A Study Comparing Maintenance Subcutaneous Rituximab With Observation Only in Participants With Relapsed or Refractory Indolent Non-Hodgkin's Lymphoma Who Had Responded to Rituximab-based Immunochemotherapy Induction and 2-year Maintenance With Subcutaneous Rituximab

Progression free survival from randomization (PFSrand) is defined as the time from date of randomization to the date of first documented disease progression or death, whichever occurs first. One participant died in Induction before randomization and one participant died in Maintenance II Observation arm due to an SAE and were not considered in the analysis as no death page was completed. The Observation arm did not include one participant with AE outcome of death reported retrospectively 2 months after discontinuation from study (censored as having no event on Day 456 post-randomization).

An adverse event is any untoward medical occurrence in a subject administered a pharmaceutical product and which does not necessarily have to have a causal relationship with the treatment. An adverse event can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding, for example), symptom, or disease temporally associated with the use of a pharmaceutical product, whether or not considered related to the pharmaceutical product. Preexisting conditions which worsen during a study are also considered as adverse events. Not all AEs were followed up for the randomized Observation arm. Only Serious AEs and AE grade 3-5 (obtained retrospectively) were collected for this arm. Therefore arms are not comparable overall.

Event-Free Survival was measured from the day of first rituximab Induction dose through Maintenance I and Maintenance II rituximab arm until the date of any treatment failure, including disease progression, or discontinuation of treatment for any reason (e.g. disease progression, toxicity, patient preference, initiation of new anti-lymphoma treatment, or death). Treatment discontinuation was considered as an event and was not applicable to the randomized observation arm.

Time to next lymphoma treatment (TNLT) is defined as the time from date of first rituximab induction dose to the date date of first documented intake of any new antilymphoma treatment (chemotherapy, radiotherapy, immunotherapy, etc.).

Overall survival from first induction treatment (OSRegist) is defined as the time from date of first rituximab induction dose to the date of death, irrespective of cause. One participant died in Induction before randomization and one participant died in Maintenance II Observation arm due to an SAE and were not considered in the analysis as no death page was completed.

Overall survival from randomization (OSrand) is defined as the time from date of randomization to the date of death, irrespective of cause.

Overall response rate is defined as the proportion of responders at the end of the Induction period. A responder is defined as a participant experiencing either CR or PR tumor response according to the Cheson response criteria for indolent lymphoma or the recommendations for Waldenström's macroglobulinemia.

Progression free survival from first induction treatment (PFSregist) is defined as the time from date of first rituximab induction dose to the date of first documented disease progression or death by any cause, whichever occurs first.