RESUMEN
Therapeutic strategies for patients with newly diagnosed multiple myeloma (NDMM) have considerably improved during the last 10 years. The IFM2014-03 trial proposed an all-oral triplet induction/consolidation regimen in transplant-eligible NDMM patients, followed by lenalidomide maintenance. Induction consisted of three 21-day cycles of ixazomib, lenalidomide and dexamethasone (IRd), before high-dose Melphalan with transplant followed by eight 28-day cycles of IRd consolidation before 13 cycles of lenalidomide maintenance. Forty-six patients were enrolled and received at least one dose of therapy, and 39 entered the maintenance phase. The primary end-point was stringent complete response after consolidation, and was achieved in nine patients (20.9%, 90% CI 11.4-33.7; p = 0.998). Ten patients (24.4%) had an undetectable minimal residual disease. The overall response rate was 95.7%. The 3-year progression-free survival was 66.3%. No unexpected toxicities were recorded, and only eight patients suspended from any study drug. Of note, 21 (45.7%) patients reported peripheral neuropathy (PN) (grades 1-2 with no serious adverse events). IRd induction and consolidation with transplant before lenalidomide maintenance shows lower response rates compared to other triplet therapies. It could be an alternative for patients who require an all-oral regimen and/or with pre-existent PN, especially if quadruplet regimens including anti-CD38 antibody are not available.
RESUMEN
In acquired thrombotic thrombocytopenic purpura (TTP), the persistence of severe ADAMTS13 deficiency (<10%) during remission is associated with more relapse. Preemptive (ie, after remission) administration of rituximab in these patients to prevent relapses remains controversial. We performed a cross-sectional analysis of 12-year follow-up data to compare the relapse incidence with or without preemptive rituximab infusion. Among 48 patients who experienced at least one episode of acquired TTP followed by severe ADAMTS13 deficiency during remission, 30 received preemptive rituximab (group 1); the other 18 did not (group 2). After a median of 17 months (interquartile range [IQR], 11-29) following rituximab, the relapse incidence decreased from 0.57 episodes/year (IQR, 0.46-0.7) to 0 episodes/year (IQR, 0-0.81) (P < .01) in group 1. ADAMTS13 activity 3 months after the first rituximab infusion increased to 46% (IQR, 30%-68%). Nine patients required additional courses of rituximab. In 5 patients, ADAMTS13 activity failed to increase durably. Four patients experienced manageable adverse effects. In group 2, the relapse incidence was higher (0.5 relapses/year; IQR, 0.12-0.5; P < .01). Relapse-free survival was longer in group 1 (P = .049). A persistent severe ADAMTS13 deficiency during TTP remission should prompt consideration of preemptive rituximab to prevent relapses.
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Anticuerpos Monoclonales de Origen Murino/administración & dosificación , Púrpura Trombocitopénica Trombótica/prevención & control , Proteínas ADAM/sangre , Proteínas ADAM/deficiencia , Proteínas ADAM/inmunología , Proteína ADAMTS13 , Adulto , Autoanticuerpos/sangre , Quimioprevención/métodos , Estudios Transversales , Femenino , Humanos , Infusiones Intravenosas , Masculino , Púrpura Trombocitopénica Trombótica/sangre , Inducción de Remisión , Estudios Retrospectivos , Rituximab , Prevención Secundaria , Resultado del TratamientoRESUMEN
Richter transformation (RT) is an aggressive lymphoma occurring in patients with chronic lymphocytic leukaemia. Here we investigated the anti-CD3/anti-CD19 T-cell-engager blinatumomab after R-CHOP (i.e. rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) in patients with untreated RT of diffuse large B-cell lymphoma histology (NCT03931642). In this multicentre phase 2 study, patients without complete response (CR) after two cycles of R-CHOP were eligible to receive an 8-week blinatumomab induction via continuous vein infusion with stepwise dosing until 112 µg/day. The primary endpoint was the CR rate after blinatumomab induction and secondary endpoint included safety, response duration, progression-free and overall survival. Thirty-nine patients started the first cycle of R-CHOP, 25 of whom received blinatumomab. After blinatumomab induction, five (20%) patients achieved CR, four (16%) achieved partial response, and six (24%) were stable. Considering the entire strategy, the overall response rate in the full-analysis-set was 46% (n = 18), with CR in 14 (36%) patients. The most common treatment-emergent adverse events of all grades in the blinatumomab-safety-set included fever (36%), anaemia (24%), and lymphopaenia (24%). Cytokine release syndrome (grade 1/2) was observed in 16% and neurotoxicity in 20% of patients. Blinatumomab demonstrated encouraging anti-tumour activity (the trial met its primary endpoint) and acceptable toxicity in patients with RT.
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Anticuerpos Biespecíficos , Protocolos de Quimioterapia Combinada Antineoplásica , Ciclofosfamida , Doxorrubicina , Linfoma de Células B Grandes Difuso , Prednisona , Rituximab , Vincristina , Humanos , Masculino , Femenino , Anticuerpos Biespecíficos/administración & dosificación , Anticuerpos Biespecíficos/efectos adversos , Anticuerpos Biespecíficos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Persona de Mediana Edad , Ciclofosfamida/uso terapéutico , Ciclofosfamida/administración & dosificación , Ciclofosfamida/efectos adversos , Rituximab/administración & dosificación , Rituximab/uso terapéutico , Rituximab/efectos adversos , Doxorrubicina/uso terapéutico , Doxorrubicina/administración & dosificación , Doxorrubicina/efectos adversos , Anciano , Prednisona/uso terapéutico , Prednisona/administración & dosificación , Prednisona/efectos adversos , Vincristina/uso terapéutico , Vincristina/efectos adversos , Vincristina/administración & dosificación , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Adulto , Anciano de 80 o más Años , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Resultado del TratamientoRESUMEN
CD38-targeting immunotherapy is approved in combination with lenalidomide and dexamethasone in patients with newly diagnosed multiple myeloma (NDMM) that are transplant ineligible (TI) and is considered the best standard of care (SOC). To improve current SOC, we evaluated the added value of weekly bortezomib (V) to isatuximab plus lenalidomide and dexamethasone (IsaRd versus Isa-VRd). This Intergroupe Francophone of Myeloma phase 3 study randomized 270 patients with NDMM that were TI, aged 65-79 years, to IsaRd versus Isa-VRd arms. The primary endpoint was a minimal residual disease (MRD) negativity rate at 10-5 by next-generation sequencing at 18 months from randomization. Key secondary endpoints included response rates, MRD assessment rates, survival and safety. The 18-month MRD negativity rates at 10-5 were reported in 35 patients (26%, 95% confidence interval (CI) 19-34) in IsaRd versus 71 (53%, 95% CI 44-61) in Isa-VRd (odds ratio for MRD negativity 3.16, 95% CI 1.89-5.28, P < 0.0001). The MRD benefit was consistent across subgroups at 10-5 and 10-6, and was already observed at month 12. The proportion of patients with complete response or better at 18 months was higher with Isa-VRd (58% versus 33%; P < 0.0001), as was the proportion of MRD negativity and complete response or better (37% versus 17%; P = 0.0003). At a median follow-up of 23.5 months, no difference was observed for survival times (immature data). The addition of weekly bortezomib did not significantly affect the relative dose intensity of IsaRd. Isa-VRd significantly increased MRD endpoints, including the 18-month negativity rate at 10-5, the primary endpoint, compared with IsaRd. This study proposes Isa-VRd as a new SOC for patients with NDMM that are TI. ClinicalTrials.gov identifier: NCT04751877 .
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Protocolos de Quimioterapia Combinada Antineoplásica , Bortezomib , Dexametasona , Lenalidomida , Mieloma Múltiple , Humanos , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/patología , Bortezomib/administración & dosificación , Bortezomib/uso terapéutico , Lenalidomida/administración & dosificación , Lenalidomida/uso terapéutico , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Anciano , Masculino , Femenino , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Monoclonales Humanizados/efectos adversos , Neoplasia Residual , Resultado del TratamientoRESUMEN
BACKGROUND: Lenalidomide in combination with dexamethasone (Len/Dex) is indicated for patients with recurrent/refractory multiple myeloma (RRMM) who were treated with 1 prior therapy until evidence of disease progression. The objective of the current study was to determine the efficacy and safety profile of long-term exposure to Len/Dex. METHODS: A total of 50 patients with RRMM who were treated with long-term Len for ≥ 2 years from 2 Intergroupe Francophone du Myélome (IFM) centers (Lille and Nancy) were included in the current study. RESULTS: The median age of the patients was 58 years, with 30% of the patients aged >65 years, 49% having an International Staging System stage of 2 and 3, 12% having severe renal insufficiency, and 8% demonstrating an adverse result on fluorescence in situ hybridization. Approximately 56% of the patients received treatment with Len/Dex for ≥ 3 years. The median duration of treatment with Len/Dex was 3 years (range, 2 years-7 years). The response rates for partial response or better and very good partial response or better for the overall cohort were 96% and 74%, respectively, which is similar to patients exposed to Len for ≥ 3 years. With a median follow-up of 4 years, 19 (38%) patients had stopped treatment with Len/Dex. The time to disease progression rate at 37 months was 78% and 91%, respectively, in patients exposed to Len for 2 years to <3 years and for ≥ 3 years (P=025). The safety profile was manageable, similar to that of Len when administered for a shorter period of time; 16% of patients had grade 3 to 4 neutropenia, 6% had thrombopenia, 6% had anemia, and 20% experienced thromboembolic events, all of venous type. The annual incidence rate of second primary malignancy was 1.96% in the current series. CONCLUSIONS: The results of the current study confirmed that the Len/Dex combination is feasible for long-term use in patients with RRMM, with a significant benefit noted in terms of time to disease progression for prolonged treatment with Len/Dex.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Resistencia a Antineoplásicos , Mieloma Múltiple/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Terapia Recuperativa , Adulto , Anciano , Dexametasona/administración & dosificación , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Lenalidomida , Masculino , Persona de Mediana Edad , Mieloma Múltiple/mortalidad , Mieloma Múltiple/patología , Recurrencia Local de Neoplasia/mortalidad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Talidomida/administración & dosificación , Talidomida/análogos & derivadosAsunto(s)
Leucemia Mieloide Aguda , Mutación , Proteínas de Neoplasias/administración & dosificación , Proteínas Nucleares/genética , Anciano , Anciano de 80 o más Años , Antineoplásicos , Supervivencia sin Enfermedad , Femenino , Humanos , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/mortalidad , Masculino , Persona de Mediana Edad , Nucleofosmina , Inducción de Remisión , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
This study investigated the impact of human herpesvirus type 6 (HHV6) reactivation within 100 days of allogeneic stem cell transplantation (allo-SCT) on patient outcomes. HHV6 plasma loads were monitored weekly by quantitative PCR. Of 235 consecutive patients, 112 (48%) had an early positive HHV6 PCR test (group A) and 123 (52%) did not (group B). HHV6 reactivation was less frequent in patients who received reduced-intensity conditioning (P = .028). In group A, only 6 patients (5%) were asymptomatic; the most common clinical manifestations were fever (n = 60), skin rash (n = 57), diarrhea (n = 51), pulmonary complications (n = 19), and neurologic disorders (n = 12). Compared with the patients in group B, those in group A experienced delayed platelet engraftment (P = .003) and more frequent grade II-IV acute graft-versus-host disease (GVHD) (47% versus 30% in group B; P = .009). In multivariate analysis, the most important factors influencing the development of grade II-IV acute GVHD development were early HHV6 reactivation (P = .03) and unrelated donor status (P < .001). HHV6 reactivation adversely influenced 6-month survival (P = .04). Of the 38 evaluable patients receiving antiviral treatment, 34 had a significantly decreased HHV6 load. Our findings indicate that HHV6 reactivation after allo-SCT is associated with delayed platelet engraftment, early posttransplantation mortality, and the development of acute GVHD. Careful monitoring of HHV6 by PCR is warranted during the early posttransplantation period.
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ADN Viral/efectos de los fármacos , Enfermedad Injerto contra Huésped/virología , Trasplante de Células Madre Hematopoyéticas , Herpesvirus Humano 6/fisiología , Infecciones por Roseolovirus/virología , Acondicionamiento Pretrasplante/métodos , Adolescente , Adulto , Antivirales/administración & dosificación , Antivirales/uso terapéutico , Plaquetas/inmunología , Niño , Preescolar , Femenino , Enfermedad Injerto contra Huésped/complicaciones , Enfermedad Injerto contra Huésped/tratamiento farmacológico , Enfermedad Injerto contra Huésped/mortalidad , Herpesvirus Humano 6/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Infecciones por Roseolovirus/complicaciones , Infecciones por Roseolovirus/tratamiento farmacológico , Infecciones por Roseolovirus/mortalidad , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Trasplante Homólogo , Donante no Emparentado , Carga Viral/inmunología , Activación Viral/inmunologíaRESUMEN
International guidelines limit the use of aminoglycosides in febrile neutropenia to severe situations. We retrospectively reviewed the use of aminoglycosides in adult acute myeloid leukaemia patients admitted in 2009. Our guidelines include precise indications (severe sepsis, shock, drug resistance), dosing regimens (once-daily 20 mg/kg/day amikacin, 5 mg/kg/day gentamicin), durations of treatment, drug monitoring timing, and target C(max) concentrations (40 mg/l amikacin, 20 mg/l gentamicin). Thirty-one patients received 46 aminoglycoside courses: 31 amikacin and 15 gentamicin. The mean prescribed dosage was 19 ± 2.8 mg/kg/day for amikacin and 4.7 ± 0.9 mg/kg/day for gentamicin. The mean duration of use was 2.9 days for both drugs. The mean C(max) for amikacin was 47 ± 13 mg/l and for gentamicin was 13.6 ± 7.5 mg/l. In compliant regimens, all amikacin patients and a third of gentamicin patients had adequate C(max). Among 23 isolated pathogens, 65.5% were susceptible to both drugs and 11.5% to amikacin only. This vindicates the 20 mg/kg/day amikacin dosage and suggests a need to increase the gentamicin dosage.
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Aminoglicósidos/uso terapéutico , Antibacterianos/uso terapéutico , Monitoreo de Drogas , Leucemia Mieloide Aguda/tratamiento farmacológico , Neutropenia/tratamiento farmacológico , Adulto , Anciano , Amicacina/administración & dosificación , Amicacina/uso terapéutico , Aminoglicósidos/administración & dosificación , Antibacterianos/administración & dosificación , Infecciones Bacterianas/prevención & control , Esquema de Medicación , Quimioterapia Combinada , Femenino , Gentamicinas/administración & dosificación , Gentamicinas/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Neutropenia/complicaciones , Guías de Práctica Clínica como Asunto , Resultado del Tratamiento , Adulto JovenRESUMEN
Waldenström macroglobulinemia (WM) is a B-cell disorder characterized primarily by bone marrow infiltration with lymphoplasmacytic cells (LPCs), along with demonstration of an IgM monoclonal gammopathy in the blood. WM remains incurable, with 5-6 yr median overall survival for patients with symptomatic WM. The main therapeutic options include alkylating agents, nucleoside analogues, and rituximab, either in monotherapy or in combination. Studies involving combination chemotherapy are ongoing, and preliminary results are encouraging. However, there are several limitations to these approaches. The complete response rate is low and the treatment free survival are short in many patients, no specific agent or regimen has been shown to be superior to another, and no treatment has been specifically approved for WM. As such, novel therapeutic agents are needed for the treatment of WM. In ongoing efforts, we and others have sought to exploit advances made in the understanding of the biology of WM so as to develop new targeted therapeutics for this malignancy. These efforts have led to the development of proteasome inhibitors, of them bortezomib, several Akt/mTor inhibitors, such as perifosine and Rad001, and immunomodulatory agents such as thalidomide and lenalidomide. Many agents and monoclonal antibodies are currently being tested in clinical trials and seem promising. This report provides an update of the current preclinical studies and clinical efforts for the development of novel agents in the treatment of WM.
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Macroglobulinemia de Waldenström/terapia , Antineoplásicos/uso terapéutico , Terapia Combinada , Diagnóstico Diferencial , Humanos , Inmunoterapia , Transducción de Señal/efectos de los fármacos , Macroglobulinemia de Waldenström/diagnóstico , Macroglobulinemia de Waldenström/inmunología , Macroglobulinemia de Waldenström/metabolismoAsunto(s)
Anemia Diseritropoyética Congénita , Eritroblastos/metabolismo , Eritroblastos/ultraestructura , Adulto , Anemia Diseritropoyética Congénita/sangre , Anemia Diseritropoyética Congénita/clasificación , Anemia Diseritropoyética Congénita/patología , Médula Ósea/metabolismo , Médula Ósea/ultraestructura , Humanos , MasculinoRESUMEN
PURPOSE: Accurate quantification of monoclonal IgM immunoglobulins is essential for response assessment in patients with Waldenström's macroglobulinaemia (WM). The propensity of IgM to form multimers in serum makes sample evaluation by current laboratory methods particularly challenging. EXPERIMENTAL DESIGN: We assessed the precision and linearity of IgMκ and IgMλ heavy/light chain (HLC, Hevylite) assays, and established reference intervals using 120 normal donor sera. We compared the quantitative performance of HLC assays with serum protein electrophoresis (SPE) and total IgM nephelometry for 78 diagnostic samples and follow-up samples from 25 patients with WM. Comparisons were made between the three methods for diagnostic sensitivity and response assessment. RESULTS: IgMκ and IgMλ HLC assays showed low imprecision and good linearity. There was good agreement between summated HLC (IgMκ + IgMλ) and total IgM (measured nephelometrically; R2 = 0.90), but only moderate agreement between involved IgM HLC and SPE densitometry (R2 = 0.49). Analysis of 120 normal donor sera produced the following normal ranges: IgMκ: 0.29-1.82 g/L; IgMλ: 0.17-0.94 g/L; IgMκ/IgMλ ratio: 0.96-2.30. Using these ranges, IgM HLC ratios were abnormal in all WM presentation sera tested, including 15 with non-quantifiable SPE. Despite discordance in quantitation, responses assigned with HLC assays showed excellent agreement to those based on international guidelines using SPE or total IgM; although abnormal HLC ratios indicated residual disease in some patients with negative electrophoresis results. CONCLUSIONS: Nephelometric assessment of IgMκ and IgMλ HLC pairs offers a quantitative alternative to traditional laboratory techniques for the measurement of monoclonal IgM and may aid in the management of WM. Clin Cancer Res; 22(20); 5152-8. ©2016 AACR.
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Anticuerpos Monoclonales/sangre , Viscosidad Sanguínea/fisiología , Cadenas Pesadas de Inmunoglobulina/sangre , Cadenas Ligeras de Inmunoglobulina/sangre , Inmunoglobulina M/sangre , Macroglobulinemia de Waldenström/diagnóstico , Humanos , Nefelometría y Turbidimetría , Macroglobulinemia de Waldenström/inmunologíaRESUMEN
Chronic CD8(+) T-cell expansions can result in parotid gland swelling and other organ infiltration in HIV-infected patients, or in persistent cytopenias. We report 14 patients with a CD8+ T-cell expansion to better characterize the clinical spectrum of this ill-defined entity. Patients (9 women/5 men) were 65 year-old (range, 25-74). Six patients had ≥ 1 symptomatic organ infiltration, and 9 had ≥ 1 cytopenia with a CD8(+) (>50% of total lymphocyte count) and/or a CD8(+)/CD57(+) (>30% of total lymphocyte count) T-cell expansion for at least 3 months. One patient had both manifestations. A STAT3 mutation, consistent with the diagnosis of large granular lymphocyte leukemia, was found in 2 patients with cytopenia. Organ infiltration involved lymph nodes, the liver, the colon, the kidneys, the skin and the central nervous system. Three patients had a HIV infection for 8 years (range, 0.5-20 years). Two non-HIV patients with hypogammaglobulinemia had been treated with a B-cell depleting monoclonal antibody (rituximab) for a lymphoma. One patient had a myelodysplastic syndrome with colon infiltration and agranulocytosis. The outcome was favorable with efficient antiretroviral therapy and steroids in HIV-infected patients and intravenous immunoglobulins in 2/3 non-HIV patients. Six patients had an agranulocytosis of favorable outcome with granulocyte-colony stimulating factor only (3 cases), cyclophosphamide, methotrexate and cyclosporine A, or no treatment (1 case each). Three patients had a pure red cell aplasia, of favorable outcome in 2 cases with methotrexate and cyclosporine A; one patient was unresponsive. Chronic CD8(+) T-cell expansions with organ infiltration in immunocompromised patients may involve other organs than parotid glands; they are non clonal and of favorable outcome after correction of the immune deficiency and/or steroids. In patients with bone marrow infiltration and unexplained cytopenia, CD8(+) T-cell expansions can be clonal or not; their identification suggests that cytopenias are immune-mediated. Our results extend the clinical spectrum of chronic CD8(+) T-cell expansions.
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Linfocitos T CD8-positivos/patología , Infecciones por VIH/complicaciones , Linfocitosis/etiología , Linfocitosis/patología , Adulto , Anciano , Relación CD4-CD8 , Linfocitos T CD8-positivos/metabolismo , Coinfección , Femenino , Estudios de Seguimiento , Infecciones por VIH/inmunología , Humanos , Leucocitosis/diagnóstico , Leucocitosis/etiología , Leucocitosis/patología , Leucopenia/etiología , Leucopenia/patología , Recuento de Linfocitos , Linfocitosis/diagnóstico , Masculino , Persona de Mediana Edad , Aplasia Pura de Células Rojas/diagnóstico , Aplasia Pura de Células Rojas/etiología , Aplasia Pura de Células Rojas/patologíaRESUMEN
The pathophysiology of Waldenström macroglobulinemia (WM), a lymphoproliferative disorder characterized by lymphoplasmacytic bone marrow infiltration associated with serum IgM paraprotein, is rather unclear; however, progress has been made in recent years to better determine the genetic profile of WM tumor cells. Studies based on high-throughput genomic analyses-including single-nucleotide polymorphism array (SNPa), array-based comparative genomic hybridization, and, recently, whole-genome sequencing--have improved deciphering some of the key molecular pathways associated with WM. Beyond the discovery of the myeloid differentiation primary response gene 88 (MYD88) L265P mutation, which will help greatly in the differential characterization of WM from other B-cell low-grade lymphomas, several other mechanisms of gene deregulation were identified and mapped that recurrently pointed out nuclear factor-kappa B (NF-κB), breakpoint cluster region (BCR), and Toll-like receptor (TLR) signaling pathways as potential targets for a better understanding of the physiopathology of WM and for future drug development. Herein, we summarize the current knowledge of the genomic patterns of WM to highlight its complexity.
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Genómica , Macroglobulinemia de Waldenström/genética , Epigénesis Genética , Estudio de Asociación del Genoma Completo , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Mutación , Factor 88 de Diferenciación Mieloide/genética , Disomía UniparentalRESUMEN
The stem cell factor receptor (SCF) c-Kit plays a pivotal role in regulating cell proliferation and survival in many cell types. In particular, c-Kit is required for early amplification of erythroid progenitors, while it must disappear from cell surface for the cell entering the final steps of maturation in an erythropoietin-dependent manner. We initially observed that imatinib (IM), an inhibitor targeting the tyrosine kinase activity of c-Kit concomitantly down-regulated the expression of c-Kit and accelerated the Epo-driven differentiation of erythroblasts in the absence of SCF. We investigated the mechanism by which IM or related masitinib (MA) induce c-Kit down-regulation in the human UT-7/Epo cell line. We found that the down-regulation of c-Kit in the presence of IM or MA was inhibited by a pre-incubation with methyl-ß-cyclodextrin suggesting that c-Kit was internalized in the absence of ligand. By contrast to SCF, the internalization induced by TKI was independent of the E3 ubiquitin ligase c-Cbl. Furthermore, c-Kit was degraded through lysosomal, but not proteasomal pathway. In pulse-chase experiments, IM did not modulate c-Kit synthesis or maturation. Analysis of phosphotyrosine peptides in UT-7/Epo cells treated or not with IM show that IM did not modify overall tyrosine phosphorylation in these cells. Furthermore, we showed that a T670I mutation preventing the full access of IM to the ATP binding pocket, did not allow the internalization process in the presence of IM. Altogether these data show that TKI-induced internalization of c-Kit is linked to a modification of the integrity of ATP binding pocket.
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Adenosina Trifosfato/metabolismo , Benzamidas/farmacología , Regulación hacia Abajo/efectos de los fármacos , Piperazinas/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-kit/metabolismo , Pirimidinas/farmacología , Tiazoles/farmacología , Sitios de Unión/efectos de los fármacos , Línea Celular , Eritroblastos/citología , Eritroblastos/efectos de los fármacos , Eritroblastos/metabolismo , Humanos , Mesilato de Imatinib , Ligandos , Lisosomas/efectos de los fármacos , Lisosomas/metabolismo , Piperidinas , Transporte de Proteínas/efectos de los fármacos , Proteolisis/efectos de los fármacos , PiridinasRESUMEN
Melphalan combined with prednisone (MP) has long been the historical treatment of reference for a large proportion of elderly myeloma (MM) patients ineligible for autologous stem cell transplantation, and is still the backbone of new regimens that include the new era of novel agents. Melphalan-prednisone-thalidomide (MPT) and melphalan-prednisone-bortezomib (Velcade((R)), MPV), proved superior to MP, currently appear to be the treatments of choice for this population. In the near future melphalan-prednisone-lenalidomide (Revlimid((R)), MPR) will also provide a third therapeutic option (MPT, MPV, and MPR), in elderly multiple myeloma, eventually. These options could lead to more personalized treatment approaches, based on patient comorbidities, as the three novel agents have somewhat different toxicity profiles. Dexamethasone-based regimen is another option and questions regarding the relative efficacy of melphalan-based versus low-dose dexamethasone-based regimens will require randomized phase III trials. More intensive approaches with new drug combinations or with the incorporation of polyethylene glycolated (PEGylated) liposomal doxorubicin will also require additional studies. Additionally, the important issue of maintenance treatment needs to be further investigated. These new and emerging therapies offer multiple effective treatment options for MM patients and greatly enhanced treatment strategies for clinicians.
RESUMEN
Despite advances in therapy, Waldenstrom's macroglobulinemia (WM) remains incurable. Guidelines on therapeutic alternatives in WM recommended the use of alkylating agents, rituximab, nucleoside analogues and anthracyclins either in first line or at relapse and in combination in fit patients. While the overall response rates of combination regimens reached up to 80 - 90% in some studies, the complete response rate is low, no greater than 10 - 20%; and the disease-related median survival for symptomatic patients is approximately 6 years. As such, new therapeutic agents are needed for the treatment of WM. In ongoing efforts, advances were made in the understanding of the biology of WM so as to better target therapeutics for this malignancy. Several preclinical studies have demonstrated that the NFkappaB pathway is a potential target for therapeutics in WM. Bortezomib (Velcade) is the first approved proteasome inhibitor for treating relapse/refractory multiple myeloma and, among other mechanisms of action, significantly inhibits the NFkB pathway. This report provides an update on biological studies and clinical efforts to develop bortezomib as a new treatment of Waldenstrom's macroglobulinemia.
Asunto(s)
Ácidos Borónicos/química , Ácidos Borónicos/uso terapéutico , Pirazinas/química , Pirazinas/uso terapéutico , Macroglobulinemia de Waldenström/tratamiento farmacológico , Animales , Bortezomib , Ensayos Clínicos como Asunto/métodos , Ensayos Clínicos como Asunto/tendencias , Humanos , Macroglobulinemia de Waldenström/fisiopatologíaRESUMEN
In the past years, new developments have occurred both in the understanding of the biology of Waldenstrom Macroglobulinemia (WM) and in therapeutic options for WM. WM is a B-cell disorder characterized primarily by bone marrow infiltration with lymphoplasmacytic cells, along with demonstration of an IgM monoclonal gammopathy. Despite advances in therapy, WM remains incurable, with 5-6 years median overall survival of patients in symptomatic WM. Therapy is postponed for asymptomatic patients, and progressive anemia is the most common indication for initiation of treatment. The main therapeutic options include alkylating agents, nucleoside analogues, and rituximab. Studies involving combination chemotherapy are ongoing, and preliminary results are encouraging. No specific agent or regimen has been shown to be superior to another for treatment of WM. As such, novel therapeutic agents are needed for the treatment of WM. In ongoing efforts, we and others have sought to exploit advances made in the understanding of the biology of WM so as to better target therapeutics for this malignancy. These efforts have led to the development of several novel agents including the proteasome inhibitor bortezomib, and several Akt/mTor inhibitors, perifosine and Rad001, and immunomodulatory agents such as thalidomide and lenalidomide. Studies with monoclonal antibodies are ongoing and promising including the use of alemtuzumab, SGN-70, and the APRIL/BLYS blocking protein TACI-Ig atacicept. Other agents currently being tested in clinical trials include the PKC inhibitor enzastaurin, the natural product resveratrol, as well as the statin simvastatin. This report provides an update of the current preclinical studies and clinical efforts for the development of novel agents in the treatment of WM.