Involvement of the JAK-STAT pathway in the molecular landscape of tyrosine kinase fusion-negative hypereosinophilic syndromes: A nationwide CEREO study.

We investigated using a custom NGS panel of 149 genes the mutational landscape of 64 consecutive adult patients with tyrosine kinase fusion-negative hypereosinophilia (HE)/hypereosinophilic syndrome (HES) harboring features suggestive of myeloid neoplasm. At least one mutation was reported in 50/64 (78%) patients (compared to 8/44 (18%) patients with idiopathic HE/HES/HEUS used as controls; p < .001). Thirty-five patients (54%) had at least one mutation involving the JAK-STAT pathway, including STAT5B (n = 18, among which the hotspot N642H, n = 13), JAK1 (indels in exon 13, n = 5; V658F/L, n = 2), and JAK2 (V617F, n = 6; indels in exon 13, n = 2). Other previously undescribed somatic mutations were also found in JAK2, JAK1, STAT5B, and STAT5A, including three patients who shared the same STAT5A V707fs mutation and features consistent with primary polycythemia. Nearly all JAK-STAT mutations were preceded by (or associated with) myelodysplasia-related gene mutations, especially in RNA-splicing genes or chromatin modifiers. In multivariate analysis, neurologic involvement (hazard ratio [HR] 4.95 [1.87-13.13]; p = .001), anemia (HR 5.50 [2.24-13.49]; p < .001), and the presence of a high-risk mutation (as per the molecular international prognosis scoring system: HR 6.87 [2.39-19.72]; p < .001) were independently associated with impaired overall survival. While corticosteroids were ineffective in all treated JAK-STAT-mutated patients, ruxolitinib showed positive hematological responses including in STAT5A-mutated patients. These findings emphasize the usefulness of NGS for the workup of tyrosine kinase fusion-negative HE/HES patients and support the use of JAK inhibitors in this setting. Updated classifications could consider patients with JAK-STAT mutations and eosinophilia as a new "gene mutated-entity" that could be differentiated from CEL, NOS, and idiopathic HES.

CALR-mutated patients with low allele burden represent a specific subtype of essential thrombocythemia: A study on behalf of FIM and GBMHM.

A low allele burden (i.e., <20%) of the CALR driver mutation is found in 10.8% of CALR-mutated MPNs, mostly in essential thrombocythemia, and correlates with a milder phenotype and a more indolent evolution compared to patients with an allele burden ≥20%.

Comparative clinical and molecular landscape of primary and secondary myelofibrosis: Superior performance of MIPSS70+ v2.0 over MYSEC-PM.

Comparative clinical characteristics, molecular landscape and prognosis scoring for primary (PMF) and secondary myelofibrosis (SMF).

Distinct clinico-molecular arterial and venous thrombosis scores for myeloproliferative neoplasms risk stratification.

Current recommended risk scores to predict thrombotic events associated with myeloproliferative neoplasms (MPN) do not discriminate between arterial and venous thrombosis despite their different physiopathology. To define novel stratification systems, we delineated a comprehensive landscape of MPN associated thrombosis across a large long-term follow-up MPN cohort. Prior arterial thrombosis, age >60 years, cardiovascular risk factors and presence of TET2 or DNMT3A mutations were independently associated with arterial thrombosis in multivariable analysis. ARTS, an ARterial Thrombosis Score, based on these four factors, defined low- (0.37% patients-year) and high-risk (1.19% patients-year) patients. ARTS performance was superior to the two-tiered conventional risk stratification in our training cohort, across all MPN subtypes, as well as in two external validation cohorts. Prior venous thrombosis and presence of a JAK2V617F mutation with a variant allelic frequency ≥50% were independently associated with venous thrombosis. The discrimination potential of VETS, a VEnous Thrombosis Score based on these two factors, was poor, similar to the two-tiered conventional risk stratification. Our study pinpoints arterial and venous thrombosis clinico-molecular differences and proposes an arterial risk score for more accurate patients' stratification. Further improvement of venous risk scores, accounting for additional factors and considering venous thrombosis as a heterogeneous entity is warranted.

[An example of Clinical Investigations Center reorganization during the COVID-19 pandemic French national lockdown]. / Un exemple de réorganisation dans le fonctionnement d'un Centre d'investigations cliniques en période de confinement national suite à la pandémie COVID-19.

BACKGROUND: The Clinical Investigations Center of Saint-Louis Hospital (CIC-1427) is a structure dedicated to clinical trials and mainly early phase trials (first-in-man administration, phase 1 and 2). These trials are conducted in a French Regional Health Agency (ARS) authorized structure. In March 2020, faced to the global COVID-19 pandemic and the French national lockdown measures, the CIC-1427 had to rapidly adapt its operating procedures to ensure the safety of both patients and staff. STUDY OBJECTIVE: Ensuring optimal management of patients included in early phase clinical trials, while respecting the good clinical and professional practices (GCP/GPP) of the CICs protocol sponsors' requirements, patients' safety and clinical research multidisciplinary staff safety (nurses, caregivers' assistants (AS), clinical research assistants (CRA), clinical trial coordinators (CTC), project leaders, health executive and investigating physicians), in the context of the health crisis related to COVID-19. METHODS AND RESULTS: Due to their activity, requiring on-site presence, each staff member of the CIC-1427 clinical research team had to adapt their daily activity to the constraints of the health crisis. New specific procedures were quickly developed to deal with the pandemic. Most of the on-site medical visits were replaced by virtual consults with biological assessments in the local laboratories. "Remote monitoring" replaced on-site monitoring visits. Treatments were sent to each patient's home via couriers after agreement of the CPPs of each protocol (Committee for the Protection of Persons). The essential visits were maintained on site thanks to the unfailing involvement of our clinical care team, with implementation of a specific sanitary protocol. CONCLUSION: The involvement of our entire multidisciplinary research team ensured that each patient was able to benefit from a personalized follow-up and to continue the treatment on-trial. The newly introduced procedures also allowed collection of a maximum of safety and efficacy data for clinical trial sponsors while complying with good regulatory practices. This set of procedures developed during the first epidemic wave, fundamentally helped setting the frame for a better coping during the subsequent pandemic waves.