Amgen announces results from three studies on the safety and efficacy of Nplate

Amgen Inc. (Nasdaq: AMGN) today announced results from three studies on the safety and efficacy of Nplate® (romiplostim) in adult patients with myelodysplastic syndromes (MDS). MDS is a pre-leukemic condition in which early blood forming cells in the bone marrow are unable to mature normally, thereby limiting their ability to produce normal mature blood elements, which can lead to low platelet counts. The results of the studies were presented at the 2009 American Society of Hematology (ASH) Annual Meeting and Exposition (ASH Abstracts #1769, #1770 and #2765).

Interim Results from Long-Term Open-Label Extension Study of Nplate in MDS (Abstract #2765)

The ongoing, open-label extension study was designed to evaluate the safety and efficacy of Nplate in lower risk MDS patients. The primary endpoints of the interim study for presentation at ASH evaluated adverse event rates with long-term use of Nplate and incidence of antibody development to Nplate and/or thrombopoietin (TPO). Secondary endpoints evaluated the incidence of bleeding events and platelet response during the study period.

Nplate was generally well-tolerated, with the majority of patients>

Results for the secondary endpoint showed that 64 percent of patients>

The data also showed that Nplate was effective with over half (54 percent) of patients>

"Both the safety and efficacy data are important given the limited treatment options available for those who suffer from low platelet counts due to MDS," said Dr. Hagop Kantarjian, Professor of Medicine and Chairman of the Department of Leukemia at The University of Texas M.D. Anderson Cancer Center.

Study Design

This long-term, follow-up, open-label global extension study included lower risk MDS patients who had completed a previous Nplate study and who had platelet counts of less than 50,000 platelets per microliter with no signs of disease progression. Patients received Nplate doses of 250 micrograms, 500 micrograms, 750 micrograms, or 1500 micrograms weekly or every two weeks based on previous dosing, with adjustments between 250 micrograms and 1000 micrograms.

Additional Phase 2 Nplate MDS Data (Abstract #1769 and #1770)

Data from two separate Phase 2 studies showed that patients with low and intermediate risk MDS currently receiving either decitabine or lenalidomide showed reduced incidence of clinically significant thrombocytopenic events and platelet transfusions with the addition of Nplate treatment.

In the study that examined patients with low and intermediate risk MDS receiving decitabine in combination with Nplate (Abstract #1769), the primary endpoint evaluated the incidence of clinically significant thrombocytopenic events as defined by platelet counts of less than 50,000 platelets per microliter by the third week of treatment, or receipt of platelet transfusions at any time during the study period.

The data showed that the primary endpoint was reached in 79 percent>

Secondary endpoints were also met with results showing that treatment was generally well-tolerated in lower-risk MDS patients (all patients in the Nplate and placebo groups experienced at least one adverse event) with improved MDS treatment response after four cycles compared to placebo (47 percent vs. 36 percent, respectively) and decreased bleeding events (27 percent vs. 43 percent, respectively) in Nplate-treated patients compared to placebo. Adverse events were mild to moderate with similar treatment-related adverse events between patients taking Nplate and placebo (33 percent vs. 21 percent, respectively). Similar findings have been reported for use of Nplate in combination with azacytidine (vidaza).

The other study (Abstract #1770) examined patients with low and intermediate risk MDS receiving lenalidomide in combination with Nplate. The objective of the study was to evaluate the effect of Nplate on the incidence of clinically significant thrombocytopenic events and the overall safety and efficacy of Nplate in combination with lenalidomide. The data showed that treatment was generally well-tolerated with a comparable incidence of adverse events between all treatment groups with most frequent adverse events (appearing in greater than or equal to 10 percent of patients) in patients taking Nplate vs. placebo being diarrhea (38.5 percent vs. 45.5 percent, respectively), thrombocytopenia (16.3 percent vs. 36.4 percent), rash (34.7 percent vs. 27.3 percent), edema peripheral (30.8 percent vs. 27.3 percent) and dizziness (11.6 percent vs. 27.3 percent). Data also showed increased platelet counts (31.5 percent vs. 17 percent) and reduced the need for platelet transfusions (19 percent vs. 25 percent) compared to placebo. Adverse events were mild to moderate with similar rates of adverse events between patients taking Nplate and placebo (100 percent vs. 91 percent).

SOURCE Amgen Inc.