Phase I-II Trial of Early Azacitidine after Matched Unrelated Donor Hematopoietic Cell Transplantation

Graft-versus-host disease (GVHD) is a major complication after allogeneic hematopoietic cell transplantation (allo-HCT). The hypomethylating agent azacitidine (AZA) has been shown to be effective in preclinical and clinical studies for the prevention of acute GVHD (aGVHD). We sought to determine the maximum tolerated dose (MTD) of AZA when given on days 1 to 5 of a 28-day cycle for 4 cycles, starting on day +7 after allo-HCT, as well as its impact on aGVHD and chronic GVHD (cGVHD), relapse, and overall survival (OS) in patients undergoing matched unrelated donor allo-HCT. This study was a single-arm, single-center, open-label phase I-II study with a total of 15 and 38 patients enrolled in the phase I and II portions of the trial, respectively. A standard 3+3 study design was used in phase I, and all patients in phase II received AZA at the MTD determined in phase I. The MTD of AZA starting at day +7 post-transplantation was 45 mg/m2. Phase II of the study was halted after enrolling 38 of the planned 46 patients following an interim analysis that suggested futility. Overall, AZA at 45 mg/m2 exhibited a side effect profile consistent with prior reports and had a minimal impact on engraftment. The cumulative incidence of clinically significant aGVHD by day +180 was 39.9% (95% confidence interval [CI], 22% to 53.7%). The incidence of all-grade cGVHD was 61.4% (95% CI, 40.3% to 75%). At 1 year, OS was 73.7% (95% CI, 60.9% to 89.1%), and the disease relapse rate was 11.4% (95% CI, .2% to 21.3%). Our results suggest that early post-allo-HCT AZA has limited efficacy in preventing aGVHD and cGVHD but could have a beneficial effect in preventing disease relapse.

Bendamustine/Rituximab Plus Cytarabine/Rituximab, With or Without Acalabrutinib, for the Initial Treatment of Transplant-Eligible Mantle Cell Lymphoma Patients: Pooled Data From Two Pilot Studies

INTRODUCTION

Mantle cell lymphoma (MCL) is a moderately aggressive lymphoma subtype, generally viewed as incurable. For younger, fit patients, the standard of care remains various high-dose cytarabine-based induction regimens followed by autologous hematopoietic cell transplant and 3 years of rituximab maintenance. Despite reasonably good outcomes, with median progression-free survival in the range of 7 to 9 years, most patients eventually relapse, indicating a need to improve the safety and tolerability of remission induction strategies.

METHODS

Given the impressive activity of bendamustine/rituximab (BR) in older patients with MCL, we developed an induction regimen modeled after the Nordic Regimen but substituted BR in place of R-CHOP. In a second pilot study, we incorporated the second-generation Bruton tyrosine kinase inhibitor (BTKi), acalabrutinib, into the regimen. The primary endpoint of both studies was stem cell mobilization success rate.

RESULTS

All patients successfully underwent stem cell harvest in both studies.

CONCLUSION

The experience from our single institution pilot study suggested that sequential rather than alternating BR and cytarabine/rituximab (CR) was easier to administer from the standpoint of toxicities and subsequent dose modifications. Safety and efficacy data from the 2 pilot studies, FitMCL 1.0 and 2.0, were similar. The pilot studies provided preliminary safety data supporting the development of the NCTN trial EA4181, assessing three different induction regimens with or without acalabrutinib.

KDM6B protects T-ALL cells from NOTCH1-induced oncogenic stress

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematopoietic neoplasm resulting from the malignant transformation of T-cell progenitors. While activating NOTCH1 mutations are the dominant genetic drivers of T-ALL, epigenetic dysfunction plays a central role in the pathology of T-ALL and can provide alternative mechanisms to oncogenesis in lieu of or in combination with genetic mutations. The histone demethylase enzyme KDM6A (UTX) is also recurrently mutated in T-ALL patients and functions as a tumor suppressor. However, its gene paralog, KDM6B (JMJD3), is never mutated and can be significantly overexpressed, suggesting it may be necessary for sustaining the disease. Here, we used mouse and human T-ALL models to show that KDM6B is required for T-ALL development and maintenance. Using NOTCH1 gain-of-function retroviral models, mouse cells genetically deficient for Kdm6b were unable to propagate T-ALL. Inactivating KDM6B in human T-ALL patient cells by CRISPR/Cas9 showed KDM6B-targeted cells were significantly outcompeted over time. The dependence of T-ALL cells on KDM6B was proportional to the oncogenic strength of NOTCH1 mutation, with KDM6B required to prevent stress-induced apoptosis from strong NOTCH1 signaling. These studies identify a crucial role for KDM6B in sustaining NOTCH1-driven T-ALL and implicate KDM6B as a novel therapeutic target in these patients.

Late cardiac events after allogeneic stem cell transplant: incidence, risk factors, and impact on overall survival

BACKGROUND

There is limited data on the impact of cardiac disease on long term outcomes of allogeneic stem cell transplant (alloSCT). Our study aims to describe the incidence of late cardiac events after alloSCT, identify risk factors for developing a late cardiac event, and illustrate the impact of late cardiac events on overall survival.

METHODS

Patients who underwent alloSCT from 2007 to 2017 and survived more than 1 year after transplant (N = 804) were included. Gray's sub-distribution methods, while accounting for death as a competing risk, were used to calculate the cumulative incidence of late cardiac events. Univariate regression models based on Gray's sub-distribution were fitted to assess the potential predictive effects of baseline characteristics on the risk of developing any late cardiac events. Univariate Cox proportional hazard regression models were used to evaluate the association between late cardiac events and overall survival.

RESULTS

The cumulative incidence of a late cardiac event at 5 years after transplant was 22% (95% CI 19-25%). The most frequent cardiac event was a decline in LVEF to < 45% with a cumulative incidence of 9% (95% CI 7-11%). Patients were at significantly increased hazard of developing a late cardiac event if they had a history of congestive heart failure prior to alloSCT (HR 4.53, 95% CI 2.57-7.97, p-value < 0.001), a decline in LVEF to < 45% (HR 3.95, 95% CI 2.09-7.47, p-value < 0.001) or cerebral vascular accident (HR 3.13, 95% CI 1.38-7.06, p-value 0.004). Transplant characteristics such as primary disease, donor type, use of TBI, myeloablative conditioning regimen or tyrosine kinase inhibitor had no significant association with late cardiac events. Almost all cardiac events demonstrated a significantly increased risk of death. This hazard was the highest in patients who experienced an atrial arrhythmia (HR 10.6, 95% CI 7.7-14.6).

CONCLUSION

Adverse cardiac events are relatively common late after alloSCT with identifiable risk factors such as medical comorbidities prior to transplant and are associated with a negative impact on overall survival.

Autologous T cell therapy for MAGE-A4+ solid cancers in HLA-A*02+ patients: a phase 1 trial

Affinity-optimized T cell receptors can enhance the potency of adoptive T cell therapy. Afamitresgene autoleucel (afami-cel) is a human leukocyte antigen-restricted autologous T cell therapy targeting melanoma-associated antigen A4 (MAGE-A4), a cancer/testis antigen expressed at varying levels in multiple solid tumors. We conducted a multicenter, dose-escalation, phase 1 trial in patients with relapsed/refractory metastatic solid tumors expressing MAGE-A4, including synovial sarcoma (SS), ovarian cancer and head and neck cancer ( NCT03132922 ). The primary endpoint was safety, and the secondary efficacy endpoints included overall response rate (ORR) and duration of response. All patients (N = 38, nine tumor types) experienced Grade ≥3 hematologic toxicities; 55% of patients (90% Grade ≤2) experienced cytokine release syndrome. ORR (all partial response) was 24% (9/38), 7/16 (44%) for SS and 2/22 (9%) for all other cancers. Median duration of response was 25.6 weeks (95% confidence interval (CI): 12.286, not reached) and 28.1 weeks (95% CI: 12.286, not reached) overall and for SS, respectively. Exploratory analyses showed that afami-cel infiltrates tumors, has an interferon-γ-driven mechanism of action and triggers adaptive immune responses. In addition, afami-cel has an acceptable benefit-risk profile, with early and durable responses, especially in patients with metastatic SS. Although the small trial size limits conclusions that can be drawn, the results warrant further testing in larger studies.

Survival after autologous versus allogeneic transplantation in patients with relapsed and refractory Hodgkin lymphoma

For relapsed Hodgkin lymphoma, salvage chemotherapy followed by auto-HCT is the standard of care. It is important to identify subpopulations who could benefit from allo-HCT. This retrospective analysis included 277 patients with rrHL who underwent first transplant with auto-HCT or allo-HCT between 2007-2017. Patients in the auto-HCT cohort (N = 218) were older, more likely to be in CR at the time of transplant and receive maintenance therapy post-transplant. Patients who underwent allo-HCT (N = 59) had a higher MSKCC relapse score. Factors associated with an inferior PFS and OS included early relapse, advanced stage, extranodal involvement and not achieving CR following salvage chemotherapy. After controlling for these 4 risk factors and MSKCC score, PFS (p = 0.112) or OS (p = 0.256) was not affected by the choice of transplant. In patients with ≥ 3 high risk features, the 4-year PFS was 51% in the allo-HCT vs. 39% (p = 0.107) in the auto-HCT cohort.

Abstract PO-06: Ultradeep sequencing of classical Hodgkin lymphoma (cHL) identifies recurrent somatic mutations and demonstrates the production of reproducible data from rare malignant cells

Purpose/Background: cHL patients who receive standard therapy have a high rate of event-free and overall survival. However, some patients (~10%) will be refractory to initial therapy and up to 1/3 will relapse. Thus, improved methods of prognostication and new treatment targets are needed. High-throughput sequencing can identify recurrent somatic mutations that drive lymphomagenesis and impact treatment response. However, Hodgkin-Reed-Sternberg (HRS) cells have a low (~1%) abundance in cHL biopsies, creating a challenge for comprehensive and accurate detection of somatic mutations in bulk lymphoma biopsies. Genomic studies of cHL have characterized HRS somatic mutations through the analysis of malignant cells obtained using purification techniques, cell-free DNA, or DNA amplified through whole-genome amplification. We hypothesized that ultradeep sequencing of bulk lymphoma biopsies provides a more accessible approach to HRS characterization while also creating robust and reproducible data.

Methods: We performed exome sequencing on 32 fresh frozen samples from 31 cHL patients obtained prior to treatment (27) or after relapse (4) with paired normal skin samples (31). The Illumina HiSeq platform (2 x 150bp reads) was used with multiple independent library constructions and a 1,000X median coverage goal. Sequence data were aligned to GRCh38. SNVs and INDELs were called using multiple algorithms. We employed several variant filtering strategies, including manual review, to remove common polymorphisms and false positives. Because we discovered mutations with VAFs close to the platform error rate (~1%), we used an orthogonal sequencing strategy (Haloplex) to validate all somatic variants.

Results: We observed 4,020 somatic variants. On average, we observed 32 protein-coding mutations/case, excluding one hypermutated case in which 3,084 variants were observed. We identified a potential loss-of-function insertion in MSH6 that could explain the hypermutated phenotype. We achieved a 99% validation rate across the cohort for somatic variants discovered in exomes. We confirmed known recurrently mutated cHL genes (e.g., SOCS1 [43%], STAT6 [20%], TNFAIP3 [40%]). We identified several significantly recurrent mutated genes not well characterized in cHL, including IGLL5 [26%] and IL4R [13%]. All IL4R mutations are potential loss-of-function mutations that could result in greater activation of STAT6 through ablation of ITIM negative modulation. We identified an enrichment of SOCS1 and IGLL5 mutations that is likely the result of aberrant somatic hypermutation. Pathway analysis also identified an enrichment of mutations in MAPK pathways.

Conclusion: These data suggest that cHL somatic mutations can be confidently identified via ultradeep exome sequencing without cell purification. We show that cHL genomes harbor somatic variation that inform new targets for treatment and prognostication.

Citation Format: Felicia Gomez, Matthew Mosior, Zachary Skidmore, Alina Schmidt, Fernanda Rodrigues-Martins, Kilannin Krysiak, Cody Ramirez, Eric Duncavage, Grace Triska, Lee Trani, Nancy Bartlett, Amanda Cashen, Neha Mehta-Shah, Friederike Kreisel, Malachi Griffith, Todd Fehniger, Obi Griffith. Ultradeep sequencing of classical Hodgkin lymphoma (cHL) identifies recurrent somatic mutations and demonstrates the production of reproducible data from rare malignant cells [abstract]. In: Proceedings of the AACR Virtual Meeting: Advances in Malignant Lymphoma; 2020 Aug 17-19. Philadelphia (PA): AACR; Blood Cancer Discov 2020;1(3_Suppl):Abstract nr PO-06.

Standard-of-Care Axicabtagene Ciloleucel for Relapsed or Refractory Large B-Cell Lymphoma: Results From the US Lymphoma CAR T Consortium

PURPOSE

Axicabtagene ciloleucel (axi-cel) is an autologous CD19-directed chimeric antigen receptor (CAR) T-cell therapy approved for relapsed/refractory large B-cell lymphoma (LBCL) on the basis of the single-arm phase II ZUMA-1 trial, which showed best overall and complete response rates in infused patients of 83% and 58%, respectively. We report clinical outcomes with axi-cel in the standard-of-care (SOC) setting for the approved indication.

PATIENTS AND METHODS

Data were collected retrospectively from all patients with relapsed/refractory LBCL who underwent leukapheresis as of September 30, 2018, at 17 US institutions with the intent to receive SOC axi-cel. Toxicities were graded and managed according to each institution's guidelines. Responses were assessed as per Lugano 2014 classification.

RESULTS

Of 298 patients who underwent leukapheresis, 275 (92%) received axi-cel therapy. Compared with the registrational ZUMA-1 trial, 129 patients (43%) in this SOC study would not have met ZUMA-1 eligibility criteria because of comorbidities at the time of leukapheresis. Among the axi-cel-treated patients, grade ≥ 3 cytokine release syndrome and neurotoxicity occurred in 7% and 31%, respectively. Nonrelapse mortality was 4.4%. Best overall and complete response rates in infused patients were 82% (95% CI, 77% to 86%) and 64% (95% CI, 58% to 69%), respectively. At a median follow-up of 12.9 months from the time of CAR T-cell infusion, median progression-free survival was 8.3 months (95% CI, 6.0 to15.1 months), and median overall survival was not reached. Patients with poor Eastern Cooperative Oncology Group performance status of 2-4 and elevated lactate dehydrogenase had shorter progression-free and overall survival on univariable and multivariable analysis.

CONCLUSION

The safety and efficacy of axi-cel in the SOC setting in patients with relapsed/refractory LBCL was comparable to the registrational ZUMA-1 trial.

Immunophenotypic Variations in Mantle Cell Lymphoma and Their Impact on Clinical Behavior and Outcome

Context.—

Immunophenotypic variations in mantle cell lymphoma (MCL) from the classic CD5+/CD10−/CD23−/FMC-7+ immunophenotype have been reported in the literature, but correlation with clinical behavior and outcome has not been fully studied.

Objective.—

To investigate clinicopathologic and prognostic differences between immunophenotypically aberrant MCL and immunophenotypically typical MCL.

Design.—

We evaluated differences in clinical presentation, laboratory parameters, prognostic indices, response to initial treatment, and progression-free and overall survival between patients with aberrant MCL and patients with immunophenotypically typical MCL.

Results.—

There were 158 patients with newly diagnosed cyclin D1 or t(11;14)(q13;q32)+ MCL identified in the original search, of which, 29 patients (18%) showed immunophenotypic aberrancies, with CD23 coexpression being the most common. When compared with 33 randomly selected patients with immunophenotypically typical MCL, statistically significant differences were seen in white blood cell counts (P = .02), in the presence of absolute lymphocytosis (P = .03), in the MCL International Prognostic Index score (P = .02), and in response to initial treatment (P = .04). The “immunophenotypic status” of the MCL was the only independent factor associated with response to treatment (P = .05), but not with the MCL International Prognostic Index score, absolute lymphocytosis, or white blood cell count. No significant differences were seen for progression-free or overall survival.

Conclusions.—

Immunophenotypic variations in MCL are associated with differences in clinical presentation and response to therapy when compared with immunophenotypically typical MCL. However, with current intensive frontline immunochemotherapy, immunophenotypic aberrations do not appear to affect progression-free or overall survival.

Abstract 2448: Deep exome sequencing reveals recurrent somatic mutations in Hodgkin's lymphoma

High-throughput sequencing provides insights into cancer pathogenesis. The application of genomics technologies to cancers characterized by rare cell populations is a challenge. DNA extracted from bulk tumor samples is a mixture of malignant and non-malignant cells. This is a problem in cancers defined by rare cell populations because it complicates the task of identifying true somatic mutations. Hodgkin lymphoma (HL) exemplifies this challenge. The pathologic hallmark of HL is Hodgkin-Reed-Sternberg (HRS) cells. HRS cells have a low abundance within an affected lymph node (1-30% of tumor microenvironment). Because HRS cells are rare, a limited number of studies have described characteristic genomic events. These studies have examined HL cell lines, and, recently, a small number of flow-sorted HRS-cells (Reichel et. al. 2015). We hypothesized that recurrent somatic mutations can be identified in HRS cells using bulk HL biopsies and ultra deep exome sequencing.

The Illumina HiSeq X,which can generate&gt; 1.6 Tb of sequence data per run, is a applicable tool for the discovery of somatic mutations in HL. Frozen tumor (lymph node)/normal (skin) pairs from 31 patients with HL were examined. Three KAPA libraries were constructed per sample. The libraries were pooled, size selected, and captured using an IDT xGen capture reagent. The pools were sequenced across eight lanes of a HiSeq X. A total of 7.04 x 1012 bases were sequenced across all samples with an average of 1.10 x 1011 bases per sample. The mean depth of coverage achieved across all samples was 783.4x (425.9x - 1091.9x). Given the low abundance of HRS cells we anticipated most somatic sites would have a VAF of 1% -5%. Given the level of coverage we anticipate that most somatic variants will have &gt;5 reads of support.

Instrument data were processed using the McDonnell Genome Institute somatic variant calling pipeline that includes 5 SNV callers and 3 indel callers. We used these steps to filter variants: min. 50x coverage, max. 5000x coverage, min. 1% tumor VAF, max. 5%, normal VAF, and min. 5 variant reads in the tumor. Here we report preliminary data on mutations in five pilot samples. The remaining 26 will be presented at the meeting. We confirmed 7 previously identified recurrent mutations in HL (Reichel et al. 2015). Within our pilot data 13 recurrently mutated genes were found. The most interesting of our recurrent genes is TNFAIP3, which was the second most frequently mutated gene in Reichel et al. 2015. These data suggest that ultra deep sequencing of tumor samples containing rare HRS cells can identify recurrent somatic mutations. Thus, ultra deep exome sequencing may be a useful discovery tool for rare tumor populations, and will improve our understanding of HL.

Citation Format: Felicia Gomez, Kilannin Krysiak, Cody Ramirez, Nancy Bartlett, Amanda Cashen, Friederike Kreisel, Eric Duncavage, Malachi Griffith, Todd Fehniger, Obi Griffith. Deep exome sequencing reveals recurrent somatic mutations in Hodgkin's lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2448. doi:10.1158/1538-7445.AM2017-2448

Mixed Donor Chimerism Following Simultaneous Pancreas-Kidney Transplant

OBJECTIVES

Graft-versus-host disease after solid-organ transplant is exceedingly rare. Although the precise pathogenetic mechanisms are unknown, a progressive increase in donor chimerism is a requirement for its development. The incidence of mixed donor chimerism and its timeline after simultaneous pancreas-kidney transplant is unknown.

MATERIALS AND METHODS

After encountering 2 cases of graft-versus-host disease after simultaneous pancreas-kidney transplant at our institution over a period of < 2 years, a collaborative pilot study was conducted by the bone marrow transplant, nephrology, and abdominal transplant surgery teams. We enrolled all consecutive patients undergoing sex-mismatched simultaneous pancreas-kidney transplant over 1 year and longitudinally monitored donor chimerism using fluorescence in situ hybridization for sex chromosomes.

RESULTS

We found no evidence for chimerism in our 7 patients. In a comprehensive literature review, we found a total of 25 previously reported cases of graft-versus-host disease after kidney, pancreas, and simultaneous pancreas-kidney transplants. The median onset of graft-versus-host disease was approximately 5 weeks after transplant, with a median of about 2 weeks of delay between first presentation and diagnosis. Skin, gut, and bone marrow were almost equally affected at initial presentation, and fever of unknown origin occurred in more than half of patients. The median survival measured from the first manifestation of graft-versus-host disease was only 48 days.

CONCLUSIONS

Within the limitations related to small sample size, our results argue against an unusually high risk of graft-versus-host disease after simultaneous pancreas-kidney transplant. Collaboration between solid-organ and stem cell transplant investigators can be fruitful and can improve our understanding of the complications that are shared between the 2 fields.

Feasibility of training nurses in motivational interviewing to improve patient experience in mental health inpatient rehabilitation: a pilot study

WHAT IS KNOWN ON THE SUBJECT?: Recently, concerns have been raised about how well United Kingdom National Health Service nurses care for their patients and their level of compassion. Motivational interviewing (MI) is an established approach to helping people make positive behaviour changes, through directive, person-centred counselling within a collaborative relationship between clinician and recipient. Based on evidence that MI may influence nursing practice positively, an investigation into the feasibility of training nurses on mental health inpatient rehabilitation wards ('rehabilitation') in MI to improve patient experience was reported. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: This pilot study demonstrates that training rehabilitation nurses in MI is feasible and provides preliminary evidence suggesting that a larger study to examine efficacy is warranted, including a calculation of sample size required to draw robust statistical conclusions. Nurses evaluated the training as highly relevant to their work. Patients responded well to interviews and focus groups with support from experts-by-experience; they were generally fairly satisfied with the rehabilitation ward and slight improvements in their experience were found following MI training for nurses but not at 6-month follow-up. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Rehabilitation nurses may face conflicting demands between ensuring patients with severe difficulties meet their basic needs and working with them to develop greater independence. Qualitative findings question whether nurse-patient interactions are fully valued as nursing interventions in inpatient rehabilitation. Learning MI might be a useful way of helping nurses think in detail about their interactions with patients and how to improve communications with their patients. The principles of MI should be incorporated into pre-registration training.

ABSTRACT

Introduction There is limited research addressing the experiences of patients in inpatient rehabilitation (rehabilitation), who often spend long periods in hospital, and the nursing approaches utilized. Aim Based on evidence that motivational interviewing (MI) may improve nursing practice, this was a pilot study evaluating the feasibility of training rehabilitation nurses in MI and measuring patient experience. Method Nurses underwent training and supervision focusing on MI spirit. Quantitative and qualitative measures were taken pretraining, 2 months post-training and 8 months post-training. Expert-by-experience research assistants facilitated patients' participation in the study. Results This study showed that training rehabilitation nurses in MI was feasible and relevant to their work. Patients participated in interviews and focus groups with support and potential improvements that require further empirical investigation in patient experience were found following the MI training. Discussion This pilot study establishes the feasibility of a larger study addressing efficacy. Tentative qualitative findings question whether interactions between nurses and patients are valued in rehabilitation and support MI as a promising skill set for rehabilitation nurses. Implications for practice Bringing MI into inpatient rehabilitation provoked reflection on nursing practice. Dilemmas for nurses about balancing safety with promoting autonomy and communicating constructively with patients emerged as important.

Phase I study of azacitidine following donor lymphocyte infusion for relapsed acute myeloid leukemia post allogeneic stem cell transplantation

Donor lymphocyte infusion (DLI) without prophylactic immunosuppression has been used for relapsed AML after allogeneic stem cell transplant (allo-SCT). However DLI is associated with an increased incidence of acute Graft vs. Host Disease (aGVHD). In mice, administration of azacitidine (AzaC) on days 4, 6, 8, and 10 post DLI increases regulatory T cell (Treg) numbers and prevents GVHD without hindering Graft vs. Leukemia (GVL). Based on these findings, we conducted a phase 1 study of AzaC post DLI for AML relapse post allo-SCT. AzaC was administered on days 4, 6, 8 and 10 post-DLI. Dose escalation was done using a 3+3 design with three AzaC dose levels: 30mg/m(2) (level -1), 45mg/m(2) (level 1) and 75mg/m(2) (level 2). Three patients were treated in the 45mg/m(2) dose level and 5 patients were treated in the 75mg/m(2) dose level; no DLTs or grade 3-5 treatment related toxicities were observed. After a median follow-up of 5.2 months, no patients developed grade III-IV aGVHD and no patients died of aGVHD. Six out of 8 patients in the treatment group responded to treatment including two cytogenetic complete remissions, one hematologic complete remission, and three complete remissions with incomplete count recovery. In conclusion, administration of AzaC early post DLI is well tolerated and can potentially prevent GVHD after DLI. Further studies are required to evaluate the effect of azacitidine early post DLI on GVHD and GVL.

NKG2D-NKG2D Ligand Interaction Inhibits the Outgrowth of Naturally Arising Low-Grade B Cell Lymphoma In Vivo

It is now clear that recognition of nascent tumors by the immune system is critical for survival of the host against cancer. During cancer immunoediting, the ability of the tumor to escape immune recognition is important for tumor development. The immune system recognizes tumors via the presence of classical Ags and also by conserved innate mechanisms. One of these mechanisms is the NKG2D receptor that recognizes ligands whose expression is induced by cell transformation. In this study, we show that in NKG2D receptor-deficient mice, increasing numbers of B cells begin to express NKG2D ligands as they age. Their absence in wild-type mice suggests that these cells are normally cleared by NKG2D-expressing cells. NKG2D-deficient mice and mice constitutively expressing NKG2D ligands had increased incidence of B cell tumors, confirming that the inability to clear NKG2D ligand-expressing cells was important in tumor suppression and that NKG2D ligand expression is a marker of nascent tumors. Supporting a role for NKG2D ligand expression in controlling the progression of early-stage B cell lymphomas in humans, we found higher expression of a microRNA that inhibits human NKG2D ligand expression in tumor cells from high-grade compared with low-grade follicular lymphoma patients.

NKG2D-NKG2D ligand interaction inhibits the outgrowth of low-grade B cell lymphoma (TUM9P.1019)

Transgenic mice we generated with ubiquitous expression of the NKG2D ligand RAE1ε, and therefore low surface NKG2D expression, developed natural, spontaneous B cell lymphoma at a younger age than wild-type mice. Transplantation of lymphomas from RAE1ε transgenic mice into lymphodeficient mice resulted in expression of NKG2D on immune cells transferred along with the tumor and rejection of the lymphoma cells, suggesting NKG2D is important in controlling lymphoma outgrowth in wild-type mice. In the absence of overt tumor masses, older mice developed lymphoid aggregates in non-lymphoid organs and these aggregates occurred at a younger age in RAE1ε transgenic and NKG2D-deficient mice. The increased incidence of both these lymphoid aggregates and tumor masses in RAE1ε transgenic mice suggests these lymphoid aggregates are slow growing indolent lymphomas. Although NKG2D ligands were undetectable on wild-type tumors, ligands were present on splenic B cells in a similar proportion of 10 month-old wild-type and NKG2D-deficient mice as those with lymphoid aggregates present. These results suggest that 1) induction of NKG2D ligands is an early marker of B cell transformation, 2) NKG2D-NKG2D ligand interaction suppresses B cell lymphoma growth, and 3) loss of NKG2D receptor-ligand interactions leads to the transformation of indolent B cell lymphomas into aggressive tumors in this model. We are now exploring whether these results are relevant to human follicular lymphoma progression.

Pathogenic regulatory circuits in B cell lymphoma (HEM8P.238)

Reprogramming gene expression via epigenetic perturbation of transcriptional control elements has emerged as a major mechanism of oncogenesis. Non-Hodgkin Lymphoma (NHL) is the most frequently diagnosed hematopoietic tumor. While distinct NHL gene expression patterns were identified a decade ago, underlying changes to the control elements driving these alterations remain poorly understood. Comparative integration of epigenome and transcriptome data from NHL cells and their normal counterpart B cells reveal the oncogenic regulatory circuitry that links differentially regulated control elements to target genes. Although many of these circuits are engaged in GC B cells or during B cell activation, a portion is commandeered from other cell lineages to promote transformation. Independent sets of transcription factors, whose expression are also deregulated in NHL, target augmented or attenuated circuit components. Importantly, these components are enriched for sequence variants that disrupt transcription factor binding and expression of circuit-linked genes. The pathogenic regulatory circuitry of NHL reveals genetic and epigenetic etiologies for B-cell transformation, providing unprecedented opportunity for therapeutic intervention.

Comparative effectiveness of anthracycline-containing chemotherapy in United States veterans age 80 and older with diffuse large B-cell lymphoma

OBJECTIVES

While anthracycline-based treatment can cure diffuse large B-cell lymphoma, most patients over age 80 do not receive doxorubicin due to toxicity concerns. This study evaluated this practice, as patients age 80 and older are largely excluded from clinical trials. The primary outcome of interest was overall survival. Secondary outcomes included treatment-related mortality and anthracycline dose intensity.

MATERIALS AND METHODS

We assembled a cohort of 530 newly diagnosed diffuse large B-cell lymphoma patients age 80 or older diagnosed within United States Veterans Health Administration. Treatment and survival information were obtained to determine associations between anthracycline use, dose intensity, treatment-related mortality and overall survival.

RESULTS

Of the 530 patients, 285 received systemic treatment and 193 received an anthracycline. After controlling for potential confounders, rituximab decreased mortality (hazard ratio, 0.62; 95% confidence interval [CI]: 0.44-0.88), while doxorubicin was not significantly associated with mortality (hazard ratio, 0.87; 95% CI: 0.64-1.17). Completion of treatment with anthracycline dose intensity ≥85% of expected was only 14%. Patients treated with anthracycline dose intensity <85% had better one year survival compared to those treated at ≥85% (70% vs. 59%, p=0.029).

CONCLUSION

These results suggest that full dose anthracycline therapy may be less important in the treatment of diffuse large B-cell lymphoma patients over age 80. The low frequency of completion of full dose intensity treatment suggests that standard doses are an unrealistic standard of care for patients this age. Alternate treatment strategies and risk stratification should be considered for these patients.

Early failure of frontline rituximab-containing chemo-immunotherapy in diffuse large B cell lymphoma does not predict futility of autologous hematopoietic cell transplantation

The poor prognosis for patients with diffuse large B cell lymphoma (DLBCL) who relapse within 1 year of initial diagnosis after first-line rituximab-based chemo-immunotherapy has created controversy about the role of autologous transplantation (HCT) in this setting. We compared autologous HCT outcomes for chemosensitive DLBCL patients between 2000 and 2011 in 2 cohorts based on time to relapse from diagnosis. The early rituximab failure (ERF) cohort consisted of patients with primary refractory disease or those with first relapse within 1 year of initial diagnosis. The ERF cohort was compared with those relapsing >1 year after initial diagnosis (late rituximab failure [LRF] cohort). ERF and LRF cohorts included 300 and 216 patients, respectively. Nonrelapse mortality (NRM), progression/relapse, progression-free survival (PFS), and overall survival (OS) of ERF versus LRF cohorts at 3 years were 9% (95% confidence interval [CI], 6% to 13%) versus 9% (95% CI, 5% to 13%), 47% (95% CI, 41% to 52%) versus 39% (95% CI, 33% to 46%), 44% (95% CI, 38% to 50%) versus 52% (95% CI, 45% to 59%), and 50% (95% CI, 44% to 56%) versus 67% (95% CI, 60% to 74%), respectively. On multivariate analysis, ERF was not associated with higher NRM (relative risk [RR], 1.31; P = .34). The ERF cohort had a higher risk of treatment failure (progression/relapse or death) (RR, 2.08; P < .001) and overall mortality (RR, 3.75; P <.001) within the first 9 months after autologous HCT. Beyond this period, PFS and OS were not significantly different between the ERF and LRF cohorts. Autologous HCT provides durable disease control to a sizeable subset of DLBCL despite ERF (3-year PFS, 44%) and remains the standard-of-care in chemosensitive DLBCL regardless of the timing of disease relapse.

Phase I study of oral clofarabine consolidation in adults aged 60 and older with acute myeloid leukemia

Clofarabine has shown activity and tolerability in older patients with acute myeloid leukemia (AML). We investigated the safety and tolerability of an oral formulation of clofarabine for consolidation therapy of patients aged 60 and older with AML. In this phase I study, twenty-two patients older than 60 years with AML in first complete remission were treated once daily with oral clofarabine for 14 or 21 days of a 28-day cycle, for up to five cycles. Dose escalation from 1 mg to 6 mg daily using a 3 + 3 design was used to determine dose-limiting toxicities (DLT), the maximum tolerated dose (MTD), and tolerability of oral clofarabine. No DLTs or Grade 3-4 nonhematologic toxicities were observed. The primary toxicities were hematologic, including uncomplicated grade 3-4 neutropenia (50%) and thrombocytopenia (50%). Given that myelosuppression necessitating dose delays/reductions was observed more commonly at higher doses, the recommended phase II dose is 2 mg daily for 21 of 28 days. At doses equal to or greater than 2 mg, the median relapse-free survival was 28.35 months. Oral clofarabine was well-tolerated with encouraging activity in patients older than 60 years. Further investigation of oral clofarabine as a consolidation and/or maintenance therapy in AML for older individuals is warranted. (ClinicalTrials.gov:NCT00727766).

Proteasome inhibitors evoke latent tumor suppression programs in pro-B MLL leukemias through MLL-AF4

Chromosomal translocations disrupting MLL generate MLL-fusion proteins that induce aggressive leukemias. Unexpectedly, MLL-fusion proteins are rarely observed at high levels, suggesting excessive MLL-fusions may be incompatible with a malignant phenotype. Here, we used clinical proteasome inhibitors, bortezomib and carfilzomib, to reduce the turnover of endogenous MLL-fusions and discovered that accumulated MLL-fusions induce latent, context-dependent tumor suppression programs. Specifically, in MLL pro-B lymphoid, but not myeloid, leukemias, proteasome inhibition triggers apoptosis and cell cycle arrest involving activation cleavage of BID by caspase-8 and upregulation of p27, respectively. Furthermore, proteasome inhibition conferred preliminary benefit to patients with MLL-AF4 leukemia. Hence, feasible strategies to treat cancer-type and oncogene-specific cancers can be improvised through harnessing inherent tumor suppression properties of individual oncogenic fusions.

Outcomes of hematopoietic cell transplantation for diffuse large B cell lymphoma transformed from follicular lymphoma

There are limited data on the outcomes of autologous or allogeneic hematopoietic cell transplantation (HCT) in diffuse large B cell lymphoma transformed from follicular lymphoma. We analyzed transplantation outcomes in 141 subjects with biopsy-proven diffuse large B-cell lymphoma transformed from follicular lymphoma reported to the Center for International Blood and Marrow Transplant Research between 1990 and 2009. Two groups were identified: autologous HCT (auto-HCT; n = 108) and allogeneic HCT (allo-HCT; n = 33). Fewer auto-HCTs were done for transformed follicular lymphoma in 2003 to 2009, with a shift favoring allo-HCT. Auto-HCT was associated with a 1-year nonrelapse mortality (NRM) of 8% (95% confidence interval [CI], 4% to 14%), 5-year progression-free survival of 35% (95% CI, 26% to 45%), and 5-year overall survival of 50% (95% CI, 40% to 59%). In contrast, allo-HCT was associated with a 1-year NRM of 41% (95% CI, 23% to 58%), 5-year progression-free survival of 18% (95% CI, 6% to 35%), and 5-year overall survival of 22% (95% CI, 8% to 41%). Auto-HCT for transformed follicular lymphoma achieves sustained remission in a high proportion of subjects. The high NRM of allo-HCT offset any benefit that might be associated with this transplantation modality.

Autologous or reduced-intensity conditioning allogeneic hematopoietic cell transplantation for chemotherapy-sensitive mantle-cell lymphoma: analysis of transplantation timing and modality

PURPOSE

To examine the outcomes of patients with chemotherapy-sensitive mantle-cell lymphoma (MCL) following a first hematopoietic stem-cell transplantation (HCT), comparing outcomes with autologous (auto) versus reduced-intensity conditioning allogeneic (RIC allo) HCT and with transplantation applied at different times in the disease course.

PATIENTS AND METHODS

In all, 519 patients who received transplantations between 1996 and 2007 and were reported to the Center for International Blood and Marrow Transplant Research were analyzed. The early transplantation cohort was defined as those patients in first partial or complete remission with no more than two lines of chemotherapy. The late transplantation cohort was defined as all the remaining patients.

RESULTS

Auto-HCT and RIC allo-HCT resulted in similar overall survival from transplantation for both the early (at 5 years: 61% auto-HCT v 62% RIC allo-HCT; P = .951) and late cohorts (at 5 years: 44% auto-HCT v 31% RIC allo-HCT; P = .202). In both early and late transplantation cohorts, progression/relapse was lower and nonrelapse mortality was higher in the allo-HCT group. Overall survival and progression-free survival were highest in patients who underwent auto-HCT in first complete response. Multivariate analysis of survival from diagnosis identified a survival benefit favoring early HCT for both auto-HCT and RIC allo-HCT.

CONCLUSION

For patients with chemotherapy-sensitive MCL, the optimal timing for HCT is early in the disease course. Outcomes are particularly favorable for patients undergoing auto-HCT in first complete remission. For those unable to achieve complete remission after two lines of chemotherapy or those with relapsed disease, either auto-HCT or RIC allo-HCT may be effective, although the chance for long-term remission and survival is lower.

Assessment of cellular proliferation in tumors by PET using 18F-ISO-1

This first study in humans was designed to evaluate the safety and dosimetry of a cellular proliferative marker, N-(4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2(1H)-yl)butyl)-2-(2-(18)F-fluoroethoxy)-5-methylbenzamide ((18)F-ISO-1), and evaluate the feasibility of imaging tumor proliferation by PET in patients with newly diagnosed malignant neoplasms.

METHODS

Patients with biopsy-proven lymphoma, breast cancer, or head and neck cancer underwent (18)F-ISO-1 PET. Tumor (18)F-ISO-1 uptake was assessed semiquantitatively by maximum standardized uptake value, ratios of tumor to normal tissue and tumor to muscle, and relative distribution volume ratio. The PET results were correlated with tumor Ki-67 and mitotic index, from in vitro assays of the tumor tissue. The biodistribution of (18)F-ISO-1 and human dosimetry were evaluated.

RESULTS

Thirty patients with primary breast cancer (n = 13), head and neck cancer (n = 10), and lymphoma (n = 7) were evaluated. In the entire group, tumor maximum standardized uptake value and tumor-to-muscle ratio correlated significantly with Ki-67 (τ = 0.27, P = 0.04, and τ = 0.38, P = 0.003, respectively), but no significant correlation was observed between Ki-67 and tumor-to-normal-tissue ratio (τ = 0.07, P = 0.56) or distribution volume ratio (τ = 0.26, P = 0.14). On the basis of whole-body PET data, the gallbladder is the dose-limiting organ, with an average radiation dose of 0.091 mGy/MBq. The whole-body and effective doses were 0.012 mGy/MBq and 0.016 mSv/MBq, respectively. No adverse effects of (18)F-ISO-1 were encountered.

CONCLUSION

The presence of a significant correlation between (18)F-ISO-1 and Ki-67 makes this agent promising for evaluation of the proliferative status of solid tumors. The relatively small absorbed doses to normal organs allow for the safe administration of up to 550 MBq, which is sufficient for PET imaging in clinical trials.

High resolution array comparative genomic hybridization identifies copy number alterations in diffuse large B-cell lymphoma that predict response to immuno-chemotherapy

Despite recent attempts at sub-categorization, including gene expression profiling into prognostically different groups of "germinal center B-cell type" and "activated B-cell type," diffuse large B-cell lymphoma (DLBCL) remains a biologically heterogenous tumor with no clear prognostic biomarkers to guide therapy. Whole genome, high resolution array comparative genomic hybridization (aCGH) was performed on four cases of chemoresistant DLBCL and four cases of chemo-responsive DLBCL to identify genetic differences that may correlate with response to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy. Array CGH analysis identified seven DNA copy number alteration (CNA) regions exclusive to the chemoresistant group, consisting of amplifications at 1p36.13, 1q42.3, 3p21.31, 7q11.23, and 16p13.3, as well as loss at 9p21.3 and 14p21.31. Copy number loss of the tumor suppressor genes CDKN2A (p16, p14) and CDKN2B (p15) at 9p21.3 was validated by fluorescence in situ hybridization and immunohistochemistry as independent techniques. In the chemo-sensitive group, 12 CNAs were detected consisting of segment gains on 1p36.11, 1p36.22, 2q11.2, 8q24.3, 12p13.33, and 22q13.2, as well as segment loss on 6p21.32. RUNX3, a tumor suppressor gene located on 1p36.11 and MTHFR, which encodes for the enzyme methylenetetrahydrofolate reductase, located on 1p36.22, are the only known genes in this group associated with lymphoma. Whole genome aCGH analysis has detected copy number alterations exclusive to either chemoresistant or chemoresponsive DLBCL that may represent consistent clonal changes predictive for prognosis and outcome of chemotherapy.

Allo-SCT conditioning for myelodysplastic syndrome and acute myeloid leukemia with clofarabine, cytarabine and ATG

The application of myeloablative Allo-SCT is limited by its associated morbidity and mortality. Reduced-intensity conditioning regimens attempt to diminish these, but are associated with a higher risk of disease relapse. Given the evidence of activity of clofarabine and cytarabine in myelodysplastic syndrome/acute myeloid leukemia (MDS/AML), we explored a novel reduced-intensity conditioning regimen based on this backbone. Patients received clofarabine 40 mg/m(2) i.v. on days -6 to -2, cytarabine 1 g/m(2) i.v. on days -6 to -2 and anti-thymocyte globulin (ATG) 1 mg/kg on day -4 and 2.5 mg/kg x 2 days on days -3 and -2. Seven patients were enrolled. Their median age was 54 years; three were with MDS and four with AML. The median duration of neutropenia was 14 days and that of thrombocytopenia was 22 days. Toxicities included hand-foot syndrome (57% grade 2), elevated alanine aminotransferase (ALT) (57% grade 3), elevated aspartate aminotransferase (AST) (86% grade 3) and hyperbilirubinemia (29% grade 3-5). No acute GVHD was observed. Enrollment to the trial was halted after three of the first seven patients expired on days +15, +26 and +32. Three of the four surviving patients have relapsed with a median TTP of 152 days. This regimen was not sufficiently immunosuppressive to ensure engraftment, and was associated with substantial morbidity and mortality.