FDA Grants Regular Approval to Blinatumomab and Expands Indication to Include Philadelphia Chromosome-Positive B-Cell Relapsed or Refractory Precursor ALL

Current supplement provides confirmation of clinical benefit required under accelerated approval and also expands indication

On 11 July 2017, the US Food and Drug Administration (FDA) approved blinatumomab (BLINCYTO, Amgen Inc.) for the treatment of relapsed or refractory B-cell precursor acute lymphoblastic leukaemia (ALL) in adults and children.

Blinatumomab received accelerated approval in December 2014 for the treatment of Philadelphia chromosome-negative relapsed or refractory B-cell precursor ALL. This current supplement provides the confirmation of clinical benefit required under the accelerated approval and also expands the indication to include Philadelphia chromosome-positive relapsed or refractory B-cell precursor ALL.

The trial that confirmed clinical benefit was a randomised, open label, multicentre clinical trial (TOWER, NCT02013167), comparing blinatumomab to standard of care (SOC) chemotherapy in 405 patients with relapsed or refractory B-cell precursor ALL. Blinatumomab was administered at 9 mcg/day on days 1, 7 and 28 mcg/day on days 8, 28 for cycle 1 in a 42-day cycle, at 28 mcg/day on days 1, 28 for cycles 2, 5 in 42 day cycles, and at 28 mcg/day on days 1, 28 for cycles 6, 9 in 84 day cycles.

The trial demonstrated a statistically significant improvement in overall survival (OS) for patients treated with blinatumomab compared to those treated with SOC (hazard ratio 0.71; 95% CI: 0.55, 0.93, p = 0.012). The estimated median OS was 7.7 months in the blinatumomab arm (95% CI: 5.6, 9.6) and 4.0 months in the SOC arm (95% CI: 2.9, 5.3). An independent data monitoring committee recommended that the study end early for efficacy based upon these results that were prespecified in an interim analysis.

The inclusion of Philadelphia chromosome-positive relapsed or refractory B cell precursor ALL in the indication was based on a single-arm, multicentre study (ALCANTARA, NCT02000427) enrolling 45 patients with Philadelphia chromosome-positive ALL. Patients either had disease resistant to second generation tyrosine kinase inhibitors (TKIs) or were intolerant to second generation TKIs and had disease resistant to imatinib. In this population, 36% of the patients achieved a complete remission with complete or partial haematological recovery. The median duration of remission was 6.7 months.

No new major adverse reactions of blinatumomab were identified in the above clinical trials. Dosage and administration schedule of blinatumomab is based on weight for patients weighing <45 kg and fixed dose for those ≥45 kg. Patients should be premedicated with dexamethasone. Hospitalization is recommended at the beginning of the first and second cycles. Details are available in the full prescribing information here.

Healthcare professionals should report all serious adverse events suspected to be associated with the use of any medicine and device to FDA’s MedWatch Reporting System.