Primary analysis confirms interim findings of CTL019 in DLBCL

Fifteen percent had double or triple hits in CMYC, BCL2, and BCL6 genes, and 52% had germinal center B-cell type disease.

Forty-four percent had 2 prior lines of therapy, 31% had 3 prior lines of therapy, and 19% had 4 to 6 prior lines of therapy. All were either refractory to or relapsed from their last therapy.

Forty-seven percent had undergone prior auto-SCT.

Eighty-nine of the 99 patients infused with tisagenlecleucel received bridging therapy, and 92 received lymphodepleting therapy.

Twenty-six patients were infused as outpatients, and 20 remained as outpatients for 3 or more days after the infusion.

Efficacy

The trial met its primary endpoint with an ORR of 53% tested against the null hypothesis of 20% or less. Forty percent of patients achieved a CR, and 14% had a partial response.

The ORR was consistent across all subgroups, including age, sex, lines of prior antineoplastic therapy, cell of origin, and rearranged MYC/BCL2/BCL6.

“The durability of response, however, which is really the message, is shown by the stability between 3- and 6-month response rates, 38% and 37%, respectively,” Dr Schuster said. “The response rate at 3 months is really indicative of the long-term benefit of this treatment approach.”

The investigators observed no apparent relationship between tumor response at month 3 and dose. And they observed responses at all dose levels.

The very early response may be due, to a certain extent, to the chemotherapy, according to Dr Schuster.

“The effect of the T cells becomes evident as you follow these patients over time,” he said.

The median duration of response and overall response have not been reached. And 74% of patients were relapse-free at 6 months.

“Importantly, almost all the complete responders at month 3 remained in complete response,” Dr Schuster said.

Safety

Adverse events of special interest that occurred within 8 weeks of the infusion included:

• Cytokine release syndrome (CRS)—58% all grades, 15% grade 3, 8% grade 4
• Neurologic events—21% all grades, 8% grade 3, 4% grade 4
• Prolonged cytopenia—36% all grades, 15% grade 3, 12% grade 4
• Infections—34% all grades, 18% grade 3, 2% grade 4
• Febrile neutropenia—13% all grades, 11% grade 3, 2% grade 4

No deaths occurred due to tisagenlecleucel, CRS, or cerebral edema.

Fifty-seven patients developed CRS. The median time to onset of CRS was 3 days (range, 1–9), and the median duration of CRS was 7 days (range, 2–30).

Twenty-eight percent of patients developed hypotension that required intervention, 6% requiring high-dose vasopressors. Eight percent were intubated, and 16% received anticytokine therapy—15% with tocilizumab and 11% with corticosteroids.

Investigators did not observe a relationship between dose and neurological events. However, they did detect a higher probability of CRS with the higher doses of tisagenlecleucel.

They also noted that dose and exposure were independent.

Dr Schuster indicated that these data are the basis for global regulatory submissions.

Manufacture of tisagenlecleucel was centralized, and investigators believe the trial shows the feasibility of global distribution of CAR T-cell therapy using cryopreserved apheresis and centralized manufacturing.

Novartis Pharmaceuticals, the sponsor of the trial, is now able to commercially manufacture the CAR T cells in 22 days.

Dr Schuster disclosed research funding and consulting fees from Novartis and Celgene.