Efficacy and safety assessment of prolonged maintenance with subcutaneous rituximab in patients with relapsed or refractory indolent non-Hodgkin lymphoma: results of the phase III MabCute study.

Rituximab plus chemotherapy induction followed by rituximab maintenance for up to 2 years confers a long-term benefit in terms of progression-free survival in patients with indolent non-Hodgkin lymphoma. It is not known whether further prolonged maintenance with rituximab provides additional benefit. The phase III MabCute study enrolled 692 patients with relapsed or refractory indolent non-Hodgkin lymphoma. Patients who responded to induction with rituximab plus chemotherapy and were still responding after up to 2 years' initial maintenance with subcutaneous rituximab were randomized to extended maintenance with subcutaneous rituximab (n=138) or observation only (n=138). The primary endpoint of investigator-assessed progression-free survival in the randomized population was un-addressed by the end of study because of an insufficient number of events (129 events were needed for 80% power at 5% significance if approximately 330 patients were randomized). In total, there were 46 progression-free survival events, 19 and 27 in the rituximab and observation arms, respectively (P=0.410 by stratified log-rank test; hazard ratio 0.76 [95% confidence interval: 0.37- 1.53]). The median progression-free survival was not reached in either randomized arm. There were no new safety signals; however, adverse events were seen slightly more frequently with rituximab than with observation during extended maintenance. Maintenance for up to 2 years with rituximab after response to initial induction therefore remains the standard of care in patients with relapsed or refractory indolent non- Hodgkin lymphoma. (Clinicaltrials.gov identifier: NCT01461928).

Daratumumab plus bortezomib and dexamethasone versus bortezomib and dexamethasone in relapsed or refractory multiple myeloma: updated analysis of CASTOR.

Daratumumab, a CD38 human monoclonal antibody, demonstrated significant clinical activity in combination with bortezomib and dexamethasone versus bortezomib and dexamethasone alone in the primary analysis of CASTOR, a phase 3 study in relapsed and/or refractory multiple myeloma. A post hoc analysis based on treatment history and longer follow up is presented. After 19.4 (range: 0-27.7) months of median follow up, daratumumab plus bortezomib and dexamethasone prolonged progression-free survival (median: 16.7 versus 7.1 months; hazard ratio, 0.31; 95% confidence interval, 0.24-0.39; P<0.0001) and improved the overall response rate (83.8% versus 63.2%; P<0.0001) compared with bortezomib and dexamethasone alone. The progression-free survival benefit of daratumumab plus bortezomib and dexamethasone was most apparent in patients with 1 prior line of therapy (median: not reached versus 7.9 months; hazard ratio, 0.19; 95% con fidence interval, 0.12-0.29; P<0.0001). Daratumumab plus bortezomib and dexamethasone was also superior to bortezomib and dexamethasone alone in subgroups based on prior treatment exposure (bortezomib, thalidomide, or lenalidomide), lenalidomide-refractory status, time since last therapy (≤12, >12, ≤6, or >6 months), or cytogenetic risk. Minimal residual disease-negative rates were >2.5-fold higher with daratumumab across subgroups. The safety profile of daratumumab plus bortezomib and dexamethasone remained consistent with longer follow up. Daratumumab plus bortezomib and dexamethasone demonstrated significant clinical activity across clinically relevant subgroups and provided the greatest benefit to patients treated at first relapse. Trial registration: clinicaltrials.gov identifier: 02136134.

Prognostic and therapeutic stratification in CLL: focus on 17p deletion and p53 mutation.

Chronic lymphocytic leukemia (CLL), a disorder for which B cell heterogeneity and increased cellular proliferation play central pathogenic roles, displays several genetic abnormalities that are associated with poor prognosis and have therapeutic implications. In this review, we discuss the prognostic role and therapeutic implications of chromosome 17p deletions and TP53 mutations in CLL. Unlike other recurrent genetic abnormalities, the frequency of TP53 alterations is relatively low in newly diagnosed patients, but increases sharply with disease progression, which suggests that these alterations represent an evolutionary mechanism of resistance. In comparison with patients without such abnormalities, those with 17p deletions and TP53 mutations have lower response rates and more aggressive disease. One important consequence of the diverse molecular mechanisms that affect the TP53 pathway is the need to assess both the presence of 17p deletion and TP53 mutations before treatment initiation. Several authors have attempted to incorporate TP53 abnormalities in different prognostic models for CLL, and the recent International Prognostic Index for Chronic Lymphocytic Leukemia formally considers patients with TP53 abnormalities (deletion 17p or TP53 mutation or both) as high-risk. Several novel agents may improve results in patients with CLL, including in those with TP53 mutations. Ibrutinib, idelalisib, and venetoclax have been approved in various settings and countries for treatment of CLL. Further progress in targeted therapy and judicious use of chemotherapy, monoclonal antibodies, and reduced-intensity allogeneic transplantation will provide patients with CLL in general, and those with TP53 abnormalities in particular, with a better prognosis.

Detection of somatic TP53 mutations and 17p deletions in patients with chronic lymphocytic leukemia: a review of the current methods.

Chronic lymphocytic leukemia is the most common hematologic malignancy among adults in Western countries. Several studies show that somatic mutations in the TP53 gene are present in up to 50% of patients with relapsed or refractory chronic lymphocytic leukemia. This study aims to review and compare the methods used to detect somatic TP53 mutations and/or 17p deletions and analyze their importance in the chronic lymphocytic leukemia diagnosis and follow-up. In chronic lymphocytic leukemia patients with refractory or recurrent disease, the probability of clonal expansion of cells with the TP53 mutation and/or 17p deletion is very high. The studies assessed showed several methodologies able to detect these changes. For the 17p deletion, the chromosome G-banding (karyotype) and interphase fluorescence in situ hybridization are the most sensitive. For somatic mutations involving the TP53 gene, moderate or high-coverage read next-generation sequencing and Sanger sequencing are the most recommended ones. The TP53 gene mutations represent a strong adverse prognostic factor for patient survival and treatment resistance in chronic lymphocytic leukemia. Patients carrying low-proportion TP53 mutation (less than 20-25% of all alleles) remain a challenge to these tests. Thus, for any of the methods employed, it is essential that the laboratory conduct its analytical validation, documenting its accuracy, precision and sensitivity/limit of detection.

Daratumumab, Bortezomib, and Dexamethasone Versus Bortezomib and Dexamethasone in Patients With Previously Treated Multiple Myeloma: Three-year Follow-up of CASTOR.

BACKGROUND: In the phase III CASTOR study in relapsed or refractory multiple myeloma, daratumumab, bortezomib, and dexamethasone (D-Vd) demonstrated significant clinical benefit versus Vd alone. Outcomes after 40.0 months of median follow-up are discussed. PATIENTS AND METHODS: Eligible patients had received ≥ 1 line of treatment and were administered bortezomib (1.3 mg/m2) and dexamethasone (20 mg) for 8 cycles with or without daratumumab (16 mg/kg) until disease progression. RESULTS: Of 498 patients in the intent-to-treat (ITT) population (D-Vd, n = 251; Vd, n = 247), 47% had 1 prior line of treatment (1PL; D-Vd, n = 122; Vd, n = 113). Median progression-free survival (PFS) was significantly prolonged with D-Vd versus Vd in the ITT population (16.7 vs. 7.1 months; hazard ratio [HR], 0.31; 95% confidence interval [CI], 0.25-0.40; P < .0001) and the 1PL subgroup (27.0 vs. 7.9 months; HR, 0.22; 95% CI, 0.15-0.32; P < .0001). In lenalidomide-refractory patients, the median PFS was 7.8 versus 4.9 months (HR, 0.44; 95% CI, 0.28-0.68; P = .0002) for D-Vd (n = 60) versus Vd (n = 81). Minimal residual disease (MRD)-negativity rates (10-5) were greater with D-Vd versus Vd (ITT: 14% vs. 2%; 1PL: 20% vs. 3%; both P < .0001). PFS2 was significantly prolonged with D-Vd versus Vd (ITT: HR, 0.48; 95% CI, 0.38-0.61; 1PL: HR, 0.35; 95% CI, 0.24-0.51; P < .0001). No new safety concerns were observed. CONCLUSION: After 3 years, D-Vd maintained significant benefits in patients with relapsed or refractory multiple myeloma with a consistent safety profile. D-Vd provided the greatest benefit at first relapse and increased MRD-negativity rates.

Daratumumab, bortezomib, and dexamethasone in relapsed or refractory multiple myeloma: subgroup analysis of CASTOR based on cytogenetic risk.

BACKGROUND: Multiple myeloma (MM) patients with high cytogenetic risk have poor outcomes. In CASTOR, daratumumab plus bortezomib/dexamethasone (D-Vd) prolonged progression-free survival (PFS) versus bortezomib/dexamethasone (Vd) alone and exhibited tolerability in patients with relapsed or refractory MM (RRMM). METHODS: This subgroup analysis evaluated D-Vd versus Vd in CASTOR based on cytogenetic risk, determined using fluorescence in situ hybridization and/or karyotype testing performed locally. High-risk patients had t(4;14), t(14;16), and/or del17p abnormalities. Minimal residual disease (MRD; 10-5 sensitivity threshold) was assessed via the clonoSEQ® assay V2.0. Of the 498 patients randomized, 40 (16%) in the D-Vd group and 35 (14%) in the Vd group were categorized as high risk. RESULTS: After a median follow-up of 40.0 months, D-Vd prolonged median PFS versus Vd in patients with standard (16.6 vs 6.6 months; HR, 0.26; 95% CI, 0.19-0.37; P < 0.0001) and high (12.6 vs 6.2 months; HR, 0.41; 95% CI, 0.21-0.83; P = 0.0106) cytogenetic risk. D-Vd achieved deep responses, including higher rates of MRD negativity and sustained MRD negativity versus Vd, regardless of cytogenetic risk. The safety profile was consistent with the overall population of CASTOR. CONCLUSION: These updated data reinforce the effectiveness and tolerability of daratumumab-based regimens for RRMM, regardless of cytogenetic risk status. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02136134 . Registered 12 May 2014.

Detection of somatic TP53 mutations and 17p deletions in patients with chronic lymphocytic leukemia: a review of the current methods

ABSTRACT Chronic lymphocytic leukemia is the most common hematologic malignancy among adults in Western countries. Several studies show that somatic mutations in the TP53 gene are present in up to 50% of patients with relapsed or refractory chronic lymphocytic leukemia. This study aims to review and compare the methods used to detect somatic TP53 mutations and/or 17p deletions and analyze their importance in the chronic lymphocytic leukemia diagnosis and follow-up. In chronic lymphocytic leukemia patients with refractory or recurrent disease, the probability of clonal expansion of cells with the TP53 mutation and/or 17p deletion is very high. The studies assessed showed several methodologies able to detect these changes. For the 17p deletion, the chromosome G-banding (karyotype) and interphase fluorescence in situ hybridization are the most sensitive. For somatic mutations involving the TP53 gene, moderate or high-coverage read next-generation sequencing and Sanger sequencing are the most recommended ones. The TP53 gene mutations represent a strong adverse prognostic factor for patient survival and treatment resistance in chronic lymphocytic leukemia. Patients carrying low-proportion TP53 mutation (less than 20-25% of all alleles) remain a challenge to these tests. Thus, for any of the methods employed, it is essential that the laboratory conduct its analytical validation, documenting its accuracy, precision and sensitivity/limit of detection.

O papel da expressão de Bcl-2 em material obtido por PAAF no diagnóstico de doenças linfoproliferativas B / The role of Bcl-2 expression in fine needle aspiration specimens for the diagnostic accuracy in lymphoproliferative diseases

INTRODUÇÃO: O diagnóstico das doenças linfoproliferativas (DLP) tradicionalmente baseia-se no estudo histológico dos linfonodos (LN) acrescido de imuno-histoquímica. A imunofenotipagem (IFT) pela citometria de fluxo (CF) é uma ferramenta sensível e rápida, que pode ser aplicada nas DLP, em material obtido por punção aspirativa por agulha fina (PAAF) de LN. O Bcl-2 é um proto-oncogene que se expressa em várias DLP, porém em níveis especialmente elevados no linfoma folicular (LF). OBJETIVOS: Diagnosticar DLP, através de morfologia e imunofenotipagem por CF, em amostras obtidas por PAAF de LN. MATERIAL e MÉTODO: Amostras de 25 pacientes com adenopatias e de duas tonsilas reacionais foram analisadas pela morfologia e IFT, utilizando um painel inicial de AcMo (CD3, CD4, CD8, CD19, anti-kappa; e anti-lambda;), ampliado conforme a necessidade (CD5, CD10, CD11c, CD23, CD79b, sIgM, FMC-7 e Bcl-2). Os resultados foram comparados com a histologia. RESULTADOS:Dos 25 casos, quatro foram classificados como reacionais e 21 como DLP-B, havendo concordância com resultados histológicos em todos os casos. A intensidade média de fluorescência (IMF) da Bcl-2 no LF (19,92) foi maior que em outras DLP-B (11,93) e que nos controles (3,49) (p = 0,032). CONCLUSÃO:A PAAF de LN combinada com a citomorfologia e a IFT por CF permite uma rápida diferenciação entre os processos reacionais e linfoproliferativos B. A elevada expressão da Bcl-2 nos LFs pela citometria mostra sua utilidade no diagnóstico do tipo mais freqüente das DLP-B. A obtenção de células por PAAF requer treinamento e recomendamos mais de uma punção.

BACKGROUND: The diagnosis of lymphoproliferative disorders (LPD) is routinely made through histological and immunohistochemical analysis of lymph nodes. Immunophenotyping by flow cytometry (FC) is a sensitive and fast tool, which may be applied in samples obtained through fine needle aspiration for the diagnosis of LPD. Bcl-2 is a proto-oncogene that appears in several LPD and it has a significantly high expression in follicular lymphomas. OBJECTIVES: to diagnose LPD in FNA samples through morphology and flow cytometry immunophenotyping. MATERIAL AND METHODS: Samples from 25 patients with lymphadenopathies and 2 reactive tonsils were studied through morphology and immunophenotyping. The antigens expressions were evaluated by using a screening panel of monoclonal antibodies (CD3, CD4, CD8, CD19, light chains kappa; and lambda), followed by CD5, CD10, CD11c, CD23, CD79b, sIgM, FMC-7 and Bcl-2 when required. The results were compared with histology. RESULTS:Four out of 25 samples were reactive processes and 21were B-LPD. In all cases there was consistency with histological results. The mean fluorescence intensity of Bcl-2 in Follicular Lymphoma (19.92) was higher compared with other lymphoproliferative diseases (11.93) and controls (3.49) (p = 0.032). CONCLUSION: Fine needle aspiration of lymph nodes associated with cytomorphology and flow cytometry immunophenotyping allows a fast differentiation between reactive processes and B lymphoproliferative cases. The high expression of Bcl-2 by cytometry shows its usefulness in the diagnosis of the most frequent type of B-LPD. Fine needle aspiration sampling requires training and more than one aspiration is recommended.