A Phase III Transition Study of DRL Rituximab to Reference Medicinal Products

This is a randomized, double-blind, parallel group, multicenter, Phase 3 transition study in subjects with active RA who are eligible for the subsequent treatment course with US-rituximab or EU-rituximab according to the clinical judgment of the investigator.

Subjects will then be randomized by interactive web response system (IWRS) to receive either two 1000 mg infusions of DRL\_RI (Arm A) or US-rituximab/EU-rituximab (Arm B) on Day 1 and Day 15.

Subjects randomized to Arm A will receive DRL\_RI and subjects randomized to Arm B will continue to receive either US-rituximab or EU-rituximab.

The study will consist of a screening period (Days -14 to 0) and a double-blind period (Day 1 to Week 12). Subjects will attend a screening visit followed by a visit at Weeks 0 (Day 1), 2, 4, 8, and 12 after randomization

It is planned that approximately 50 sites will be initiated for this study in up to 7 countries (including but not restricted to United States). There has been no randomization of patients till date for this study.

The study endpoints include:

The immunogenicity endpoint is:

• The incidence of anti-drug antibodies (ADA), including titer and neutralizing antibodies (NAb).

The primary safety endpoints are:

* Incidence of treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs). * Incidence of anaphylactic reactions, hypersensitivity reactions, and IRRs.