The U.S. Food and Drug Administration (FDA) today approved Amgen’s Blincyto (blinatumomab) to treat patients with Philadelphia chromosome-negative (Ph-) precursor B-cell acute lymphoblastic leukemia (ALL), a rare form of ALL.
A decision on the drug was not expected until May 19, 2015. Why the drug by Amgen was approved over 5 months ahead of schedule is not certain but the novel immunotherapeutic agent was granted breakthrough therapy designation, priority review, and orphan product designation to help speed up the process. And according to the FDA, they worked with Amgen to facilitate the review process.
Richard Pazdur, M.D., director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research said
“Recognizing the potential of this novel therapy, the FDA worked proactively with the sponsor under our breakthrough therapy designation program to facilitate the approval of this novel agent.”
Anthony S. Stein, M.D., clinical professor, Hematology/Oncology at City of Hope stated
"The approval of Blincyto represents a significant milestone in immunotherapy research, providing clinicians the opportunity to offer a new single-agent therapy to patients fighting this highly aggressive cancer with previously limited options."
The safety and effectiveness of Blincyto were evaluated in a Phase 2, multicenter, single-arm open-label study involving 185 adults with relapsed or refractory Ph- precursor B-cell ALL.
Of the 185 patients evaluated in the trial, 41.6% (77/185; 95%CI: 34.4-49.1) achieved complete remission or complete remission with partial hematologic recovery (CR/CRh*) within two cycles of treatment with Blincyto, which was the primary endpoint of the study. The majority of responses (81% [62/77]) occurred within the first cycle of treatment. Among patients who achieved CR/CRh*, 39% (30/77) went on to HSCT, and 75.3% (58/77 95%CI: 64.2-84.4) achieved minimal residual disease (MRD) response, a measure of eradication of residual disease at the molecular level.
Blincyto carries a boxed warning alerting patients and health care professionals that some clinical trial participants had problems with low blood pressure and difficulty breathing (cytokine release syndrome) at the start of the first treatment, experienced a short period of difficulty with thinking (encephalopathy) or other side effects in the nervous system.
The most common side effects seen in Blincyto-treated participants were fever (pyrexia), headache, swelling of tissues (peripheral edema), fever with a low number of white blood cells (febrile neutropenia), nausea, low potassium (hypokalaemia), fatigue, constipation, diarrhea and tremor.
Blincyto is being approved under the FDA’s accelerated approval program, which allows approval of a drug to treat a serious or life-threatening disease based on clinical data showing the drug has an effect on a surrogate endpoint reasonably likely to predict clinical benefit to patients. This program provides earlier patient access to promising new drugs while the company conducts confirmatory clinical trials. The FDA is requiring Blincyto’s manufacturer to conduct a study to verify that the drug improves survival in participants with relapsed or refractory Philadelphia-negative precursor B-cell ALL.