Impact of CD19 CAR T-cell product type on outcomes in relapsed or refractory aggressive B-NHL

CD19-targeted chimeric antigen receptor-engineered (CD19 CAR) T cells are novel therapies showing great promise for patients with relapsed or refractory (R/R) aggressive B-cell non-Hodgkin lymphoma (B-NHL). Single-arm studies showed significant variations in outcomes across distinct CD19 CAR T-cell products. To estimate the independent impact of the CAR T-cell product type on outcomes, we retrospectively analyzed data from 129 patients with R/R aggressive B-NHL treated with cyclophosphamide and fludarabine lymphodepletion followed by either a commercially available CD19 CAR T-cell therapy (axicabtagene ciloleucel [axicel] or tisagenlecleucel [tisacel]), or the investigational product JCAR014 on a phase 1/2 clinical trial (NCT01865617). After adjustment for age, hematopoietic cell transplantation-specific comorbidity index, lactate dehydrogenase (LDH), largest lesion diameter, and absolute lymphocyte count (ALC), CAR T-cell product type remained associated with outcomes in multivariable models. JCAR014 was independently associated with lower cytokine release syndrome (CRS) severity compared with axicel (adjusted odds ratio [aOR], 0.19; 95% confidence interval [CI]; 0.08-0.46), with a trend toward lower CRS severity with tisacel compared with axicel (aOR, 0.47; 95% CI, 0.21-1.06; P = .07). Tisacel (aOR, 0.17; 95% CI, 0.06-0.48) and JCAR014 (aOR, 0.17; 95% CI, 0.06-0.47) were both associated with lower immune effector cell-associated neurotoxicity syndrome severity compared with axicel. Lower odds of complete response (CR) were predicted with tisacel and JCAR014 compared with axicel. Although sensitivity analyses using either positron emission tomography- or computed tomography-based response criteria also suggested higher efficacy of axicel over JCAR014, the impact of tisacel vs axicel became undetermined. Higher preleukapheresis LDH, largest lesion diameter, and lower ALC were independently associated with lower odds of CR. We conclude that CD19 CAR T-cell product type independently impacts toxicity and efficacy in R/R aggressive B-NHL patients.

Matching-adjusted indirect treatment comparison of liso-cel versus axi-cel in relapsed or refractory large B cell lymphoma

Background

In the absence of randomized studies directly comparing chimeric antigen receptor T cell therapies, this study used matching-adjusted indirect comparisons (MAIC) to evaluate the comparative efficacy and safety of lisocabtagene maraleucel (liso-cel) versus axicabtagene ciloleucel (axi-cel) in patients with relapsed or refractory large B cell lymphoma (LBCL).

Methods

Primary data sources included individual patient data from the TRANSCEND NHL 001 study (TRANSCEND [NCT02631044]; N = 256 for efficacy set, N = 269 for safety set) for liso-cel and summary-level data from the ZUMA-1 study (NCT02348216; N = 101 for efficacy set, N = 108 for safety set) for axi-cel. Inter-study differences in design, eligibility criteria, baseline characteristics, and outcomes were assessed and aligned to the extent feasible. Clinically relevant prognostic factors were adjusted in a stepwise fashion by ranked order. Since bridging therapy was allowed in TRANSCEND but not ZUMA-1, the initial efficacy and safety analyses included bridging therapy use as a matching factor (TRANSCEND patients who received bridging therapy were removed). Subsequent sensitivity analyses excluded this matching factor.

Results

The initial analysis showed similar MAIC-weighted efficacy outcomes between TRANSCEND and ZUMA-1 for overall and complete response rates (odds ratio [95% confidence interval (CI)], 1.40 [0.56–3.49] and 1.21 [0.56–2.64], respectively) and for overall survival and progression-free survival (hazard ratio [95% CI], 0.81 [0.44–1.49] and 0.95 [0.58–1.57], respectively). MAIC-weighted safety outcomes favored liso-cel, with significantly lower odds of all-grade and grade ≥ 3 cytokine release syndrome (odds ratio [95% CI], 0.03 [0.01–0.07] and 0.08 [0.01–0.67], respectively) and study-specific neurological events (0.16 [0.08–0.33] and 0.05 [0.02–0.15], respectively). Efficacy and safety outcomes remained similar in sensitivity analyses, which did not include use of bridging therapy as a matching factor.

Conclusions

After matching and adjusting for clinically relevant prognostic factors, liso-cel demonstrated comparable efficacy and a more favorable safety profile compared with axi-cel in patients with third- or later-line relapsed or refractory LBCL.

Trial registration: NCT02631044 and NCT02348216

Supplementary Information

The online version contains supplementary material available at 10.1186/s13045-021-01144-9.

γ-Secretase inhibitor in combination with BCMA chimeric antigen receptor T-cell immunotherapy for individuals with relapsed or refractory multiple myeloma: a phase 1, first-in-human trial

BACKGROUND

γ-Secretase inhibitors (GSIs) increase B cell maturation antigen (BCMA) density on malignant plasma cells and enhance antitumour activity of BCMA chimeric antigen receptor (CAR) T cells in preclinical models. We aimed to evaluate the safety and identify the recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat (LY3039478) for individuals with relapsed or refractory multiple myeloma.

METHODS

We conducted a phase 1, first-in-human trial combining crenigacestat with BCMA CAR T-cells at a single cancer centre in Seattle, WA, USA. We included individuals aged 21 years or older with relapsed or refractory multiple myeloma, previous autologous stem-cell transplant or persistent disease after more than four cycles of induction therapy, and Eastern Cooperative Oncology Group performance status of 0-2, regardless of previous BCMA-targeted therapy. To assess the effect of the GSI on BCMA surface density on bone marrow plasma cells, participants received GSI during a pretreatment run-in, consisting of three doses administered 48 h apart. BCMA CAR T cells were infused at doses of 50 × 106 CAR T cells, 150 × 106 CAR T cells, 300 × 106 CAR T cells, and 450 × 106 CAR T cells (total cell dose), in combination with the 25 mg crenigacestat dosed three times a week for up to nine doses. The primary endpoints were the safety and recommended phase 2 dose of BCMA CAR T cells in combination with crenigacestat, an oral GSI. This study is registered with ClinicalTrials.gov, NCT03502577, and has met accrual goals.

FINDINGS

19 participants were enrolled between June 1, 2018, and March 1, 2021, and one participant did not proceed with BCMA CAR T-cell infusion. 18 participants (eight [44%] men and ten [56%] women) with multiple myeloma received treatment between July 11, 2018, and April 14, 2021, with a median follow up of 36 months (95% CI 26 to not reached). The most common non-haematological adverse events of grade 3 or higher were hypophosphataemia in 14 (78%) participants, fatigue in 11 (61%), hypocalcaemia in nine (50%), and hypertension in seven (39%). Two deaths reported outside of the 28-day adverse event collection window were related to treatment. Participants were treated at doses up to 450 × 106 CAR+ cells, and the recommended phase 2 dose was not reached.

INTERPRETATIONS

Combining a GSI with BCMA CAR T cells appears to be well tolerated, and crenigacestat increases target antigen density. Deep responses were observed among heavily pretreated participants with multiple myeloma who had previously received BCMA-targeted therapy and those who were naive to previous BCMA-targeted therapy. Further study of GSIs given with BCMA-targeted therapeutics is warranted in clinical trials.

FUNDING

Juno Therapeutics-a Bristol Myers Squibb company and the National Institutes of Health.

Nonmyeloablative unrelated donor hematopoietic cell transplantation to treat patients with poor-risk, relapsed, or refractory multiple myeloma

The purpose of this study was to determine long-term outcome of unrelated donor nonmyeloablative hematopoietic cell transplantation (HCT) in patients with poor-risk multiple myeloma. A total of 24 patients were enrolled; 17 patients (71%) had chemotherapy-refractory disease, and 14 (58%) experienced disease relapse or progression after previous autologous transplantation. Thirteen patients underwent planned autologous transplantation followed 43-135 days later with unrelated transplantation, whereas 11 proceeded directly to unrelated transplantation. All 24 patients were treated with fludarabine (90 mg/m(2)) and 2 Gy of total body irradiation before HLA-matched unrelated peripheral blood stem cell transplantation. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. The median follow-up was 3 years after allografting. One patient experienced nonfatal graft rejection. The incidences of acute grades II and III and chronic graft-versus-host disease were 54%, 13%, and 75%, respectively. The 3-year nonrelapse mortality (NRM) was 21%. Complete responses were observed in 10 patients (42%); partial responses, in 4 (17%). At 3 years, overall survival (OS) and progression-free survival (PFS) rates were 61% and 33%, respectively. Patients receiving tandem autologous-unrelated transplantation had superior OS and PFS (77% and 51%) compared with patients proceeding directly to unrelated donor transplantation (44% and 11%) (PFS P value = .03). In summary, for patients with poor-risk, relapsed, or refractory multiple myeloma, cytoreductive autologous HCT followed by nonmyeloablative conditioning and unrelated HCT is an effective treatment approach, with low NRM, high complete remission rates, and prolonged disease-free survival.

Allografting after nonmyeloablative conditioning as a treatment after a failed conventional hematopoietic cell transplant

Outcomes with conventional allogeneic hematopoietic cell transplantation (HCT) after failed HCT are typically poor. To reduce transplantation-related mortality (TRM), 55 patients (median age, 43 years; range, 18-69 years) who had failed conventional autologous (n = 49), allogeneic (n = 4), or syngeneic (n = 2) HCT received human leukocyte antigen-matched related (n = 31) or unrelated (n = 24) donor allografts after nonmyeloablative conditioning with 2 Gy of total body irradiation or 2 Gy of total body irradiation and 90 mg/m(2) of fludarabine. Postgrafting immunosuppression consisted of cyclosporine and mycophenolate mofetil. One rejection occurred. Thirty-three patients died a median of 127 days (range, 7-834 days) after HCT: 21 of relapse, 11 of TRM, and 1 of suicide. The TRM rate on day 100 was 11% with an estimated 1-year TRM rate of 20% (95% confidence interval [CI], 9% to 31%). The median follow-up among the 22 survivors is 368 days (range, 173-796 days). Seventeen of 22 survivors are progression-free. One-year estimates of overall and progression-free survival rates are 49% (95% CI, 35% to 62%) and 28% (95% CI, 16% to 41%), respectively. Untreated disease at the time of allografting after nonmyeloablative conditioning increased the risk of death (hazard ratio = 2.4; P =.04). Although the length of follow-up is still short, it appears that encouraging outcomes can be achieved with nonmyeloablative conditioning in patients expected to have poor outcomes with conventional allografting.

Relapse or progression after hematopoietic cell transplantation using nonmyeloablative conditioning: effect of interventions on outcome

OBJECTIVE

This study analyzes the effect of interventions aimed at reinducing remissions in patients with relapse or progression of malignant disease following allogeneic hematopoietic cell transplantation (HCT) using nonmyeloablative conditioning.

METHODS

We performed a retrospective analysis of 81 instances of relapse or progression occurring among 224 patients given HCT as treatment of their hematologic malignancies. All patients received conditioning with 2 Gy total-body irradiation with or without fludarabine and with postgrafting immunosuppression with mycophenolate mofetil and cyclosporine.

RESULTS

Overall survival of patients after relapse or progression was 36%. Fifteen of the 81 patients were given no interventions. Three of these 15 (20%) patients are alive with disease while 12 died with disease progression. Sixty-six patients (81%) received interventions, including withdrawal of immunosuppression (n=32), donor lymphocyte infusions (n=13), or chemotherapy (n=21). Twenty of the 66 (30%) are alive, 5 in complete remission, 4 in partial remission, 1 with stable and 10 with progressive disease. The overall response rate to intervention was 27%. Forty-six (70%) of the patients given interventions died, mainly due to relapse/progression. Patients not receiving interventions had a 1-year survival estimate of 15% compared to 41% in patients given interventions. Factors associated with survival in patients given intervention were disease response (p=0.002), disease category (p=0.001), and time to relapse from transplantation (p=0.0005).

CONCLUSIONS

While the overall prognosis of patients relapsing or progressing after nonmyeloablative HCT is poor, interventions such as the combined use of immunotherapy and chemotherapy can improve patient survival.

Allogeneic hematopoietic cell transplantation following minimal intensity conditioning: predicting acute graft-versus-host disease and graft-versus-tumor effects

Most patients with hematologic malignancies have received extensive chemotherapy before hematopoietic cell transplantation (HCT), resulting in neutropenia, lymphocytopenia, and use of antibiotics. Accordingly, patients have a wide range of neutrophil counts, lymphocyte counts, and previous antibiotic use. The minimal toxicity of the current conditioning regimen allowed us to ask whether peritransplantation neutrophil or lymphocyte levels influences the risks of acute graft-versus-host disease (GVHD) or relapse. We analyzed outcomes in 459 patients age 7-75 years (median, 57 years) who received conditioning with fludarabine and low-dose total body irradiation for HLA-matched HCT. We report 2 key findings. First, low neutrophil nadirs within the first 3 weeks post-HCT had significant associations with increased risks of acute GVHD and 5-year nonrelapse mortality, but showed no association with the risk of relapse. Second, high lymphocyte counts immediately before HCT had significant associations with reduced risks of relapse and overall mortality, but no association with the risks of GVHD or nonrelapse mortality. These findings suggest that the immunologic mechanisms involved in acute GVHD might differ from those that initiate graft-versus-tumor effects.

Nonmyeloablative hematopoietic cell transplantation: status quo and future perspectives

In nonmyeloablative allogeneic hematopoietic stem cell transplantation (HSCT), high-dose cytotoxic therapy as the conceptual basis for treating hematopoietic malignancies has been replaced by graft-versus-tumor effects. The use of potent pre- and postgrafting immunosuppression derived from preclinical studies has allowed omission of myeloablative cytotoxic therapy without compromising hematopoietic donor cell engraftment. This results in a marked reduction in transplant-related toxicities that makes older or medically infirm patients candidates for this treatment option. This patient group is more representative of the population with cancer and would have been ineligible for conventional HSCT. Initial results in patients with a variety of hematologic malignancies have been encouraging with documented sustained cytogenetic and molecular remissions in a substantial number of sometimes heavily pretreated and previously refractory patients. Even though patients with hematologic malignancies will likely require conversion to full donor hematopoiesis for long-term disease control, a state of mixed hematopoietic chimerism might suffice to "cure" the disease phenotypes in various nonmalignant diseases. Strategies aimed at optimizing peritransplant immunosuppression may eventually eliminate the need for pretransplant total body irradiation, which is relevant for minimizing late toxicities. Enhancing graft-versus-tumor effects by virtue of postgrafting vaccination of recipients against tumor-specific antigens may help to use this transplant approach more effectively in the treatment of solid tumors.

Long-term sustained disease control in patients with mantle cell lymphoma with or without active disease after treatment with allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning

BACKGROUND

Previously, early results were reported for allogeneic hematopoietic cell transplantation (HCT) after nonmyeloablative conditioning with 2 Gy of total body irradiation with or without fludarabine and/or rituximab in 33 patients with mantle cell lymphoma (MCL).

METHODS

This study examined the outcomes of 70 patients with MCL and included extended follow-up (median, 10 years) for the 33 initial patients. Grafts were obtained from human leukocyte antigen (HLA)-matched, related donors (47%), unrelated donors (41%), and HLA antigen-mismatched donors (11%).

RESULTS

The 5-year incidence of nonrelapse mortality was 28%. The relapse rate was 26%. The 5-year rates of overall survival (OS) and progression-free survival (PFS) were 55% and 46%, respectively. The 10-year rates of OS and PFS were 44% and 41%, respectively. Eighty percent of surviving patients were off immunosuppression at the last follow-up. The presence of relapsed or refractory disease at the time of HCT predicted a higher rate of relapse (hazard ratio [HR], 2.94; P = .05). Despite this, OS rates at 5 (51% vs 58%) and 10 years (43% vs 45%) were comparable between those with relapsed/refractory disease and those undergoing transplantation with partial or complete remission. A high-risk cytomegalovirus (CMV) status was the only independent predictor of worse OS (HR, 2.32; P = .02). A high-risk CMV status and a low CD3 dose predicted PFS (HR, 2.22; P = .03).

CONCLUSIONS

Nonmyeloablative allogeneic HCT provides a long-term survival benefit for patients with relapsed MCL, including those with refractory disease or multiple relapses.

Hodgkin lymphoma, version 2.2015

Hodgkin lymphoma (HL) is an uncommon malignancy involving lymph nodes and the lymphatic system. Classical Hodgkin lymphoma (CHL) and nodular lymphocyte-predominant Hodgkin lymphoma are the 2 main types of HL. CHL accounts for most HL diagnosed in the Western countries. Chemotherapy or combined modality therapy, followed by restaging with PET/CT to assess treatment response using the Deauville criteria (5-point scale), is the standard initial treatment for patients with newly diagnosed CHL. Brentuximab vedotin, a CD30-directed antibody-drug conjugate, has produced encouraging results in the treatment of relapsed or refractory disease. The potential long-term effects of treatment remain an important consideration, and long-term follow-up is essential after completion of treatment.

Factors affecting lymphocyte collection efficiency for the manufacture of chimeric antigen receptor T cells in adults with B-cell malignancies

BACKGROUND

The clinical and procedural parameters that affect the optimal collection of lymphocytes for the production of chimeric antigen receptor (CAR) T cells remain undefined but are increasingly important, as commercial products are now available. We evaluated determinants of low lymphocyte collection efficiency (CE) and the rate of successful CAR T-cell manufacture in middle-aged and older adults with advanced B-cell malignancies.

STUDY DESIGNS AND METHODS

Mononuclear cell collections using two apheresis platforms (COBE Spectra and Spectra Optia, Terumo BCT) from patients participating in a CD19-directed CAR T-cell therapy trial were reviewed. Patient- and disease-specific factors, peripheral blood counts, apheresis parameters, and product cell counts were analyzed to determine effects on lymphocyte CE.

RESULTS

Ninety-two apheresis events from patients with acute lymphocytic leukemia (ALL) (n = 28), chronic lymphocytic leukemia (n = 18), and non-Hodgkin lymphoma (n = 46) were available for analysis. Forty-one collections (45%) had a lymphocyte CE of <40%. On multivariable analysis, age (every 10-year increase, odds ratio [OR] = 1.51; p = 0.034), disease type (chronic lymphocytic leukemia vs. ALL, OR = 0.24; p = 0.052; non-Hodgkin lymphoma vs. ALL, OR = 0.20; p = 0.009) and precollection platelets (every 10 × 10³ /μL increase, OR = 1.07; p = 0.005) were appreciably associated with a lymphocyte CE of <40%. No major apheresis complications occurred.

CONCLUSIONS

Lymphocyte collection at our center was well tolerated and 100% successful in manufacturing CD19-directed CAR T cells from adult patients with B-cell malignancies despite low CE in some patients. A diagnosis of ALL, advancing age, and higher preapheresis platelet counts were observed to be associated with low CE.

Antibody-directed therapies for hematological malignancies

Malignant hematopoietic cells express lineage-restricted antigens that serve as suitable targets for antibody-directed therapy. Although several highly specific, potent and relatively nontoxic, engineered antibodies, immunoglobulin fragments and antibody conjugates have been developed, only three have gained approval for clinical use. Of these, a chimeric mouse-human anti-CD20 antibody has yielded the most impressive clinical results. Encouraging data with the other approved antibodies, and with agents in clinical trials, suggest that rational antibody design will generate effective products for several different hematological malignancies. Despite these advances, significant challenges remain in the identification of optimal cellular targets, antibody forms and treatment schedules for therapeutic applications.

Follicular NHL: from antibodies and vaccines to graft-versus-lymphoma effects

Monoclonal antibody therapy with rituximab in combination with standard chemotherapy has improved the survival of patients with advanced-stage follicular lymphoma (FL). A series of next-generation anti-CD20 antibodies may be less immunogenic and have even greater antitumor activity through augmented interactions with host effector mechanisms responsible for tumor cell kill. Additional approaches with patient-specific immunoglobulin idiotype vaccines; novel monoclonal antibodies binding to biologically active cell-surface antigen are also demonstrating early clinical activity. Antibodies targeting radioisotopes, toxins or drugs are also slowly entering clinical trials and practice. Last, allogeneic stem cell transplantation following reduced-intensity conditioning provides graft-versus-tumor immune responses that may be able to control FL and allow this risky but potentially curative treatment option to older patents or those with comorbidities.

Prilocaine 3% is superior to a mixture of bupivacaine and lignocaine for peribulbar anaesthesia

We have compared motor block of the extraocular muscles produced by injections of 3% prilocaine and a mixture of equal parts of 2% lignocaine and 0.75% bupivacaine into the medial compartment of the orbit. A volume of 8 ml was used initially, and a vasoconstrictor and hyaluronidase were added to both solutions. Ninety patients undergoing cataract surgery were allocated randomly to one of two groups in double-blind study. Eight minutes after block insertion, the median ocular movement score in the prilocaine group was 1 and in the lignocaine-bupivacaine group 3. This difference was statistically significant (P = 0.016). Twenty of the patients who received prilocaine and 29 of the patients who received the lignocaine-bupivacaine mixture required an additional inferotemporal injection. This difference was not statistically significant (P = 0.094).

Interleukin-7 improves reconstitution of antiviral CD4 T cells

We evaluated whether long-term (2 months) administration of interleukin-7 (IL7) hastens immune recovery in baboons rendered severely lymphopenic by total body irradiation and antithymocyte globulin (ATG). Four baboons were treated with recombinant baboon IL7 and three baboons with placebo. Median CD4 T cell count at the end of IL7/placebo treatment was higher in the IL7-treated animals (2262 vs. 618/microl, P = 0.03). This appeared to be a result of peripheral expansion rather than de novo generation. Median cytomegalovirus (CMV)-specific IFNgamma-producing CD4 T cell count at the end of IL7/placebo treatment was higher in the IL7-treated animals (122 vs. 1/microl, P = 0.03). All animals were pretransplant cytomegalovirus-seropositive. One animal died at the end of IL7 treatment; necropsy showed extensive T cell infiltration of kidneys and lungs. In conclusion, IL7 stimulates the expansion of CD4 T cells, including functional antiviral cells. Clinical risk-benefit ratio needs to be evaluated.

Autologous haematopoietic cell transplantation for non-Hodgkin lymphoma with secondary CNS involvement

Pre-existing central nervous system (CNS) involvement may influence referral for autologous haematopoietic cell transplantation (AHCT) for patients with non-Hodgkin lymphoma (NHL). The outcomes of 151 adult patients with NHL with prior secondary CNS involvement (CNS(+) ) receiving an AHCT were compared to 4688 patients without prior CNS lymphoma (CNS(-) ). There were significant baseline differences between the cohorts. CNS(+) patients were more likely to be younger, have lower performance scores, higher age-adjusted international prognostic index scores, more advanced disease stage at diagnosis, more aggressive histology, more sites of extranodal disease, and a shorter interval between diagnosis and AHCT. However, no statistically significant differences were identified between the two groups by analysis of progression-free survival (PFS) and overall survival (OS) at 5 years. A matched pair comparison of the CNS(+) group with a subset of CNS(-) patients matched on propensity score also showed no differences in outcomes. Patients with active CNS lymphoma at the time of AHCT (n = 55) had a higher relapse rate and diminished PFS and OS compared with patients whose CNS lymphoma was in remission (n = 96) at the time of AHCT. CNS(+) patients can achieve excellent long-term outcomes with AHCT. Active CNS lymphoma at transplant confers a worse prognosis.

Long-term follow up of tandem autologous-allogeneic hematopoietic cell transplantation for multiple myeloma

We previously reported initial results in 102 multiple myeloma (MM) patients treated with sequential high-dose melphalan and autologous hematopoietic cell transplantation followed by 200 cGy total body irradiation with or without fludarabine 90 mg/m² and allogeneic hematopoietic cell transplantation. Here we present long-term clinical outcomes among the 102 initial patients and among 142 additional patients, with a median follow up of 8.3 (range 1.0-18.1) years. Donors included human leukocyte antigen identical siblings (n=179) and HLA-matched unrelated donors (n=65). A total of 209 patients (86%) received tandem autologous-allogeneic upfront, while thirty-five patients (14%) had failed a previous autologous hematopoietic cell transplantation before the planned autologous-allogeneic transplantation. Thirty-one patients received maintenance treatment at a median of 86 days (range, 61-150) after allogeneic transplantation. Five-year rates of overall survival (OS) and progression-free survival (PFS) were 54% and 31%, respectively. Ten-year OS and PFS were 41% and 19%, respectively. Overall non-relapse mortality was 2% at 100 days and 14% at five years. Patients with induction-refractory disease and those with high-risk biological features experienced shorter OS and PFS. A total of 152 patients experienced disease relapse and 117 of those received salvage treatment. Eighty-three of the 117 patients achieved a clinical response, and for those, the median duration of survival after relapse was 7.8 years. Moreover, a subset of patients who became negative for minimal residual disease (MRD) by flow cytometry experienced a significantly lower relapse rate as compared with MRD-positive patients (P=0.03). Our study showed that the graft-versus-myeloma effect after non-myeloablative allografting allowed long-term disease control in standard and high-risk patient subsets. Ultra-high-risk patients did not appear to benefit from tandem autologous/allogeneic hematopoietic cell transplantation because of early disease relapse. Incorporation of newer anti-MM agents into the initial induction treatments before tandem hematopoietic cell transplantation and during maintenance might improve outcomes of ultra-high-risk patients. Clinical trials included in this study are registered at: clinicaltrials.gov identifiers: 00075478, 00005799, 01251575, 00078858, 00105001, 00027820, 00089011, 00003196, 00006251, 00793572, 00054353, 00014235, 00003954.

A randomized study of melphalan 200 mg/m(2) vs 280 mg/m(2) as a preparative regimen for patients with multiple myeloma undergoing auto-SCT

We aimed to examine whether doses of melphalan higher than 200 mg/m(2) improve response rates when used as conditioning before autologous transplant (ASCT) in multiple myeloma (MM) patients. Patients with MM, n=131, were randomized to 200 mg/m(2) (mel200) vs 280 mg/m(2) (mel280) using amifostine pretreatment. The primary end point was the proportion of patients achieving near complete response (⩾nCR). No treatment-related deaths occurred in this study. Responses following ASCT were for mel200 vs mel280, respectively, ⩾nCR 22 vs 39%, P=0.03, ⩾PR 57 vs 74%, P=0.04. The hazard of mortality was not statistically significantly different between groups (mel200 vs mel280; hazard ratio (HR)=1.15 (95% confidence interval (CI), 0.62-2.13, P=0.66)) nor was the rate of progression/mortality (HR=0.81 (0.52-1.27, P=0.36)). The estimated PFS at 1 and 3 years were 83 and 46%, respectively, for mel200 and 78 and 54%, respectively, for mel280. Amifostine and mel280 were well tolerated, with no grade 4 regimen-related toxicities and only one grade 3 mucositis (none with mel200) and three grade 3 gastrointestinal (GI) toxicities (two in mel200). Hospitalization rates were more frequent in the mel280 group (59 vs 43%, P=0.08). Mel280 resulted in a higher major response rate (CR+nCR) and should be evaluated in larger studies.

High durable CR rates and preliminary safety profile for JCAR017 in R/R aggressive b-NHL (TRANSCEND NHL 001 Study): A defined composition CD19-directed CAR T-cell product with potential for outpatient administration

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Background: JCAR017 is a defined composition, CD19-directed 4-1BB CAR T cell product administered at a precise dose of CD8 and CD4 CAR T cells in a seamless design Phase 1 pivotal trial of relapsed/refractory (R/R) B-cell NHL (TRANSCEND NHL 001; NCT02631044). Methods: Patients (pts) with R/R DLBCL NOS, PMBCL, FL grade 3B, or MCL and adequate organ function are eligible. The FULL dataset includes all pts in the DLBCL cohort (i.e. excludes MCL). The CORE dataset includes pts meeting inclusion for a planned pivotal DLBCL cohort (DLBCL NOS [ de novo or transformed from follicular lymphoma], ECOG 0-1, no prior allo-SCT). Results: As of July 7, 2017, 69 pts were treated in the DLBCL cohort and evaluable for safety. In the FULL dataset, 21 pts (30%) had cytokine release syndrome (CRS), with 1 serious CRS event (1%; Gr 4). Neurotoxicity (NT) at any grade developed in 14 (20%), including 10 (14%) with Gr 3-4 events. There were no Gr 5 CRS or NT events. Median time to onset of first CRS and NT was 5 days and 10 days, respectively, 13 (19%) received anti-cytokine therapy and only one required vasopressor support. In the CORE dataset (n = 49), similar rates of CRS and NT were shown. The majority of pts, 64% (44/69), had no CRS or NT, and median onset of CRS and NT were 5 and 11 days, respectively, suggesting outpatient delivery of JCAR017 may be feasible. In the DLBCL cohort, 68 pts were evaluable for efficacy; best overall response, 3-month, and 6-month response rates in the FULL dataset were 75% (51/68), 49% (27/55), and 40% (14/35), respectively; and, in the CORE dataset, were 84% (41/49), 65% (26/40), and 57% (13/23). The best overall, 3-month, and 6-month CR rates were 61% (30/49), 53% (21/40), and 52% (12/23), respectively, in the CORE dataset. Among 16 double/triple hit pts, best ORR was 81%, and 3-month CR rate was 60%. A trend toward improved response rate at 3 months was observed in pts treated at DL2 compared to DL1. Conclusions: At the symposium, we will report updated efficacy and the preliminary safety profile for JCAR017, which supports potential outpatient administration in R/R Aggressive B-NHL patients. Clinical trial information: NCT02631044.

Myeloablative I-131-tositumomab with escalating doses of fludarabine and autologous hematopoietic transplantation for adults age ≥ 60 years with B cell lymphoma

Myeloablative therapy and autologous stem cell transplantation (ASCT) are underutilized in older patients with B cell non-Hodgkin (B-NHL) lymphoma. We hypothesized that myeloablative doses of (131)I-tositumomab could be augmented by concurrent fludarabine, based on preclinical data indicating synergy. Patients were ≥ 60 years of age and had high-risk, relapsed, or refractory B-NHL. Therapeutic infusions of (131)I-tositumomab were derived from individualized organ-specific absorbed dose estimates delivering ≤ 27 Gy to critical organs. Fludarabine was initiated 72 hours later followed by ASCT to define the maximally tolerated dose. Thirty-six patients with a median age of 65 years (range, 60 to 76), 2 (range, 1 to 9) prior regimens, and 33% with chemoresistant disease were treated on this trial. Dose-limiting organs included lung (30), kidney (4), and liver (2) with a median administered (131)I activity of 471 mCi (range, 260 to 1620). Fludarabine was safely escalated to 30 mg/m(2) × 7 days. Engraftment was prompt, there were no early treatment-related deaths, and 2 patients had ≥ grade 4 nonhematologic toxicities. The estimated 3-year overall survival, progression-free survival, and nonrelapse mortality were 54%, 53%, and 7%, respectively (median follow up of 3.9 years). Fludarabine up to 210 mg/m(2) can be safely delivered with myeloablative (131)I-tositumomab and ASCT in older adults with B-NHL.

Allogeneic hematopoietic cell transplantation with non-myeloablative conditioning for patients with hematologic malignancies: Improved outcomes over two decades

We have used a non-myeloablative conditioning regimen for allogeneic hematopoietic cell transplantation for the past twenty years. During that period, changes in clinical practice have been aimed at reducing morbidity and mortality from infections, organ toxicity, and graft-versus-host disease. We hypothesized that improvements in clinical practice led to better transplantation outcomes over time. From 1997-2017, 1,720 patients with hematologic malignancies received low-dose total body irradiation +/- fludarabine or clofarabine before transplantation from HLA-matched sibling or unrelated donors, followed by mycophenolate mofetil and a calcineurin inhibitor ± sirolimus. We compared outcomes in three cohorts by year of transplantation: 1997 +/- 2003 (n=562), 2004 +/- 2009 (n=594), and 2010 +/- 2017 (n=564). The proportion of patients ≥60 years old increased from 27% in 1997 +/- 2003 to 56% in 2010-2017, and with scores from the Hematopoietic Cell Transplantation Comborbidity Index of ≥3 increased from 25% in 1997 +/- 2003 to 45% in 2010 +/- 2017. Use of unrelated donors increased from 34% in 1997 +/- 2003 to 65% in 2010-2017. When outcomes from 2004 +/- 2009 and 2010-2017 were compared to 1997 +/- 2003, improvements were noted in overall survival (P=.0001 for 2004-2009 and P <.0001 for 2010-2017), profression-free survival (P=.002 for 2004-2009 and P <.0001 for 2010 +/- 2017), non-relapse mortality (P<.0001 for 2004 +/- 2009 and P <.0001 for 2010 +/- 2017), and in rates of grades 2 +/- 4 acute and chronic graft-vs.-host disease. For patients with hematologic malignancies who underwent transplantation with non-myeloablative conditioning, outcomes have improved during the past two decades. Trials reported are registered under ClinicalTrials.gov identifiers: NCT00003145, NCT00003196, NCT00003954, NCT00005799, NCT00005801, NCT00005803, NCT00006251, NCT00014235, NCT00027820, NCT00031655, NCT00036738, NCT00045435, NCT00052546, NCT00060424, NCT00075478, NCT00078858, NCT00089011, NCT00104858, NCT00105001, NCT00110058, NCT00397813, NCT00793572, NCT01231412, NCT01252667, NCT01527045.

Extended mycophenolate mofetil and shortened cyclosporine failed to reduce graft-versus-host disease after unrelated hematopoietic cell transplantation with nonmyeloablative conditioning

We previously reported data from 103 patients with hematologic malignancies (median age 54 years) who received peripheral blood stem cell (PBSC) grafts from HLA-matched unrelated donors after nonmyeloablative conditioning and were given postgrafting immunosuppression consisting of mycophenolate mofetil (MMF; administered from day 0 until day +40 with taper through day +96) and cyclosporine (CSP; given from day -3 to day +100, with taper through day 180) (historical patients). The incidences of grade II-IV acute and extensive chronic graft-versus-host disease (aGVHD, cGVHD) were 52% and 49%, respectively, and the 1-year probabilities of relapse, nonrelapse mortality (NRM), and progression-free survival (PFS) were 26%, 18%, and 56%, respectively. Here, we treated 71 patients with hematologic malignancies (median age 56 years) with unrelated PBSC grafts and investigated whether postgrafting immunosuppression with an extended course of MMF, given at full dosing until day +150 and then tapered through day +180, and a shortened course of CSP, through day +80, would promote tolerance induction and reduce the incidence of GVHD (current patients). We observed 77% grade II-IV aGVHD and 45% extensive cGVHD (P=.03, and P=.43, respectively, in current compared to historical patients). The 1-year probabilities of relapse, NRM, and PFS were 23%, 29%, and 47%, respectively (P=.89, P=.02, and P=.08 compared to the historical patients). We conclude that postgrafting immunosuppression with extended MMF and shortened CSP failed to decrease the incidence of GVHD among unrelated PBSC recipients given nonmyeloablative conditioning.

Fludarabine and 2-Gy TBI is superior to 2 Gy TBI as conditioning for HLA-matched related hematopoietic cell transplantation: a phase III randomized trial

The risks and benefits of adding fludarabine to a 2-Gy total body irradiation (TBI) nonmyeloablative regimen are unknown. For this reason, we conducted a prospective randomized trial comparing 2-Gy TBI alone, or in combination with 90 mg/m(2) fludarabine (FLU/TBI), before transplantation of peripheral blood stem cells from HLA-matched related donors. Eighty-five patients with hematological malignancies were randomized to be conditioned with TBI alone (n = 44) or FLU/TBI (n = 41). All patients had initial engraftment. Two graft rejections were observed, both in the TBI group. Infection rates, nonrelapse mortality, and graft-versus-host disease (GVHD) were similar between groups. Three-year overall survival was lower in the TBI group (54% versus 65%; hazard ratio [HR], .57; P = .09), with higher incidences of relapse/progression (55% versus 40%; HR, .55; P = .06), relapse-related mortality (37% versus 28%; HR, .53; P = .09), and a lower progression-free survival (36% versus 53%; HR, .56; P = .05). Median donor T cell chimerism levels were significantly lower in the TBI group at days 28 (61% versus 90%; P < .0001) and 84 (68% versus 92%; P < .0001), as was NK cell chimerism on day 28 (75% versus 96%; P = .0005). In conclusion, this randomized trial demonstrates the importance of fludarabine in augmenting the graft-versus-tumor effect by ensuring prompt and durable high-level donor engraftment early after transplantation.

Concepts in radiotherapy and immunotherapy: Anti-CD20 mechanisms of action and targets

Immunotherapy became a feasible therapeutic approach following the development of monoclonal antibody technology. Despite many small clinical trials using a wide variety of antibodies, in hematologic malignancies, success has largely been restricted to a few antibodies generated against antigens expressed on the tumor cell surface: rituximab (anti-CD20) and alemtuzumab (anti-CD52) are the most widely used monoclonal antibodies. CD20 is expressed on B cells, and rituximab has been widely used in the treatment of various histologies of B-cell non-Hodgkin's lymphoma. The mode of action of rituximab is discussed in this article. Despite extensive empiric clinical trial experience, the critical factors important in the mechanism of tumor cell kill by monoclonal antibodies continue to be elusive and the subject of debate. The major immune mechanisms of action of rituximab include complement-dependent cytotoxicity and antibody-dependent cellular cytotoxicity. While some investigations have suggested that the complement system is essential to tumor cell kill with rituximab; most lines of evidence point to the importance of antibody-dependent cellular cytotoxicity. Fc receptor binding appears to be critical in determining efficacy. Observations from several studies have shown that the response rate to single-agent rituximab is better in patients who have higher affinity polymorphisms in their Fc receptors. The other mechanisms that may play a role in rituximab therapy include direct anti-tumor effects mediated by the antibody binding to cell-surface CD20 antigen. Although this is more controversial, observations in tumor cell lines following CD20 ligation suggest that direct effects may be important.