A Snapshot of the Management of Chronic Lymphocytic Leukemia in Italy. Preliminary Analysis on over 3000 Patients Enrolled in the Gimema CLL2121 Trial

In recent years the management of patients (pts) with chronic lymphocytic leukemia (CLL) has benefited from a deeper knowledge of the mechanisms underlying the disease and from the development of novel therapeutic approaches. That notwithstanding, local and national accessibility to drugs and tests may lead to distinct “real-world” practices in terms of management of pts that are worth of being recorded and compared to understand the degree of reproducibility and applicability of international guidelines. This could also be relevant for the design of future clinical trials, more tailored to the true patient's needs. To this end, within the GIMEMA cooperative study group the observational retrospective and prospective CLL2121 study (NCT04867915) has been designed with the objective of evaluating the diagnosis and management of CLL in all hematological centers in Italy through the assessment of: 1) the methods and the actual diagnostic/prognostic work-up capacity; 2) the algorithms applied to define disease progression and treatment requirements with respect to national and international guidelines; 3) the clinical and biological variables not strictly associated with CLL, but capable of influencing the clinical course and overall survival; 4) the true incidence of some rarer complications associated with CLL. The study consists of a collection of clinico-biological data from all pts with newly diagnosed CLL, small lymphocytic lymphoma (SLL) or CLL-like monoclonal B-cell lymphocytosis (MBL), according to the iwCLL 2018 criteria in Italy. The retrospective part aims at including all cases followed at the participating centers with a diagnosis between January 2010 and September 2021, while the prospective part will include all pts with a documented diagnosis of CLL, SLL or MBL between September 2021 and September 2025. In this pilot analysis of the study, we examined pts' demographics, diagnosis, treatment line and type. Data were collected using the REDCap electronic data capture platform, analyzed using the SAS software v.9.4 and reported as numbers and frequencies. Between 2 November 2021 and 28 June 2023, 3294 eligible pts were enrolled in 75 hematology centers (out of the total of 110 centers who will be activated during the study) across the entire Italian territory. At the time of the present report, 3033 pts had clinical data available for our preliminary analysis. The vast majority of pts registered (N=2599, 85.7%) belonged to the retrospective cohort while only a minority (N=434, 14.3%) to the prospective cohort. Pts had a median age of 68 years ranging from 29 to 97; 60% of pts were males. 2630 pts (86.8%) had a diagnosis of CLL, 187 (6.2%) of SLL and 214 (7.0%) of MBL (2 missing information). Among those with available results 112 pts (12.6%) were TP53mutated, 526 (45.6%) del(13q) positive, 174 (14.9%) del(11q) positive, 142 (11.9%) del(17p) positive and 226 (20.4%) presented a trisomy 12. The majority of pts (57.6%) were untreated, while 42.4% have been treated. Within the latter subset, 67.3% of pts have received one line of therapy, 21.4% 2 lines of therapy, 11.3% ≥3 lines of therapy. The most common therapeutic regimens were the combination of chemotherapy with an anti-CD20 antibody (39.3%), mainly rituximab, and those based on BTK inhibitors (33.3%), mainly ibrutinib. Chemotherapy alone was used in 12% of pts. Only 5% of pts was treated with the BCL2 inhibitor venetoclax. In the remaining 10% of pts, other approaches were used. This is the initial report of a nation-based real-world data collection aimed at describing the biological and clinical features of pts diagnosed with CLL in virtually all Italian hematology centers starting from 2010. The pattern of treatments highlighted in our preliminary analysis, with a wide use of the watch & wait policy and of chemoimmunotherapy, will help understand how the introduction of novel therapies impacted treatment habits also in light of the timing of the local reimbursement policy. The different time of drug access in Italy, typically delayed after the EU approval, may also have affected the limited use of venetoclax-based treatment. The continuous accrual of pts in this study will allow to obtain a close-to-registry vision of CLL management in Italy over time, in terms of coverage of the entire country but enriched with the granularity of the data and flexibility of the collection typical of a real-world study.