Amgen announced new data from a prespecified interim analysis of the phase 3 TOWER study, in which Blincyto (blinatumomab) demonstrated an almost two-fold increase in median overall survival (OS) compared to standard of care (SOC). The randomized, open-label TOWER study evaluated the efficacy of Blincyto versus SOC chemotherapy in adult patients with Philadelphia chromosome-negative (Ph-) relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL).
Results from the analysis showed that median OS was 7.7 months (95 per cent CI: 5.6, 9.6) for Blincyto versus 4 months (95 per cent CI: 2.9, 5.3) for SOC (stratified log-rank test p=.012; hazard ratio=0.71). As per the recommendation of an independent data monitoring committee, Amgen ended the study early for efficacy based on these results. The data will be presented during The Presidential Symposium at the 21st Congress of the European Hematology Association (EHA) in Copenhagen.
"Acute lymphoblastic leukaemia is the most aggressive type of B-cell malignancy," said Max S. Topp, M.D., professor and head of haematology, University Hospital of Wuerzburg, Germany. "The data presented today not only reinforce the potential of immunotherapy delivered by T cell engaging bispecific antibody constructs but also validate the efficacy of Blincyto in these heavily pretreated patients."
"This is the first study of an immunotherapy to demonstrate overall survival benefit in adult patients with Ph-negative B-cell precursor relapsed or refractory ALL, a very complex-to-treat disease with limited treatment options," said Sean E. Harper, M.D., executive vice president of Research and Development at Amgen. "Blincyto is currently approved for the treatment of Ph-negative B-cell precursor relapsed or refractory ALL under accelerated approval, and we look forward to working with regulatory authorities for a full approval for Blincyto in this patient population."
The TOWER study was a phase 3, randomized, open-label study investigating the efficacy of Blincyto versus SOC chemotherapy in adult patients with Ph-relapsed or refractory B-cell precursor ALL. Patients were randomized in a 2:1 ratio to receive Blincyto or treatment with investigator choice of one of four protocol defined SOC chemotherapy regimens. The primary endpoint was OS. Secondary endpoints included complete remission and the combined endpoint of complete remission plus complete remission with partial or incomplete hematologic recovery.
The TOWER study is the confirmatory trial for Blincyto, and Amgen plans to file for full approval of Blincyto based on results from the study. Blincyto is a bispecific CD19-directed CD3 T cell engager (BiTE) antibody construct that binds specifically to CD19 expressed on the surface of cells of B-lineage origin and CD3 expressed on the surface of T cells.
In November 2015 Blincyto was granted conditional marketing authorization in the EU for the treatment of adults with Ph- relapsed or refractory B-cell precursor ALL.
