Overall, biosimilar rituximab was used in more than 50% of patients, both as first-line therapy, second line or later.
The first biosimilar rituximab launched in the United States in the late fall of 2019. In Germany, rituximab biosimilars have been available since the European Medicines Agency approved the first ones in 2017. A recent article describes the experience of physicians in Germany using biosimilar rituximab during the first 24 months they were on the market, illustrating a fast-growing acceptance and increased use over time.
After launch, during those 24 months, the proportion of rituximab prescriptions that were for biosimilars increased from 12.0% to 83.0%, reported the researchers, who captured real-world data for both originator rituximab as well as biosimilars in extrapolated indications in non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). Rituximab biosimilars are increasingly being used for the treatment of patients with NHL and CLL.
Researchers collected electronic data from 71 physicians across 23 office-based, networked oncology practices in Germany between July 2017 to June 2019.
The information included demographics and prescription data for rituximab-based regimens in patients with NHL and CLL; the information was analyzed as part of the multicenter software-based epidemiological healthcare research project that launched in 2011. This system is less prone to error, as defined patient and treatment data from routine care are prospectively and automatically documented.
Patients were treated with reference rituximab (Rituxan); a rituximab biosimilar from either Sandoz or Celltrion; or nonspecified rituximab. All were intravenously administered. The analysis also included patients treated with the subcutaneous (SC) formulation of reference rituximab but made up less than 2% of the population.
Most patients (58.8%) were aged 60—80 years; 57.0% were male, and 43% were female. Of the 1741 patients, 1241 had NHL and 500 had CLL.
Overall, biosimilars were used in more than 50% of patients, both as first-line therapy, second line or later. Over the course of the 2 years, the proportion of biosimilar rituximab prescriptions increased 7-fold, primarily driven by an increase in prescriptions of Sandoz rituximab. Its rituximab product, Rixathon, was approved for European marketing in June 2017.
Of 7595 therapy cycles, 28.3% used reference rituximab; 55.2% used rituximab biosimilars; 2.0% used subcutaneous rituximab; 14.5% used unspecified rituximab.
Approximately 38 different rituximab-containing therapeutic protocols were used 1540 times, compared with 15 protocols for obinutuzumab and ofatumumab, which were used 179 times.
Rituximab biosimilars were used across all indications; 57.3% of cycles were administered in extrapolated indications, indicating a high acceptance of biosimilars.
The authors could not explain why there was more use of Rixathon over the Celltrion product, Truxima. Overall, biosimilars provide significant cost savings over reference products. The authors noted that a previous study showed that the top 3 reasons for prescribing biosimilar rituximab in patients with NHL were approved standard of care, proven efficacy, and were on the formulary or hospital policy.
Otremba B, Borchardt J, Kuske A, Hollnagel-Schmitz M, Losch FO. Real-world use and acceptance of rituximab biosimilars in non-Hodgkin lymphoma in an oncologist network in Germany [published online April, 14, 2020]. Future Oncol. doi: 10.2217/fon-2020-0180.