Summary Rituximab is a standard treatment for non‐Hodgkin diffuse large B‐cell (DLBCL) and follicular (FL) lymphomas. A subcutaneous formulation was developed to improve the resource use of intravenous rituximab, with comparable efficacy and safety profiles except for increased administration‐related reactions (ARRs). MabRella was a phase IIIb trial to assess the safety of switching from intravenous to subcutaneous administration of rituximab during first‐line induction/maintenance for DLBCL or FL, focusing on ARRs. Efficacy, satisfaction and quality of life were also assessed. Patients received subcutaneous rituximab plus standard induction chemotherapy for DLBCL or FL for 4–7 cycles, and/or every 2 months maintenance monotherapy for FL for 6–12 cycles. The study included 140 patients: DLBCL, n = 29; FL, n = 111. Ninety‐five percent of patients experienced adverse events, reaching grade ≥3 in 38·6% and were serious in 30·0%. AARs occurred in 48·6%, mostly (84·9%) at the injection site, with only 2·1% of patients reaching grade 3. The end‐of‐induction complete/unconfirmed complete response rate was 69·6%. After a median follow‐up of 33·5 months, median disease‐/event‐/progression‐free and overall survivals were not attained. The Rituximab Administration Satisfaction Questionnaire showed improvements in overall satisfaction and the EuroQoL‐5D a good quality‐of‐life perception at induction/maintenance end. Therefore, switching to subcutaneous rituximab showed no new safety issues and maintained efficacy with improved satisfaction and quality of life.

Although rituximab is generally well-tolerated, infusion-related reactions (IRRs) are common with the initial dose when administered intravenously according to standard recommendations. To prevent IRRs, premedication and low-speed infusion rates have been recommended. Consequently, intravenous (i.v.) infusion of rituximab can become a labor-intensive process. Rapid i.v. rituximab infusion over 90 min has demonstrated a favorable safety profile for the second and subsequent infusions during the course of therapy. The aim of this study was to investigate the safety and tolerability of 90-min rapid infusion of Sandoz rituximab biosimilar (SDZ-RTX) for patients with CD20+ lymphoma or chronic lymphocytic leukemia (CLL). We retrospectively reviewed all patients with CD20+ lymphoma or CLL who received SDZ-RTX infusions in 90 min from July 2019 to July 2021 at seven Spanish hospitals. The primary end point was the incidence of IRRs. We identified 124 patients and 576 rapid administrations of SDZ-RTX, with an average of five rapid infusions per patient. Most rapid infusions of SDZ-RTX were in combination with CHOP/CHOP-like therapy (48.4%), followed by