Argentine-Approved Biosimilar Rituximab Has Similar Safety Profile to Its Reference

At the American Society of Hematology’s 59th Annual Meeting and Exposition in Atlanta, Georgia, researcher Gustavo Milone, MD, and his team will present a study that investigates the post-marketing trends of Novex, a biosimilar rituximab that has been approved in Argentina for the same indications as the reference product (MabThera, Rituxan).¹ Since Novex’s commercial launch, the first national pharmacovigilance plan for a biosimilar monoclonal antibody has been implemented, and data from this post-marketing surveillance show that, in terms of tolerability, this biosimilar has a similar safety profile to that of the reference product.

In order to determine deviations from expected frequencies of adverse events (AEs), a prospective treatment registry for the biosimilar was implemented from the start of its commercialization on November 26, 2014. Data in the study are reported until June 30, 2017. Physicians, 180 in total, tracked age, gender, indication, dose, dose frequency, and date of treatment initiation and finalization for each patient receiving the biosimilar.

The study comprised the records of 525 patients who had at least 1 follow-up. The majority of patients were female (52%), the mean age was 63.3 years (range, 10-90), and most patients received the biosimilar rituximab for hematological disease (91.2% of cases). The treatment duration ranged from 154 to 309 days, with the number of treatment cycles varying from 1 to 12. Individual Case Safety Reports (ICSRs) were collected from 24 patients with 29 AEs.

The most frequently reported AEs were:

• Acute infusion-related reaction (14)
• Arrhythmia (3)
• Pneumonia (2)
• Stroke (2)

The researchers noted that 41 treatments with rituximab were initiated before the launch of the product; assuming treatment began with MabThera, these 41 treatments imply switching to the biosimilar from the reference.

Researchers investigating data from the post-marketing surveillance found a similar incidence of AEs after the use of rituximab biosimilar when compared to the published data of the reference product. Thus, in terms of tolerability, the biosimilar has a similar safety profile compared with its reference.

Reference

1. Milone G, Penna M, Fernandez F, et al. Post-marketing surveillance with a biosimilar of rituximab (Novex) in Argentina. Presented at the American Society of Hematology 59th Annual Meeting and Exposition 2017, December 9, 2017; Atlanta, Georgia. Abstract 2131. https://ash.confex.com/ash/2017/webprogram/Paper102866.html