Experimental Drug Led to Remission in Pediatric Patients with Leukemia

Novartis recently announced positive, updated results from the phase 2 ELIANA clinical trial of CTL019 (tisagenlecleucel) in pediatric patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (ALL), according to a press release. CTL019 is an investigational chimeric antigen receptor T (CAR-T) cell therapy.

Included in the study were 88 patients with r/r B-cell ALL aged 3 to 23; however, prior to infusion, 16 patients discontinued.

The investigators found that 9 of the patients who discontinued did so due to rapid disease progression, which reflects the progressive nature of r/r B-cell ALL, according to the release.

The investigators found that 83% of patients achieved complete remission (CR) or CR with incomplete blood count recovery within 3 months of treatment.

Among these patients, no minimal residual disease was discovered. This measure is important because it determines the elimination of residual disease in blood and bone marrow at the molecular level after treatment, which can be used to detect potential relapse, according to Novartis.

New findings from the ELIANA study show that patients have a relapse-free probability of 75% at 6 months. At 12 months, the probability dips to 64%, according to the release. The investigators also discovered that the probability of survival was 89% at 6 months and 79% at 12 months.

"The updated CTL019 ELIANA data illustrating early observed response rates that have held steady over 6 months' time are exciting findings,” said lead investigator Stephan Grupp, MD, PhD. “Durability is an important measure for children and young adults with relapsed or refractory B-cell ALL, and we are truly encouraged by the results of this study.”

Approximately 47% of patients experienced grade 3 or 4 cytokine release syndrome (CRS), which is a known complication that may occur when engineered cells become active in the patient’s body, according to Novartis.

There were no deaths resulting from CRS and no cases of cerebral edema; however, 15% of patients experienced grade 3 neurological events.

The study was designed to identify safety issues with CTL019. The investigators did not discover any new safety issues and were able to manage CRS and neurologic events, according to the release. However, additional follow ups are needed to determine the safety of B-cell aplasia, Novartis reported.

CTL019 was previously granted priority review for the treatment of pediatric and adult patients with B-cell ALL and was granted breakthrough therapy for adults with r/r diffuse large B-cell lymphoma who have progressed on or after at least 2 drugs, according to the study.

Novartis plans to file with the European Medicines Agency this year. Previously, the drug received priority medicines designation from the agency.

"These positive, updated ELIANA data help us better understand the ability for CTL019 to maintain durable responses in r/r ALL," said Vas Narasimhan, MD, global head of Drug Development and Chief Medical Officer, Novartis. "The results, including relapse-free survival findings at six and 12 months, reaffirm our confidence in CTL019 to potentially become an effective treatment for pediatric and young adult patients with r/r ALL in need of more options."