Amgen announced that new data from a pivotal phase 2 study evaluating Blincyto (blinatumomab) for the treatment of adult patients with relapsed/refractory B-cell precursor acute lymphoblastic leukaemia (ALL) was presented at the 56th American Society of Hematology (ASH) Annual Meeting and Exposition.
In one analysis from the '211 study, 40 per cent of patients treated with Blincyto who achieved a complete remission (CR) or complete remission with partial hematologic recovery (CRh) were enabled to proceed to allogeneic hematopoietic stem cell transplant (HSCT). Additionally, a secondary analysis from the study found that 82 per cent of patients who had a CR or CRh also had a minimal residual disease (MRD) response, a measure used to predict disease recurrence in patients with ALL.
"The data from the '211 study expand the evidence of Amgen's BiTE immunotherapy as an advance in the management of this difficult-to-treat cancer, and importantly, served as the basis for the recent US Food and Drug Administration (US FDA) approval of Blincyto," said Sean E. Harper, MD, executive vice president of Research and Development at Amgen. "In this study, Blincyto helped patients bridge to a stem cell transplant after achieving a remission, a key goal in the management of ALL, and achieved MRD response in patients, an important parameter in predicting relapse."
In the study, the most frequent grade >3 adverse events (AEs) occurring in >5 per cent of patients were febrile neutropenia (25 per cent), neutropenia (16 percent), anemia (14 per cent), pneumonia (9 percent), thrombocytopenia (8 per cent), hyperglycemia (8 per cent), leukopenia (8 per cent), alanine aminotransferase increased (7 per cent), hypokalemia (7 per cent), pyrexia (7 per cent), sepsis (6 per cent), hypophosphatemia (5 per cent). Grade > 3 neurologic events occurred in 13 per cent of patients, and grade > 3 cytokine release syndrome occurred in 2 per cent of patients.
ASH Abstract 965: Allogeneic Hematopoietic Stem Cell Transplantation Following anti-CD19 BiTE Blinatumomab in Adult Patients with Relapsed/Refractory B-precursor Acute Lymphoblastic Leukaemia,
In one analysis of the '211 study, 40 per cent of patients treated with Blincyto who achieved a CR or CRh were enabled to proceed to HSCT, including both patients who had received prior HSCT and patients who had not received prior HSCT. Additionally, the analysis found that responses to Blincyto were similar between patients who had received prior HSCT and patients who had not received HSCT (45 per cent versus 42 per cent, respectively).
ASH Abstract 3704: An Evaluation of Molecular Response in a phase 2 Open-Label, Multicenter Confirmatory Study in Patients With Relapsed/Refractory B-Precursor Acute Lymphoblastic Leukaemia Receiving Treatment with the BiTE antibody construct Blinatumomab
A secondary analysis of the study demonstrated that, among patients receiving Blincyto who had a CR or CRh and had evaluable MRD data (n=73), 82 per cent had an MRD response, with 70 percent of those patients achieving a complete MRD response. Median overall survival was longer among patients who had a CR or CRh and an MRD response compared to patients who didn't have an MRD response (11.5 months [95 per cent CI, 8.5 - not estimable] versus 6.7 months [95 per cent CI, 2.0 - not estimable], respectively).
In the US, more than 6,000 cases of ALL will be diagnosed in 2014, and in the European Union, it is estimated that more than 7,000 cases of ALL are diagnosed each year. In adult patients with relapsed or refractory ALL, median overall survival is just three to five months.
The single arm, open-label, multicentre phase 2 trial evaluated the safety and efficacy of Blincyto in adult patients with Philadelphia chromosome-negative (Ph-) B-precursor ALL who had relapsed or were refractory following treatment with standard front-line chemotherapy or allogeneic stem cell transplant. Patients received up to five four-week cycles of intravenous Blincyto treatment. The primary endpoint of the study was the rate of CR/CRh within the first two treatment cycles. Secondary endpoints include duration of CR and CRh, relapse-free survival, overall survival, HSCT realisation rate, 100-day mortality rate and adverse events.
Blincyto is the first BiTE antibody construct and the first single-agent immunotherapy to be approved by the US FDA.4 Blincyto was granted breakthrough therapy and priority review designations by the FDA, and is now approved in the US for the treatment of Ph- relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (ALL).
Bispecific T cell engager (BiTE) antibody constructs are a type of immunotherapy being investigated for fighting cancer by helping the body's immune system to detect and target malignant cells. The modified antibodies are designed to engage two different targets simultaneously, thereby juxtaposing T cells (a type of white blood cell capable of killing other cells perceived as threats) to cancer cells. BiTE antibody constructs help place the T cells within reach of the targeted cell, with the intent of allowing T cells to inject toxins and trigger the cancer cell to die (apoptosis). BiTE antibody constructs are currently being investigated for their potential to treat a wide variety of cancers. For more information, visit www.biteantibodies.com.
Blincyto is indicated for the treatment of Philadelphia chromosome-negative relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (ALL). This indication is approved under accelerated approval. Continued approval for this indication may be contingent upon verification of clinical benefit in subsequent trials.