New pharmacodynamic parameters linked with ibrutinib responses in chronic lymphocytic leukemia: Prospective study in real-world patients and mathematical modeling.

BACKGROUND: One of the first clinical observations of ibrutinib activity in the treatment of chronic lymphocytic leukemia (CLL) is a rapid decline in lymph nodes size. This phenomenon is accompanied by an hyperlymphocytosis, either transient or prolonged, which is associated with distinct clinical responses and thus has an impact on long-term outcomes. Understanding which factors determine distinct disease courses upon ibrutinib treatment remains a scientific challenge. METHODS AND FINDINGS: From 2016 to 2021, we conducted a longitudinal and observational study in 2 cohorts of patients with chronic lymphocytic leukemia (CLL) (cohort 1, n = 41; cohort 2, n = 81). These cohorts reflect the well-known clinical features of CLL patients, such as Male/Female sex ratio of 2/1, a median age of 70 years at diagnosis, and include patients in first-line therapy (27%) or relapsed/refractory patients (73%). Blood cell counts were followed for each patient during 2 years of ibrutinib treatment. In addition, immunophenotyping and whole-body magnetic resonance imaging (MRI) were assessed in patients from cohort 1. These data were integrated in a newly built mathematical model, inspired by previous mathematical works on CLL treatment and combining dynamical and statistical models, leading to the identification of biological mechanisms associated with the 2 types of clinical responses. This multidisciplinary approach allowed to identify baseline parameters that dictated lymphocytes kinetics upon ibrutinib treatment. Indeed, ibrutinib-induced lymphocytosis defined 2 CLL patient subgroups, transient hyperlymphocytosis (tHL) or prolonged hyperlymphocytosis (pHL), that can be discriminated, before the treatment, by absolute counts of CD4+ T lymphocytes (p = 0.026) and regulatory CD4 T cells (p = 0.007), programmed cell death protein 1 PD1 (p = 0.022) and CD69 (p = 0.03) expression on B leukemic cells, CD19/CD5high/CXCR4low level (p = 0.04), and lymph node cellularity. We also pinpointed that the group of patients identified by the transient hyperlymphocytosis has lower duration response and a poor clinical outcome. The mathematical approach led to the reproduction of patient-specific dynamics and the estimation of associated patient-specific biological parameters, and highlighted that the differences between the 2 groups were mainly due to the production of leukemic B cells in lymph node compartments, and to a lesser extent to T lymphocytes and leukemic B cell egress into bloodstream. Access to additional data, especially longitudinal MRI data, could strengthen the conclusions regarding leukemic B cell dynamics in lymph nodes and the relevance of 2 distinct groups of patients. CONCLUSIONS: Altogether, our multidisciplinary study provides a better understanding of ibrutinib response and highlights new pharmacodynamic parameters before and along ibrutinib treatment. Since our results highlight a reduced duration response and outcome in patients with transient hyperlymphocytosis, our approach provides support for managing ibrutinib therapy after 3 months of treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT02824159.

Relapsing Polychondritis Can Be Characterized by Three Different Clinical Phenotypes: Analysis of a Recent Series of 142 Patients.

OBJECTIVE: Relapsing polychondritis (RP) is a rare condition characterized by recurrent inflammation of cartilaginous tissue and systemic manifestations. Data on this disease remain scarce. This study was undertaken to describe patient characteristics and disease evolution, identify prognostic factors, and define different clinical phenotypes of RP. METHODS: We performed a retrospective study of 142 patients with RP who were seen between 2000 and 2012 in a single center. RESULTS: Of the 142 patients, 86 (61%) were women. The mean ± SD age at first symptoms was 43.5 ± 15 years. Patients had the following chondritis types: auricular (89%; n = 127), nasal (63%; n = 89), laryngeal (43%; n = 61), tracheobronchial (22%; n = 32), and/orcostochondritis (40%; n = 57). The main other manifestations were articular (69%; n = 98), ophthalmologic (56%; n = 80), audiovestibular (34%; n = 48), cardiac (27%; n = 38), and cutaneous (28%; n = 40). At a mean ± SD followup of 13 ± 9 years, the 5- and 10-year survival rates were 95 ± 2% and 91 ± 3%, respectively. Factors associated with death on multivariable analysis were male sex (P = 0.01), cardiac abnormalities (P = 0.03), and concomitant myelodysplastic syndrome (MDS) (P = 0.004) or another hematologic malignancy (P = 0.01). Cluster analysis revealed that separating patients into 3 groups was clinically relevant, thereby separating patients with associated MDS, those with tracheobronchial involvement, and those without the 2 features in terms of clinical characteristics, therapeutic management, and prognosis. CONCLUSION: This large series of patients with definite RP revealed an improvement in survival as compared with previous studies. Factors associated with death were male sex, cardiac involvement, and concomitant hematologic malignancy. We identified 3 distinct phenotypes.