REALMA: Subset of patients with Marginal Zone Lymphomas from the French nationwide REALYSA real‐world prospective cohort.

Background: Marginal Zone Lymphomas (MZL) are a heterogeneous group of lymphomas that include three subtypes: extranodal MZL (EMZL), splenic MZL (SMZL) and nodal MZL (NMZL). Since most of the knowledge comes from clinical trials (with stringent inclusion criteria and limited representativeness), there is a crucial need for real-world evidence in MZL. In 2018 the French REALYSA (Real world dAta in LYmphoma in Adults) study was initiated as a nationwide multicentric prospective cohort of patients newly diagnosed with lymphoma. By Dec 31, 2021, a total of 207 patients with MZL were included in the study. Methods: Patients were recruited in 35 French hematology centers and received routine care. Data were collected from medical records and questionnaires. A first abstraction was performed on Jan 1, 2023, to parse out the available data regarding MZL patients with >1 year of follow-up. Each case was reviewed by medical and pathological experts, and treatments were classified on an intent-to-treat basis. Results: Of the 207 patients with MZL included up to Dec 31, 2021, 111 (53%) presented with EMZL, 47 (23%) with SMZL and 49 (24%) with NMZL. At baseline, median age was of 67 years old (IQR 60,75), 53% of patients were females, 5.5% of patients had a PS of 2–4, 70% were stage III-IV, 19% presented with B-symptoms, 20% had a bulky mass >7 cm and 5.8% had a compressive syndrome. Only 7% of patients reported an auto-immune disease. Diagnosis of MZL was mostly evoked by general practitioners (48%) but patients were finally treated by hematologists (98%). Only 9 patients were referred to an onco-geriatrician. Regarding the initial workup, while at least one imagery was offered in 97% of patients, 18FDG-PET/CT (EMZL 78%, SMZL 62%, NMZL 78%) was performed more frequently than CT-scan at baseline (EMZL 73%, SMZL 62%, NMZL 71%), although 47% patients underwent both procedures. Among the 207 patients, 58 (28%) were not treated. Only 10 patients exclusively received local therapy (radiotherapy n = 6, surgery n = 2, antibiotics n = 2). Regarding systemic therapies, rituximab-chlorambucil was mainly offered in patients with EMZL (40%), while rituximab-monotherapy was preferred in SMZL (60%). For patients with NMZL, physicians mainly offered RCHOP (33%) and rituximab-bendamustine (27%). Only 7 patients with EMZL received the combination of ibrutinib and rituximab. At end of 1st line, 93% of patients had responded to therapy and 75% were in complete response. Among patients assessed with 18FDG-PET/CT, a metabolic complete response was observed in 52/58 (90%) of cases. Conclusion: This is the first analysis describing real-world data of patients with MZL in France. Our cohort features high-quality data both on epidemiological and clinical outcomes. When the total number of patients will increase and data will mature, this dataset will provide insightful information regarding both endpoints and treatment evaluations. Keyword: Indolent non-Hodgkin lymphoma Conflicts of interests pertinent to the abstract. C. Bommier Research funding: Inserm/AvieSan/ITMO Cancer, LYSA/ELI (Bertrand Coiffier Prize), Philippe Foundation, Institut Servier