Idecabtagene vicleucel chimeric antigen receptor T-cell therapy for relapsed/refractory multiple myeloma with renal impairment

We evaluated patients with relapsed multiple myeloma with renal impairment (RI) treated with standard of care idecabtagene vicleucel (ide-cel), as outcomes with chimeric antigen receptor (CAR) T-cell therapy are unknown in this population. RI was defined as creatinine clearance (CrCl) <50 mL/min. CrCl of <30 mL/min or dialysis dependence were defined as severe RI. The study cohort included 214 patients, 28 (13%) patients with RI, including 11 patients severe RI (dialysis, N=1). Patients with RI were older, more likely to be female and had higher likelihood of having Revised International Staging System stage 3 disease. Rates and severity of cytokine release syndrome (89% vs. 84%, grade ≥3: 7% vs. 2%) and immune effector cell-associated neurotoxicity syndrome (23% vs. 20%) were similar in patients with and without RI, respectively. Patients with RI had higher incidence of short-term grade ≥3 cytopenias, although cytopenias were similar by 3 months following CAR T-cell therapy. Renal function did not worsen after CAR T-cell therapy in patients with RI. Response rates (93% vs. 82%) and survival outcomes (median progression-free survival: 9 vs. 8 months; P=0.26) were comparable in patients with and without RI, respectively. Treatment with ide-cel is feasible in patients with RI, with a comparable safety and efficacy profile as patients without RI, with notable exception of higher short-term high-grade cytopenias.

Sirolimus Is an Acceptable Alternative to Tacrolimus for Graft-versus-Host Disease Prophylaxis after Haploidentical Peripheral Blood Stem Cell Transplantation with Post-Transplantation Cyclophosphamide

Graft-versus-host disease (GVHD) prophylaxis with post-transplantation cyclophosphamide (PTCy), tacrolimus (Tac), and mycophenolate mofetil (MMF) for allogeneic haploidentical donor (haplo) hematopoietic cell transplantation (HCT) results in comparable outcomes to matched unrelated donor HCT. A phase II study from the Moffitt Cancer Center substituting sirolimus (Siro) for Tac in this prophylactic regimen reported comparable rates of grade II-IV acute GVHD (aGVHD). Many centers have substituted Siro for Tac in this setting based on a preferable side effect profile, although comparative data are limited. In this study, we retrospectively compared outcomes in haplo-HCT with PTCy/Siro/MMF versus haplo-HCT with PTCy/Tac/MMF. The study cohort included all consecutive patients receiving haploidentical donor T cell-replete peripheral blood stem cell (PBSC) HCT for hematologic malignancies at Moffitt Cancer Center or the City of Hope National Medical Center between 2014 and 2019. A total of 423 patients were included, of whom 84 (20%) received PTCy/Siro/MMF and 339 (80%) received PTCy/Tac/MMF. The median age for the entire cohort was 54 years (range, 18 to 78 years), and the median follow-up was 30 months. The Siro group had a higher proportion of patients age ≥60 years (58% versus 34%; P < .01), and the groups also differed in diagnosis type, conditioning regimen, and cytomegalovirus serostatus. There were no significant differences in the rates of grade II-IV aGVHD (45% versus 47%; P = .6) at day +100 or chronic GVHD (cGVHD) (47% versus 54%; P = .79) at 2 years post-HCT. In multivariate analysis, neutrophil engraftment at day +30 was significantly better in the Tac group (odds ratio, .30; 95% confidence interval, .1 to .83; P = .02), with a median time to engraftment of 17 days versus 18 days in the Siro group, but platelet engraftment was similar in the 2 groups. Otherwise, in multivariate analysis, GVHD prophylaxis type had no significant influence on aGVHD or cGVHD, nonrelapse mortality, relapse, GVHD-free relapse-free survival, disease-free survival, or overall survival after PBSC haplo-HCT. These findings suggest that Siro is a comparable alternative to Tac in combination with PTCy/MMF for GVHD prophylaxis, with overall similar clinical outcomes despite delayed engraftment after peripheral blood stem cell haplo-HCT. Although Tac remains the standard of care, Siro may be substituted based on the side effect profile of these medications, with consideration of patient medical comorbidities at HCT.

Inferior Outcomes of EU Versus US Patients Treated With CD19 CAR-T for Relapsed/Refractory Large B-cell Lymphoma: Association With Differences in Tumor Burden, Systemic Inflammation, Bridging Therapy Utilization, and CAR-T Product Use

Real-world evidence suggests a trend toward inferior survival of patients receiving CD19 chimeric antigen receptor (CAR) T-cell therapy in Europe (EU) and with tisagenlecleucel. The underlying logistic, patient- and disease-related reasons for these discrepancies remain poorly understood. In this multicenter retrospective observational study, we studied the patient-individual journey from CAR-T indication to infusion, baseline features, and survival outcomes in 374 patients treated with tisagenlecleucel (tisa-cel) or axicabtagene-ciloleucel (axi-cel) in EU and the United States (US). Compared with US patients, EU patients had prolonged indication-to-infusion intervals (66 versus 50 d; P < 0.001) and more commonly received intermediary therapies (holding and/or bridging therapy, 94% in EU versus 74% in US; P < 0.001). Baseline lactate dehydrogenase (LDH) (median 321 versus 271 U/L; P = 0.02) and ferritin levels (675 versus 425 ng/mL; P = 0.004) were significantly elevated in the EU cohort. Overall, we observed inferior survival in EU patients (median progression-free survival [PFS] 3.1 versus 9.2 months in US; P < 0.001) and with tisa-cel (3.2 versus 9.2 months with axi-cel; P < 0.001). On multivariate Lasso modeling, nonresponse to bridging, elevated ferritin, and increased C-reactive protein represented independent risks for treatment failure. Weighing these variables into a patient-individual risk balancer (high risk [HR] balancer), we found higher levels in EU versus US and tisa-cel versus axi-cel cohorts. Notably, superior PFS with axi-cel was exclusively evident in patients at low risk for progression (according to the HR balancer), but not in high-risk patients. These data demonstrate that inferior survival outcomes in EU patients are associated with longer time-to-infusion intervals, higher tumor burden/LDH levels, increased systemic inflammatory markers, and CAR-T product use.

The role of allogeneic transplant for adult Ph+ ALL in CR1 with complete molecular remission: a retrospective analysis

Historically, Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) has been associated with poor outcomes, and allogeneic hematopoietic cell transplantation (allo-HCT) is recommended in first complete remission (CR1). However, in the tyrosine kinase inhibitor (TKI) era, rapid attainment of a complete molecular remission (CMR) is associated with excellent outcomes without allo-HCT, suggesting transplant may not be required for these patients. To test this hypothesis, we retrospectively identified adult patients with Ph+ ALL treated with induction therapy, including TKIs, and attained CMR within 90 days of diagnosis at 5 transplant centers in the United States. We compared outcomes of those who did and did not receive allo-HCT in first remission. We identified 230 patients (allo-HCT: 98; non-HCT: 132). The allo-HCT cohort was younger with better performance status. On multivariable analysis (MVA), allo-HCT was not associated with improved overall survival (adjusted hazard ratio [aHR]: 1.05; 95% CI, 0.63-1.73) or relapse-free survival (aHR: 0.86; 95% CI, 0.54-1.37) compared with non-HCT treatment. Allo-HCT was associated with a lower cumulative incidence of relapse (aHR: 0.32; 95% CI, 0.17-0.62) but higher non-relapse mortality (aHR: 2.59; 95% CI, 1.37-4.89). Propensity score matching analysis confirmed results of MVA. Comparison of reduced-intensity HCT to non-HCT showed no statistically significant difference in any of the above endpoints. In conclusion, adult patients with Ph+ ALL who achieved CMR within 90 days of starting treatment did not derive a survival benefit from allo-HCT in CR1 in this retrospective study.

Dihydroorotate dehydrogenase inhibition acts synergistically with tyrosine kinase inhibitors to induce apoptosis of mantle cell lymphoma cells

Mantle cell lymphoma (MCL) is a non‐Hodgkin lymphoma that remains incurable with the treatment options available today. In the present study, we have identified the dihydroorotate dehydrogenase (DHODH), an essential enzyme for the de novo biosynthesis of pyrimidine‐based nucleotides, to be overexpressed in MCL in comparison to healthy peripheral blood mononuclear cells (PBMC). In vitro inhibition of the DHODH activity using a newly developed DHODH inhibitor, namely (R)‐HZ05, can induce MCL cell death in the nanomolar range independently than the P53 status of the investigated cell lines. Moreover, the combination of (R)‐HZ05 with tyrosine kinase inhibitor shows the synergistic activity on cell death. Pre‐clinical investigation on the efficacy of (R)‐HZ05 shows that it can be prolonged animal lifespan similar to ibrutinib. (R)‐HZ05 use in combination with tyrosine kinase inhibitor demonstrated a superior efficacy on tumor burden reduction and survival than either drug alone. We have demonstrated that the depletion of the pyrimidine nucleotide pool, using DHODH inhibitor, represents a new therapeutic strategy that may benefit MCL patients.

105 4–1BB and optimized CD28 co-stimulation enhances function of human mono- and bi-specific third-generation CAR T cells

Background

Co-stimulatory signals regulate the expansion, persistence, and function of chimeric antigen receptor (CAR) T cells. Most studies have focused on the co-stimulatory domains CD28 or 4-1BB. CAR T cell persistence is enhanced by 4-1BB co-stimulation leading to NF-κB signaling, while resistance to exhaustion is enhanced by mutations of the CD28 co-stimulatory domain.

Methods

We hypothesized that a third-generation CAR containing 4-1BB and CD28 with only PYAP signaling motif (mut06) would provide beneficial aspects of both. We designed CD19-specific CAR T cells with 4-1BB or mut06 together with the combination of both (BB06). We evaluated their immune-phenotype, cytokine secretion, real-time cytotoxic ability and polyfunctionality against CD19-expressing cells. We analyzed LCK recruitment by the different constructs by immunoblotting. We further determined their ability to control growth of Raji cells in NSG mice. Additionally, we engineered bi-specific CARs against CD20/CD19 combining 4-1BB and mut06 and performed repeated in vitro antigenic stimulation experiments to evaluate their expansion, memory phenotype and phenotypic (PD1+CD39+) and functional exhaustion. Bi-specific CAR T cells were transferred into Raji or Nalm6-bearing mice to study their ability to eradicate CD20/CD19-expressing tumors.

Results

Co-stimulatory domains combining 4-1BB and mut06 confers CAR T cells with an increased polyfunctionality and LCK recruitment to the CAR (figure 1A), after repeated-antigen stimulation these cells expanded significantly better than second-generation CAR T cells (figure 1B). A bi-specific CAR targeting CD20/CD19, incorporating 4-1BB and mut06 co-stimulation, showed enhanced antigen-dependent in vitro expansion with lower exhaustion-associated markers (figure 1C). Bi-specific CAR T cells exhibited improved in vivo anti-tumor activity with increased persistence and decreased exhaustion (figure 1D).

Abstract 105 Figure 1

A. pLCK is increased in h19BB06z CAR T cells and associated with the CAR. CAR T cells were stimulated with irradiated 3T3-hCD19 cells at a 10:1 E:T ratio for 24hr. Cells were lysed and CAR bound and unbound fractions were western blotted. A single-cell measure of polyfunctional strength index (PSI) of CAR T cells. B. h19BB06z CAR T cells have the highest proliferation after repeated antigen stimulations. 5x105 CAR T cells were stimulated with 1x105 irradiated 3T3-hCD19 cells. After 1 week, half of the cells were enumerated by flow cytometry and the other half was re-stimulated with 1x105 fresh irradiated 3T3-hCD19 cells. This was repeated for a total of 4 weeks. C. 5x105 CAR T cells were co-cultured with 5x105 target cells (Raji-CD19High). After 1 week half the cells were harvested enumerated and stained by flow cytometry while the other half was re-stimulated with 5x105 fresh target cells (indicated by arrows). This was repeated for a total of 4 weeks. Frequency of PD1+CD39+ cells within CD8+ CAR T cells. D. Raji-FFLuc-bearing NSG mice were treated with 1x106 CAR T cells 5 days after initial tumor cell injection. Tumor burden (average luminescence) of mice treated with bi-specific or monospecific CAR T cells, UT and tumor control. Each line represents an individual mouse. (n = 7 mice per group).

Conclusions

These results demonstrate that co-stimulation combining 4-1BB with an optimized form of CD28 is a valid approach to optimize CAR T cell function. Cells with both mono- and bi-specific versions of this design showed enhanced in vitro and in vivo features such as expansion, persistence and resistance to exhaustion. Our observations validate the approach and justify clinical studies to test the efficacy and safety of this CAR in patients.

675 Genomic drivers of large B-cell lymphoma resistance to CD19 CAR-T therapy

Background

CD19-directed chimeric antigen receptor-reprogrammed autologous T cells are breakthrough immunotherapies for heavily pretreated patients with diffuse large B-cell lymphoma (DLBCL), but across CAR-19 products, ~60% of patients fail to respond or relapse. Inflammatory markers and clinical factors associate with impaired responses, but tumor-intrinsic resistance drivers are largely undefined.

Methods

To characterize the genomic mechanisms involved resistance to CAR-19, we interrogated whole genome sequencing (WGS) from 28 relapsed/refractory (r/r) aggressive lymphoma patients uniformly treated with axicabtagene ciloleucel (axi-cel).

Results

Because prognostic factors defined in the frontline treatment setting are largely inapplicable to CAR-19, we leveraged the WGS data, including comparative analyses with untreated DLBCL cases in the Pan-Cancer Analysis of Whole Genomes (PCAWG) (figure 1). In analyses of individual mutated genes, TP53 was significantly enriched (p=0.002) in CAR-19 patients, but did not predict outcome. However, mutations in either NFKBIA or MYC associated with worse PFS after CAR-19 (p=0.04, p=0.025 respectively). We next identified 12 single base substitution (SBS) mutational signatures in our cohort and found presence of APOBEC (SBS2 and SBS13) signatures associated with worse PFS, with 4/5 patients progressing (p=0.03). Copy number analysis by GISTIC2.0 revealed focal deletions of RHOA and RB1 to be significantly enriched in our cohort and independently predicted poor outcome (p=0.0007, p=0.05 respectively). WGS identifies structural variants and complex events. We found chromothripsis, a catastrophic shattering and reassembly of chromosomes, in 39.3% of r/r DLBCL, which was strongly associated with poor CAR-19 outcome, with 9/11 affected cases progressing (p=0.041). Finally, reduced expression (n=3) or genomic alteration (n=3) of CD19 did not associate with poor outcome. One case with durable response contained a sub-clonal CD19 mutation (L174V) previously reported as associated with CAR-19 resistance. These findings demonstrate predominance of CD19-independent resistance and indicate antigen-mediated tumor killing is not the only mechanism of tumor eradication. Genomic complexity appears to promote an immunosuppressive tumor microenvironment (TME), limiting CAR-19 efficacy.

Conclusions

Leveraging the resolution of WGS, we observed that markers of genomic complexity (chromothripsis and APOBEC) and specific genomic alterations (RHOA and RB1 deletions) associate with resistance to CAR-19 immunotherapy for aggressive B-cell lymphomas (figure 1). 93.8% of CAR-19 relapsed patients contained at least one or these genomic alterations. Recent patient data demonstrate that an immunosuppressed TME leads to CAR-19 failure. Combining these findings with our genomics findings, successful CAR-19 therapy must overcome the immune-exhausted TME to mobilize the host immune system and eliminate the tumor.

Abstract 675 Figure 1

Genomic alterations associated with disease progression. (a) The heatmap shows the significant genomic alteration present in at least 4 patients associated with progression after CD19 CAR-T cell therapy. (b) Kaplan-Meier curve of progression free survival with the combination of statistically significant genomic anomalies

Impact of Total Body Irradiation-Based Myeloablative Conditioning Regimens in Patients with Acute Lymphoblastic Leukemia Undergoing Allogeneic Hematopoietic Stem Cell Transplantation: Systematic Review and Meta-Analysis

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative treatment option for patients with acute lymphoblastic leukemia (ALL). Both total body irradiation (TBI)-based and chemotherapy only-based myeloablative transplantation conditioning regimens have been applied, but the optimal regimen remains unclear. We performed a systematic review to assess the efficacy of TBI-based versus chemotherapy only-based myeloablative conditioning regimens. We searched PubMed, Embase, and Cochrane databases and meeting abstracts for all studies comparing TBI-based and chemotherapy only-based conditioning regimens in patients who underwent allo-HCT for ALL. Two authors independently reviewed all studies for inclusion and extracted data related to overall survival (OS), progression-free survival (PFS), nonrelapse mortality (NRM), relapse, and acute and chronic graft-versus-host disease (GVHD). Eight studies were included in the final analysis. The overall methodological quality of the included studies was optimal. TBI-based regimens showed evidence of benefit compared with chemotherapy only-based conditioning regimens in terms of relapse (relative risk [RR], 0.82; 95% confidence interval [CI], 0.72 to 0.94; 6 studies, 5091 patients), OS (hazard ratio [HR], 0.76; 95% CI, 0.64 to 0.89; 7 studies, 4727 patients), and PFS (HR, 0.74; 95% CI, 0.63 to 0.85; 7 studies, 4727 patients). The TBI-based regimen did not increase the likelihood of grade II-IV acute GVHD (RR, 1.12; 95% CI, 0.92 to 1.36; 5 studies, 4996 patients) or chronic GVHD (RR, 1.10; 95% CI, 1.00 to 1.21; 5 studies, 4490 patients), or NRM (RR, 0.94; 95% CI, 0.69 to 1.28; 6 studies, 4522 patients). However, TBI-based regimens were associated with an increased risk of grade III-IV acute GVHD (RR, 1.29; 95% CI, 1.01 to 1.63; 3 studies, 3675 patients). A subgroup comparison of patients age ≥16 years showed similar results. This systematic review represents evidence supporting the use of TBI-based conditioning regimen in patients undergoing allo-HCT for ALL who are candidates for myeloablative conditioning, as it offers better OS, PFS, and less relapse with acceptable NRM.

Real-world evidence of tisagenlecleucel for pediatric acute lymphoblastic leukemia and non-Hodgkin lymphoma

Tisagenlecleucel is a CD19 chimeric antigen receptor (CAR) T-cell therapy approved for treatment of pediatric and young adult patients with relapsed/refractory acute lymphoblastic leukemia (ALL) and adults with non-Hodgkin lymphoma (NHL). The initial experience with tisagenlecleucel in a real-world setting from a cellular therapy registry is presented here. As of January 2020, 511 patients were enrolled from 73 centers, and 410 patients had follow-up data reported (ALL, n = 255; NHL, n = 155), with a median follow-up of 13.4 and 11.9 months for ALL and NHL, respectively. Among patients with ALL, the initial complete remission (CR) rate was 85.5%. Twelve-month duration of response (DOR), event-free survival, and overall survival (OS) rates were 60.9%, 52.4%, and 77.2%, respectively. Among adults with NHL, the best overall response rate was 61.8%, including an initial CR rate of 39.5%. Six-month DOR, progression-free survival, and OS rates were 55.3%, 38.7%, and 70.7%, respectively. Grade ≥3 cytokine release syndrome and neurotoxicity were reported in 11.6% and 7.5% of all patients, respectively. Similar outcomes were observed in patients with in-specification and out-of-specification products as a result of viability <80% (range, 61% to 79%). This first report of tisagenlecleucel in the real-world setting demonstrates outcomes with similar efficacy and improved safety compared with those seen in the pivotal trials.

NCMP-27. THE USE OF INTRAVENOUS IMMUNOGLOBULIN (IVIG) DURING SEVERE NEUROTOXICITY AMONG THE RECIPIENTS OF CHIMERIC ANTIGEN RECEPTOR T-CELLS (CAR-T) THERAPY

INTRODUCTION

Severe Immune effector Cell-Associated Neurotoxicity Syndrome (ICANS) occurs in ~ 30% of Diffuse Large B Cell Lymphoma (DLBCL) patients treated with CAR-T cell therapy. The current treatment for severe ICANS is glucocorticoids, and this may be combined with tocilizumab for concurrent cytokine release syndrome. Even with these treatments, neurotoxicity can persist. It is essential, therefore, to find additional treatments to more effectively reverse CAR-T neurotoxicity.

OBJECTIVE

We summarize our institutional experience using IVIG to treat severe or refractory ICANS after glucocorticoids alone.

METHOD

This is a single center retrospective cohort study of neurologic and oncologic outcomes among patients who received axicabtagene ciloleucel (axi-cel) for DLBCL or its variants from May 2015 to February 2019. We identified those patients who developed severe ICANS subsequently treated with glucocorticoids alone (n = 10) or glucocorticoids plus IVIG (n = 9).

RESULTS

The median age of all 19 patients was 63 (range 47-75, and 68% were males). All IVIG recipients received glucocorticoids prior to IVIG administration. There was no significant difference in time to resolution (TTR) of severe ICANS between both groups (median 3 vs. 3 days, Log-rank p = 0.331). However, we found that all IVIG recipients had experienced either escalation of their neurotoxicity grade or persistent severe neurotoxicity after initiation of steroids (p = 0.001). Moreover, IVIG recipients had worse ECOG performance status prior to axi-cel therapy (p = 0.03).

CONCLUSION

Although we found no difference in TTR of severe ICANS with addition of IVIG to glucocorticoids, our analysis suggests that the addition of IVIG blunted the effects of steroid-refractory neurotoxicity. Patients who received IVIG had worsening ICANS despite administration of steroids and therefore might have benefited from the earlier addition of IVIG. Controlled studies may clarify the potential efficacy of IVIG in severe neurotoxicity after CAR-T therapy.

NCMP-13. BRAIN MRI FINDINGS IN PATIENTS TREATED WITH CHIMERIC ANTIGEN RECEPTOR T-CELLS (CAR-T) DURING SEVERE NEUROTOXICITY

INTRODUCTION

Severe neurotoxicity occurs in ~30% of Diffuse Large B Cell Lymphoma (DLBCL) patients treated with CAR-T cell therapy. Brain MRI is used to assess and manage patients during neurotoxicity. Brain MRI can help understand which brain locations are affected during neurotoxicity. However, in majority of patients brain MRI is normal. It is unclear if the MRI findings are time dependent. Here we review our institutional experience with MRI findings.

METHOD

We reviewed MRI brain of 38 patients who received CAR-T at Moffitt Cancer Center from October, 2017 to March, 2019.

RESULTS

We identified 8 patients (21%) who had abnormal MRI findings. Five (63%) of these patients showed increased T2 FLAIR changes in bilateral mesial temporal lobes consistent with limbic encephalitis. One patient showed restricted diffusion and abnormal T2 FLAIR and T2 weighted images within the splenium of the corpus callosum plus increased T2 FLAIR changes in bilateral mesial temporal lobe, which resolved with follow up MRI in a month. One patient showed increased FLAIR signal intensity in left lateral cerebellum and cerebellar vermis. Two patients showed multiple new tiny areas of acute ischemic changes post CAR-T. One patient had several small and subtle areas of increased FLAIR signal intensity in bilateral frontal and parietal cortex on day 5 post CAR-T and multiple tiny areas of acute ischemia on day 10 post CAR-T. The median time to performing brain MRI was 8 days (range: 5–14).

CONCLUSIONS

MRI can show T2 FLAIR changes consistent with limbic encephalitis mostly in temporal lobes but also in frontal, parietal lobes, and cerebellum. The MRI changes can happen anytime from day 5 to day 14 post CAR-T infusion. We need larger, controlled studies to have better understanding of MRI findings and whether they are time dependent in relation to when CAR-T was given.

Management of Immunotherapy-Related Toxicities, Version 1.2019, NCCN Clinical Practice Guidelines in Oncology

The aim of the NCCN Guidelines for Management of Immunotherapy-Related Toxicities is to provide guidance on the management of immune-related adverse events resulting from cancer immunotherapy. The NCCN Management of Immunotherapy-Related Toxicities Panel is an interdisciplinary group of representatives from NCCN Member Institutions and ASCO, consisting of medical and hematologic oncologists with expertise in a wide array of disease sites, and experts from the fields of dermatology, gastroenterology, neuro-oncology, nephrology, emergency medicine, cardiology, oncology nursing, and patient advocacy. Several panel representatives are members of the Society for Immunotherapy of Cancer (SITC). The initial version of the NCCN Guidelines was designed in general alignment with recommendations published by ASCO and SITC. The content featured in this issue is an excerpt of the recommendations for managing toxicity related to immune checkpoint blockade and a review of existing evidence. For the full version of the NCCN Guidelines, including recommendations for managing toxicities related to chimeric antigen receptor T-cell therapy, visitNCCN.org.

Mechanisms and Management of Chimeric Antigen Receptor T-Cell Therapy-Related Toxicities

Chimeric antigen receptor T-cell (CAR-T) therapy has proven to be a very effective cancer immunotherapy. Axicabtagene ciloleucel and tisagenlecleucel are the first-in-class anti-CD19 CAR-T currently available for relapsed/refractory adult large B-cell lymphoma. Tisagenlecleucel is also available for pediatric and young adult (up to age 25 years) patients with relapsed/refractory B-acute lymphoblastic leukemia. Cytokine release syndrome (CRS) and CAR-T-associated encephalopathy syndrome (neurotoxicity) are the most common adverse effects associated with CAR-T therapy. They can lead to significant morbidity and preclude widespread use of this treatment modality. Treatment-related deaths from severe CRS and cerebral edema have been reported. There is a significant heterogeneity in the side-effect profile of different CAR-T products under investigation and there is a need to develop standardized guidelines for toxicity grading and management. Here, we summarize the current literature on pathogenesis, clinical presentation, and management of CRS and neurotoxicity. The different grading systems of CRS and management protocols used in different trials have made it difficult to compare the outcomes of different CAR-T therapies. Several prevention strategies such as predictive biomarkers of CRS and neurotoxicity and modified CAR-T with 'built-in' safety mechanisms are being studied, with the potential to greatly expand the safety and applicability of CAR-T treatment across various malignancies.

Revised International Staging System Is Predictive and Prognostic for Early Relapse (<24 months) after Autologous Transplantation for Newly Diagnosed Multiple Myeloma

The revised International Staging System (R-ISS) combines ISS with genetic markers and lactate dehydrogenase and can prognosticate newly diagnosed multiple myeloma (MM). Early relapse (<24 months) after upfront autologous hematopoietic cell transplantation (AHCT) strongly predicts inferior overall survival (OS). We examined the ability of R-ISS in predicting early relapse and its independent prognostic effect on postrelapse survival after an early relapse. Using the Center for International Blood and Marrow Transplant Research database we identified MM patients receiving first AHCT within 18 months after diagnosis with available R-ISS stage at diagnosis (n = 628). Relative risks of relapse/progression, progression-free survival (PFS), and OS were calculated with the R-ISS group as a predictor in multivariate analysis. Among early relapsers, postrelapse survival was tested to identify factors affecting postrelapse OS. The cumulative incidence of early relapse was 23%, 39%, and 50% for R-ISS I, R-ISS II, and R-ISS III, respectively (P < .001). Shorter PFS and OS were seen with higher stage R-ISS. R-ISS was independently predictive for inferior postrelapse OS among early relapsers, as was the presence of ≥3 comorbidities and the use of ≥2 induction chemotherapy lines. R-ISS stage at diagnosis predicts early post-AHCT relapse and independently affects postrelapse survival among early relapsers.

IMMEDIATE EFFECTS OF A DYNAMIC ROTATION-SPECIFIC WARM-UP ON X-FACTOR AND X-FACTOR STRETCH IN THE AMATEUR GOLFER

BACKGROUND

Recent evidence suggests performing a warm-up prior to golf can improve performance and reduce injuries. While some characteristics of effective golf warm-ups have been determined, no studies have explored the immediate effects of a rotational-specific warm-up with elements of motor control on the biomechanical aspects of the full X-Factor and X-Factor Stretch during the golf swing.

METHODS

Thirty-six amateur golfers (mean ± SD age: 64 ± 8 years old; 75% male) were randomized into a Dynamic Rotation-Specific Warm-up group (n=20), or a Sham Warm-up group (n=16). X-Factor and X-Factor Stretch were measured at baseline and immediately following the warm-up. Mixed model ANCOVAs were used to determine if a Group*Time interaction existed for each variable with group as the between-subjects variable and time as the within-subjects variable.

RESULTS

The mixed model ANCOVAs did not reveal a statistically significant group*time interaction for X-Factor or X-Factor Stretch. There was not a significant main effect for time for X-Factor but there was for X-Factor Stretch. These results indicate that neither group had a significant effect on improving X-Factor, however performing either warm-up increased X-Factor Stretch without significant difference between the two.

CONCLUSIONS

The results of this study suggest that performing the Dynamic Rotation-Specific Warm-up did not increase X-Factor or X-Factor Stretch when controlled for age compared to the Sham Warm-up. Further study is needed to determine the long-term effects of the Dynamic Rotation-Specific Warm-up on performance factors of the golf swing while examining across all ages.

LEVEL OF EVIDENCE

2b.

Myeloablative intravenous pharmacokinetically targeted busulfan plus fludarabine as conditioning for allogeneic hematopoietic cell transplantation in patients with non-Hodgkin lymphoma

BACKGROUND

Mortality associated with allogeneic hematopoietic cell transplantation (allo-HCT) has limited its broader application in patients with non-Hodgkin lymphoma (NHL). Pharmacokinetic treatment with targeted intravenous busulfan combined with fludarabine (BuFlu) was developed as a preparative regimen for acute leukemia and myelodysplasia. Data from this regimen in lymphoid malignancies are limited.

PATIENTS AND METHODS

We assessed outcomes in 60 consecutive patients with various subtypes of NHL and a median age of 54 years (range, 27-68 years) who received allo-HCT with targeted intravenous BuFlu between December 2004 and August 2010. The median number of previous therapies was 3 (range, 1-8) and median time from diagnosis to HCT was 32 months (range, 4.5-177.5 months).

RESULTS

At conditioning, 28 (47%) patients had a complete response (CR). Graft versus host disease (GVHD) prophylaxis consisted of tacrolimus plus methotrexate in 65% of cases. Donors were matched/related (n = 32 [53%]), matched/unrelated (n = 21 [35%]), or mismatched/unrelated (n = 7 [12%]). All patients underwent grafting. The cumulative incidence of grade II/IV acute GVHD was 74% (grade III/IV was 20%). The 2-year cumulative incidence of moderate to severe chronic GVHD was 62%. Nonrelapse mortality (NRM) at 100 days and 3 years was 10% and 25%, respectively. The cumulative incidence of relapse was 27%. Three-year progression-free and overall survival for all patients was 47.8% and 55%, respectively.

CONCLUSION

Targeted intravenous BuFlu is a relatively well tolerated regimen and offers an alternative option when myeloablation is deemed necessary in patients with NHL.

Pharmacokinetically-targeted BU and fludarabine as conditioning before allogeneic hematopoietic cell transplantation for adults with ALL in first remission

Allogeneic hematopoietic cell transplantation offers improved survival in patients with ALL, but with regimens containing TBI, the nonrelapse mortality is 20-40%. Efforts to lessen transplant toxicities by reducing conditioning regimen intensity have led to increased relapse risk. Therefore, there is a need for less toxic regimens that maintain an anti-leukemia effect. We report here a retrospective review of 65 patients with ALL in first remission receiving grafts from allogeneic donors after fludarabine 40 mg/m(2)/day for 4 days and i.v. BU targeted to a median daily area under the concentration-time curve below 6000 μmoles min/L. At 2 years after transplantation, OS was 65% (95% confidence interval (CI): 52-77%), relapse-free survival was 61% (95% CI: 48-73%), cumulative incidence of relapse was 26% (95% CI: 17-39%) and cumulative incidence of nonrelapse mortality was 14% (95% CI: 8-26%). Age over 35 years, Ph chromosome positivity and minimal residual disease at transplant did not adversely affect outcomes. Pharmacokinetically targeted BU and fludarabine can provide intensive pre-transplant conditioning for adults with ALL in first remission, with promising relapse-free and OS rates.

Phase II study of CD4+-guided pentostatin lymphodepletion and pharmacokinetically targeted busulfan as conditioning for hematopoietic cell allografting

One limitation of reduced-intensity preparative regimens is potential for graft failure. We have developed a regimen that targets CD4(+) lymphodepletion to ensure early and durable engraftment. The primary endpoint was achievement of ≥50% CD3(+) donor chimerism by day +28. Forty-two patients (median age, 53 years; range, 29 to 73 years) received pentostatin 4 mg/m(2) i.v. on days -28, -21, and -14 when the CD4(+) cell count was >100 cells/μL and on days -4 and -3 regardless of CD4(+) level. Rituximab 375 mg/m(2) was administered to patients with CD20(+) malignancies on days -21, -14, -7, +1, and +8. Busulfan 200 mg/m(2) i.v. was administered on days -4 and -2 at a dose to target a cumulative AUC dose of 16,000 (±10%) μmol·min/L. Graft-versus-host disease (GVHD) prophylaxis consisted of tacrolimus plus methotrexate in 86% of patients. Donors were matched-related (47%), matched unrelated (43%), or mismatched unrelated (10%). Chronic lymphocytic leukemia (45%) and follicular non-Hodgkin lymphoma (14%) were the most common diagnoses. Disease status at initiation of the preparative regimen was complete remission in 22%, partial response in 55%, and stable/progression in 24%. The median percent CD4(+) cell count decrease from baseline (day -28) was 52% to day -21, 66% to day -14, 62% to day -7, and 91% to day 0. At day +28, all 42 patients (100%) had ≥50% CD3(+) donor chimerism. No patient experienced graft failure. Overall response rate was 82% (complete remisson, 67%). The day +100 cumulative incidence of grade II-IV acute GVHD was 59% (grade III-IV acute GVHD, 19%), and the 2 year cumulative incidence of chronic GVHD was 69% (moderate/severe, 58%). Nonrelapse mortality was 2% at day +100 and 17% at 2 years. Two-year PFS was 55%, and OS was 68%. This regimen ensures durable engraftment, is effective against persistent disease, and results in relatively low mortality from causes other than relapse.

Transcriptional regulator early growth response gene 2 (Egr2) is required for T cell anergy in vitro and in vivo

Deletion of early growth response gene Egr2 prevents anergy induction through diacylglycerol kinase α and restores Ras/MAPK signaling in T cells.

T cell receptor engagement in the absence of costimulation results in a hyporesponsive state termed anergy. Understanding the transcriptional regulation of other T cell differentiation states has provided critical information regarding the biology of T cell regulation in vivo. However, the transcriptional regulation of T cell anergy has been poorly understood. Using the key anergy target gene diacylglycerol kinase (DGK) α as a focal point, we identified early growth response gene 2 (Egr2) as a central transcription factor that regulates the anergic state. Conditional Egr2 deletion in peripheral T cells abolishes induced expression of DGK-α and other anergy genes and restores Ras/MAPK signaling, IL-2 production, and proliferation upon attempted anergy induction. Using superantigen- and tumor-induced anergy models, we found that Egr2 is necessary for anergy induction in vivo. Collectively, our results implicate Egr2 as an essential transcriptional regulator of the T cell anergy program.

Beta-catenin inhibits T cell activation by selective interference with linker for activation of T cells-phospholipase C-γ1 phosphorylation

Despite the defined function of the β-catenin pathway in thymocytes, its functional role in peripheral T cells is poorly understood. We report that in a mouse model, β-catenin protein is constitutively degraded in peripheral T cells. Introduction of stabilized β-catenin into primary T cells inhibited proliferation and cytokine secretion after TCR stimulation and blunted effector cell differentiation. Functional and biochemical studies revealed that β-catenin selectively inhibited linker for activation of T cells phosphorylation on tyrosine 136, which was associated with defective phospholipase C-γ1 phosphorylation and calcium signaling but normal ERK activation. Our findings indicate that β-catenin negatively regulates T cell activation by a previously undescribed mechanism and suggest that conditions under which β-catenin might be inducibly stabilized in vivo would be inhibitory for T cell-based immunity.

β-catenin inhibits T cell activation by selective interference with LAT-PLC-γ1 phosphorylation. (50.12)

The functional role of β-catenin in post-thymic T cells is poorly understood. We observed that β-catenin protein was constitutively degraded in peripheral T cells. Introduction of a stabilized mutant of β-catenin into primary T cells resulted in reduced proliferation and cytokine secretion following TCR/CD28 stimulation, and interfered with effector cell differentation. The biochemical mechanism of blunted T cell activation was investigated. Stable β-catenin was predominantly localized to the cytosol, and cytokine production was rescued with PMA+Ionomycin, arguing for an inhibitory effect on early TCR signaling. Analysis of specific signaling events revealed a selective inhibition of LAT phosphorylation on tyrosine 136, which was associated with defective PLC-γ1 phosphorylation and calcium signaling but normal ERK activation. Stable β-catenin was detected constitutively in regulatory T cells, and conditional deletion of β-catenin in these cells caused rapid cell death. Contrary to a recent report using GSK-3 inhibitors, we saw no effect on T cell memory differentiation with direct genetic manipulation of β-catenin. Our findings indicate that β-catenin negatively regulates effector T cell activation via a unique biochemical mechanism. Functionally, our observations suggest that conditions under which β-catenin might be inhibited in vivo would potentiate T cell-based immunity at the level of both effector and regulatory T cells.

A phase II study of oxaliplatin, docetaxel, and GM-CSF in patients with previously treated advanced melanoma

PURPOSE

Although much focus has been placed on immunotherapy for melanoma, further development of chemotherapy approaches is needed. Melanoma is responsive to platinum compounds and taxanes, but there is limited experience with combinations of these agents. Oxaliplatin has been reported to have detectable activity in melanoma, and a phase I study has identified a tolerable dose and schedule of oxaliplatin in combination with docetaxel and hematopoietic growth factor support. GM-CSF has a theoretical advantage of immune potentiation. These considerations supported the study of oxaliplatin, docetaxel, and GM-CSF in patients with advanced melanoma.

METHODS

Eligibility included adequate organ function, PS<or=2, at most one prior chemotherapy and one prior immunotherapy, no prior treatment with oxaliplatin or taxanes and no chremophor allergy. After premedication, docetaxel was administered day 1 at 75 mg/m2, then oxaliplatin on day 2 at 85 mg/m2. GM-CSF (250 mcg/m2) was administered s.c. days 3-12. Cycles were 21 days in length, and disease reevaluation was performed every two cycles by RECIST criteria.

RESULTS

Nineteen patients received at least one cycle, eight with one prior systemic therapy, five with two prior systemic therapies. Five patients did not complete two cycles and were not formally evaluable for response. Five patients had stable disease (SD), including one who failed two prior therapies and went on to receive ten cycles. The remaining nine patients displayed progressive disease (PD) after two cycles. Notable toxicities included seven cases (37%) of grade III/IV neutropenia and two (11%) hypersensitivity reactions.

CONCLUSIONS

This combination of oxaliplatin, docetaxel, and GM-CSF has limited clinical activity in previously treated patients with advanced melanoma. Exploration in treatment-naïve patients may still be warranted.

Use of Cre-adenovirus and CAR transgenic mice for efficient deletion of genes in post-thymic T cells

Conditional gene deletion using lineage-specific transgenic expression of Cre has been useful for defining the role of specific gene products in mice in vivo. However, this technology has had limitations for studies of peripheral T cell biology, since the T-lineage promoters commonly used are active early in thymic development. As such, T cell development can be altered by the resulting genetic alterations, thus limiting the interpretation of the data in post-thymic T cell studies. Thus, new strategies are needed to delete targeted genes directly in peripheral T lymphocytes. The availability of transgenic mice expressing the CAR in the T cell compartment enabled testing of Cre-mediated recombination using an adenoviral vector in naïve peripheral T cells in vitro, even without cellular activation. Using Rosa26R reporterxCAR transgenic mice, we describe conditions by which Cre-mediated deletion of targeted genes can be achieved with primary T cells in vitro. These cells can also be adoptively transferred into defined recipient mice for study in vivo. We use conditional PTEN-deficient mice as proof of concept to confirm the value of this technique for deleting a negative regulator of T cell activation. This technology should be broadly applicable for studies of T cell-specific gene deletion to gain understanding of function in the post-thymic T cell compartment.

Epidemiologic pathology of gastric ulcer and gastric carcinoma among Japanese in Hawaii

This case-control study of Hawaiian Japanese indicated that gastric ulcer in the proximal portion of the pyloric antrum has features similar to those of gastric cancer. Such ulcers occurred at sites most frequently and most severely affected by intestinal metaplasia, although metaplasia tended to be more extensive with cancer than with ulcer. Metaplastic mucosa was more vulnerable to the action of pepsin and acid than was normal mucosa. The risk of ulceration would rise when a sufficiently lagrge area of the antrum was intestinalized and when the corpus continued to produce significant quantities of these substances. This study showed a strong association between salt intake, ulcer, and metaplasia. Significant but less dramatic associations were demonstrated between metaplasia and the use of traditional Japanese foods and smoking. The question was raised as to whether salt promotes ulceration or whether it potentiates the action of a mutagen that causes intestinal metaplasia.