Impact of concurrent antiplatelet use on the safety and efficacy of thromboprophylaxis with apixaban in patients with cancer: A post-hoc analysis of the AVERT trial.

BACKGROUND

Data on bleeding risk from combining prophylactic anticoagulation with drugs that have antiplatelet properties (antiplatelet agents or nonsteroidal anti-inflammatory drugs (NSAIDs)) in patients with active cancer are limited. We evaluated the impact of concurrent antiplatelet/NSAID use on the safety and efficacy of apixaban thromboprophylaxis in ambulatory cancer patients.

METHODS

This post-hoc analysis of the AVERT trial assessed clinically relevant bleeding (major plus clinically relevant non-major bleeding [CRNMB]) as the primary outcome. Secondary outcomes included major VTE, major bleeding, CRNMB, and all-cause mortality. Hazard ratios (HRs) were estimated using Cox models adjusted for age, sex, and center. Subgroup analyses examined antiplatelet agents (aspirin or clopidogrel) and NSAIDs separately.

RESULTS

Among 563 included patients, 184 used drugs with antiplatelet properties (apixaban n = 99; placebo n = 85) and 379 did not. In the apixaban arm, concurrent use of these drugs increased clinically relevant bleeding (HR 1.80; 95% CI 1.15-2.82) and CRNMB (HR 2.01; 95% CI 1.21-3.34) without reducing VTE (HR 0.61; 95% CI 0.26-1.45). Among antiplatelet users (n = 61), risks of clinically relevant bleeding (HR 2.02; 95% CI 1.29-3.18) and CRNMB (HR 2.63; 95% CI 1.59-4.35) were higher. NSAID users (n = 42) showed no significant differences in bleeding outcomes. In the placebo arm, concurrent use was not associated with increased clinically relevant bleeding but was linked to more CRNMB (HR 1.88; 95% CI 1.00-3.55). No impact on all-cause mortality was observed.

CONCLUSIONS

Concurrent use of antiplatelet drugs during apixaban thromboprophylaxis in cancer patients increases clinically relevant bleeding without reducing VTE.