Do age, fitness, and concomitant medications influence management and outcomes of patients with CLL treated with ibrutinib?

Functional reserve of organs and systems is known to be relevant in predicting immunochemotherapy tolerance. Age and comorbidities, assessed by the cumulative illness rating scale (CIRS), have been used to address chemotherapy intensity. In the ibrutinib era, it is still unclear whether age, CIRS, and Eastern Cooperative Oncology Group performance status (ECOG-PS) retain their predictive role on treatment vulnerability. In this series of 712 patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib outside clinical trials, baseline ECOG-PS and neutropenia resulted as the most accurate predictors of treatment feasibility and outcomes. Age did not independently influence survival and ibrutinib tolerance, indicating that not age per se, but age-related conditions, may affect drug management. We confirmed the role of CIRS > 6 as a predictor of a poorer progression- and event-free survival (PFS, EFS). The presence of a severe comorbidity was significantly associated with permanent dose reductions (PDRs), not translating into worse outcomes. As expected, del(17p) and/or TP53mut and previous therapies affected PFS, EFS, and overall survival. No study so far has analyzed the influence of concomitant medications and CYP3A inhibitors with ibrutinib. In our series, these factors had no impact, although CYP3A4 inhibitors use correlated with Cox regression analysis, with an increased risk of PDR. Despite the limitation of its retrospective nature, this large study confirmed the role of ECOG-PS as the most accurate predictor of ibrutinib feasibility and outcomes, and importantly, neutropenia emerged as a relevant tool influencing patients' vulnerability. Although CIRS > 6 retained a significant impact on PFS and EFS, its value should be confirmed by prospective studies.

TP53 Mutations with Low Variant Allele Frequency Predict Short Survival in Chronic Lymphocytic Leukemia.

PURPOSE: In chronic lymphocytic leukemia (CLL), TP53 mutations are associated with reduced survival and resistance to standard chemoimmunotherapy (CIT). Nevertheless, the clinical impact of subclonal TP53 mutations below 10% to 15% variant allele frequency (VAF) remains unclear. EXPERIMENTAL DESIGN: Using a training/validation approach, we retrospectively analyzed the clinical and biological features of TP53 mutations above (high-VAF) or below (low-VAF) the previously reported 10.0% VAF threshold, as determined by deep next-generation sequencing. Clinical impact of low-VAF TP53 mutations was also confirmed in a cohort (n = 251) of CLL treated with fludarabine-cyclophosphamide-rituximab (FCR) or FCR-like regimens from two UK trials. RESULTS: In the training cohort, 97 of 684 patients bore 152 TP53 mutations, while in the validation cohort, 71 of 536 patients had 109 TP53 mutations. In both cohorts, patients with the TP53 mutation experienced significantly shorter overall survival (OS) than TP53 wild-type patients, regardless of the TP53 mutation VAF. By combining TP53 mutation and 17p13.1 deletion (del17p) data in the total cohort (n = 1,220), 113 cases were TP53 mutated only (73/113 with low-VAF mutations), 55 del17p/TP53 mutated (3/55 with low-VAF mutations), 20 del17p only, and 1,032 (84.6%) TP53 wild-type. A model including low-VAF cases outperformed the canonical model, which considered only high-VAF cases (c-indices 0.643 vs. 0.603, P < 0.0001), and improved the prognostic risk stratification of CLL International Prognostic Index. Clinical results were confirmed in CIT-treated cases (n = 552) from the retrospective cohort, and the UK trials cohort. CONCLUSIONS: TP53 mutations affected OS regardless of VAF. This finding can be used to update the definition of TP53 mutated CLL for clinical purposes.

Impaired nodal shrinkage and apoptosis define the independent adverse outcome of NOTCH1 mutated patients under ibrutinib therapy in chronic lymphocytic leukaemia.

The introduction of agents inhibiting the BCR-associated kinases such as ibrutinib has dramatically changed treatments algorithms of chronic lymphocytic leukaemia (CLL) as well as the role of different adverse prognosticators. We evaluated the efficacy of ibrutinib as single agent, in a real-life context, on 180 patients with CLL mostly pre-treated, recruited from three independent cohorts from Italy. Patients received 420 mg oral ibrutinib once daily until progression or occurrence of unacceptable side effects. Seventy-three patients discontinued ibrutinib for progression or for adverse events. NOTCH1 mutations (M) were correlated with a reduced redistribution lymphocytosis, calculated at 3 months on ibrutinib (p=0.022). Moreover, NOTCH1 mutated patients showed inferior nodal response at 6 months on ibrutinib compared to NOTCH1 wild type patients (p<0.0001). Significant shorter progression free survival (PFS) and overall survival (OS) were observed in NOTCH1 mutated patients (p=0.00002 and p=0.001). Interestingly, NOTCH1 M plus lower bax/bcl-2 ratio identified a CLL subset showing the worst PFS and OS (p=0.0002 and p=0.005). In multivariate analysis of PFS and OS, NOTCH1 M were confirmed an independent prognosticator (p=0.00006 and p=0.0039). In conclusion, NOTCH1 M are strongly associated with lower bax/bcl-2 ratio, consistent with a defective apoptosis, lower redistribution lymphocytosis and lower nodal shrinkage under ibrutinib treatment, this last responsible for partial responses, subsequent relapses, shorter PFS and OS. The therapeutic options for NOTCH1 mutated patients could be represented by either new small molecules combination approaches or from antibodies targeting NOTCH1.

Comparison of ibrutinib and idelalisib plus rituximab in real-life relapsed/resistant chronic lymphocytic leukemia cases.

OBJECTIVES: To compare the capacity of ibrutinib (IB) and idelalisib-rituximab (IDELA-R) of prolonging overall survival (OS) as in CLL patients, previously treated with chemotherapy only. METHODS: A real-life cohort of 675 cases has been identified and investigated in the database of the groups participating in the study. RESULTS: At an unadjusted univariate analysis, a significant death risk reduction was observed favoring IB (IDELA-R vs IB HR = 0.5, 95% CI = 0.36-0.71) although with some limitations due to the non-randomized and retrospective nature of the study and to the lower number of patients in the IDELA-R group (112 cases) related to the current prescribing practice. To overcome the potential problem of confounding by indication, we adjusted the association between the type of therapy and mortality for all variables significantly associated with OS at Cox univariate analysis. Furthermore, those variables, differently distributed between the two study groups, were introduced into the multivariate Cox model to improve the effectiveness of the analysis. By introducing all these variables into the multiple Cox regression model, we confirmed the protective effect of IB vs IDELA-R (HR = 0.67, 95% CI = 0.45-0.98, P = .04) independent of potential confounders. CONCLUSIONS: Although our analysis presents some constraints, that is, the unavailability of additional potential confounders, and the retrospective nature of the study, this observation may be of help for the daily clinical practice, particularly in the absence of randomized trials comparing the two schedules.

Minimal residual disease as a biomarker for outcome prediction and therapy optimization in acute myeloid leukemia.

INTRODUCTION: Response to therapy is affected by the genetic heterogeneity of acute myeloid leukemia (AML) and persistence of leukemic cells below the threshold of morphological complete remission (mCR). Such persistence is called minimal (or measurable) residual disease (MRD). Areas covered: MRD assessment allows early identification of patients who are at high risk of relapse and who should timely receive aggressive therapy (e.g. allogeneic stem cell transplantation) and of those with a good quality mCR in whom an aggressive front-line therapy can be spared, avoiding the harm of excessive treatment toxicity. The most exploited methods to assess MRD are multiparameter flow cytometry (via identification of immunophenotypic aberrancies) or PCR-based assays (via identification of cytogenetic/molecular abnormalities). Expert commentary: A growing body of evidences demonstrates that positive MRD-testing at various time-points throughout the treatment course identifies patients at high risk of relapse. We will focus on the role of MRD as a biomarker to refine risk assessment and to prospectively direct treatment choices in adult with AML.

CD69 is independently prognostic in chronic lymphocytic leukemia: a comprehensive clinical and biological profiling study.

BACKGROUND: CD69 is expressed in several hemopoietic cells and is an early activation marker in chronic lymphocytic leukemia. Chronic lymphocytic leukemia is a clinically heterogeneous disease which needs novel prognostic parameters which can be easily and efficiently managed. DESIGN AND METHODS: We investigated CD69 by flow cytometry in a series of 417 patients affected by chronic lymphocytic leukemia and compared this to other biological and clinical prognosticators. RESULTS: CD69 was associated with Rai stages (P=0.00002), ß(2)-microglobulin (P=0.0005) and soluble CD23 (P<0.0001). CD69 and ZAP-70 (P=0.018) or CD38 (P=0.00015) or immunoglobulin variable heavy chain gene mutations (P=0.0005) were also significantly correlated. Clinically, CD69 positive chronic lymphocytic leukemias received chemotherapy more frequently (74%; P<0.0001), and presented a shorter duration of response after fludarabine plus rituximab (P=0.010) as well as shorter progression free survival and overall survival (P<0.0001). CD69 demonstrated true additive prognostic properties, since the CD69(+) plus ZAP-70(+) or CD38(+) or immunoglobulin variable heavy chain gene unmutated patients had the worst progression free survival and overall survival (P<0.0001). Interestingly, low CD69 expression was necessary to correctly prognosticate the longer progression free survival of patients with a low tumor burden of ß(2)-microglobulin (P=0.002), of soluble CD23 (P=0.020), or of Rai stages 0-I (P=0.005). CD69 was confirmed to be an independent prognostic factor in multivariate analysis of progression free survival (P=0.017) and overall survival (P=0.039). CONCLUSIONS: Our data indicate that CD69 is significantly correlated with poor clinical and biological prognostic factors and is confirmed to be an independent disease prognosticator. This supports its introduction in a routine laboratory assessment and, possibly, in a prognostic scoring system for chronic lymphocytic leukemia, after an adequate standardization process.