Acute Myeloid Leukemia Causes T Cell Exhaustion and Depletion in a Humanized Graft-versus-Leukemia Model

Allogeneic hematopoietic stem cell transplantation (alloSCT) is, in many clinical settings, the only curative treatment for acute myeloid leukemia (AML). The clinical benefit of alloSCT greatly relies on the graft-versus-leukemia (GVL) effect. However, AML relapse remains the top cause of posttransplant death; this highlights the urgent need to enhance GVL. Studies of human GVL have been hindered by the lack of optimal clinically relevant models. In this article, we report, the successful establishment of a novel (to our knowledge) humanized GVL model system by transplanting clinically paired donor PBMCs and patient AML into MHC class I/II knockout NSG mice. We observed significantly reduced leukemia growth in humanized mice compared with mice that received AML alone, demonstrating a functional GVL effect. Using this model system, we studied human GVL responses against human AML cells in vivo and discovered that AML induced T cell depletion, likely because of increased T cell apoptosis. In addition, AML caused T cell exhaustion manifested by upregulation of inhibitory receptors, increased expression of exhaustion-related transcription factors, and decreased T cell function. Importantly, combined blockade of human T cell-inhibitory pathways effectively reduced leukemia burden and reinvigorated CD8 T cell function in this model system. These data, generated in a highly clinically relevant humanized GVL model, not only demonstrate AML-induced inhibition of alloreactive T cells but also identify promising therapeutic strategies targeting T cell depletion and exhaustion for overcoming GVL failure and treating AML relapse after alloSCT.

CD26lowPD-1+ CD8 T cells are terminally exhausted and associated with leukemia progression in acute myeloid leukemia

Acute myeloid leukemia (AML) is a devastating blood cancer with poor prognosis. Novel effective treatment is an urgent unmet need. Immunotherapy targeting T cell exhaustion by blocking inhibitory pathways, such as PD-1, is promising in cancer treatment. However, results from clinical studies applying PD-1 blockade to AML patients are largely disappointing. AML is highly heterogeneous. Identification of additional immune regulatory pathways and defining predictive biomarkers for treatment response are crucial to optimize the strategy. CD26 is a marker of T cell activation and involved in multiple immune processes. Here, we performed comprehensive phenotypic and functional analyses on the blood samples collected from AML patients and discovered that CD26^lowPD-1⁺ CD8 T cells were associated with AML progression. Specifically, the percentage of this cell fraction was significantly higher in patients with newly diagnosed AML compared to that in patients achieved completed remission or healthy controls. Our subsequent studies on CD26^lowPD-1⁺ CD8 T cells from AML patients at initial diagnosis demonstrated that this cell population highly expressed inhibitory receptors and displayed impaired cytokine production, indicating an exhaustion status. Importantly, CD26^lowPD-1⁺ CD8 T cells carried features of terminal exhaustion, manifested by higher frequency of T_EMRA differentiation, increased expression of transcription factors that are observed in terminally exhausted T cells, and high level of intracellular expression of granzyme B and perforin. Our findings suggest a prognostic and predictive value of CD26 in AML, providing pivotal information to optimize the immunotherapy for this devastating cancer.

IMPROVE-BMT: a protocol for a pilot randomised controlled trial of prehabilitation exercise for adult haematopoietic stem cell transplant recipients

INTRODUCTION

Haematopoietic stem cell transplant (HSCT) in adults is an intensive medical procedure for a variety of haematological malignancies. Although there is a large body of evidence demonstrating the negative effects of HSCT on physical function and psychosocial parameters, there is limited evidence on the impact of HSCT on body composition and bone health. Further, aerobic and resistance-training exercise interventions aimed at improving physical function and patient-reported outcomes largely take place during the peritransplant and post-transplant period. Prehabilitative exercise, or exercise prior to medical treatment, has been successfully deployed in presurgical candidates and other tumour sites, yet there is a paucity of evidence on the effect of prehabilitation in HSCT patients. The aim of this study is to investigate the feasibility, acceptability and safety of a resistance training exercise programme in patients with haematological malignancies prior to HSCT.

METHODS AND ANALYSIS

IMpact of PRehabilitation in Oncology Via Exercise-Bone Marrow Transplant is a single-site, pilot randomised controlled trial of an exercise intervention compared with usual care. The primary aim is to assess the feasibility, acceptability and safety of the resistance-training exercise intervention prior to HSCT. Secondary aims include evaluating the differences in physical function, body composition, bone mineral density and patient-reported outcomes between the exercise group and usual care control group. Outcome measurements will be assessed: prior to HSCT, on/around day of HSCT admission, +30 days post-HSCT and +100 days post-HSCT. The exercise intervention is a home-based resistance training exercise programme that incorporates resistance band and body weight exercises. The primary outcomes will be reported as percentages and/or mean values. The secondary outcomes will be analysed using appropriate statistical methods to portray within-group and between-group differences.

ETHICS AND DISSEMINATION

The study has Penn State College of Medicine approval. Results will be disseminated through scientific publication and presentation at exercise-related and oncology-related scientific meetings.

TRIAL REGISTRATION NUMBER

NCT03886909.

A novel clinically relevant graft-versus-leukemia model in humanized mice

The prognosis for acute myeloid leukemia (AML) relapse post allogeneic hematopoietic stem cell transplantation (alloSCT) is dismal. Novel effective treatment is urgently needed. Clinical benefit of alloSCT greatly relies on the graft-versus-leukemia (GVL) effect. The mechanisms that mediate immune escape of leukemia (thus causing GVL failure) remain poorly understood. Studies of human GVL have been hindered by the lack of optimal clinically relevant models. Here, using our large, longitudinal clinical tissue bank that include AML cells and G-CSF mobilized donor hematopoietic stem cells (HSCs), we successfully established a novel GVL model in humanized mice. Donor HSCs were injected into immune-deficient NOD-Cg-Prkdcscid IL2rgtm1Wjl /SzJ (NSG) mice to build humanized mice. Immune reconstitution in these mice recapitulated some clinical scenario in the patient who received the corresponding HSCs. Allogeneic but HLA partially matched patient-derived AML cells were successfully engrafted in these humanized mice. Importantly, we observed a significantly reduced (yet incomplete elimination of) leukemia growth in humanized mice compared with that in control NSG mice, demonstrating a functional (but defective) GVL effect. Thus, for the first time, we established a novel humanized mouse model that can be used for studying human GVL responses against human AML cells in vivo. This novel clinically relevant model provides a valuable platform for investigating the mechanisms of human GVL and development of effective leukemia treatments.

Abstract 874: Adoptive transfer of cytotoxic lymphocytes generated by engineered human dendritic cells for AML treatment

Introduction: Acute myeloid leukemia (AML) is a devastating blood cancer. The clinical benefit of allogeneic stem cell transplantation (alloSCT) greatly relies on the graft-versus-leukemia (GVL) effect mediated by donor T cells, but it may also cause graft-versus-host disease (GVHD). One strategy to improve GVL without promoting GVHD is to adoptive transfer of cytotoxic T cells (CTLs) against leukemia-associated antigen (LAA). Generating potent CTLs is challenging. Stimulating naïve T cells with monocyte-derived dendritic cells loaded with LAA is commonly used, but it is severely limited due to low efficacy. We have developed a novel DC methodology and established immortalized human primary blood DC lines (ihv-DCs) by transducing human peripheral blood mononuclear cells (PBMCs) with a viral protein Tax. The constitutively activated ihv-DCs expand efficiently in vitro and can potently prime naïve T cells. They can be genetically modified to deliver given tumor antigens and stimulate antigen-specific CTLs in high efficiency. Here, we generate CTLs by stimulating donor PBMCs with ihv-DCs that carry HLA-A2 restrict human telomerase reverse transcriptase (hTERT), a known LAA. We investigate, in vitro and in vivo, the CTL killing efficacy.

Methods: ihv-DCs that carry HLA-A2 restrict hTERT was engineered as previously described (Wu et al., PNAS 2018). HLA-A2 restrict hTERT-specific CTLs were generated by co-culturing ihv-DCs in the presence of IL-2 with donor PBMCs. In vitro cytotoxicity was performed by culturing CTLs with target cells that labeled with cell-track dye at different E:T ratio. Cell lysis was tested by flow-cytometry-based cell apoptosis analysis. In vivo cytotoxicity was examined by adoptive transfer CTLs into xenograft AML model. Flow cytometry was used to detect the leukemia burden.

Results: Although variable, THP-1 cell line and blasts from all HLA-A2+ AML patients (11/11) in our study express significant intracellular hTERT. CTLs were successfully established by co-culturing ihv-DCs carrying hTERT with PBMCs from HLA-A2+ healthy donors. We observed an increasing proportion of effector memory T cells over time. We observed significant cytotoxic activities of purified CD8 T cells to U2OS that engineered to express hTERT, THP-1 cells, and primary leukemia blasts from AML patients in vitro. The cytotoxicity is predominantly hTERT specific as the killing to the primary U2OS cell line (negative for hTERT) is minimal. In addition, the cytotoxic effect was significantly diminished upon adding blockade antibody against HLA-A2, indicating the killing is through an HLA-A2 restrict manner. To study whether the CTLs can eradicate AML in vivo, we adoptively transferred CTLs into a xenograft AML model generated by engrafting primary AML into NSG mice (n=5), 5 × 106 cells were injected every 5 days for 4 times. Mice injected with PBS were set as control. On day 20, we found significant reduction of leukemia burden in blood and bone marrow from mice treated with CTLs. Importantly, no GVHD was observed. Persistent CTLs were detected in all organs (blood, bone marrow, liver, spleen, and lungs).

Conclusion: Using a novel ihv-DC delivering LAA, we established CTLs that are highly efficient in killing primary leukemia blasts derived from AML patients both in vitro and in vivo. Our study provides a proof of principle for applying the novel DC methodology to AML treatment.

Citation Format: Chenchen Zhao, Bei Jia, Yixing Jiang, Hiroko Shike, David F. Claxton, W Christopher Ehmann, Todd D. Schell, Hua Cheng, Bei Liu, Hong Zheng. Adoptive transfer of cytotoxic lymphocytes generated by engineered human dendritic cells for AML treatment [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 874.

Multi-dimensional analysis identifies an immune signature predicting response to decitabine treatment in elderly patients with AML

Decitabine is a DNA‐hypomethylating agent that has been widely applied for the treatment of acute myeloid leukaemia (AML) patients who are elderly or unfit for intensive therapy. Although effective, the complete response rate to decitabine is only around 30% and the overall survival remains poor. Emerging data support that regulation of DNA methylation is critical to control immune cell development, differentiation and activation. We hypothesize that defining how decitabine influences the immune responses in AML will facilitate the development of novel immune‐based leukaemia therapeutics. Here, we performed phenotypic and functional immune analysis on clinical samples from AML patients receiving decitabine treatment and demonstrated a significant impact of decitabine on the immune system. T‐cell expression of inhibitory molecules was upregulated and the ability of CD8 T cells to produce cytokines was decreased upon decitabine treatment. Importantly, in an unbiased comprehensive analysis, we identified a unique immune signature containing a cluster of key immune markers that clearly separate patients who achieved complete remission after decitabine from those who failed to do so. Therefore, this immune signature has a strong predictive value for clinical response. Collectively, our study suggests that immune‐based analyses may predict clinical response to decitabine and provide a therapeutic strategy to improve the treatment of AML.

Eomes+T-betlow CD8+ T Cells Are Functionally Impaired and Are Associated with Poor Clinical Outcome in Patients with Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is a devastating blood cancer with poor prognosis. Immunotherapy targeting inhibitory pathways to unleash the antileukemia T-cell response is a promising strategy for the treatment of leukemia, but we must first understand the underlying molecular mechanisms. Eomesodermin (Eomes) and T-bet are both T-box transcription factors that regulate CD8⁺ T-cell responses in a context-specific manner. Here, we examined the role of these transcription factors in CD8⁺ T-cell immunity in AML patients. We report that the frequency of Eomes⁺T-bet^low CD8⁺ T cells increased in newly diagnosed AML. This cell subset produced fewer cytokines and displayed reduced killing capacity, whereas depletion of Eomes by siRNA reversed these functional defects. Furthermore, Eomes bound the promoter of T-cell immunoglobulin and ITIM domain (TIGIT) and positively regulated the expression of this inhibitory receptor on patient-derived T cells. A high frequency of Eomes⁺T-bet^low CD8⁺ T cells was associated with poor response to induction chemotherapy and shorter overall survival in AML patients. These findings have significant clinical implications as they not only identify a predictive and prognostic biomarker for AML, but they also provide an important target for effective leukemia therapeutics. SIGNIFICANCE: These findings reveal that a high frequency of Eomes⁺T-bet^low CD8⁺ T cells predicts poor clinical outcome in AML and that targeting Eomes may provide a therapeutic benefit against AML.

VISTA is highly expressed on MDSCs and mediates an inhibition of T cell response in patients with AML

Treatment of acute myeloid leukemia (AML) remains challenging. Enhancement of anti-tumor responses by blocking negative immune regulators is a promising strategy for novel effective leukemia therapeutics. V-domain Ig suppressor of T-cell activation (VISTA) is a recently defined negative regulator mediating immune evasion in cancer. To investigate the effect of VISTA on anti-leukemia immune response in AML, we initiated a study using clinical samples collected from AML patients. Here we report that VISTA is highly expressed on myeloid-derived suppressor cells (MDSCs) in the peripheral blood of AML patients. Both the frequency and intensity of VISTA expression on MDSCs are significantly higher in newly diagnosed AML than in healthy controls. Importantly knockdown of VISTA by specific siRNA potently reduced the MDSCs-mediated inhibition of CD8 T cell activity in AML, suggesting a suppressive effect of VISTA on anti-leukemia T cell response. Furthermore, we observed a strong positive association between MDSC expression of VISTA and T cell expression of PD-1 in AML. These results support the strategy of VISTA-targeted treatment for AML and underscore the strong potential for combined blockade of VISTA and PD-1 pathways in effective leukemia control.

PIGN gene expression aberration is associated with genomic instability and leukemic progression in acute myeloid leukemia with myelodysplastic features

Previous studies have linked increased frequency of glycosylphosphatidylinositol-anchor protein (GPI-AP) deficiency with genomic instability and the risk of carcinogenesis. However, the underlying mechanism is still not clear. A randomForest analysis of the gene expression array data from 55 MDS patients (GSE4619) demonstrated a significant (p = 0.0007) correlation (Pearson r =-0.4068) between GPI-anchor biosynthesis gene expression and genomic instability, in which PIGN, a gene participating in GPI-AP biosynthesis, was ranked as the third most important in predicting risk of MDS progression. Furthermore, we observed that PIGN gene expression aberrations (increased transcriptional activity but diminished to no protein production) were associated with increased frequency of GPI-AP deficiency in leukemic cells during leukemic transformation/progression. PIGN gene expression aberrations were attributed to partial intron retentions between exons 14 and 15 resulting in frameshifts and premature termination which were confirmed by examining the RNA-seq data from a group of AML patients (phs001027.v1.p1). PIGN gene expression aberration correlated with the elevation of genomic instability marker expression that was independent of the TP53 regulatory pathway. Suppression/elimination of PIGN protein expression caused a similar pattern of genomic instability that was rescued by PIGN restoration. Finally, we found that PIGN bound to the spindle assembly checkpoint protein, MAD1, and regulated its expression during the cell cycle. In conclusion, PIGN gene is crucial in regulating mitotic integrity to maintain chromosomal stability and prevents leukemic transformation/progression.

Blimp-1 impairs T cell function via upregulation of TIGIT and PD-1 in patients with acute myeloid leukemia

Background

T cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) and programmed cell death protein 1 (PD-1) are important inhibitory receptors that associate with T cell exhaustion in acute myeloid leukemia (AML). In this study, we aimed to determine the underlying transcriptional mechanisms regulating these inhibitory pathways. Specifically, we investigated the role of transcription factor B lymphocyte-induced maturation protein 1 (Blimp-1) in T cell response and transcriptional regulation of TIGIT and PD-1 in AML.

Methods

Peripheral blood samples collected from patients with AML were used in this study. Blimp-1 expression was examined by flow cytometry. The correlation of Blimp-1 expression to clinical characteristics of AML patients was analyzed. Phenotypic and functional studies of Blimp-1-expressing T cells were performed using flow cytometry-based assays. Luciferase reporter assays and ChIP assays were applied to assess direct binding and transcription activity of Blimp-1. Using siRNA to silence Blimp-1, we further elucidated the regulatory role of Blimp-1 in the TIGIT and PD-1 expression and T cell immune response.

Results

Blimp-1 expression is elevated in T cells from AML patients. Consistent with exhaustion, Blimp-1⁺ T cells upregulate multiple inhibitory receptors including PD-1 and TIGIT. In addition, they are functionally impaired manifested by low cytokine production and decreased cytotoxicity capacity. Importantly, the functional defect is reversed by inhibition of Blimp-1 via siRNA knockdown. Furthermore, Blimp-1 binds to the promoters of PD-1 and TIGIT and positively regulates their expression.

Conclusions

Our study demonstrates an important inhibitory effect of Blimp-1 on T cell response in AML; thus, targeting Blimp-1 and its regulated molecules to improve the immune response may provide effective leukemia therapeutics.

Electronic supplementary material

The online version of this article (doi:10.1186/s13045-017-0486-z) contains supplementary material, which is available to authorized users.

Outcomes of G-CSF alone vs G-CSF with upfront plerixafor vs G-CSF/chemotherapy for collection of autologous stem cells in patients with multiple myeloma

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Background: Strategies for optimizing the collection of peripheral blood stem cells (PBSC) for autologous stem cell transplant (ASCT) in patients with multiple myeloma (MM) vary among transplant centers, and include the use of G-CSF alone or in combination with plerixafor, or mobilization chemotherapy + G-CSF. In 2010, we started using “upfront” plerixafor, given on the day before the PBSC collection. Methods:We retrospectively analyzed the outcomes of 423 consecutive MM patients who underwent PBSC collections at the Penn State Hershey Cancer Institute. PBSC were collected after mobilization chemotherapy + G-CSF 5 mcg/Kg/day (group A, 91 pts), G-CSF alone, 10-16 mcg/Kg/day (group B, 72 pts), and G-CSF with “upfront” plerixafor 0.16-0.24 mg/Kg on the day before the stem cell collection (group C, 245 pts). Fifteen patients were excluded from the analysis because they collected with chemotherapy + plerixafor, received pegylated G-CSF, or plerixafor “on demand”, i.e., after failure to achieve an adequate number of stem cells on the first day of collection. We compared yields, number of days required for apheresis, clinical outcomes, and adverse events among these groups. Results: The median number of PBSC collected was 16.4 (range, 0.1-134), 4.2 (range, 0-12), and 6.2 (range, 0.2-41.2) million CD34+ cells/Kg in group A, B, and C, respectively (p<0.001). The mean number of days to collect PBSC was 1.5, 1.5, and 1.3 in group A, B, and C, respectively (p=0.033). Collection failure, defined as a yield <2 million CD34+cells/Kg, was observed in 5 (5.5%), 9 (12.5%), and 15 (6.1%) patients of group A, B, and C, respectively (p<0.001). Twenty patients in group A developed neutropenic fever requiring hospital admission, and 1 of them died of septic shock, whereas no mortality was observed in groups B or C. No difference in the rapidity of PBSC engraftment, progression-free survival, and overall survival was observed among the 3 groups. Conclusions:In patients with MM, the upfront use of plerixafor with G-CSF provided the best collection strategy: it avoided the morbidity and mortality associated with the mobilization chemotherapy, and it provided higher yields than G-CSF alone.

Rituximab extended schedule or retreatment trial for low tumour burden non-follicular indolent B-cell non-Hodgkin lymphomas: Eastern Cooperative Oncology Group Protocol E4402

The rituximab extended schedule or retreatment trial (RESORT; E4402) was a phase 3 randomized prospective trial comparing maintenance rituximab (MR) versus a retreatment (RR) dosing strategy in asymptomatic, low tumour burden indolent lymphoma. A planned exploratory sub-study compared the two strategies for small lymphocytic (SLL) and marginal zone lymphomas (MZL). Patients responding to rituximab weekly × 4 were randomized to MR (single dose rituximab every 3 months until treatment failure) or RR (rituximab weekly × 4) at the time of each progression until treatment failure. The primary endpoint was time to treatment failure (TTTF). Patients with SLL (n = 57), MZL (n = 71) and unclassifiable small B-cell lymphoma (n = 3) received induction rituximab. The overall response rate (ORR) was 40% [95% confidence interval (CI) 31-49%; SLL ORR 22·8%; MZL ORR 52·1%]; all 52 responders were randomized. At a median of 4·3 years from randomization, treatment failure occurred in 18/23 RR and 15/29 MR. The median TTTF was 1·4 years for RR and 4·8 years for MR (P = 0·012); median time to first cytotoxic therapy was 6·3 years for RR and not reached for MR (P = 0·0002). Survival did not differ (P = 0·72). In low tumour burden SLL and MZL patients responding to rituximab induction, MR significantly improved TTTF as compared with RR.

T-Cell Immunoglobulin and ITIM Domain (TIGIT) Associates with CD8+ T-Cell Exhaustion and Poor Clinical Outcome in AML Patients

PURPOSE

T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) is a recently identified T-cell coinhibitory receptor. In this study, we aimed to determine the clinical impact of TIGIT in patients with acute myelogenous leukemia (AML) and dissect the role of TIGIT in the pathogenesis of leukemia progression.

EXPERIMENTAL DESIGN

TIGIT expression on T cells from peripheral blood collected from patients with AML was examined by flow cytometry. The correlation of TIGIT expression to clinical outcomes, including rate of complete remission and relapse post-allogeneic stem cell transplantation (alloSCT) in AML patients, was analyzed. Phenotypic and functional study (cytokine release, proliferation, killing, and apoptosis) of TIGIT-expressing T cells were performed. Using siRNA to silence TIGIT, we further elucidated the regulatory role of TIGIT in the T-cell immune response by dissecting the effect of TIGIT knockdown on cytokine release and apoptosis of T cells from AML patients.

RESULTS

TIGIT expression on CD8(+) T cells is elevated in AML patients and high-TIGIT correlates with primary refractory disease and leukemia relapse post-alloSCT. TIGIT(+) CD8(+) T cells display phenotypic features of exhaustion and exhibit functional impairment manifested by low production of cytokines and high susceptibility to apoptosis. Importantly, their functional defects are reversed by TIGIT knockdown.

CONCLUSIONS

TIGIT contributes to functional T-cell impairment and associates with poor clinical outcome in AML. Our study suggests that blockade of TIGIT to restore T-cell function and antitumor immunity may represent a novel effective leukemia therapeutic. Clin Cancer Res; 22(12); 3057-66. ©2016 AACR.

A phase 2 study of inotuzumab ozogamicin and rituximab, followed by autologous stem cell transplant in patients with relapsed/refractory diffuse large B-cell lymphoma

This study evaluated the safety and efficacy of inotuzumab ozogamicin (INO), a targeted humanized anti-CD22 antibody conjugated to calicheamicin, plus rituximab (R-INO) every 3 weeks, up to six cycles, followed by high dose therapy and autologous stem cell transplant (HDT-aSCT) in patients with high-risk relapsed/refractory diffuse large B-cell lymphoma (DLBCL). The primary endpoint was overall response (OR) rate after three cycles of R-INO. Sixty-three patients were enrolled. Common grade 3/4 adverse events during R-INO treatment were thrombocytopenia, lymphopenia and neutropenia. OR rate after three cycles of R-INO was 28.6% (95% confidence interval: 17.9-41.4). Eighteen patients underwent HDT-aSCT; 2-year progression-free survival (PFS) for these patients was 61.1%. Serious infections and hepatic toxicity following aSCT occurred in 33% and 22%, respectively. One- and 2-year PFS rates for all enrolled patients were 28.9% and 25.3%, respectively (median, 3.0 months). R-INO had lower than expected activity as a salvage regimen for transplant eligible patients with DLBCL.

Rituximab extended schedule or re-treatment trial for low-tumor burden follicular lymphoma: eastern cooperative oncology group protocol e4402

PURPOSE

In low-tumor burden follicular lymphoma (FL), maintenance rituximab (MR) has been shown to improve progression-free survival when compared with observation. It is not known whether MR provides superior long-term disease control compared with re-treatment rituximab (RR) administered on an as-needed basis. E4402 (RESORT) was a randomized clinical trial designed to compare MR against RR.

PATIENTS AND METHODS

Eligible patients with previously untreated low-tumor burden FL received four doses of rituximab, and responding patients were randomly assigned to either RR or MR. Patients receiving RR were eligible for re-treatment at each disease progression until treatment failure. Patients assigned to MR received a single dose of rituximab every 3 months until treatment failure. The primary end point was time to treatment failure. Secondary end points included time to first cytotoxic therapy, toxicity, and health-related quality of life (HRQOL).

RESULTS

A total of 289 patients were randomly assigned to RR or MR. With a median follow-up of 4.5 years, the estimated median time to treatment failure was 3.9 years for patients receiving RR and 4.3 years for those receiving MR (P = .54). Three-year freedom from cytotoxic therapy was 84% for those receiving RR and 95% for those receiving MR (P = .03). The median number of rituximab doses was four patients receiving RR and 18 for those receiving MR. There was no difference in HRQOL. Grade 3 to 4 toxicities were infrequent in both arms.

CONCLUSION

In low-tumor burden FL, a re-treatment strategy uses less rituximab while providing disease control comparable to that achieved with a maintenance strategy.

A phase II pilot efficacy trial of the combination regimen peg asparaginase/peg liposomal doxorubicin/dexamethasone (ODD) in patients with refractory lymphoid malignancies (NCT00837200)

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Background: Asparaginase is a mainstay of the treatment for ALL depriving the malignant cells of asparagine leading to cell death. There are reports of asparaginase activity in non-ALL malignancies including CLL, NHL, and multiple myeloma. We developed a combination regimen with full dose PEG-Asparagase (O) together with low dose liposomal doxorubin (D) and dexamethasone (D) (ODD regimen) as a non-myelotoxic regimen for pts with advanced lymphoid malignancies and impaired bone marrow function, hoping this novel approach of inducing asparaginine deficiency would translate into benefit. Methods: A phase II trial of ODD with the O given D1 and D15 at 2500 IU/m2, D given D1 and D15 as 20 mg/m2 and the Dex given as 20 mg D1, D8, D15 and D22 of a 28 day cycle was initiated. Pts with any non-ALL lymphoid malignancy were eligible if they had failed at least one prior standard regimen. The study had a Simon 2-stage design with Response Rate as the primary endpoint. Secondary endpoints were safety and correlation of asparginase levels with response/toxicity. Results: 13 pts enrolled of 16 screened of whom 12 were evaluable for response. These included 7 MM pts and 6 with diffuse large B-cell lymphoma. The pts were heavily pre-treated with 3 (range 1 to 8) median prior regimens. 6 of the13 pts were over 70 yrs. One pt progressed before one complete cycle was given so was not evaluable for response. 2 pts (both MM) had a response which was defined as Stable Disease > 2 months; the other 10 had Progressive Disease. One responding pt was later taken off for O-related toxicities (DVT/PE, elevated enzyme levels). Effective Asparaginase levels were obtained in the serum of most tested pts. In general, the regimen was well tolerated considering the advanced nature of these cases, but typical O related toxicities were observed. Conclusions: We conclude that the ODD regimen, although well tolerated, had little appreciable activity in this heavily pre-treated group of pts with refractory DLBCL and MM. Whether it would have meaningful activity in less advanced states of these diseases or other lymphoid neoplasms remains an open question. Clinical trial information: NCT00837200.

Retrospective analysis of second malignancies in patients with multiple myeloma

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Background: Recent data from patients with multiple myeloma (MM) enrolled in randomized clinical trials have shown an increased incidence of second malignancies after treatment with lenalidomide, but the prevalence of second malignancies in the overall MM population is uncertain. Methods: We retrospectively analyzed the medical records of 320 consecutive MM patients followed at the Penn State Hershey Cancer Institute between 2006 and 2010. We excluded from the analysis basocellular and squamocellular carcinomas of the skin. Results: Forty-three patients (13%) were found to have second malignancies, and 5 of them had a third cancer. One pt had 4 cancers. They included cancers of the prostate (8 pts), breast (8), MDS/leukemia (6), colon/rectum (5), melanoma (5), lung (4), uterus (4), bladder (3), kidneys (2), pancreas (2), testicle (1), myeloproliferative disorders (1), and sarcoma (1). Of 50 cancers, 36 (72%) developed before the diagnosis of MM, at a median of 65 months (range, 1-372), and 14 after that, at a median of 37 months (range, 3-104). Lenalidomide was used in 239 (75%) patients, and in 9 of 14 cases of post-MM second malignancies. Conclusions: Second malignancies usually develop before the diagnosis of MM, i.e., MM is the second malignancy for the majority of patients. The use of lenalidomide could not be indicated as a possible carcinogenic factor for the majority of MM patients with second malignancies.

Two Unstable β Chain Variants Associated with β-Thalassemia: Hb Miami [β116(G18)His→Pro], and Hb Hershey [β70(E14)Ala→Gly], and a Second Unstable Hb Variant at β70: Hb Abington [β70(E14)Ala→Pro]

We report on three previously undescribed unstable hemoglobin (Hb) variants: Hb Miami, Hb Hershey and Hb Abington. Hb Miami was associated with a beta(+)-thalassemia (thal) mutation [IVS-I-110 (G-->A)], whereas Hb Hershey was associated with a B0-thal mutation [IVS-I-1 (G-->A)]. Hb Hershey also has decreased oxygen affinity. These three Hb variants illustrate the range of clinical severity that can be seen with unstable Hb variants, particularly when combined with a thalassemic mutation.

Phase III Randomized Multicenter Study of a Humanized Anti-CD33 Monoclonal Antibody, Lintuzumab, in Combination With Chemotherapy, Versus Chemotherapy Alone in Patients With Refractory or First-Relapsed Acute Myeloid Leukemia

Purpose

Lintuzumab (HuM195) is an unconjugated humanized murine monoclonal antibody directed against the cell surface myelomonocytic differentiation antigen CD33. In this study, the efficacy of lintuzumab in combination with induction chemotherapy was compared with chemotherapy alone in adults with first relapsed or primary refractory acute myeloid leukemia (AML).

Patients and Methods

Patients with relapsed or primary resistant AML (duration of first response, zero to 12 months) were randomly assigned to receive either mitoxantrone 8 mg/m2, etoposide 80 mg/m2, and cytarabine 1 g/m2 daily for 6 days (MEC) in combination with lintuzumab 12 mg/m2, or MEC alone. Overall response, defined as the rate of complete remission (CR) and CR with incomplete platelet recovery (CRp), was the primary end point of the study, with additional analyses of survival time and toxicity.

Results

A total of 191 patients were randomly assigned from November 1999 to April 2001. The percent CR plus CRp with MEC plus lintuzumab was 36% v 28% in patients treated with MEC alone (P = .28). The overall median survival was 156 days and was not different in the two arms of the study. Apart from mild antibody infusion–related toxicities (fever, chills, and hypotension), no differences in chemotherapy-related adverse effects, including hepatic and cardiac dysfunction, were observed with the addition of lintuzumab to induction chemotherapy.

Conclusion

The addition of lintuzumab to salvage induction chemotherapy was safe, but did not result in a statistically significant improvement in response rate or survival in patients with refractory/relapsed AML.

Lacunar and reed-sternberg-like cells in follicular lymphomas are clonally related to the centrocytic and centroblastic cells as demonstrated by laser capture microdissection

Two cases of follicular lymphoma (FL) with numerous large cells resembling the lacunar and Hodgkin and Reed-Sternberg (HRS) cells of classic Hodgkin lymphoma were studied to determine clonal relationships between the HRS-like cells and centrocytic and centroblastic (CCCB) cells. In both cases, CCCB cells were typical of FL; CD45RB, CD20, CD10 and BCL-2 positive. In case 1, the HRS-like cells were positive for CD45RB, CD20, CD10, CD30, OCT2, and BOB.1 and negative for CD15 and bcl-2. In case 2, the HRS-like cells were positive for CD30, fascin, CD20, OCT2, and BOB.1 and negative for CD45RB, CD10, CD15, and bcl-2. CCCB and single HRS-like cells were isolated by laser capture microdissection followed by polymerase chain reaction amplification and sequencing of immunoglobulin heavy chain gene rearrangements. In both cases, identical sequences were obtained from CCCB and HRS-like cells. These findings confirm that although the HRS cells and CCCB cells in these cases demonstrate morphologic and immunophenotypic divergence, they share a common cell of origin. These cases further highlight the potential diagnostic pitfall presented by FL with HRS-like cells.

Cutaneous B-cell lymphoma with loss of CD20 immunoreactivity after rituximab therapy

BACKGROUND

Antibodies to the B-cell-specific antigen CD20 are widely used for immunohistochemical identification of B-cell lymphomas, approximately 95% of which are strongly CD20-positive.

METHODS

We report a 51-year-old male with a CD20-positive systemic B-cell lymphoma who developed a CD20-negative relapse with secondary cutaneous involvement after therapy with the anti-CD20 monoclonal antibody rituximab (Rituxan).

RESULTS

Biopsy of a skin nodule demonstrated an atypical lymphocytic infiltrate that was negative for CD20, CD3, lysozyme, and myeloperoxidase, but strongly positive for CD45rb (LCA) and the B-cell marker CD79a.

CONCLUSIONS

We conclude that loss of CD20 expression in cutaneous B-cell lymphoma (both primary and secondary) is important to recognize, that immunohistochemistry for CD79a, another widely expressed B-cell marker, is useful in the identification of CD20-negative B cells in such cases, and that loss of CD20 expression may become more common, as use of rituximab is expected to increase.

Favorable outcome after infusion of coagulase-negative staphylococci-contaminated peripheral blood hematopoietic cells for autologous transplantation

Bacterial contamination of peripheral blood hematopoietic cells collected for autologous bone marrow transplantation occurs sporadically. Although transfusion of contaminated hematopoietic cells without adverse clinical sequelae has been reported, detailed guidelines for transfusing cells with contamination are not available. We report a case of autologous hematopoietic cell transplantation that necessitated using multiple aliquots of peripheral blood hematopoietic cells known to be contaminated with coagulase-negative Staphylococcus bacteria. Prophylactic intravenous antibiotic therapy was given with the infusion of contaminated hematopoietic cells. The patient had positive results on a blood culture, but engraftment was successful, and serious adverse effects did not occur. With appropriate microbial identification and prophylactic antibiotic therapy, contaminated hematopoietic products can be safely infused when necessary with a good clinical outcome.

Increased expression of the differentiation-defective granulocyte colony-stimulating factor receptor mRNA isoform in acute myelogenous leukemia

Granulocyte colony-stimulating factor (G-CSF) critically affects all stages of granulopoiesis by activating a signaling cascade initiated by dimerization of its receptor (G-CSFR). Five human G-CSFR isoforms have been identified (classes I-V). A quantitative polymerase chain reaction (Q-PCR) technique was used to examine the expression of these five isoforms in normal and leukemic myeloid cells. We demonstrated that neutrophils expressed predominantly the class I isoform and low levels of class IV isoform (IV/I = 0.037 +/- 0.005). No expression of the class II, class III, or class V isoform was detected. In contrast, all AML cell lines and acute myelogenous leukemia (AML) patient samples expressed increased relative amounts of the class IV isoform (IV/I = 0.047-0.350). When compared to normal immature myeloid cells, as represented by the CD34+ fraction of adult bone marrow (ABM) cells, three of eight AML cell lines and three of six AML patient samples expressed significantly increased levels of the class IV isoform relative to class I. This suggests that the increase in the relative expression of the class IV isoform seen in a considerable portion of AML cell samples is related to their leukemic phenotype. Given the inability of the class IV G-CSFR to drive myeloid maturation, the relative increase in class IV expression in AML cells may contribute to their aberrant response to G-CSF.

Sweet's syndrome without granulocytosis

BACKGROUND

Sweet's syndrome (SS), acute febrile neutrophilic dermatosis, has been linked to hematologic malignancies and presents with characteristic edematous dermal plaques. Peripheral blood neutrophilia is frequently seen in association with SS and is one of the diagnostic criteria.

OBJECTIVE

To report the clinical, laboratory, and hematologic data of four patients with myeloid leukemia who developed SS after chemotherapy. Three of these patients were neutropenic.

METHODS

A retrospective study of four patients with SS and hematologic malignancies was undertaken. Three patients had de novo acute myelogenous leukemia and one was in the acute blast crisis of chronic myelogenous leukemia.

RESULTS

Sweet's syndrome was not originally suspected in these patients because of the low peripheral white blood cell counts caused by chemotherapy. All of the patients presented with fevers, arthralgias, and an eruption. They had been treated with antibiotics because of a presumed infection. Once the correct diagnosis was made and oral prednisolone was started, a rapid response followed.

CONCLUSIONS

Sweet's syndrome should be considered in the differential diagnosis when acute myeloid leukemic patients develop skin lesions and unexplained fevers regardless of the peripheral blood counts.

Thrombocytopenia in HIV-infected and uninfected hemophiliacs. Multicenter Hemophilia Cohort study

To determine the incidence and prognostic significance of thrombocytopenia among hemophiliacs, we analyzed clinical and hematologic data from the Multicenter Hemophilia Cohort study. Nineteen percent of HIV-infected subjects had thrombocytopenia (platelet count of <100,000/mm3) noted at least once, compared to 3% of HIV-uninfected subjects. For HIV-infected subjects, the prevalence of thrombocytopenia rose in the first 5 years after seroconversion and was twice as common in subjects age >35 years compared to younger subjects. The risk increased after an AIDS-defining illness, particularly among older subjects, nearly one-half of whom had thrombocytopenia within 1 year after AIDS. When adjusted for age and CD4-positive lymphocyte counts, thrombocytopenia was associated with an increased risk of death [relative risk (RR) 1.7, 95%CI = 1.2-2.3] but with little change in the risk of progression to AIDS (RR = 1.2, 95%CI = 0.8-1.7). Treatment with zidovudine was associated with a decreased risk of thrombocytopenia (RR = 0.5, 95%CI = 0.3-0.7). Although 59 HIV-infected subjects died of hemorrhage, only 11 (19%) of the 59 had a reported platelet count of <50,000/mm3, and only 2 (3%) of the deaths were temporally associated with thrombocytopenia. Thus, the risk of death was increased for thrombocytopenic HIV-infected hemophiliacs but this was not explained by an increased risk of developing AIDS and was rarely associated with death from bleeding.

Lamivudine plus zidovudine compared with zalcitabine plus zidovudine in patients with HIV infection. A randomized, double-blind, placebo-controlled trial. North American HIV Working Party

OBJECTIVE

To compare the safety and activity of lamivudine plus zidovudine with the safety and activity of zalcitabine plus zidovudine in patients with moderately advanced human immunodeficiency virus (HIV) infection who had received zidovudine.

DESIGN

A multicenter, randomized, double-blind, three-arm, 24-week study with a blinded extension through at least 52 weeks.

SETTING

21 sites in the United States, Canada, and Puerto Rico.

PATIENTS

254 patients who had received zidovudine (median duration of previous therapy, 20 months) and had absolute CD4+ cell counts of 100 to 300 cells/mm3.

INTERVENTIONS

Patients were randomly assigned to receive one of three regimens: 150 mg of lamivudine twice daily plus 200 mg of zidovudine three times daily (low-dose lamivudine group); 300 mg of lamivudine twice daily plus 200 mg of zidovudine three times daily (high-dose lamivudine group); or 0.75 mg of zalcitabine plus 200 mg of zidovudine three times daily (zalcitabine group).

MEASUREMENTS

Immunologic activity was assessed primarily by changes in absolute CD4+ cell counts; virologic activity was assessed by changes in plasma HIV RNA levels as measured by reverse transcriptase polymerase chain reaction. Safety of the treatment regimens was assessed through the reporting of adverse events.

RESULTS

78% of patients completed 24 weeks of study treatment, and 63% of patients completed 52 weeks of study treatment. Changes in absolute CD4+ cell counts were significantly better for the low-dose and the high-dose lamivudine groups than for the zalcitabine group (median changes at 52 weeks were +42.5 cells/mm3 in the low-dose lamivudine group, +23.33 cells/mm3 in the high-dose lamivudine group, and -29.58 cells/mm3 in the zalcitabine group). Suppression of plasma HIV RNA levels was similar for all groups (median changes at 52 weeks were -0.48 log10 copies/mL in the low-dose lamivudine group, -0.51 log10 copies/mL in the high-dose lamivudine group, and -0.39 log10 copies/mL in the zalcitabine group). No significant differences in safety were seen among the three regimens, although the low-dose lamivudine regimen appeared to be better tolerated than the others.

CONCLUSIONS

In patients with HIV infection who had previously received zidovudine, 150 mg of lamivudine plus zidovudine resulted in greater immunologic evidence of benefit than did 0.75 mg of zalcitabine plus zidovudine and was better tolerated than 300 mg of lamivudine plus zidovudine.

Relationship of CD4 lymphocyte counts to survival in a cohort of hemophiliacs infected with HIV. Multicenter Hemophilia Cohort Study

Although CD4 positive lymphocyte counts are important predictors of clinical events in persons infected with human immunodeficiency virus (HIV), little is known about their predictive value for survival. We analyzed CD4 counts obtained regularly since 1983 with regard to survival in a multicenter cohort study of 921 HIV-infected hemophiliacs of whom 177 have died. Dates of seroconversion were determined from stored serum samples. Cumulative mortality and actuarial survival rates were calculated from the first time the mean of two consecutive CD4 counts decreased from levels of > 500 to 200-499, 100-199, 50-99, and < 50 cells/microliter. The death rate per 100 patient years of observation was 0.87 (95% CI 0.27, 1.47) for those with CD4 counts of > 500 cells/microliter and increased progressively to 26.23 (95% CI 21.29, 31.17) for those with CD4 counts of < 50/microliter. HIV-related deaths occurred in 50 of 58 who died with CD4 counts of < 300/microliter compared to 0 of 6 who died with CD4 counts of > 500/microliter. The median CD4 count most proximal to death was 39.5 (range, 1-945). The 10-year actuarial estimate of survival from seroconversion was 77.3 +/- 2% for 546 persons who seroconverted at age > or = 18 years compared to 90.5 +/- 2% for 375 persons who seroconverted at age < 18. Survival decreased at each CD4 level to a median of 27 months at CD4 counts of < 50/microliter. At each CD4 level, younger patients survived longer than older patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Congenital afibrinogenemia

Congenital afibrinogenemia is a rare disorder with unusual clinical manifestations. The disease is inherited as an autosomal recessive trait and consanguinity is common among affected families. Clinical manifestations range from minimal bleeding to catastrophic hemorrhage. Congenitally afibrinogenemic patients seem to be peculiarly susceptible to spontaneous rupture of the spleen. Coagulation tests which depend on clot formation as an end point may be infinitely prolonged and abnormalities of platelet function are usually present. The diagnosis is established by demonstrating trace or no immunoreactive fibrinogen. The disease is caused by markedly reduced or absent synthesis of fibrinogen by liver cells, but the genetic defect remains unknown. Bleeding episodes can be effectively treated with cryoprecipitate. Purified virally inactivated fibrinogen concentrates have been used in Europe and may soon be widely available.

Natural history of hepatitis C virus infection in multitransfused hemophiliacs: effect of coinfection with human immunodeficiency virus. The Multicenter Hemophilia Cohort Study

The objective of this prospective cohort study was to describe the natural history of hepatitis C virus (HCV) infection and the effect of human immunodeficiency virus (HIV) on the clinical manifestations of HCV liver disease. Two hundred twenty-three hemophiliacs were followed in a comprehensive care setting with periodic clinical and laboratory evaluations. Dates of HIV seroconversion were determined retrospectively from frozen sera. HCV assays were performed by a "second generation" four-antigen recombinant immunoblot assay (RIBA 2). Liver failure was found after a latency period of 10 to 20 years in 9% of multitransfused HCV-positive/HIV-positive adult hemophiliacs without an AIDS-defining opportunistic infection or malignancy. Lymphocytopenia, decreased CD4 counts, and, possibly, thrombocytopenia were associated with liver failure which appeared to be accelerated by HIV disease and its treatment. This form of severe liver disease is being seen with increasing frequency among multi-transfused persons with hemophilia who are coinfected with HCV and HIV.

Hormonal and immunological regulation of 2', 5'-oligoadenylate synthetase activity in human peripheral blood mononuclear cells

A newly developed method for assaying 2', 5'-oligoadenylate (2, 5A) synthetase activity by polyacrylamide gel electrophoresis was applied to peripheral blood mononuclear cells (PBMC) from normal subjects, HIV-positive subjects, and renal cell carcinoma (RCC) patients. Sex differences were observed in 2, 5A synthetase activity of PBMC from normal young adults, males having eightfold higher activities of this enzyme than females. Moreover, compared to values for postmenopausal (PM) females receiving estrogen replacement, untreated PM females had higher activities. Collectively, these results suggest that estrogen downregulates 2, 5A synthetase activity. Activities of 2, 5A synthetase were investigated in two disease states associated with altered immune function. In one patient with AIDS-related Kaposi's sarcoma, interferon-alpha (IFN-alpha) therapy increased 2, 5A synthetase activity twofold. In addition, combined therapy with interleukin-2 (IL-2) and IFN-alpha increased 2, 5A synthetase activities in eight of nine patients with RCC. Therefore, in patients receiving immunotherapy with IL-2 and IFN-alpha, our new assay could contribute to evaluation of immune stimulation. In general, studies in vitro confirmed these observations; however, exposure of PBMC from RCC patients revealed that in vitro IL-2 failed to induce this enzyme activity as it did in PBMC from normal volunteers.