US Rheumatologists Reluctant to Switch to Biosimilars for Patients Doing Well on a Reference Product

While US rheumatologists understand and accept biosimilars, they are hesitant to switch patients doing well on a reference to a biosimilar, according to the results of a new survey published in Rheumatology.

A 19-question online survey was conducted from May 6, 2019, to June 1, 2019, with the purpose of evaluating the perceptions of biosimilars among US rheumatologists who prescribe tumor necrosis factor α (TNFα) inhibitors. There are 11 TNF inhibitor biosimilars and 2 rituximab biosimilars approved by the FDA:

• Infliximab (Remicade) biosimilars: Avsola (Amgen), Inflecta (Pfizer), Ixifi (Pfizer), Renflexis (Merck)
• Adalimumab (Humira) biosimilars: Abrilada (Pfizer), Amjevita (Amgen), Cyltezo (Boehringer Ingelheim), Hadlima (Samsung Bioepis), Hyrimoz (Sandoz)
• Etanercept (Ebrel) biosimilars: Erelzi (Sandoz), Eticovo (Samsung Bioepis)
• Rituximab (Rituxan) biosimilars: Ruxience (Pfizer), Truxima (Teva/Celltrion)

Although TNFα inhibitors are the “cornerstones” of treating rheumatoid arthritis (RA) and other immune-mediated diseases, these biologics are expensive. Biosimilars have arisen as an option to provide lower-cost options.

“It is important to understand physicians’ awareness and attitudes toward biosimilars, as it is anticipated that they will require education about the biosimilars of these agents before they are comfortable offering them to their patients,” the authors explained.

The study results included responses from 320 rheumatologists. Overall, 83% said they were very/extremely familiar with the FDA definition of a biosimilar; however, their familiarity with the types of biosimilars approved varied. Nearly all respondents (96%) were aware that the FDA had approved an infliximab biosimilar, but awareness was lower that etanercept (62%), adalimumab (56%), and rituximab (39%) biosimilars were approved by the FDA.

When considering whether to prescribe a biosimilar vs the reference product, the respondents ranked effectiveness of the biosimilar as most important followed by the safety profile of the biosimilar.

“The goal of biosimilar development is to provide cost savings for the patient by offering an alternative to more expensive treatment options; however, this was deemed important only by slightly more than a quarter of rheumatologists surveyed,” the authors noted.

More than half (54%) of the respondents were familiar with the term “nonmedical switching,” and among those who were familiar with it, 50% said it had been suggested for patients they treated. Pharmacy benefit insurance/formulary coverage was by far the biggest reason for nonmedical switching (80%), followed by hospital system formulary (67%) and requirement for step therapy (63%).

Rheumatologists showed a reluctancy for nonmedical switching. Among rheumatologists whose patient with RA was doing well on the reference product, only 35% were very likely or likely to switch to a biosimilar. An even smaller proportion (21%) said they were very likely or likely to switch to a biosimilar for patients with a condition other than the one on which the biosimilar approval was based if the patient was doing well on the reference.

In both instances, the respondents indicated they were far more willing to initiate treatment on a biosimilar for patients who were biologic-naïve: 73% very likely/likely in RA and 40% very likely/likely in another condition.

“These findings suggest that US rheumatologists are more comfortable initiating treatment with biosimilars for patients who are biologic treatment-naïve, rather than switching treatment for patients who are doing well on the reference product,” the authors wrote.

Reference

Gibofsky A, McCabe D. US rheumatologists' beliefs and knowledge about biosimilars: a survey. Rheumatology (Oxford). Published online November 4, 2020. doi:10.1093/rheumatology/keaa502