Citations

7512 Background: Outcomes in activated B cell subtype diffuse large B cell lymphoma (ABC-DLBCL) and r-NHL are poor (Sehn Blood 2015, Crump ASCO 2016). ZUMA-1 is the first, multicenter trial of anti-CD19 chimeric antigen receptor (CAR) T cells, axi-cel, in r-NHL. Methods: Dosing and eligibility were per Neelapu ASH 2016. The primary endpoint was objective response rate (ORR); secondary endpoints were duration of response (DOR), overall survival (OS), and safety. Cell of origin (COO) and CD19 status were assessed centrally using Lymphoma Subtyping Test NanoString (Wallden JCO 2015) and a validated immunohistochemistry assay, respectively. Results: As of Jan 27, 2017, 111 patients (pts) were enrolled; the manufacturing success rate was 99% with an average 17-d turnaround time; 101 pts (modified intent-to-treat [mITT] population) received axi-cel. In the mITT population, the ORR was 82% (complete response [CR], 54%). With 8.7 m median follow-up, 44% remain in response and 39% in CR. The median DOR was 8.1 m and not reached (NR) for pts with CR. Median OS was NR. Results for clinical and biologic covariates are listed in the table. In pts who received tocilizumab (n = 43) and/or steroids (n = 27) for cytokine release syndrome (CRS) and/or neurologic events (NE), ORR was 84% and 78%, respectively. Most common grade ≥3 adverse events (AEs) were neutropenia (66%), leukopenia (44%), anemia (43%), febrile neutropenia (31%), thrombocytopenia (24%), and encephalopathy (21%). Rates of grade ≥3 CRS and NE were 13% and 28%, respectively. There were 3 grade 5 AEs (Neelapu ASH 2016). Conclusions: Axi-cel induced an ORR of 82% in pts with r-NHL, response is ongoing in 44% of pts at 8.7 m. Similar clinical responses were observed in pts with r-ABC-DLBCL. AEs were manageable and the use of tocilizumab/steroids did not appear to impact ORR. Drs Locke and Neelapu contributed equally. Funding source: Kite Pharma and Leukemia & Lymphoma Society Therapy Acceleration Program Clinical trial information: NCT02348216. [Table: see text]

3025 Background: Axi-cel is an autologous anti-CD19 CAR T cell therapy. ZUMA-1 is a multicenter, registrational trial of axi-cel in patients (pts) with refractory/aggressive B-cell non-Hodgkin lymphoma (NHL). In a pre-specified interim analysis, ZUMA-1 met its primary endpoint with 76% objective response rate and 47% complete response (Blood 2016;128:LBA-6). We describe, for the first time, a tumor microenvironment immune gene signature associated with CAR T cell treatment (tx) of NHL pts. Methods: Paired biopsies, pre- and within 3 weeks post-axi-cel tx, were analyzed by digital gene expression followed by a pre-specified bioinformatics algorithm applied to IGES15 and IGES21 genes involved in immune-mediated tumor regression (Immunosign; Galon Immunity 2013). Immunosign profiles expression of a pre-defined set of effector T cell, Th1, chemokine, and cytokine genes. Expression analysis and hierarchical clustering were used to define an axi-cel-related tumor immune gene signature. Wilcoxon signed rank test with multiple test correction by FDR (Benjamini-Yekutieli) was used. Results: Gene expression profile comparisons of pre- and post-axi-cel tx biopsies from 14 pts showed profound changes in gene expression within the tumor environment after infusion. The most upregulated genes post-axi-cel tx were CCL5 (RANTES), CTLA4, and GZMA (log2 fold change > 2, P< 0.05, FDR < 0.050). Immune checkpoints PD-L1 and LAG3 were also upregulated post-axi-cel (log2 fold change > 1.6, P< 0.05, FDR < 0.055). Other genes associated with T cell proliferation, homing, and effector function were also upregulated: IL-15, GZMK, CXC3CL1 (Fractalkine), CD8A, and STAT4 (log2 fold change > 1.6; P< 0.05, FDR < 0.074). Additional baseline tumor characteristics and associative analysis will be presented. Conclusions: We define a mechanistic tumor immune gene signature in NHL pts associated with axi-cel tx. This signature comprises upregulation of T cell activation, effector, chemokine, and immune checkpoint genes. These data will potentially lead to rational optimization of T cell interventions in cancer Clinical trial information: NCT02348216.

3023 Background: Axi-cel (formerly KTE-C19) is an autologous anti-CD19 chimeric antigen receptor (CAR) T cell therapy. ZUMA-1 is a multicenter, registrational trial of axi-cel in patients (pts) with refractory aggressive non-Hodgkin lymphoma. In a prespecified interim analysis, ZUMA-1 met its primary endpoint, with a 76% objective response rate and a 47% complete response rate ( Blood 2016;128:LBA-6). Post-treatment CAR T cell blood levels were associated with objective response. Here, we describe novel associations between product characteristics and CAR T cell levels in pts. Methods: CAR T cell characteristics in axi-cel produced from 62 pts were analyzed by flow cytometry and modeled against CAR T cell levels. In vivo CAR T cell levels were measured by qPCR. T cell expansion during production (fold expansion/total days in culture) was compared with CAR T cell blood levels, using a partition analysis with expansion rates of ≥1 vs < 1. Wilcoxon 2-sample test and linear regression were used. Results: Axi-cel contained CCR7+ T cells (median, 42%; range, 15–73%), with naïve (CD45RA+/CCR7+; median, 12%; range, 1–57%), central memory (CD45RA−/CCR7+; median, 29%; range, 12–49%) phenotypes, and more differentiated CCR7− effector memory and effector T cells. On infusion, CAR T cells expanded rapidly, reaching peak levels within 2 weeks (median, 43 cells/μL; range, 1–1513), and were also measurable in all pts at 1 month (median, 2 cells/μL; range, 0.03–89). The CCR7+/CCR7− T cell ratio in axi-cel associated positively with peak ( P =0.001) and cumulative ( P =0.003) CAR T cell levels through 1 month. Axi-cel lots that expanded more rapidly during production (≥1.0-fold/d; n = 18/62) associated with higher cumulative levels of CAR T cells ( P =0.03). Other product characteristics, eg, CD4/CD8 ratio or number of infused T cells, were not significantly associated with CAR T cell blood levels. Conclusions: An association was observed between CAR T cell expansion in vivo and both the T cell growth rate during production and product cell phenotype pretreatment. A key attribute of axi-cel product was the presence of CCR7+ naïve/central memory T cells, without upfront T cell subset selection. Clinical trial information: NCT02348216.

1005 Background: Evidence-based treatments (tx) for metastatic, HER2+ BCBM are limited. We previously found a central nervous system (CNS) objective response rate (ORR) of 8% (95% CI 2-22%) for the irreversible, EGFR/HER2-targeted kinase inhibitor, neratinib. To enhance CNS activity, we evaluated the combination of neratinib + capecitabine in a subsequent cohort, and report results here. Methods: Pts with measurable BCBM (≥ 1 cm in longest dimension) and no prior lapatinib or capecitabine were eligible. All but 3 had CNS progression after local CNS tx. During 21 day cycles, pts received capecitabine 750 mg/m2 twice daily x 14 days followed by 7 days off + neratinib 240 mg orally once daily. Loperamide prophylaxis (16 mg total daily) was recommended during cycle 1. Brain MRI and non-CNS imaging were repeated every 2 cycles until 18 wks, then every 3 cycles. The primary endpoint was composite CNS ORR, requiring all of the following: ≥50% reduction in volumetric sum of target CNS lesions (central review, VORR), no progression of non-target or non-CNS lesions, no new lesions, no escalating steroids, and no progressive neurologic signs/symptoms. We used a two-stage design with hypotheses ORR 15% and 35% (error rates 5% and 20%), responses in ≥5/19 pts to enter 2ndstage; responses in ≥9/35 [26%] pts to be promising. Results: 39 pts enrolled between 4/2014-11/2016 (2 withdrew before tx, 37 analyzed); median age 51, median prior metastatic lines 2 (range 0-6), 65% had prior WBRT. As of 11/15/16, 23 (62%) patients are alive and 7 remain on protocol tx; median number of cycles initiated = 5 (range 1-26). 18 women (49%) had a VORR (95% CI 32-66%, neurologic exams not yet available on all pts). Overall 12-month survival is 63% (95% CI 43%-77%); 4/7 pts still on protocol therapy have not yet reached 6 cycles. No pts had grade 4 toxicity; 18 (49%) had grade 3 toxicity, with diarrhea most common (32%), and 6 pts discontinued tx for toxicity. Conclusions: The combination of neratinib and capecitabine is active for BCBM with VORR in nearly half of pts, supporting further development of the regimen for BCBM. Updated results will be presented at the meeting. Clinical trial information: NCT01494662.

3010 Background: To test the safety and efficacy of the CAR T cell modality in relapsed/refractory multiple myeloma (MM), we have designed a second-generation CAR construct targeting B cell maturation antigen (BCMA) to redirect T cells to MM. bb2121 consists of autologous T cells transduced with a lentiviral vector encoding a novel CAR incorporating an anti-BCMA scFv, a 4-1BB costimulatory motif and a CD3-zeta T cell activation domain. We will report updated safety and efficacy following initial results (Berdeja et al, ENA 2016). Methods: CRB-401 (NCT02658929) is a multi-center phase 1 dose escalation trial of bb2121 in patients with relapsed and/or refractory MM who have received ≥ 3 prior regimens, including a proteasome inhibitor and an immunomodulatory agent, or are double-refractory, and have ≥ 50% BCMA expression on plasma cells. Peripheral blood mononuclear cells are collected via leukapheresis. Patients undergo lymphodepletion with Flu (30 mg/m 2 ) / Cy (300 mg/m 2 ) daily for 3 days then receive 1 infusion of bb2121. The study follows a standard 3+3 design with planned dose levels of 5, 15, 45, 80 and 120 x 10 7 CAR+ T cells. Results: As of November 18, 2016, 11 patients had been infused with bb2121 in the first 4 dose cohorts, and 9 patients had reached at least 1 month of follow-up. As of data cut-off, no dose-limiting toxicities and no > Grade 2 neurotoxicities or cytokine release syndrome (CRS) had been observed. Grade 1-2 CRS had been reported in 8/11 (73%) treated patients. All patients treated with doses of 15.0 x 10 7 or higher remained on study and the overall response rate (ORR) in the 6 evaluable patients at these doses was 100%, including 2 sCRs and 2 MRD-negative responses (1 sC, 1 VGPR). CAR+ T cell expansion has been demonstrated consistently. An additional 6 months of follow up on previously reported results and initial data from an additional ~10 patients will be presented. Conclusions: bb2121 shows promising efficacy at dose levels above 5 x 10 7 CAR+ T cells, including 2 sCRs and ongoing clinical responses at 6 months, with mild and manageable CRS to date. These initial data support the potential of CAR T therapy with bb2121 as a new treatment paradigm in MM. Study sponsored by bluebird bio. Clinical trial information: NCT02658929.