LAUSR

Clinical data on primary central nervous system (CNS) lymphoma (PCNSL) patients is mostly generated from prospective studies, and many frail real‐world patients are not included. Recently,the diagnosis and treatment of PCNSL patients was confounded by the COVID‐19 pandemic. In particular, treatment with high‐dose cytarabine was linked to increased risk of pneumonia and virus persistence. We report on outcome of the induction regimen R‐MIV (rituximab, methotrexate, ifosfamide, and vincristine) involving intensive administration of high‐dose methotrexate (3.5 g/m2) with ifosfamide, every 2 weeks and rituximab once per week for six doses. The median age and performance status (PS) for 64 patients was 58 years and 2 (PS 3; 22%) respectively. The overall response rate by magnetic resonance imaging/computed tomography (MRI/CT) was 73% (n = 46/63), with an additional 17.5% (n = 11/63) patients without measurable disease at baseline. Grade 3–4 haematological toxicity was low for R‐MIV (neutropenia: 25% and thrombocytopenia: 1%). Three patients (4.7%) died from treatment‐related toxicity. Co‐existence of SARS‐CoV‐2 infection with cytomegalovirus reactivation and the varicella‐zoster virus in two patients was fatal. Fifty patients (78%) were eligible for consolidation. Median progression‐free and overall survival were not reached (median follow‐up: 44 months). In conclusion, the R‐MIV regimen is feasible in routine practice, effective and safe, even during the COVID‐19 pandemic.