Photo courtesy of Amgen
Vials of blinatumomab powder and solution
The US Food and Drug Administration (FDA) has approved the supplemental biologics license application (sBLA) for blinatumomab (Blincyto®).
The aim of the sBLA was to expand the indication for blinatumomab to include all patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) and to convert blinatumomab’s accelerated approval to a full approval.
Blinatumomab is a bispecific, CD19-directed, CD3 T-cell engager (BiTE®) antibody construct that binds to CD19 expressed on the surface of cells of B-lineage origin and CD3 expressed on the surface of T cells.
In 2014, the FDA granted blinatumomab accelerated approval to treat adults with Philadelphia chromosome-negative (Ph-) relapsed or refractory BCP-ALL.
In 2016, the FDA granted the therapy accelerated approval for pediatric patients with Ph- relapsed/refractory BCP-ALL.
Now, the FDA has granted blinatumomab full approval for pediatric and adult patients with Ph- or Ph+ relapsed/refractory BCP-ALL.
The FDA also recently approved the sBLA for blinatumomab to be infused over 7 days with preservative, adding to the previously approved administration options for infusion over 24 and 48 hours (preservative-free).
The blinatumomab intravenous bag for a 7-day infusion contains Bacteriostatic 0.9% Sodium Chloride, USP (containing 0.9% benzyl alcohol), which permits continuous intravenous infusion of blinatumomab at 28 mcg/day or 15 mcg/m²/day for a total of 7 days.
The 7-day infusion is not recommended for patients weighing less than 22 kg due to the risk of serious and sometimes fatal adverse events associated with benzyl alcohol in pediatric patients. See the full prescribing information for details.
The prescribing information for blinatumomab includes a boxed warning detailing the risk of cytokine release syndrome and neurologic toxicities. Blinatumomab is also under a Risk Evaluation and Mitigation Strategy program in the US intended to inform healthcare providers about these risks.
Blinatumomab is marketed by Amgen.
Trial results
With this sBLA, Amgen sought to make blinatumomab available as a treatment for patients with Ph+ relapsed/refractory BCP-ALL (as well as Ph-).
To this end, the application included data from the ALCANTARA study, which were published in the Journal of Clinical Oncology.
In this trial, researchers evaluated blinatumomab in adults with Ph+ relapsed/refractory BCP-ALL who had failed treatment with at least 1 tyrosine kinase inhibitor.
Thirty-six percent of patients achieved a complete response or complete response with partial hematologic recovery within the first 2 cycles of blinatumomab treatment. Of these patients, 88% were minimal residual disease-negative.
The most frequent adverse events (AEs) in this trial were pyrexia (58%), neurologic events (47%), febrile neutropenia (40%), and headache (31%). Three patients had grade 1/2 cytokine release syndrome, and 3 patients had grade 3 neurologic AEs.
The sBLA also included overall survival (OS) data from the phase 3 TOWER trial, which was intended to support the conversion of blinatumomab’s accelerated approval to a full approval.
Results from the TOWER trial were published in NEJM.
In this study, researchers compared blinatumomab to standard of care (SOC) chemotherapy (4 different regimens) in adults with Ph- relapsed/refractory BCP-ALL.
Blinatumomab produced higher response rates and nearly doubled OS compared to SOC. The median OS was 7.7 months in the blinatumomab arm and 4 months in the SOC arm. The hazard ratio for death was 0.71 (P=0.012).
The incidence of grade 3 or higher AEs was higher in the SOC arm, but the incidence of serious AEs was higher in the blinatumomab arm.
