SHEFFIELD, UK—A model comparing costs and effectiveness of the biologics currently covered for treating rheumatoid arthritis (RA) in US Medicare beneficiaries has shown that etanercept (ETN) (Enbrel^®, Amgen/Wyeth Pharmaceuticals) and adalimumab (ADA) (Humira^®, Abbott Laboratories) are both more cost-effective than infliximab (INF) (Remicade^®, Centocor, Inc); anakinra (ANA) (Kineret^®, Amgen Inc) is less costly but also less effective. The study by Allan J. Wailoo, PhD, et al is reported in Arthritis & Rheumatism.¹

“ETN, ADA, and INF were similar in terms of effectiveness, but INF was more costly. If decision makers are willing to pay a maximum of $50,000/QALYs [quality-adjusted life years], the probability that INF is cost-effective is <1%,” said Dr. Wailoo, who is at the University of Sheffield in the UK.

The study, which was funded by the US Department of Health and Human Services’ Agency for Healthcare Research and Quality, used data from a meta-analysis of randomized controlled trials and from a large longitudinal outcomes databank to develop a cost-effectiveness model for the 4 biologic agents currently covered by the Medicare prescription drug program.

“Biologic drugs are relatively expensive,” Dr. Wailoo said. “A recent study in the US demonstrated that the introduction of this new class of therapies has increased 3-fold the total annual direct cost of treating a patient with RA.”

The model estimated the incremental cost-effectiveness ratio of ETN, ADA, and ANA compared with INF. It included mean lifetime costs, quality-adjusted life expectancy, and duration of biologic treatment per Medicare beneficiary. The analysis did not include the newer biologics abatacept (Orencia^®, Bristol-Myers Squibb Co) and rituximab (Rituxan^®, Genentech/Biogen Idec). The analysis also did not include comparison to conventional DMARDs.

Translating research into practice

“The model predicts that INF generates costs that are ~$13,000 higher than those for ETN or ADA, while ANA is substantially less expensive than the TNFα inhibitors, mainly because of the shorter duration of treatment. ANA also generates ~0.2 QALYs less than the 3 TNFα inhibitors, which are approximately equal. In none of the model simulations does ANA generate more QALYs than any of the TNFα inhibitors. ETN and ADA may be said to dominate INF, that is, they are approximately equal in terms of effectiveness but are less costly strategies,” Dr. Wailoo concluded [Table].

ETN generated an additional cost of $92,058 per QALY gained compared with ADA. According to the researchers, the use of ETN or ADA as first-line biologic is likely to be cost-effective compared with INF, and this finding was “robust to all sensitivity analyses.” The only exception was if the dose of INF was assumed not to increase at all over time. “However,” the authors wrote, “the INF dose has been shown to increase over time, and in the absence of such an increase it is likely that patients would be withdrawn from treatment much earlier.”

Cost-Effectiveness of Biologic Drugs for Medicare Patients with RA

	Infliximab	Etanercept	Adalimumab
Mean lifetime cost	$94,029	$81,181	$79,535
Mean QALY gained*	7.64	7.66	7.64
ICER vs infliximab**	__	Dominates	Dominates

*QALY = quality-adjusted life year
**ICER=incremental cost-effectiveness ratio

Adapted from Arthritis Rheum. 2008;58:939-946.¹

Reference

1. Wailoo AJ, Bansback N, Brennan A, et al. Biologic drugs for rheumatoid arthritis in the Medicare program. A cost-effectiveness analysis. Arthritis Rheum. 2008;58:939-946.