FDA Approves Historic Treatment for Acute Lymphoblastic Leukemia

The FDA issued a historic decision today in approving the first gene therapy in the United States to treat certain pediatric and young adult patients with refractory B-cell precursor acute lymphoblastic leukemia (ALL) or who are in second or later relapse.

Tisagenlecleucel (Kymriah) is a personalized genetically-modified autologous T cell immunotherapy designed to use a patient’s own T cells to target and kill leukemia cells with CD19 antigens on the surface, according to a press release.

“We’re entering a new frontier in medical innovation with the ability to reprogram a patient’s own cells to attack a deadly cancer,” FDA Commissioner Scott Gottlieb, MD, said in the release. “New technologies such as gene and cell therapies hold out the potential to transform medicine and create an inflection point in our ability to treat and even cure many intractable illnesses. At the FDA, we’re committed to helping expedite the development and review of groundbreaking treatments that have the potential to be life-saving.”

The treatment involved collecting a patient’s T cells, which are sent to a manufacturing center to undergo genetic modification to include a chimeric antigen receptor (CAR) gene. CAR directs the T cells to target and attack leukemia cells that have CD19 on the surface. Once modified, the cells are infused back into the patient to kill the cancer cells.

“Kymriah is a first-of-its-kind treatment approach that fills an important unmet need for children and young adults with this serious disease,” Peter Marks, MD, PhD, direct of the Center for Biologics Evaluation and Research, FDA, said in the release. “Not only does Kymriah provide these patients with a new treatment option where very limited options existed, but a treatment option that has shown promising remission and survival rates in clinical trials.”

Safety and efficacy of tisagenlecleucel were demonstrated in a multicenter clinical trial comprising 63 pediatric and young adult patients with relapsed or refractory B-cell precursor ALL. Within 3 months of treatment, the overall remission rate was 83%.

Tisagenlecleucel carries a boxed warning for cytokine release syndrome (CRS) and neurological events, which can be life threatening. According to the release, other adverse events include serious infections, hypotension, acute kidney injury, fever, and hypoxia, with most symptoms appearing within 22 days after tisagenlecleucel.

The FDA also expanded approval of tocilizumab (Actemra) for the treatment of CAR-T cell-induced severe or life-threatening CRS in patients 2 years or older, according to the release. Clinical trials using CAR-T cells showed 69% of patients had complete resolution of CRS within 2 weeks following 1 or 2 doses of tocilizumab, according to the release.