverage, Amgen continues to offer another program for all of its innovative products, including Nplate, which provides product free of charge to eligible, low-income patients without insurance.

"Amgen is committed to advancing the discovery and development of new therapies for grievous illnesses where there is unmet medical need," said Roger M. Perlmutter, M.D., Ph.D., executive vice president of Research and Development at Amgen. "The FDA approval of Nplate is the result of more than 15 years of research and represents an important biotechnology milestone as it is the first FDA-approved peptibody protein, an innovative platform for delivering targeted therapies."

Nplate was also approved for ITP by Australia's Therapeutic Goods Administration (TGA) in July 2008. Amgen has filed for regulatory approval of Nplate in the European Union (EU), Canada, and Switzerland and these applications are currently under review. Nplate has also received orphan designation for ITP in the EU (2005), Switzerland (2005) and Japan (2006).

Platelets are blood cells needed to prevent bleeding. Low platelet counts leave adult ITP patients open to sudden serious bleeding events, making it impossible to arrest blood flow. The risk for serious bleeding events increases when platelet counts drop to less than 30,000 platelets per microliter.

There are limited approved treatments (i.e., corticosteroids, immunoglobulins) or surgical therapy (removal of the spleen) available to adult patients with chronic ITP. Currently, there are 140,000 treated chronic ITP patients in the US and Europe. ITP affects about twice as many adult women as men.

With ITP, platelets are destroyed by the patient's own immune system. ITP has historically been considered a disease of platelet destruction. However, recent data also suggest that the body's natural platelet production processes are unable to compensate for low levels of platelets in the blood. Increasing the rate of platelet production may address low platelet levels associated with ITP.

Amgen discovers, develops, manufactures and delivers innovative human therapeutics. A biotechnology pioneer since 1980, Amgen was one of the first companies to realize the new science's promise by bringing safe and effective medicines from lab, to manufacturing plant, to patient.