The Switch From Filgrastim to a Cheaper Alternative: Tbo-Filgrastim

With the emergence of cheaper alternatives to filgrastim, specifically tbo-filgrastim, some health systems are shifting to use these alternatives as their preferred granulocyte-colony stimulating factor (G-CSF), according to a study published in the Journal of Managed Care & Specialty Pharmacy.

Tbo-filgrastim was approved in the United States in 2012 with 1 similar indication to filgrastim. Because the FDA biosimilar approval pathway did not exist at the time, tbo-filgrastim was approved as a biologic. Coming with a cheaper price tag, the Pharmacy & Therapeutics Committee of a large health system deemed tbo-filgrastim the G-CSF of choice.

“These follow-on drugs are typically priced lower than the original filgrastim product and represent an opportunity for cost savings,” wrote the authors. “In the United States, the wholesale acquisition cost of tbo-filgrastim is approximately 20% less than filgrastim, offering significant cost savings.”

The authors of the study assessed the results of a large health system switching to using tbo-filgrastim by analyzing the conversion in 2 of its hospitals. The authors collected data on 204 patients who received filgrastim and/or tbo-filgrastim from July 2015 to December 2015, which included information on each patient for each episode of care, defined as the set of services provided by clinical providers to treat a clinical condition for which either of the 2 drugs was indicated.

Data from each episode of care included:

• G-CSF type
• Indication requiring use of G-CSF
• Setting of care
• Payer type

Patient demographics such as age, sex, and race were also collected.

Of the 204 patients, 28 received both filgrastim and tbo-filgrastim for different episodes of care, 59 used filgrastim, and 174 used tbo-filgrastim. Approximately 1 in 3 patients had more than 1 episode of care, resulting in 261 episodes of care; filgrastim was used 65 times and tbo-filgrastim was used 196 times.

The majority of indications for the use of G-CSF was for febrile neutropenia, support care after transplantation, stem cell mobilization, and severe chronic neutropenia. Tbo-filgrastim was the preferred G-CSF by clinical providers for all indications.

Data also showed that 62% of the total episodes of care were conducted in the inpatient setting, and the remaining 38% were conducted in the outpatient setting. Tbo-filgrastim accounted for 90% of G-CSF use in the inpatient setting, with support care after transplantation and treatment of febrile neutropenia being the main indications. Filgrastim and tbo-filgrastim were used equally for the outpatient setting, and stem cell mobilization and febrile neutropenia prophylaxis were the major indications.

The analysis by payers was only conducted for the outpatient setting. The authors found that the majority of the patients were on Medicare of commercial plans. For the 12 self-paying patients, only tbo-filgrastim was used, which the authors say echoes the importance of cost in the therapeutic choices made by patients. Filgrastim and tbo-filgrastim were each used for 50% of the 24 Medicare patients. For the 45 patients on commercial plans, 58% used filgrastim, and 42% used tbo-filgrastim.

“With the rising healthcare costs in the United States, the role of less expensive alternatives, such as biosimilars, becomes more important in the medical community,” concluded the authors.