In one of the first studies to examine real-world evidence on rituximab biosimilars in the United States, investigators found that many providers treating patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) are regularly prescribing a biosimilar rituximab.
Real-world data reveal generally good acceptance for prescribing biosimilar rituximab-pvvr (Ruxience; Pfizer) among providers treating patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL), according to a recent study.
The retrospective study, published in Future Oncology, is one of the first to investigate the acceptance of rituximab biosimilars in the United States in an oncology setting and the first study to examine real-world data for rituximab-pvvr.
“Although rituximab-pvvr was only recently introduced to market, our preliminary results suggest that this medication is being accepted in US oncology practice and is being used in a manner consistent with clinical guidelines in which the use of rituximab is recommended as part of a combination regimen with chemotherapy, targeted therapy, or immunotherapy,” wrote the investigators.
Oncology biosimilars have the potential to improve patient access to treatments and reduce biologics spending by $44 billion over a 10-year period. Reference rituximab (Rituxan; Genentech) was the first monoclonal antibody to receive FDA approval for B-cell NHL and is considered the standard of care for CLL.
“To realize these potential economic benefits, it is necessary to implement policies that encourage or incentivize biosimilar use at the government and payer levels for wider acceptance among health care providers and patients in the USA,” said the investigators.
As of August 2021, there are 3 rituximab biosimilars approved and marketed in the United States and 6 rituximab biosimilars have received marketing authorization in the European Union, including rituximab-pvvr, according to the Biosimilar Approvals directory from The American Journal of Managed Care®’s sister site, The Center for Biosimilars®. Biosimilars face several barriers to uptake in the United States, including lack of reimbursement and perception issues. In addition, although there have been some studies examining biosimilar acceptance, studies on rituximab biosimilars, especially in oncology, are limited.
Investigators collected US medical and prescription claims data from Komodo Health spanning from January 1, 2019, a year prior to rituximab-pvvr entering the market, and July 31, 2020. To be included in the analysis, patients had to be 18 years or older, live in the United States, and have a billable National Drug Code indicating use of rituximab-pvvr during the study period.
In total, 249 patients were treated with rituximab-pvvr during the study period, a majority of whom were 65 years or older (63.5%), male (54.6%), and lived in the South (54.2%). Among the providers who prescribed rituximab-pvvr, 54.2% and 22.9% specialized in hematology oncology and medical oncology, respectively. Additionally, 59.0% of providers practiced in the South. Providers prescribed rituximab-pvvr most commonly for patients with NHL (n = 193; 77.5%) and CLL (n = 28; 11.2%).
Prior to rituximab-pvvr treatment, 48.7% of the patients with NHL received chemotherapy, and 42.5% received either reference rituximab or another rituximab biosimilar.
After the index date for the biosimilar, 63.2% of patients with NHL were treated with rituximab-pvvr in combination with chemotherapy. The most common combination therapies used for patients with NHL were rituximab-pvvr/cyclophosphamide/doxorubicin/vincristine/prednisone (33.2%) and rituximab-pvvr/bendamustine (15.0%).
Before rituximab-pvvr initiation, 60.7% of patients with CLL received chemotherapy and 39.3% were receiving the reference product or another rituximab biosimilar. Half of the patients with CLL received combination therapy involving rituximab-pvvr.
Patients who resided in the South were more likely to receive rituximab-pvvr than the reference product (57.9% vs 34.1%; P < .001), whereas patients who lived in the Northeast were more likely to receive the reference product (18.4% vs 6.8%; P < .001).
The potential for missing, inaccurate, or inconsistent data entered into databases was listed as a limitation of the study. Other limitations included that the data only represented the insured US population and that data on treatment utilization patterns post initiation of therapy with rituximab-pvvr could not be evaluated.
The investigators said that future analyses are needed to examine the longitudinal trends in uptake and to assess the cost-effectiveness for rituximab-pvvr, preferably with longer follow-up periods.
“Head-to-head comparisons between rituximab biosimilar products, standardizing the indications of interest and methodology, would be required to ascertain whether any practically meaningful differences exist between these biosimilars in terms of their clinical outcomes and treatment patterns,” the investigators wrote.
Shelbaya A, Kelton JM, Thompson J, Alvir JMJ, Maculaitis MC, Yang J. Real-world use and acceptance of biosimilar monoclonal antibodies of rituximab in oncology practice in the USA. Future Oncol. Published online July 14, 2021. doi:10.2217/fon-2021-0618