Coinhibition of the deubiquitinating enzymes, USP14 and UCHL5, with VLX1570 is lethal to ibrutinib- or bortezomib-resistant Waldenstrom macroglobulinemia tumor cells

The survival of Waldenstrom macroglobulinemia (WM) tumor cells hinges on aberrant B-cell receptor (BCR) and MYD88 signaling. WM cells upregulate the proteasome function to sustain the BCR-driven growth while maintaining homeostasis. Clinically, two treatment strategies are used to disrupt these complementary yet mutually exclusive WM survival pathways via ibrutinib (targets BTK/MYD88 node) and bortezomib (targets 20 S proteasome). Despite the success of both agents, WM patients eventually become refractory to treatment, highlighting the adaptive plasticity of WM cells and underscoring the need for development of new therapeutics. Here we provide a comprehensive preclinical report on the anti-WM activity of VLX1570, a novel small-molecule inhibitor of the deubiquitinating enzymes (DUBs), ubiquitin-specific protease 14 (USP14) and ubiquitin carboxyl-terminal hydrolase isozyme L5 (UCHL5). Both DUBs reside in the 19 S proteasome cap and their inhibition by VLX1570 results in rapid and tumor-specific apoptosis in bortezomib- or ibrutinib-resistant WM cells. Notably, treatment of WM cells with VLX1570 downregulated BCR-associated elements BTK, MYD88, NFATC, NF-κB and CXCR4, the latter whose dysregulated function is linked to ibrutinib resistance. VLX1570 administered to WM-xenografted mice resulted in decreased tumor burden and prolonged survival (P=0.0008) compared with vehicle-treated mice. Overall, our report demonstrates significant value in targeting USP14/UCHL5 with VLX1570 in drug-resistant WM and carries a high potential for clinical translation.

Efficacy and safety of lenalidomide oral monotherapy in patients with relapsed or refractory diffuse large B-cell lymphoma: Results from an international study (NHL-003)

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Background: Patients with diffuse large-B-cell lymphoma (DLBCL) who are not cured with R-CHOP or high-dose chemotherapy with autologous stem cell rescue have a dismal prognosis. A recent phase II trial (NHL-002) of lenalidomide in patients with relapsed or refractory aggressive non-Hodgkin's lymphoma (NHL) demonstrated a 19% overall response rate (ORR) with a 7-month median duration of response (DR) in the subset of patients with DLBCL. A supporting international phase II trial (NHL-003) of single-agent lenalidomide was initiated for patients with relapsed or refractory aggressive NHL that had received at least one prior treatment and had measurable disease. Herein, we report the data from the DLBCL patients enrolled in this trial. Methods: Patients received 25 mg oral lenalidomide once daily on days 1–21 of every 28-day cycle and continued therapy until disease progression or toxicity. The 1999 IWLRC methodology was used to assess response and progression. Results: One hundred-three DLBCL patients were enrolled and were evaluable for response assessment. The median age was 66 years (21–87) and 70 patients (68%) were male. Median time from diagnosis was 2 years (0.4–18.6), patients had received a median of 3 prior treatment regimens (1–10) and 46 of the patients (45%) had received a prior stem cell transplant (DLBCL-stem cell). Response rates are shown in the Table . Grade 3 or 4 adverse events occurring in more than 5% of patients were neutropenia (34%), thrombocytopenia (18%), asthenia (9%), anemia (8%), leucopenia (7%), back pain (6%) and dyspnea (6%). Conclusions: This international study demonstrates that lenalidomide is active in heavily pre-treated patients with relapsed or refractory DLBCL and has manageable side effects.

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Salvage chemotherapy with rituximab, oxaliplatin, cytosine arabinoside, and dexamethasone (ROAD) in patients with relapsed CD20+ aggressive B-cell lymphoma

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Background: In the original PARMA trial it was demonstrated that salvage chemotherapy with DHAP followed by autologous bone marrow transplant resulted in increased overall survival over salvage chemotherapy with DHAP alone in patients with aggressive lymphomas. The current study was designed to assess safety and feasibility of ROAD as a salvage chemotherapy regimen which could be administered as an inpatient or outpatient. Methods: Patients received immunochemotherapy on the following schedule: rituximab 375 mg/m2 weekly × 4, oxaliplatin 130 mg/m2 on day 2, Ara C 2000mg/m2 x 2 doses on day 2 and dexamethasone 40 mg on days 2–5, with OAD repeated at 3 week intervals (up to 6 cycles). Patients were considered for autologous stem cell transplantation after 2 cycles if eligible. Eligible histologies included diffuse large B cell lymphoma, mantle cell lymphoma and transformed lymphoma in first relapse. Results: 50 patients were accrued from Aug 2006 through Jul 2008: 5 patients were deemed ineligible after central pathology review. Baseline characteristics of eligible patients included median age 69 (range 23 - 77), 53% were male, 53% had advanced stage at relapse, LDH was elevated in 58% and all patients had an ECOG PS of 2 or less. Patients received a median of 2 cycles of therapy (range 1–6) with 39/45 receiving treatment in cycle 2, with 12 patients continuing beyond 2 cycles. 31 patients experienced grade III/IV hematologic toxicity and 22 patients had grade III/IV non-hematologic toxicity, primarily febrile neutropenia. One patient developed grade III nephrotoxicity due to disease progression. Twenty patients received their treatments exclusively as outpatients. 26 responses were seen in the 45 eligible patients (58%, 95% CI: 44–74%), with 20 responding patients proceeding to autologous SCT. Conclusions: ROAD is a safe and effective salvage chemotherapy regimen for relapsed aggressive lymphoma, including as a preparatory regimen prior to stem cell transplant. It appears to have similar response rates to R-DHAP in a similar patient population, but without the potential nephrotoxicity (data from prior published study from NCCTG). ROAD can be safely administered as an inpatient or outpatient.

No significant financial relationships to disclose.

MicroRNAs 15a and 16–1 regulates tumor proliferation in multiple myeloma

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Background: MicroRNAs (miRNAs) are non-coding RNAs that act as negative regulators of gene expression. They have been described to play roles in solid tumors and hematologic malignancies. However the role of miRNAs in multiple myeloma (MM) has not been yet fully described. Methods: We performed miRNA-profiling of primary bone marrow-derived CD138+ MM cells, compared to their normal cellular counterparts and validated data by qRT-PCR. In vitro and in vivo functional studies were performed on miRNA-15a- and -16–1-precursors-transfected MM cells. Effect of miRNA-15a and -16–1 on signaling cascades have been evaluated by western blot and immunofluorescence. NF-kB activity has been studied using the Active Motif TransAM kit. In vivo MM cell growth has been evaluated by either using an in vivo imaging model or bioluminescence. Angiogenesis has been studied both in vitro and in vivo using the chorioallantoic membrane model. Results: We identified a MM-specific miRNA signature characterized by down-expression of miRNA-15a, -16–1 and over-expression of miRNA-222/-221/-382/-181a/-181b (P<0.01). Data were confirmed by qRT-PCR on matched samples. Predicted targets for the decreased miRNAs in MM patients included pro-angiogenic cytokines, oncogenes, cell cycle regulators, NFkB activators. Conversely, predicted targets for the increased miRNAs included cell cycle inhibitors, suppressors of cytokine signaling, and pro-apoptotic factors. We demonstrated that miRNA-15a and - 16–1 regulate proliferation and growth of MM cells. Indeed, transfected cells showed decreased DNA synthesis; decreased cyclinD1/cyclinD3/CDC25a/pRb protein expression; phase G1 cell cycle arrest. Moreover, transfected cells showed inhibition of NFkB pathway as shown by reduced p65-/p50-/p52-NFkB activities; downregulation of p-p65/p50/p52 nuclear protein level; upregulation of cttosolic phospho-IkB; and inhibited translocation of p-p65 from the cytolplasm to the nucleus. Similarly, inhibition of MM cell growth was confirmed in vivo; and anti-angiogenic properties of miRNA-15a and -16–1 were demonstrated both in vitro and in vivo. Conclusions: These data indicate that miRNAs play a pivotal role in the biology of MM; providing the basis for the development of new miRNA-based targeted therapies in this disease.

No significant financial relationships to disclose.

Novel therapy with 2-methoxyestradiol (2ME2) for the treatment of relapsed and plateau phase multiple myeloma

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Background: 2-methoxyestradiol (2ME2) is a natural endogenous product of estradiol metabolism with anti-angiogenic and anti-neoplastic properties that has demonstrated activity against multiple myeloma cell lines and xenografts in immunocompromised mice. We report results of the first phase II clinical trial of 2ME2 in pts with relapsed and plateau phase myeloma. Methods: This trial was designed with a one-stage design to accrue 60 pts in the setting of relapsed and plateau phase myeloma. 2ME2 was administered orally at a dose of 1000 mg daily. After the first 39 pts were accrued, based on the results of ongoing phase I trials, the dose of 2ME2 was increased to 800 mg twice daily for the remaining patients. Pts who were already on study at that point were also allowed to escalate their dose to 800 mg twice daily. The primary endpoint was overall response rate. Responses were assessed using Eastern Cooperative Oncology Group criteria. Results: Sixty patients were treated at Mayo Clinic and Dana Farber Cancer Institute. Median age was 60 years (range, 28–99). Thirty-one patients had relapsed/refractory myeloma and 29 patients had plateau phase myeloma. Median number of prior therapies was 4 including stem cell transplant (48%), thalidomide (62%), bortezomib (6%) and lenalidomide (3%). Therapy was well tolerated. Adverse events were anemia (35%), fatigue (35%), nausea (25%), diarrhea (20%), hot flashes (20%), headache (17%), muscle cramps (15%), and upper respiratory tract infection (15%). Most toxicities were mild (grade 1–2). Estimated progression-free survival rates for all pts at one, two, and three years are 24%, 16%, and 9% respectively. Three pts with plateau phase disease, have been on study for over 4 years without progression at 50, 60, and 63 months. Response assessment is ongoing; so far, whilst no partial responses have been seen, prolonged stable disease has been observed in 3 pts (5%). Conclusions: 2ME2 is a novel agent that appears to be safe and well tolerated. Although no responses have been seen, prolonged stable disease in some pts is promising. Preliminary pharmacokinetic data indicate that the dose of 2ME2 used in this study may be inadequate, and a new formulation with significantly better bioavailability will be tested soon in this patient population.

No significant financial relationships to disclose.

Abnormal cytogenetics predict poor survival after high-dose therapy and autologous blood cell transplantation in multiple myeloma

We compared the prognostic value of conventional cytogenetic analysis and established factors such as beta2-microglobulin and plasma cell labeling index in 70 patients undergoing autologous blood cell transplantation for multiple myeloma. Patients underwent transplantation 5 to 88 months (median, 20 months) after the initial diagnosis of myeloma. Factors studied were age, sex, beta2-microglobulin, response to prior therapy, plasma cell labeling index, cytogenetic analysis, bone marrow plasma cell percentage, lactate dehydrogenase and C-reactive protein. Twenty-eight of 65 patients (43%) had abnormal marrow cytogenetics. Overall survival measured from transplantation was significantly better in patients with normal cytogenetics than in those with abnormal cytogenetics (median survival, 25 vs 12 months, P = 0.003). Progression-free survival was better, with median times of 12 vs7 months, respectively (P = 0.005); overall survival measured from the time myeloma was first diagnosed was also longer, with median survivals of 62 and 39 months, respectively (P = 0.001). Median plasma cell labeling index was 1.5% in patients with abnormal cytogenetics and 0. 2% in those with normal cytogenetics (P < 0.001). Abnormal bone marrow cytogenetics predict poor survival after blood cell transplantation for myeloma. There is a significant correlation between abnormal cytogenetics and high plasma cell labeling index, suggesting that certain cytogenetic abnormalities may offer a proliferative advantage to myeloma cells.

Interleukin-10 levels are often elevated in serum of adults with Hodgkin's disease and are associated with inferior failure-free survival

BACKGROUND

Interleukin-10 (IL-10) is a pleiotropic cytokine that protects B- or T-lymphocytes and hemopoietic progenitors from apoptosis induced by doxorubicin, glucocorticoids, or deprivation of growth factors. IL-10 is also immunosupressive, and tumor cells secreting IL-10 can grow in syngeneic or allogeneic hosts, and can inhibit the generation of tumor-specific cytotoxic T cells. Hodgkin-Reed-Sternberg cells are derived from follicular center B cells and they may be latently infected by EBV. When this occurs they often express IL-10. Based on these considerations we investigated the relationship between pretreatment serum IL-10 levels and failure-free survival (FFS) in Hodgkin's disease (HD).

PATIENTS AND METHODS

Untreated patients, older than 16 years, with biopsy-proven HD, were included if treated with ABVD or equivalent regimens, and if pretreatment serum was available. IL-10 levels were determined with a capture enzyme-linked immunoassay specific for cellular IL-10.

RESULTS

Among healthy adult volunteers serum IL-10 levels ranged from 4.8-9.8 pg/ml (mean 7.1, standard deviation 1.5 pg/ml). Therefore levels > or = 10 pg/ml were considered elevated. We identified 101 patients with available serum. Their median age was 32 years, and 60% had B-symptoms. Ann Arbor stage was I in 4, II in 21, III in 35, and IV in 41 patients. Histology was nodular sclerosis in 74, mixed cellularity in 12, lymphocyte predominance in six, lymphocyte depletion in one, and unclassified in eight patients. Pretreatment serum IL-10 levels were elevated in 51 patients, and were higher in those with serum albumin < 3.5 g/dl, B symptoms, serum beta 2-microglobulin > or = 2.5 mg/l, anemia, and AAS III or IV. After a median follow-up of 32 months for survivors, 20 patients have progressed, and the three-year FFS of those with high vs. normal serum IL-10 was 60% +/- 9 vs. 91 +/- 9% (50% vs. 50% of the population; P = 0.004 by log-rank). Among patients with Ann Arbor stage III or IV the three-year FFS for those with high vs. normal serum IL-10 (58 vs. 42% of the population) was 57 +/- 9% vs. 92 +/- 6% (P = 0.008 by log-rank). Multivariate analysis using Cox's proportional hazards model confirmed that IL-10 was an independent variable associated with inferior FFS in this population.

CONCLUSIONS

Elevation of serum IL-10 levels is frequent and is associated with inferior FFS in adults with ABVD-treated HD. This observation should be verified in other patient populations. In addition, the source and the role of IL-10 in the biology of HD should be further investigated.

Biology and treatment of myeloma

New strategies for the treatment of multiple myeloma, particularly high-dose therapy with peripheral blood stem cell transplantation, can achieve complete response in up to 50% of cases. The patient's condition eventually relapses because transplantation does not completely eliminate myeloma. Posttreatment interferon may prolong responses achieved by transplantation or chemotherapy, but it does not necessarily prolong survival. New approaches are being developed to further eliminate myeloma cells after an incomplete response achieved by transplantation or other chemotherapy. These approaches aim at myeloma cell surface antigens, T-cell immunity, and biological mechanisms of myeloma growth and dissemination. Biological targets include interleukin-6 (the central myeloma growth factor), interleukin-1 beta (an amplifier of stromal and bone cell production of interleukin-6), and serum soluble interleukin-6 receptor (an enhancer of myeloma cell response to interleukin-6). Efforts to eliminate circulating myeloma cells from peripheral blood stem cell harvests use positive selection or purging to provide a product that will engraft only normal stem cells, not myeloma cells. Multidrug resistance, a major factor in treatment failure, can be reversed by agents that inhibit the multidrug resistance protein on the myeloma cell surface. Finally, expanded knowledge of biologic mechanisms has led to the development of new prognostic factors. These aim to identify patients in clinical trials who can benefit from treatment regimens designed to overcome their impact on survival. Translating new biological advances into treatment programs is essential to improving therapy for patients with myeloma.