Transcend NHL 001: Immunotherapy with the CD19-Directed CAR T-Cell Product JCAR017 Results in High Complete Response Rates in Relapsed or Refractory B-Cell Non-Hodgkin Lymphoma

Background:

Based on promising results seen in patients treated with CD19-directed CAR-T cells in relapsed or refractory (R/R) pediatric B-cell acute lymphoblastic leukemia (Gardner, ASCO 2016) and adult B-cell non-Hodgkin lymphoma (Turtle, ASCO 2016), we are conducting a multicenter phase 1 trial of JCAR017 in R/R diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL) (ClinicalTrials.gov Identifier: NCT02631044). JCAR017 is a second-generation, CD19-directed CAR-T cell product of defined cellular composition consisting of a 1:1 ratio of CD8⁺:CD4⁺ CAR⁺ T cells.

Methods:

Patients with R/R DLBCL (de novo or transformed from indolent lymphoma), follicular lymphoma grade 3B, or MCL and adequate organ function are eligible. There was no minimum absolute lymphocyte count (ALC) requirement for apheresis and no test expansion required. Treatment includes lymphodepletion (fludarabine 30 mg/m² and cyclophosphamide 300 mg/m² daily for 3 days) and JCAR017 given 2-7 days post-lymphodepletion at a starting dose of 5 x 10⁷ CAR⁺ T cells (DL1). Single-dose and two-dose schedules are being evaluated. Primary objectives include safety and pharmacokinetics (PK) of JCAR017 measured by flow cytometry and quantitative PCR. Secondary objectives include complete and overall response (CR, OR) rates and duration of response (DOR). Response is assessed using the Lugano (2014) criteria.

Results:

As of August 1, 2016, 39 patients have been enrolled and 28 patients apheresed. Fourteen patients have been treated, all at DL1. Eight were male and 6 female. Thirteen patients had DLBCL and 1 had MCL. Median age was 61 years (range 37-79) and median number of prior therapies was 5 (range 2-9). Ten patients had undergone prior transplant (7 autologous; 3 allogeneic). Of the 14 patients, there were no cases of severe cytokine release syndrome (sCRS); 3 patients had low grade CRS (21%) (2 grade 1; 1 grade 2) and none required treatment with tocilizumab. Two of the 14 treated patients (14%) had neurotoxicity: 1 grade 4 encephalopathy and 1 grade 4 seizure. Both were in patients with DLBCL and were dose-limiting toxicities. Two deaths were seen in the DLBCL group and were due to disease progression. Twelve patients had at least 1 post-treatment response assessment; 11 patients with DLBCL and 1 with MCL. The patient with MCL had progressive disease at day 29 (D29). In the DLBCL group, response rates were: 82% (9/11) OR, 73% (8/11) CR, 9% (1/11) PR and 18% (2/11) PD at the time of post-treatment assessment on D29. All but one patient who achieved a CR were in remission at the time of this data cut. One DLBCL patient in CR had a parenchymal brain lesion in the right temporal lobe that also completely resolved. Of note, this patient had no CRS or neurotoxicity associated with JCAR017 treatment. The PK profile of JCAR017 in the peripheral blood and bone marrow show cellular expansion in all patients with persistence out to at least 3 months in patients with adequate follow up. Exploratory biomarker analyses will be presented at the meeting along with updated clinical data.

Conclusions: Treatment with the defined cellular composition product JCAR017 following lymphodepletion with fludarabine and cyclophosphamide results in high CR rates in patients with heavily pretreated DLBCL, including the first report of a CR in a patient with secondary CNS lymphoma. Observed toxicities are manageable and compare favorably to other reported CAR T-cell products.