The following is a summary of the major changes implemented with Protocol Amendment 1, Version 2.0, dated 12 Aug 2019: • Updated exclusion criterion 2 for clarity. • Added exclusion criterion 18: Subjects with hypogammaglobulinemia (low IgG) are immunocompromised and more susceptible for both infections and side effects; hence, such subjects should be excluded. • Guidance in Section 5.4.1 Packaging was reworded for better clarity. Sentence modified to: “Rituximab concentrate for solution for infusion will be packaged in a carton or kit.” • Added the following text in Section 6.1 of Schedule of Assessments to clarify data capture at unscheduled visits: “If any unscheduled visits happen at any time during the study, visit details/appropriate data including reason will be captured in the eCRF.” • Added assessment of IgG (Section 6.1.1) to align with addition of new exclusion criterion 18 to exclude the subjects with low IgG. • Added clarification for estimation of rituximab concentration in Section 3.1.2 and Section 6.2.1: time-matched blood samples for estimation of rituximab concentration were added to aid in subsequent data interpretation as and if needed. Relevant procedures (i.e., time-matched blood sample collection and blood loss for estimation of rituximab concentration) were added in Section 6.1.2, Section 6.1.3, Section 6.1.4, Section 6.5, and Appendix 1.

Summary of the major changes implemented with Protocol Amendment 2, Version 3.0 dated 10 Jul 2020: • Study was extended to 6 months and included an additional follow-up visit at Week 26 with safety and serum pregnancy test in WOCBP. • Reconsent was mandated for additional follow-up. • A new Section 3.2 was included for contingency measures to be taken for smooth functioning of the study during the COVID-19 pandemic. • Exclusion criterion 6 was revised to update the requirement of historical “severe” hypersensitivity to reference product or any of its excipients. • Exclusion criterion 16 was updated to include definition of WOCBP and birth control measures • Exclusion criterion 17 was updated to clarify that sexually active male subjects, who do not agree to use one of the highly effective methods of birth control during treatment and for at least 12 months after the last administration of study drug, will be excluded from the study. • Section 4.2.2 was revised to emphasize that subjects could take their own independent decision to withdraw from study drug and/or study participation at any time. • Section 6.1 and Appendix 1 were updated to include information that complete physical examination was to be performed at all study visits. • Information regarding immunological testing in humans was included in Section 6.2.2 • Detailed definitions of IRRs and hypersensitivity reactions were added in Section 6.3 • Section 6.3.1.2 was updated to clarify that all ongoing SAEs were to be followed up until resolution or stabilization or until a predefined outcome was reached. • Text was clarified regarding the assessment of adverse events outcome in Section 6.3.1.4 • ANC count was added to Section 6.3.4 • Clarified requirement of serum FSH testing (Section 6.3.4). • A note of clarification was added for HBcAb evaluation in across protocol • Clarified that the study sites were advised to follow local or country-specific guidelines while obtaining consent.