Heart: Dabi cost-effective in U.K. analysis

Dabigatran, like other novel drugs, has upped the ante for the anticoagulant market due its ability to prevent stroke in atrial fibrillation (AF) patients without the need for continuous monitoring, like warfarin. However, while dabigatran has become a hit with some clinicians, many wonder whether the drug’s use is cost-effective.

It might be so, at least in the U.K. population. A cost-effectiveness study comparing dabigatran etexilate (Pradaxa, Boehringer Ingelheim) and warfarin, aspirin or no therapy found that the drug could be cost-effective as a first-line treatment for the prevention of stroke and systemic embolism (SE) in AF patients in the U.K. The study was published April 23 in Heart. 

“[W]arfarin treatment is complex; it has many important interactions with food and drugs, requires frequent laboratory monitoring of the international normalized ratio (INR), and has potential to cause serious hemorrhagic events that can be catastrophic,” the authors wrote. “Due to these concerns, many patients in the U.K. are under-treated with aspirin or remain untreated. There is a need, therefore, for safer, more efficacious and less complex stroke prevention therapy.”

In the economic analysis, Anuraag R. Kansal, PhD, of United BioSource in Bethesda, Md., and colleagues looked at whether the use of dabigatran was cost-effective in two patient cohorts with AF (those up to age 80 starting treatment and those starting treatment at age 80 and older). The authors looked at clinical events, quality-adjusted life years (QALYs), total costs and incremental cost-effectiveness ratios (ICERs).

The study used a model that assumed that patients received dabigatran 150 mg twice daily until age 80 and 110 mg twice daily thereafter. This model reflects the current clinical indications approved in the U.K.

The authors reported that patients who were treated sequentially over their lives with dabigatran experienced fewer total intracranial hemorrhages and ischemic stroke events per 100 patient years (0.43 vs. 0.99; and 3.74 vs. 3.97). However, dabigatran patients compared with those treated with warfarin saw a greater number of extracranial hemorrhage (3.88 vs. 3.57) and acute MI (1.27 vs. 1.06) events per 100 patient years. The authors also found that the rate of fatal intracranial hemorrhages to be lower with dabigatran when compared with warfarin but ischemic stroke events were similar in both groups.  

Because the researchers found differences in clinical event rates between the warfarin and dabigatran groups, QALYs increased for dabigatran-treated patients versus those treated with warfarin (8.06 vs. 7.82). This also resulted in higher lifetime costs per patients for disease management, £19,645 (U.S. $31, 669) vs. £18,474 (U.S. $29,782). This was a result of higher drug costs. Follow-up costs represented 47 percent of total costs for dabigatran and 61 percent for warfarin.

Aspirin patients and patients who underwent no treatment had fewer QALYs, 7.59 and 7.12, respectively, when compared with dabigatran. However, those who underwent no treatment had higher event rates, which resulted in higher management costs, even despite the absence of drug costs (£18,561/U.S. $29,922 for aspirin and £20,475/U.S. $33,007 for no treatment).

The authors also noted that patients 80 or older saw decreased QALYs and costs (4.11 QALYs and £10,424/U.S. $16,804 management costs for dabigatran vs 4.04 QALYs and £9,919/U.S. $15,990 management costs for warfarin).

“In the population initiating treatment before age 80, the incremental cost-effectiveness ratio (ICER) was £4,831 [U.S. $7,788]/QALY gained, while in the population initiating treatment at 80 the ICER was £7,090 [U.S. $11,429]/QALY gained,” the authors wrote.

“The modeled evaluation estimated that use of dabigatran was likely to be cost effective in all comparisons and analyses conducted," they wrote.

“It was demonstrated that average population warfarin control would need to be raised to levels not observed in routine practice for £20,000 [U.S. $32,242]/QALY gained to be exceeded. These consistent cost-effectiveness results are in line with the improved efficacy and safety outcomes demonstrated in RE-LY,” the authors noted.

Kansal et al added that the current results were similar to economic analyses conducted in both Canada and U.S. populations.

“These clinical benefits offset a substantial portion of the additional drug cost associated with dabigatran, yielding favorable cost-effectiveness ratios well below standard WTP [willingness-to-pay] thresholds. Overall, this economic evaluation supports the use of dabigatran as a cost-effective first-line treatment for the prevention of stroke and SE in eligible U.K. patients with AF,” the authors summed.