Regulatory Decision Summary for Riabni

Riabni was developed as a biosimilar to the Canadian reference biologic drug, Rituxan (rituximab).

In support of the biosimilarity of Riabni and Rituxan, the sponsor submitted a nonclinical data package that included pharmacokinetic (PK), pharmacology, and toxicology program elements. In vitro primary biofunctional assays were also conducted as part of the analytical comparability package.

The clinical development program consisted of 2 pivotal studies:

• A pharmacokinetic (PK) study in patients with rheumatoid arthritis who were intolerant to, or had inadequate disease control on, at least 1 prior anti-TNF treatment. The 90% confidence intervals (CIs) of the PK parameters (AUC_T, and C_max [as point estimate]) were within the acceptance margins of 80.0% to 125.0%. The PK study was supported by additional PK-related data in the patient population. The pharmacokinetic study also provided supportive evidence for the similar efficacy and safety of Riabni and reference rituximab.

• The pivotal comparative clinical efficacy and safety study was conducted in patients with CD20-positive low tumor burden follicular lymphoma. The study met its primary objective as the upper and lower 95% confidence limits of the risk difference in overall response rate (ORR) were contained within the pre-defined noninferiority and nonsuperiority margins. The safety profile of Riabni was considered comparable to Rituxan.

A scientific rationale, provided to support the authorization of Riabni in the proposed indications held by the reference product Rituxan, was considered in accordance with Health Canadas biosimilar guidance document, and was considered satisfactory.

The final decision for this product was based on the totality of evidence, including structural, functional, non-clinical, pharmacokinetic/pharmacodynamic (PK/PD) and clinical comparisons.

A Notice of Compliance was issued in accordance with the Food and Drug Regulations.