CAR met primary endpoint at interim analysis in DLBCL

Fifty-six DLBCL patients (77%) were refractory to their second or later line of therapy, and 15 (21%) had relapsed after autologous stem cell transplant.

Sixteen PMBCL/TFL patients (80%) were refractory to their second or later line of therapy, and 4 (20%) relapsed after autologous stem cell transplant.

Results

Dr Neelapu indicated that patients responded rapidly to treatment, and most responses were evident at the first tumor assessment.

At 3 months’ follow-up or longer, the ORR was 76% and the CR rate 47% for the 51 DLBCL patients in cohort 1. This was a 6-fold higher CR rate compared with historical outcomes.

For the 11 PMBCL/TFL patients in cohort 2, the ORR was 91% and the CR rate was 73% at 3 months or longer.

Both cohorts combined yielded an ORR of 79% and a CR rate of 52%.

The treatment effect was consistent across key covariates—refractory patients, disease stage, IPI risk score, CD4/CD8 ratio, and steroid and tocilizumab use.

Dr Neelapu described the case of a 62-year-old male with refractory DLBCL who had 4 prior rituximab-based therapies. He had no response to his last 3 therapies combining rituximab with GDP (gemcitabine, cisplatin, and dexamethasone), ICE (ifosfamide, carboplatin, and etoposide), or lenalidomide.

After KTE-C19 therapy, the patient has an ongoing CR that has lasted more than 9 months.

Adverse events

Sixty-eight DLBCL patients (93%) experienced grade 3 or higher adverse events (AEs). These included 10 patients (14%) with cytokine release syndrome (CRS) and 18 (25%) with neurologic events.

Eighteen PMBCL/TFL patients (90%) experienced grade 3 or higher AEs, 2 (10%) with grade 3 or higher CRS and 9 (45%) with grade 3 or higher neurologic events.

CRS and neurological events were generally reversible, Dr Neelapu said. All CRS events resolved except 1 in the PMBCL/TFL cohort.

In both cohorts combined, 38% of patients received tocilizumab, 17% received corticosteroids, and 17% received both.

Three neurological events were ongoing at the data cut-off—grade 1 memory impairment, grade 1 tremor, and grade 2 tremor.

There were no cases of cerebral edema.

Three patients died from causes other than progressive disease—1 DLBCL patient and 2 in the PMBCL/TFL cohort.

Investigators considered the DLBCL patient death (due to hemophagocytic lymphohistiocytosis) and 1 death in the PMBCL/TFL arm (due to cardiac arrest) to be treatment-related.

Investigators did not consider the other death in the PMBCL/TFL arm (due to pulmonary embolism) to be treatment-related.

The most frequent grade 3 or higher treatment-emergent AEs in both arms combined included neutropenia (63%), anemia (42%), leukopenia (40%), febrile neutropenia (29%), thrombocytopenia (26%), encephalopathy (19%), hypophosphatemia (17%), and decreased lymphocyte count (17%).

Peak CAR T-cell expansion occurred between 7 and 14 days and was associated with ongoing CRs and grade 3 or greater neurological events, but not with CRS.

AEs were managed effectively across the 22 study sites, Dr Neelapu added, and most sites had no prior CAR T-cell therapy experience.

Dr Neelapu noted that the ZUMA-1 results are consistent with earlier KTE-C19 trials in aggressive NHL.

The primary analysis for this phase 2 study is expected to occur when all treated patients have 6 months of follow-up in the first quarter of 2017.

The study is sponsored by Kite Pharma but is also funded, in part, by the Leukemia and Lymphoma Society Therapy Acceleration Program.

*Information in the abstract differs from that presented at the meeting.