Apixaban tops rivaroxaban for repeat-VTE protection in real-world analysis

NEW YORK (Reuters Health) - 06/12/2021 - Apixaban appears to be safer and more effective than rivaroxaban in adults with venous thromboembolism (VTE) starting a direct oral anticoagulant (DOAC), according to a real-world analysis.

Using a U.S. health-insurance database, the researchers constructed a propensity-score-matched cohort of adults with VTE starting apixaban or rivaroxaban, with 18,618 in each cohort.

In the apixaban cohort, with mean follow-up of 102 days, there were 475 recurrent VTE events and 386 gastrointestinal or intracranial bleeding events. In the rivaroxaban cohort, with mean follow-up of 105 days, there were 595 recurrent VTE events and 577 GI or intracranial bleeding events.

Compared with rivaroxaban, apixaban was associated with a lower rate for recurrent VTE (hazard ratio, 0.77; 95% CI: 0.69 to 0.87) and bleeding (HR, 0.60; 95% CI, 0.53 to 0.69), researchers report in the Annals of Internal Medicine.

The absolute reduction in the probability of recurrent VTE with apixaban versus rivaroxaban was 0.006 within two months and 0.011 within six months of initiation; for GI or intracranial bleeding, the absolute reductions with apixaban versus rivaroxaban were 0.011 within two months and 0.015 within six months of initiation.

"Results from subgroup and sensitivity analyses using different analytic approaches were consistent with the primary analysis, including comparing patients with VTE provoked by a transient risk factor versus VTE that was unprovoked or provoked by a chronic risk factor," report Dr. Ghadeer Dawwas with University of Pennsylvania, Philadelphia and colleagues.

"These findings support superior effectiveness and safety of apixaban for the prevention of recurrent VTE relative to rivaroxaban," they say.

The researchers say their findings are in line with an analysis of the Truven MarketScan database, which showed similar findings.

It's unclear why apixaban may be more effective and safer than rivaroxaban, but one possible explanation is pharmacokinetics, the researchers note. Rivaroxaban is administered as a single daily dose compared with apixaban's twice-daily dosing.

"A randomized crossover study that compared the pharmacokinetics and pharmacodynamics of both drugs found that apixaban had significantly less fluctuation in plasma concentrations, a lower peak-to-trough ratio, and less variability in pharmacokinetic variables (that is, maximum concentration and area under the curve) compared with rivaroxaban, potentially accounting for its superior effectiveness and safety," Dr. Dawwas and colleagues say.

The study had no specific funding.

SOURCE: https://bit.ly/3pu1NiJ Annals of Internal Medicine, online December 6, 2021.

 



Posted on 6 December 202114 December 2021