Study findings presented at the virtual 2021 ASCO Annual Meeting suggest there may be economic benefit in replacing a proportion of flat-fixed rituximab/hyaluronidase human subcutaneous injection use with body surface area-based rituximab-abbs for patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) from a US payer perspective.

“The first rituximab biosimilar approved in the US, rituximab-abbs, is a CD20-directed monoclonal antibody that is expected to significantly reduce drug acquisition costs,” explained Stephen Thompson, Teva Pharmaceuticals Inc., Parsippany, NJ, and colleagues.

This study aimed to evaluate the budgetary impact of body surface area-based rituximab-abbs vs flat-fixed rituximab/hyaluronidase human subcutaneous injection from a US healthcare insured population for patients with NHL and CLL.

An illustrative budget impact model was constructed to estimate 1-year costs for body surface area-based rituximab-abbs and flat-fixed rituximab/hyaluronidase human subcutaneous injection. Values for epidemiology, market share distribution, drug dosing, administration, and costs were determined using scientific literature, product labels, and resources available to the public. The 2020 Average Sales Price pricing file and Centers for Medicare and Medicaid Services Physician Fee Schedule were used to determine drug acquisition and administration costs.

Body surface area-based rituximab-abbs doses used body surface areas of 1.6 m2, 1.8 m2. Infusions lasted 3 hours.

“Annual dose counts of rituximab-abbs or flat-fixed rituximab/hyaluronidase human subcutaneous injections were: 9 untreated FL with maintenance; 7 untreated FL (without maintenance), relapsed/refractory FL, or untreated DLBCL; 5 CLL,” reported Dr Thompson and colleagues.

The model revealed that 1-year savings with body surface area-based rituximab-abbs for 1.8 m2 body surface area dosing were between $1067 and $6893, while 1-year savings with body surface area-based rituximab-abbs for 1.6 m2 body surface area dosing were between $3819 and $10,856. Two-year savings with body surface area-based rituximab-abbs for FL maintenance dosing were 1.8 m2 and $14,475 for 1.6 m2.

Higher-than-average body surface area dosing resulted in savings of up to $1900.

“These findings demonstrate the potential economic benefits of replacing a proportion of flat-fixed rituximab/hyaluronidase human subcutaneous injection use with BSA [body surface area]-based rituximab-abbs from a US payer perspective, especially when lower BSA dosing is used,” concluded Dr Thompson, adding, “Savings are driven by drug costs and may increase with rituximab-abbs as patient BSA decreases due to static costs with flat-fixed rituximab/hyaluronidase human subcutaneous injection doses.”—Marta Rybczynski