The clinical efficacy displayed by ibrutinib in chronic lymphocytic leukemia (CLL) has been challenged by the frequent emergence of resistant clones. The ibrutinib target, Bruton's tyrosine kinase ...(BTK), is essential for B-cell receptor signaling, and most resistant cases carry mutations in
or
, a downstream effector target of BTK. Recent findings show that MI-2, a small molecule inhibitor of the para-caspase MALT1, is effective in preclinical models of another type of BCR pathway-dependent lymphoma. We therefore studied the activity of MI-2 against CLL and ibrutinib-resistant CLL. Treatment of CLL cells
with MI-2 inhibited MALT1 proteolytic activity reduced BCR and NF-κB signaling, inhibited nuclear translocation of RelB and p50, and decreased Bcl-xL levels. MI-2 selectively induced dose and time-dependent apoptosis in CLL cells, sparing normal B lymphocytes. Furthermore, MI-2 abrogated survival signals provided by stromal cells and BCR cross-linking and was effective against CLL cells harboring features associated with poor outcomes, including 17p deletion and unmutated
Notably, MI-2 was effective against CLL cells collected from patients harboring mutations conferring resistance to ibrutinib. Overall, our findings provide a preclinical rationale for the clinical development of MALT1 inhibitors in CLL, in particular for ibrutinib-resistant forms of this disease.
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B-cell acute lymphoblastic leukemia (B-ALL) remains a hard-to-treat disease with a poor prognosis in adults. Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) is a ...para-caspase required for B-cell receptor (BCR)-mediated NF-κB activation. Inhibition of MALT1 in preclinical models has proven efficacious in many B-cell malignancies including chronic lymphocytic leukemia, mantle cell lymphoma and diffuse large B-cell lymphoma. We sought to examine the role of MALT1 in B-ALL and determine the biological consequences of its inhibition. Targeting MALT1 with both Z-VRPR-fmk and MI-2 efficiently kills B-ALL cells independent of the cell-of-origin (pro, pre, mature) or the presence of the Philadelphia chromosome, and spares normal B cells. The mechanism of cell death was through apoptotic induction, mostly in cycling cells. The proteolytic activity of MALT1 can be studied by measuring its ability to cleave its substrates. Surprisingly, with the exception of mature B-ALL, we did not detect cleavage of MALT1 substrates at baseline, nor after proteasomal inhibition or following activation of pre-BCR. To explore the possibility of a distinct role for MALT1 in B-ALL, independent of signaling through BCR, we studied the changes in gene expression profiling following a 24-hour treatment with MI-2 in 12 B-ALL cell lines. Our transcriptome analysis revealed a strong inhibitory effect on MYC-regulated gene signatures, further confirmed by Myc protein downregulation, concomitant with an increase in the Myc degrader FBXW7. In conclusion, our evidence suggests a novel role for MALT1 in B-ALL through Myc regulation and provides support for clinical testing of MALT1 inhibitors in B-ALL.
The treatment landscape for acute myeloid leukemia (AML) has changed substantially in recent years. The introduction of newer therapies, including oral agents, less myelosuppressive agents, and ...parenteral regimens suitable for outpatient administration, has made it feasible for select patients to receive therapy in the outpatient setting and in community practices. Thorough patient evaluation (including molecular testing), planned supportive care (eg, transfusion support, antimicrobial prophylaxis), and vigilant patient monitoring (for tumor lysis syndrome and adverse events) by a multidisciplinary team are required for successful management of patients both in the community and at specialized leukemia centers. Some patients are unable or unwilling to travel to larger academic centers for treatment, and treatment of AML in the community setting may have potential advantages compared to less conveniently located academic/leukemia centers. This includes reduction of financial hardship for patients and their families and often better opportunities for family/caregiver support. Additionally, partnership between community practices and academic/leukemia centers is often crucial to optimizing AML management for many patients, as collaboration may facilitate access to additional expertise and trials, multidisciplinary teams for supportive care, easier transition to hematopoietic cell transplantation, and access to sophisticated molecular testing. In this review, we discuss AML treatment and management in the community setting, available therapies, and circumstances in which a referral to and co-management with an academic/leukemia center is more strongly recommended.
Abstract
Background
Most older patients with acute myeloid leukemia (AML) who attain morphologic remission with intensive chemotherapy (IC) will eventually relapse and post-relapse prognosis is ...dismal. In the pivotal QUAZAR AML-001 trial, oral azacitidine maintenance therapy significantly prolonged overall survival by 9.9 months (
P
< 0.001) and relapse-free survival by 5.3 months (
P
< 0.001) compared with placebo in patients with AML in first remission after IC who were not candidates for transplant. Currently, the QUAZAR AML-001 trial provides the most comprehensive safety information associated with oral azacitidine maintenance therapy. Reviewed here are common adverse events (AEs) during oral azacitidine treatment in QUAZAR AML-001, and practical recommendations for AE management based on guidance from international cancer consortiums, regulatory authorities, and the authors’ clinical experience treating patients in the trial.
Methods
QUAZAR AML-001 is an international, placebo-controlled randomized phase 3 study. Patients aged ≥ 55 years with AML and intermediate- or poor-risk cytogenetics at diagnosis, who had attained first complete remission (CR) or CR with incomplete blood count recovery (CRi) within 4 months before study entry, were randomized 1:1 to receive oral azacitidine 300 mg or placebo once-daily for 14 days in repeated 28-day cycles. Safety was assessed in all patients who received ≥ 1 dose of study drug.
Results
A total of 469 patients received oral azacitidine (
n
= 236) or placebo (
n
= 233). Median age was 68 years. Patients received a median of 12 (range 1–80) oral azacitidine treatment cycles or 6 (1–73) placebo cycles. Gastrointestinal AEs were common and typically low-grade. The most frequent grade 3–4 AEs during oral azacitidine therapy were hematologic events. AEs infrequently required permanent discontinuation of oral azacitidine (13%), suggesting they were effectively managed with use of concomitant medications and oral azacitidine dosing modifications.
Conclusion
Oral azacitidine maintenance had a generally favorable safety profile. Prophylaxis with antiemetic agents, and blood count monitoring every other week, are recommended for at least the first 2 oral azacitidine treatment cycles, and as needed thereafter. Awareness of the type, onset, and duration of common AEs, and implementation of effective AE management, may maximize treatment adherence and optimize the survival benefits of oral azacitidine AML remission maintenance therapy.
Trial registration
This trial is registered on clinicaltrials.gov: NCT01757535 as of December 2012.
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Mantle cell lymphoma rarely presents with testicular involvement.
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Testicular MCL may be associated with more aggressive features of MCL.
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Testicular involvement of MCL may be associated with ...decreased overall survival.
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Patients with testicular MCL are at higher risk of CNS involvement.
Mantle cell lymphoma (MCL) with testicular involvement is a rare presentation and only a few cases have been described in the literature. We present a case of MCL with testicular involvement and the first analysis of all previously reported cases assessing trends in immunohistochemical features, prognostic indicators, and survival. Our data suggest that among all MCL, testicular MCL is more likely to present with aggressive features: blastoid/pleomorphic morphology, high Ki-67 proliferative index, and CNS involvement. Testicular MCL is also associated with shorter overall survival.
Lymphoma of the central nervous system (CNS) forms a rare type of lymphoma with a poor prognosis. Chemo-immunotherapy containing a methotrexate backbone remains the treatment of choice in the first ...line setting. When responses are achieved, this treatment needs to be followed, whenever possible, by treatment intensification followed by autologous stem cell transplantation (ASCT). There is no consensus on the optimal conditioning regimen for ASCT. Most studied regimens contain thiotepa, an agent that can cross the blood brain barrier, which confer excellent survival outcomes. However, this drug is not widely accessible in the United States for multiple reasons. An alternative to thiotepa-based regimens is the combination of busulfan, cyclophosphamide, and etoposide (BuCyE), which has resulted in conflicting outcomes. Here we report our experience with 3 cases of CNS lymphoma, treated with BuCyE, with a protocol using dosages different from what was previously reported, specifically with busulfan 3.2 mg/kg at days -8 to -5 (with pharmacokinetics adapted dosing at days -6 and -5), etoposide 30 mg/kg on day -4, and cyclophosphamide 60 mg/kg on day -3. Treatment resulted in excellent long-term outcomes with all 3 patients being alive at least 4 years following ASCT with no evidence of relapse. The side effect profile was acceptable, with the exception of a case of pulmonary toxicity. This cohort is limited by its small size, and further work comparing it to other treatments is being done at our institution.
To date, there are only a few case reports of cyclophosphamide (Cy)-induced hemorrhagic cystitis (HC) in adult or pediatric allogeneic stem cell transplant (SCT) patients treated successfully with ...hyperbaric oxygen (HBO). In all the reported cases, Cy was used as a part of the conditioning regimen, rather than post-transplant for graft-versus-host-disease (GVHD) prophylaxis. More recently, the risk of HC in allogeneic SCT is further increased by the widespread use of post-transplantation cyclophosphamide (PTCy) as a highly effective strategy for GVHD prophylaxis. This is the first case reported of PTCy-induced HC successfully treated with HBO to the best of our knowledge.
In this article, we present a 58-year-old Caucasian male case of allogeneic SCT complicated by severe HC following PTCy, which was successfully treated with HBO, eliminating the need for cystectomy.
HBO can be a safe, noninvasive, alternative treatment modality for PTCy-induced HC developing in allogeneic SCT patients.
Free light chains (FLCs) induce inflammatory pathways in proximal tubule cells (PTCs). The role of TLRs in these responses is unknown. Here we present findings on the role of TLRs in FLC-induced PTC ...injury. We exposed human kidney PTC cultures to κ and λ FLCs and used cell supernatants and pellets for ELISA and gene expression studies. We also analyzed tissues from Stat1-/- and littermate control mice treated with daily i.p. injections of a κ FLC for 10 days. FLCs increased the expression of TLR2, TLR4, and TLR6 via HMGB1, a damage-associated molecular pattern. Countering TLR2, TLR4, and TLR6 through GIT-27 or specific TLR siRNAs reduced downstream cytokine responses. Blocking HMGB1 through siRNA or pharmacologic inhibition, or via STAT1 inhibition, reduced FLC-induced TLR2, TLR4, and TLR6 expression. Blocking endocytosis of FLCs through silencing of megalin/cubilin, with bafilomycin A1 or hypertonic sucrose, attenuated FLC-induced cytokine responses in PTCs. IHC showed decreased TLR4 and TLR6 expression in kidney sections from Stat1-/- mice compared with their littermate controls. PTCs exposed to FLCs released HMGB1, which induced expression of TLR2, TLR4, and TLR6 and downstream inflammation. Blocking FLCs' endocytosis, Stat1 knockdown, HMGB1 inhibition, and TLR knockdown each rescued PTCs from FLC-induced injury.
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