ALBERT

Description: CD19-targeted chimeric antigen receptor-engineered (CD19 CAR) T cell therapy has shown significant efficacy for relapsed or refractory (R/R) B-cell malignancies. Yet CD19 CAR T cells fail to induce durable responses in most patients. Second infusions of CD19 CAR T cells (CART2) have been considered as a possible approach to improve outcomes. We analyzed data from 44 patients with R/R B-cell malignancies (ALL, n=14; CLL, n=9; NHL, n=21) who received CART2 on a phase 1/2 trial at our institution. Despite a CART2 dose increase in 82% of patients, we observed a low incidence of severe toxicity after CART2 (grade ≥3 CRS, 9%; grade ≥3 neurotoxicity, 11%). After CART2, CR was achieved in 22% of CLL, 19% of NHL, and 21% of ALL patients. The median durations of response after CART2 in CLL, NHL, and ALL patients were 33, 6, and 4 months, respectively. Addition of fludarabine to cyclophosphamide-based lymphodepletion before CART1 and an increase in the CART2 dose compared to CART1 were independently associated with higher overall response rates and longer progression-free survival after CART2. We observed durable CAR T-cell persistence after CART2 in patients who received Cy-Flu lymphodepletion before CART1 and a higher CART2 compared to CART1 cell dose. The identification of two modifiable pre-treatment factors independently associated with better outcomes after CART2 suggests strategies to improve in vivo CAR T-cell kinetics and responses after repeat CAR T-cell infusions, and has implications for the design of trials of novel CAR T-cell products after failure of prior CAR T-cell immunotherapies.

Description: CD19-targeted chimeric antigen receptor (CAR)-T cell therapy is a novel treatment with promising results for patients with relapsed/refractory lymphoid malignancies. CAR-T cell therapy has known early toxicities of cytokine release syndrome (CRS) and neurotoxicity, but little is known about long-term neuropsychiatric adverse effects. We have utilized patient-reported outcomes (PROs), including PROMIS®measures, to assess outcomes of patients with relapse/refractory chronic lymphocytic leukemia (CLL), non-Hodgkin lymphoma (NHL), and acute lymphoblastic leukemia (ALL) who were treated with CD19-targeted CAR-T cells on a clinical trial in our institution (NCT01865617) and survived at least one year after treatment. Between October 2018 to February 2019, 52 patients (at their 1-5 year anniversary after CAR-T cell therapy) were sent a questionnaire. The questionnaire included the PROMIS Scale v1.2-Global Health and the PROMIS-29 Profile v2.1, as well as 30 additional questions, including questions pertaining to cognitive function. As of February 28, 2019, 40 questionnaires were returned (76.9% response rate) and were included in the analysis. Patients' characteristics are summarized in Table 1. Cognitive function was assessed by asking if patients had experienced difficulties with concentration, finding words, memory, or solving problems since their CAR-T cell therapy; answer "yes" to each of the questions received "1" point to determine the total cognitive difficulty score (0-4). PROMIS measures are standardized to a T-score metric, with a score of 50 representing the general US population mean. Clinically meaningful differences were defined as a 5-point difference in scores (1/2 standard deviation). The cohort's self-reported cognitive difficulties and PROMIS mean T scores are shown in Table 2. Mean T scores of PROMIS domains of Global Mental health, Global Physical Health, Social Function, anxiety, depression, fatigue, pain and sleep disturbance were not clinically meaningfully different from the mean in the general US population. However, 19 participants (47.5%) reported at least one cognitive difficulty and/or clinically meaningful depression and/or anxiety (Figure 1), and 7 participants (17.5%) scored ≤ 40 in Global Mental Health, indicating at least one standard deviation worse than the general population mean. On risk factor analysis, younger age was found to be associated with worse Global Mental Health (p=0.02), anxiety (p=0.01) and depression (p=0.01). Anxiety prior to CAR-T cell therapy was associated with increased likelihood of anxiety after CAR-T cell therapy (p=0.001). Multivariate analysis confirmed association between age and PROMIS Global Mental Health score (p=0.03). 15 participants (37.5%) reported cognitive difficulties post CAR-T cell therapy. On multivariate analysis, depression prior to CAR-T cell therapy was statistically significantly associated with higher likelihood of self-reported cognitive difficulties after CAR-T therapy (p=0.02) and there was a trend for association between acute neurotoxicity after CAR-T cell infusion and self-reported long-term cognitive difficulties (p=0.08). Having more cognitive difficulties was associated with worse Global Mental Health (p=0.0001) and worse Global Physical Health (p= 0.01). Similarly, worse scores for pain interference, sleep disturbance, fatigue, depression, anxiety, physical function, and social function were associated with more long-term self-reported cognitive difficulties (p=0.007,p=0.0003, p=0.00006, p=0.01, p=0.0007, p=0.003, p=0.0004 respectively). Our study demonstrates overall good neuropsychiatric outcomes in 40 long-term survivors after CAR-T cell therapy. However, despite good overall mean scores, nearly 50% of patients in the cohort reported at least one negative neuropsychiatric outcome (anxiety, depression or cognitive difficulty), and almost 20% scored at least one standard deviation lower than the general US population mean in Global Mental Health, indicating that there is a significant number of patients who would likely benefit from mental health services following CAR-T cell therapy. Younger age, anxiety and depression pre-CAR-T cell therapy, and acute neurotoxicity after CAR-T cell infusion may be risk factors for long-term neuropsychiatric problems in this patient population. Larger studies are needed to confirm these findings. Disclosures Shaw: Therakos: Other: Speaker Engagement. Lee:AstraZeneca: Research Funding; Incyte: Research Funding; Syndax: Research Funding; Amgen: Research Funding; Novartis: Research Funding; Takeda: Research Funding; Kadmon: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding. Turtle:T-CURX: Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Other: Ad hoc advisory board member; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Allogene: Other: Ad hoc advisory board member; Humanigen: Other: Ad hoc advisory board member; Juno Therapeutics: Patents & Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Ad hoc advisory board member. Maloney:Juno Therapeutics: Honoraria, Patents & Royalties: patients pending , Research Funding; A2 Biotherapeutics: Honoraria, Other: Stock options ; Celgene,Kite Pharma: Honoraria, Research Funding; BioLine RX, Gilead,Genentech,Novartis: Honoraria.

Description: Background CD19-targeted chimeric antigen receptor-engineered (CD19 CAR)-T cell immunotherapy has shown promising efficacy in patients with relapsed or refractory (R/R) B-cell malignancies. The potential benefits of repeat infusions of CD19 CAR-T cells are unknown, and the factors associated with response, CAR-T cell in vivo expansion, and progression-free survival (PFS) after repeat infusion of CD19 CAR-T cells have not been investigated. Methods We analyzed the outcomes of patients with R/R B-cell malignancies after a second infusion of CD19 CAR-T cells (CART2) on a phase 1/2 trial (NCT01865617) at our institution. Responses after CAR-T cell therapy were evaluated around day 28 after infusion and defined according to the 2018 NCCN guidelines for acute lymphoblastic leukemia (ALL), 2018 iwCLL for chronic lymphocytic leukemia (CLL), and the Lugano criteria for non-Hodgkin lymphoma (NHL). Logistic, Cox and linear regression were used for multivariable analyses of response, progression-free survival and peak CD8+ CAR-T in blood, respectively. Bayesian model averaging was performed for variable selection. Results Forty-four patients evaluable for response (ALL, n=14; CLL, n=11; NHL, n=19) were included in this study. The median age at the time of CART2 was 58 (range, 23-73). Patients were heavily pre-treated (median prior therapies, 6; range, 2-13), and 16 patients (36%) had bulky (≥ 5cm) nodal or extramedullary disease. The median time from the first CAR-T infusion (CART1) to CART2 was 70 days (range, 28-712). Twenty-eight patients (64%) had received a CART1 dose ≥ 2x106 CAR-T cells/kg. Fifteen patients (32%) had not responded to CART1, 22 (50%) relapsed or progressed after having initially responded (complete response [CR], n=15; partial response [PR], n=7) to CART1; 7 (16%) received CART2 in PR after CART1. All characteristics are shown in the Table. We observed responses in all disease types, including 3 of 14 ALL patients (21%; all CR/CRi), 4 of 11 CLL patients (36%; CR/CRi, n=3; partial response [PR], n=1), and 9 of 19 NHL patients (47%; CR, n=2; PR, n=7). After a median follow-up of 43 months (range, 16-66) in alive and responding patients, the estimated 4-year PFS probability in responders was 23% (95% CI, 9-59%). The 4-year overall survival probability in responders was 36% (95% CI 19-71%) compared to 24% (95% CI, 12-47) in non-responders. Multivariable logistic regression modeling identified predictors of response after CART2: CART1 lymphodepletion (high-intensity cyclophosphamide and fludarabine [CyFlu] vs no CyFlu, OR=12.19, 95% CI, 1.10-1689.85, p=0.04), and peak of in vivo CAR-T cell expansion after CART2 (OR=2.31 per log10 CD8+ CAR-T cell/µL increase, 95% CI, 1.17-5.29, p=0.01). In a multivariable Cox model, a higher peak of CD8+ CAR-T cells after CART2 (HR=0.47 per log10 CD8+ CAR-T cell/µL increase, 95%CI, 0.33-0.68, p CART1 cell dose was associated with longer PFS (HR=0.36, 95% CI, 0.16-0.86, p=0.02). This suggested that CD8+ CAR-T cell peak after CART2 and factors increasing CART2 peak (e.g. prevention of immune rejection or increase in the infused cell dose) are key elements associated with outcomes of CART2. Hence, we looked at factors associated with higher CD8+ CART2 peak. In multivariable linear regression, CART1 CyFlu predicted a higher peak of CD8+ CAR-T cells after CART2 (high-intensity CyFlu vs no CyFlu, p

Description: Key PointsPriming of CMV-specific CD4+ and CD8+ T cells occurs as early as day 42 in patients undergoing UCBT. Lack of CMV control in UCBT patients could be related to low absolute frequency of T cells and lack of in vivo expansion of T cells.

Description: Background: IL-15-mediated responses have been shown to have a crucial role in the development, function, and survival of CD8+ T cells, natural killer (NK) cells, and NK T cells. However, exploiting native IL-15 is challenging due to its unfavorable pharmacokinetics and tolerability. NKTR-255 is a polymer-conjugated IL-15 that retains binding affinity to IL-15Ra, maintaining full spectrum of IL-15 biology. NKTR-255 also exhibits improved pharmacokinetics, thereby providing sustained pharmacodynamic responses without the need for daily dosing. Studies have indicated that NK cells from patients with multiple myeloma (MM) appear to be dysfunctional, and successful activity against MM cells requires highly active NK cells ideally activated from immunomodulatory agents or cytokine support. In recent years, several new agents have been introduced in the MM landscape to engage NK-mediated myeloma cell elimination, including the CD38-targeting monoclonal antibody daratumumab, and elotuzumab, further supporting the anti‐MM effect of NK cells in the post-autologous transplant setting. In non-Hodgkin lymphoma (NHL), studies have shown low peripheral blood NK cell counts are associated with poor clinical outcomes in diffuse large B-cell lymphoma patients receiving R-CHOP chemotherapy regimens. Recently published data indicate that NKTR-255 in combination with CAR T cells decreases tumor burden and increases survival compared to CAR T cells alone. NKTR-255 may address the need to boost NK cell quality and numbers in these patients with the purpose of aiding current approved therapies. Methods: In this phase 1, open-label, multi-center, dose escalation and dose expansion study of NKTR-255, patients with relapsed or refractory (r/r) MM or NHL with no available therapies will be eligible. In the dose escalation portion, approximately 46 patients will be enrolled. Successive cohorts of 3 patients each will receive single increasing doses of NKTR-255 until the maximum tolerated dose (MTD) is determined. All patients will receive NKTR-255 once every three weeks. Patients will be observed for a dose-limiting toxicity (DLT) window of three weeks following the first NKTR-255 dose. A two-parameter Bayesian logistic regression model (BLRM) will be used during the escalation part of the study for dose level selection and for determination of MTDs. The selected recommended phase 2 dose (RP2D) of NKTR-255 will be evaluated in two dose expansion cohorts. Cohort A will expand NKTR-255 in patients with r/r MM or NHL as a salvage regimen to further characterize safety and tolerability. Cohort B will combine NKTR-255 with daratumumab in patients with MM with progressive disease who have had at least 3 prior lines of therapy with no other regimens that would confer clinical benefit. Daratumumab will be administered IV at the standard approved regimen. The primary objectives of the study are to evaluate: safety, tolerability, MTD, and RP2D of NKTR-255 as a single agent, as well as safety and tolerability of NKTR-255 in combination with daratumumab in patients with r/r MM. Secondary objectives include measures biomarker and pharmacokinetic analyses. Figure Disclosures Shah: University of California, San Francisco: Employment; Nkarta: Consultancy, Membership on an entity's Board of Directors or advisory committees; Kite: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene, Janssen, Bluebird Bio, Sutro Biopharma: Research Funding; Poseida: Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Teneobio: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech, Seattle Genetics, Oncopeptides, Karoypharm, Surface Oncology, Precision biosciences GSK, Nektar, Amgen, Indapta Therapeutics, Sanofi: Membership on an entity's Board of Directors or advisory committees; Indapta Therapeutics: Equity Ownership. Turtle:Nektar Therapeutics: Other: Ad hoc advisory board member, Research Funding; T-CURX: Membership on an entity's Board of Directors or advisory committees; Allogene: Other: Ad hoc advisory board member; Humanigen: Other: Ad hoc advisory board member; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Patents & Royalties: Co-inventor with staff from Juno Therapeutics; pending, Research Funding; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Kite/Gilead: Other: Ad hoc advisory board member; Novartis: Other: Ad hoc advisory board member. Cowan:Cellectar: Consultancy; Juno: Research Funding; Sanofi: Consultancy; Janssen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Abbvie: Research Funding. Chavez:Kite: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees; Genentech: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Bayer: Membership on an entity's Board of Directors or advisory committees; Karyopharm: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees. Budde:F. Hoffmann-La Roche Ltd: Consultancy. Marcondes:Nektar Therapeutics: Employment, Equity Ownership. Lee:Nektar Therapeutics: Employment. Lin:Nektar Therapeutics: Employment, Equity Ownership. Zalevsky:Nektar Therapeutics: Employment, Equity Ownership. Tagliaferri:Nektar Therapeutics: Employment, Equity Ownership. Patel:Poseida Therapeutics, Cellectis, Abbvie: Research Funding; Oncopeptides, Nektar, Precision Biosciences, BMS: Consultancy; Takeda, Celgene, Janssen: Consultancy, Research Funding.

Description: Introduction Lymphodepletion chemotherapy followed by infusion of T cells engineered to express a CD19-specific chimeric antigen receptor (CAR) has shown remarkable efficacy in patients (pts) with relapsed/refractory (R/R) CD19+ B-cell malignancies, with high response rates reported in non-Hodgkin lymphoma (NHL). Durable responses have been observed in a subset of pts, but the factors associated with these long-term remissions have not been identified. We studied adults with R/R CD19+ B-cell NHL treated with cyclophosphamide and fludarabine lymphodepletion followed by infusion of 2 x 106 CD19 CAR-T cells/kg, and identified factors before and after CAR-T cell infusion that are associated with progression-free survival (PFS). Methods We conducted a phase 1/2 open-label clinical trial (NCT01865617) with the primary objective of evaluating the feasibility and safety of infusing a defined composition of CD4+ and CD8+ CD19 CAR-T cells after lymphodepletion chemotherapy in pts with R/R CD19+ B-cell malignancies. Best responses are reported according to the Lugano criteria (Cheson, JCO 2014). PFS was defined as the time from CAR-T cell infusion until disease progression or death, without censoring for new therapy. Logistic regression and penalized Cox regression multivariable modeling using elastic net were performed for analysis of response and PFS, respectively. Results Characteristics of the 57 pts in the study are shown in Table 1. One patient with incomplete response assessment was excluded. For the 56 remaining pts, the best overall response rate (ORR) without additional therapy was 57% (95% confidence interval [CI], 43-70%), with 48% achieving complete remission (CR; 95% CI, 35-62%). Most pts with partial response (PR) or stable disease (SD) after initial restaging at 4 weeks after CAR-T cell infusion received new therapy (11 of 15, 73%). All pts with PR/SD on initial restaging who did not receive additional therapy after CAR-T cells (n = 4) subsequently achieved CR. The duration of persistence of CAR-T cells was longer in pts who did not receive new therapy (15.7 vs. 5.3 months; P = .06). Eight of 9 pts with indolent histology achieved CR (89%; 95% CI, 51-99%). For the 47 pts with aggressive NHL, the best ORR was 51% (95% CI, 36-66%), with 40% (95% CI, 27-56%) achieving CR. Among aggressive NHL subtypes, pts with DLBCL (n = 28) had best ORR and CR rates of 50% (95% CI, 33-67%) and 43% (95% CI, 25-63%), respectively. In pts with aggressive lymphoma, multivariable analysis showed that the probability of achieving CR was independently associated with a lower pre-lymphodepletion serum LDH concentration (P = .003) and greater increase in serum MCP-1 concentration from a pre-lymphodepletion timepoint to immediately before CAR-T cell infusion (P = .01). Analysis of pts with all histologic subtypes showed that those achieving CR had better PFS and overall survival (OS) compared to those who did not achieve CR (median PFS: CR, not reached; non-CR, 1.35 month; Figure 1). In pts achieving CR, after a median follow-up of 20.2 months (range 2.5-32.4 months), the 24-month probabilities of PFS and OS were 59% (95% CI, 41-84%) and 79% (95% CI, 64-97%), respectively. No pts with indolent NHL who achieved CR (n = 8) have relapsed with a median follow-up of 14.5 months (range, 10.7-30.1 months). For pts with aggressive lymphoma who achieved CR, after a median follow-up of 26.9 months (range, 2.5-32.4 months), the median PFS was 20.0 months (95% CI, 9.2-not reached), and 24-month probabilities of PFS and OS were 46% (95% CI, 28-76%) and 72% (95% CI, 54-96%), respectively. In aggressive NHL, multivariable analysis suggested that, in addition to being associated with the probability of achieving CR, serum LDH and MCP-1 concentration also impacted the probability of longer PFS. The model found that lower pre-lymphodepletion serum LDH (P = .0004) and higher serum MCP-1 peak after CAR-T cell infusion (P = .05), along with higher serum IL-7 (P = .02) and lower serum IL-18 (P = .02) concentrations before lymphodepletion were independently associated with better PFS. Similar findings were obtained after multivariable analysis was performed only in those who had achieved CR. Conclusion CR after CD19 CAR-T cell therapy appears to be a strong predictor of PFS in adult pts with B-cell NHL. Identification of additional factors associated with better PFS might guide future management strategies for pts achieving CR after CD19 CAR-T cell therapy. Disclosures Hirayama: DAVA Oncology: Honoraria. Hay:DAVA Oncology: Honoraria. Li:Juno Therapeutics: Employment, Equity Ownership. Lynch:Incyte: Research Funding; Johnson Graffe Keay Moniz and Wick LLP: Consultancy; Juno Therapeutics: Research Funding; Rhizen Pharmaceuticals: Research Funding; Takeda: Research Funding. Till:Mustang Bio: Patents & Royalties, Research Funding. Kiem:Homology Medicine: Consultancy; Rocket Pharmaceuticals: Consultancy; Magenta: Consultancy. Ramos:Seattle Genetics: Employment, Equity Ownership. Shadman:Gilead Sciences: Research Funding; Genentech: Consultancy; Pharmacyclics: Research Funding; Celgene: Research Funding; Mustang Biopharma: Research Funding; Genentech: Research Funding; TG Therapeutics: Research Funding; Acerta Pharma: Research Funding; AbbVie: Consultancy; Verastem: Consultancy; Beigene: Research Funding; AstraZeneca: Consultancy; Qilu Puget Sound Biotherapeutics: Consultancy. Cassaday:Jazz Pharmaceuticals: Consultancy; Amgen: Consultancy, Research Funding; Kite Pharma: Research Funding; Adaptive Biotechnologies: Consultancy; Merck: Research Funding; Pfizer: Consultancy, Research Funding; Seattle Genetics: Other: Spouse Employment, Research Funding; Incyte: Research Funding. Acharya:Juno Therapeutics: Research Funding; Teva: Honoraria. Riddell:Cell Medica: Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; NOHLA: Consultancy; Adaptive Biotechnologies: Consultancy. Maloney:GlaxoSmithKline: Research Funding; Juno Therapeutics: Research Funding; Roche/Genentech: Honoraria; Seattle Genetics: Honoraria; Janssen Scientific Affairs: Honoraria. Turtle:Bluebird Bio: Consultancy; Juno Therapeutics / Celgene: Consultancy, Patents & Royalties, Research Funding; Nektar Therapeutics: Consultancy, Research Funding; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Consultancy; Gilead: Consultancy; Adaptive Biotechnologies: Consultancy; Aptevo: Consultancy.

Description: Background We reported durable responses to CD19-specific chimeric antigen receptor-modified T-cell therapy (JCAR014) in relapsed/refractory (R/R) chronic lymphocytic leukemia (CLL) patients (pts) after prior failure of ibrutinib (Turtle, JCO 2017; NCT01865617). In those pts, ibrutinib was not administered during CAR-T cell immunotherapy. Continuation of ibrutinib through leukapheresis, lymphodepletion and CAR-T cell therapy may prevent tumor progression after ibrutinib withdrawal, mobilize tumor into the blood, improve CAR-T cell function, and decrease cytokine release syndrome (CRS). Methods We conducted a phase 1/2 study of CD19 CAR-T cell immunotherapy in R/R CLL pts and established a regimen of cyclophosphamide and fludarabine (Cy/Flu) lymphodepletion followed by JCAR014 at 2 x 106 CAR-T cells/kg (Turtle, JCO 2017). We then compared outcomes of these pts (No-ibr cohort) with a subsequent cohort that received Cy/Flu with 2 x 106/kg JCAR014 CAR-T cells with concurrent ibrutinib (420 mg/d) from at least 2 weeks prior to leukapheresis until at least 3 months after JCAR014 infusion (Ibr cohort). Dose reduction was permitted for toxicity. CRS was graded by consensus criteria (Lee, Blood 2014) and neurotoxicity and other adverse events were graded by CTCAE v4.03. Response was evaluated according to 2008 IWCLL criteria. Results Seventeen and 19 pts were treated in the Ibr and No-ibr cohorts, respectively. Pt characteristics were comparable (Table 1). Progression on ibrutinib was noted in 16 (94%) and 18 pts (95%) in the Ibr and No-ibr cohorts, respectively, and prior ibrutinib intolerance was reported in 1 pt in each cohort. The time to intolerance or failure of ibrutinib prior to treatment with JCAR014 was longer, and the pre-leukapheresis LDH was lower in the Ibr compared to the No-ibr cohort. The median follow-up in responders was 98 and 764 days in the Ibr and No-ibr cohorts, respectively. Administration of ibrutinib with Cy/Flu and JCAR014 was well tolerated in most pts; ibrutinib was reduced or discontinued in 6 pts (35%) at a median of 21 days after JCAR014 infusion. In the Ibr cohort, 1 pt with grade 2 CRS developed fatal presumed cardiac arrhythmia and 1 pt developed a subdural hematoma in the setting of trauma and thrombocytopenia. No differences in the incidences of grade ≥3 cytopenias were observed. Concurrent ibrutinib administration did not appear to affect the frequency or severity of neurotoxicity. Although the proportions of pts with grade ≥1 CRS were similar between cohorts (76% vs 89%, P = 0.39), the severity of CRS (grade ≥3 CRS: Ibr, 0%; No-Ibr, 26%; P = 0.05) and serum peak IL-8 (P = 0.04), IL-15 (P = 0.003) and MCP-1 (P = 0.004) concentrations were lower in the Ibr cohort. However, we found comparable CD8+ (P = 0.29) and higher CD4+ (P = 0.06) CAR-T cell counts in blood in the Ibr cohort. Sixteen pts (94%) and 18 pts (95%) in the Ibr and No-ibr cohorts, respectively, have completed response assessment. We observed a higher proportion of responders (complete and partial remission) by IWCLL criteria in the Ibr compared to the No-ibr cohort (88% vs 56%, respectively, P = 0.06). Ten of 12 pts (83%) with lymph node disease before treatment with Cy/Flu and JCAR014 in the Ibr cohort achieved CR or PR by IWCLL imaging criteria, compared to 10/17 pts (59%) in the No-ibr cohort (P = 0.23). The proportion of pts with pretreatment bone marrow (BM) disease who had no disease by flow cytometry after CAR-T cell immunotherapy was similar in the Ibr compared to the No-ibr cohort (75% vs 65%, P = 0.71). However, among pts with no disease by BM flow cytometry after CAR-T cell immunotherapy, a higher proportion of pts in the Ibr cohort had no malignant IGH sequences at 4 weeks (83% vs 60%, respectively, P = 0.35). We performed univariate logistic regression analysis for response by IWCLL criteria and variables with P 〈 0.10 were considered for stepwise multivariable analysis (Table 2). In the multivariable analysis, the Ibr cohort and a lower pre-treatment SUVmax on PET imaging were each associated with a higher probability of response by IWCLL criteria (Ibr cohort, OR = 14.02, 95%CI [0.52-379.61], P = 0.05; SUVmax, OR = 1.31 per SUV unit decrease, 95%CI [1.05-1.67], P 〈 0.001). Conclusion Administration of ibrutinib from 2 weeks before leukapheresis until 3 months after JCAR014 was well tolerated in most pts. This approach might decrease the incidence of severe CRS and improve responses in pts with R/R CLL. Disclosures Hirayama: DAVA Oncology: Honoraria. Hay:DAVA Oncology: Honoraria. Li:Juno Therapeutics: Employment, Equity Ownership. Lymp:Juno Therapeutics: Employment, Equity Ownership. Till:Mustang Bio: Patents & Royalties, Research Funding. Kiem:Magenta: Consultancy; Homology Medicine: Consultancy; Rocket Pharmaceuticals: Consultancy. Shadman:TG Therapeutics: Research Funding; Celgene: Research Funding; Gilead: Research Funding; Qilu Puget Sound Biotherapeutics: Consultancy; AstraZeneca: Consultancy; Verastem: Consultancy; Beigene: Research Funding; Mustang: Research Funding; Genentech: Consultancy, Research Funding; Pharmacyclics: Research Funding; Acerta: Research Funding; Abbvie: Consultancy. Cassaday:Merck: Research Funding; Pfizer: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Seattle Genetics: Other: Spouse Employment, Research Funding; Incyte: Research Funding; Kite Pharma: Research Funding; Adaptive Biotechnologies: Consultancy; Jazz Pharmaceuticals: Consultancy. Acharya:Juno Therapeutics: Research Funding; Teva: Honoraria. Riddell:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Adaptive Biotechnologies: Consultancy; NOHLA: Consultancy; Cell Medica: Membership on an entity's Board of Directors or advisory committees. Maloney:GlaxoSmithKline: Research Funding; Juno Therapeutics: Research Funding; Seattle Genetics: Honoraria; Roche/Genentech: Honoraria; Janssen Scientific Affairs: Honoraria. Turtle:Nektar Therapeutics: Consultancy, Research Funding; Juno Therapeutics / Celgene: Consultancy, Patents & Royalties, Research Funding; Aptevo: Consultancy; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Caribou Biosciences: Consultancy; Adaptive Biotechnologies: Consultancy; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Consultancy; Gilead: Consultancy.

Description: BACKGROUND: CD19-specific chimeric antigen receptor (CAR) T-cell therapy has proven to be highly effective in patients with relapsed or refractory large B-cell lymphomas, yielding early complete response (CR) rates of ~40%, which are typically sustained. Unfortunately, most patients will not experience prolonged disease control. Despite this fact, little data exist defining the outcomes and impact of subsequent therapies for such individuals. Limited data also exist on the ability for such patients to pursue further clinical trials or allogeneic hematopoietic stem-cell transplant (HSCT). This project details the specific interventions and outcomes of this population to better inform the management of patients who suffer progressive disease (PD) after CD19-specific CAR T-cell therapy. METHODS: Adults with diffuse large B-cell lymphoma (DLBCL), transformed follicular lymphoma (tFL), primary mediastinal B-cell lymphoma (PMBCL), and high-grade B-cell lymphomas (HGBCL) who received CD19-specific CAR T-cells at the University of Washington/Seattle Cancer Care Alliance were included in this analysis. Patients who received CAR T-cell therapy in conjunction with additional protocol-specified therapy were excluded. Those who exhibited PD or persistent lymphoma after CAR T-cell therapy were the focus of this study. We defined initial PD as patients who had evidence of disease progression on the initial response assessment. Delayed PD was defined as achieving a CR, partial response (PR), or stable disease (SD) on the initial response assessment, but eventually progressed or received subsequent anti-lymphoma therapy. Baseline characteristics and all data were retrieved from the electronic medical record up until date of death or date of last contact in our system, including subsequent interventions and outcomes. Primary endpoint of this analysis was overall survival (OS). RESULTS: Between October 2013 and May 2018, we identified 51 patients with PD following CD19-specific CAR T-cell therapy. Baseline characteristics are listed in the Table 1. Histologies included DLBCL (29), HGBCL (11), tFL (8) and PMBCL (3). Median age was 60 years (range 26-75), 65% were male, median prior regimens was 3 (range 1-8). Median time from CAR T infusion to PD was 42 days (range 11-609), with 27 (53%) patients exhibiting initial PD. Median follow up after time of progression was 4.2 months. Initial PD was associated with a higher risk of death (HR 2.376, 95% CI 1.19-4.75, p=0.0143, Figure 1). The median OS for those with initial PD and delayed PD was 5.1 months (95% CI 2.0-9.3) and 13.6 months (4.1-not reached) respectively. 39 (76%) patients received ≥ 1 subsequent therapies after PD. Initial therapies included: 2nd CAR T infusion (14), targeted therapy (10), chemotherapy +/- rituximab (7), other immunotherapy (3), radiotherapy (3), intrathecal chemotherapy (1) and allogeneic HSCT (1). 12 (24%) patients received no further therapy despite PD. Those who received ≥ 1 subsequent therapies after PD had a lower risk of death (HR 0.344, 95% CI 0.149-0.793, P=0.0122) compared to those who did not. There was no difference in survival if 2nd CAR T infusion was the next line therapy compared to others (p=0.449), targeted therapy compared to others (p=0.417), or chemotherapy compared to others (p=0.565). 5 (10%) patients enrolled onto a clinical trial as next line therapy. 4 (8%) patients eventually received an allogeneic HSCT after PD, 2 of whom are still alive. We identified 8 patients who were alive for ≥ 12 months after progression without evidence of lymphoma. Last line of therapy for these patients included allogeneic HSCT (2), subsequent CD19-specific CAR-T cell infusion (2), ibrutinib (2), lenalidomide/rituximab (1), and radiotherapy (1). CONCLUSIONS: Patients with PD post anti-CD19 CAR T-cell therapy, particularly those exhibiting initial PD, have poor long-term outcomes. Patients receiving at least one anti-lymphoma therapy after PD had improved overall survival, although no single approach appeared to confer a survival benefit. Few enrolled onto a clinical trial or received an allogeneic HSCT. These data reinforce the need to both further improve the durable CR rate after CAR T-cell therapy and to develop effective strategies for those not achieving a CR. Figure 1 Figure 1. Disclosures Gopal: Spectrum: Research Funding; Pfizer: Research Funding; BMS: Research Funding; Seattle Genetics: Consultancy, Research Funding; Merck: Research Funding; Takeda: Research Funding; Brim: Consultancy; Janssen: Consultancy, Research Funding; Asana: Consultancy; Gilead: Consultancy, Research Funding; Aptevo: Consultancy; Incyte: Consultancy; Teva: Research Funding. Maloney:Juno Therapeutics: Research Funding; Roche/Genentech: Honoraria; Janssen Scientific Affairs: Honoraria; Seattle Genetics: Honoraria; GlaxoSmithKline: Research Funding. Turtle:Caribou Biosciences: Consultancy; Adaptive Biotechnologies: Consultancy; Nektar Therapeutics: Consultancy, Research Funding; Bluebird Bio: Consultancy; Precision Biosciences: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Juno Therapeutics / Celgene: Consultancy, Patents & Royalties, Research Funding; Eureka Therapeutics: Equity Ownership, Membership on an entity's Board of Directors or advisory committees; Aptevo: Consultancy; Gilead: Consultancy. Smith:Genentech: Research Funding; Acerta Pharma BV: Research Funding; Incyte Corporation: Research Funding; Merck Sharp and Dohme Corp.: Consultancy, Research Funding; Pharmacyclics: Research Funding; Portola Pharmaceuticals: Research Funding; Seattle Genetics: Research Funding. Shadman:TG Therapeutics: Research Funding; Mustang Biopharma: Research Funding; Acerta Pharma: Research Funding; AstraZeneca: Consultancy; Verastem: Consultancy; Gilead Sciences: Research Funding; AbbVie: Consultancy; Qilu Puget Sound Biotherapeutics: Consultancy; Beigene: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Genentech: Consultancy; Celgene: Research Funding. Cassaday:Seattle Genetics: Other: Spouse Employment, Research Funding; Incyte: Research Funding; Jazz Pharmaceuticals: Consultancy; Pfizer: Consultancy, Research Funding; Kite Pharma: Research Funding; Merck: Research Funding; Amgen: Consultancy, Research Funding; Adaptive Biotechnologies: Consultancy. Till:Mustang Bio: Patents & Royalties, Research Funding. Shustov:Seattle Genetics: Research Funding. Acharya:Juno Therapeutics: Research Funding; Teva: Honoraria. Lynch:Takeda Pharmaceuticals: Research Funding; T.G. Therapeutics: Research Funding; Rhizen Pharmaceuticals S.A.: Research Funding; Johnson Graffe Keay Moniz & Wick LLP: Consultancy; Incyte Corporation: Research Funding.

Description: BACKGROUND: Autologous T cells genetically modified to express a CD19-specific chimeric antigen receptor (CAR) have demonstrated activity in patients with relapsed or refractory B cell NHL and CLL. The functional heterogeneity that is inherent in CAR-T cell products that are manufactured from undefined T cell subsets has hindered definition of dose-response relationships and identification of factors that may impact efficacy and toxicity, such as the lymphodepletion regimen and infused cell dose. We manufactured anti-CD19 CAR-T cells from a defined composition of CD4+ and CD8+ T cell subsets to treat adults with relapsed or refractory B cell NHL or CLL. T cell subsets were enriched from each patient, transduced with a CD19 CAR lentivirus and separately expanded in vitro before formulation for infusion in a 1:1 ratio of CD8+:CD4+ CAR+ T cells at one of three dose levels (2x105, 2x106 or 2x107 CAR-T cells/kg). CAR-T cells were administered 48-96 hours after lymphodepletion with either cyclophosphamide (Cy, 60 mg/kg)+/- etoposide or Cy (60 mg/kg) and fludarabine (25 mg/m2 daily for 3-5 days (Cy/Flu). RESULTS: Adult patients with relapsed/refractory CD19 expressing B cell NHL (n=28, median age 59 years, range 36-70) or CLL (n=6, median age 60 years, range 54-64) were treated with at least one CAR-T cell infusion. NHL histologies include diffuse large B cell or transformed NHL (DLBCL, n=18), follicular NHL (FL, n= 6) or mantle cell lymphoma (MCL, n=4). 15 patients had failed prior autologous (n=13) or allogeneic (n=3) transplants. Twelve of the 28 NHL patients received lymphodepletion with Cy-based regimens without fludarabine. Expansion of CAR-T cells and clinical responses were observed in 50% (CR=1 (DLBCL), PR=5 (2 FL, 2 DLBCL, 1 MCL), no response=6). Patients were treated at all three dose levels without dose limiting toxicity or severe cytokine release syndrome (sCRS). With this regimen, we observed short CAR-T cell persistence in most patients and demonstrated a CD8-mediated immune response to the murine scFv component of the CAR transgene that correlated with loss of CAR-T cells. Retreatment with CAR-T cells with or without chemotherapy in 5 patients led to no significant T cell expansion or clinical responses. To minimize transgene rejection fludarabine was added to the lymphodepletion regimen administered to the subsequent 16 NHL patients. Clinical responses were evaluated in 12 of 16 patients (2 not yet evaluable, 2 early deaths). Addition of Flu to the lymphodepletion regimen increased the CR rate to 42%, compared to 8% with Cy alone. Clinical responses were identified in 6 of 8 patients with DLBCL (3 CR, 3 PR) and 2 of 3 patients with FL (2 CR). The overall response rate was 67%. We noted higher peak CAR-T cell levels in blood in the Cy/Flu group (n=13) compared with the Cy only group (n=11) (CD8+ CAR-T cells, median 31.9 cells/ml vs 0.55 cells/ml, p = 0.009; CD4+ CAR-T cells, median 16.5 cells/ml vs 0.31 cells/ml, p= 0.007), and CAR-T cell persistence was longer in Flu-treated patients (see Figure 1 for patients treated at 2 x 107/kg). Surprisingly, 2 of 7 patients who received 2 x 107 CAR-T cells/kg experienced dose-limiting toxicity necessitating dose de-escalation. Markedly elevated IL-6 levels were observed within the first day after CAR-T cell infusion in patients who subsequently developed severe toxicity, which may provide an opportunity to test early interventional approaches to minimize toxicity. Six patients with relapsed and refractory CLL received CAR-T cells. Five of 6 restaged patients had complete clearance of blood and/or marrow disease by high-resolution flow cytometry 4 weeks following treatment. Overall clinical responses included 3 CR, 1 PR and 2 no response. One patient with a PR died from refractory pulmonary aspergillus infection. Patients with CR remain in remission at 1-10 months after therapy. CONCLUSION: Immunotherapy with CD19 CAR-T cells of defined subset composition is feasible in patients with NHL and CLL and has potent anti-tumor activity. Toxicity is related to cell dose. The addition of Flu to a Cy-based lymphodepletion regimen results in greater CAR-T cell expansion and persistence, and improves the CR rate after CD19 CAR-T cell therapy. Disclosures Turtle: Juno Therapeutics: Patents & Royalties, Research Funding. Berger:Juno Therapeutics: Patents & Royalties. Jensen:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding. Riddell:Juno Therapeutics: Equity Ownership, Patents & Royalties, Research Funding; Cell Medica: Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Consultancy. Maloney:Juno Therapeutics: Research Funding; Janssen Scientific Affairs: Honoraria; Seattle Genetics: Honoraria; Roche/Genentech: Honoraria.

Description: BACKGROUND: Chemotherapy followed by autologous T cells that are genetically modified to express a CD19-specific chimeric antigen receptor (CAR) has shown promise as a novel therapy for patients with relapsed or refractory B cell acute lymphoblastic leukemia (B-ALL); however, the risk of severe cytokine release syndrome (sCRS) and neurotoxicity has tempered enthusiasm for widespread application of this approach. The functional heterogeneity that is inherent in CAR-T cell products that are manufactured from undefined T cell subsets has hindered definition of dose-response relationships and identification of factors that may impact efficacy and toxicity. METHODS: We are conducting the first clinical trial that administers CD19 CAR-T cells manufactured from a defined composition of T cell subsets to adults with relapsed or refractory B-ALL. CD8+ and CD4+ T cells were enriched from each patient, transduced with a CD19 CAR lentivirus and separately expanded in vitro before formulation for infusion in a 1:1 ratio of CD8+:CD4+ CAR+ T cells at 2x105, 2x106 or 2x107 CAR-T cells/kg. Prior to CAR-T cell infusion, patients underwent lymphodepletion with a high-dose cyclophosphamide (Cy)-based regimen with or without fludarabine (Flu). RESULTS: Twenty-nine adults with B-ALL (median age 40, range 22 - 73 years; median 17% marrow blasts, range 0 - 97%), including 10 patients who had relapsed after allogeneic transplantation, received at least one CAR-T cell infusion. Twenty-four of 26 restaged patients (92%) achieved bone marrow (BM) complete remission (CR) by flow cytometry. CD4+ and CD8+ CAR-T cells expanded in vivo after infusion and their number in blood correlated with the infused CAR-T cell dose. Thirteen patients received lymphodepletion with Cy-based regimens without Flu. Ten of 12 restaged patients (83%) achieved BM CR by flow cytometry; however, 7 of these (70%) relapsed a median of 66 days after CAR-T cell infusion. Disease relapse correlated with a loss of CAR-T cell persistence in blood. We observed a CD8 cytotoxic T cell response to the murine scFv component of the CAR transgene that contributed to CAR-T cell rejection, and resulted in lack of CAR-T cell expansion after a second CAR-T cell infusion in 5 patients treated for persistent or relapsed disease. To minimize immune-mediated CAR-T cell rejection 14 patients were treated with Cy followed by Flu lymphodepletion (Cy/Flu, Cy 60 mg/kg x 1 and Flu 25 mg/m2 x 3-5) before CAR-T cell infusion. All patients (100%) who received Cy/Flu lymphodepletion achieved BM CR after CAR-T cell infusion. CAR-T cell expansion and persistence in blood was higher in Cy/Flu-lymphodepleted patients compared to their counterparts who received Cy alone (Day 28 after 2x106 CAR-T cells/kg: CD8+ CAR-T cells, mean 55.8/μL vs 0.10/μL, p