Retrospective evaluation of the efficacy and safety of rivaroxaban in patients with cancer-associated venous thromboembolism: A single-center study

Effectiveness and Safety of Lower Dose of Rivaroxaban for Cancer-Related Venous Thromboembolism: A Retrospective Cohort Study

BACKGROUND

Primary and recurrent venous thromboembolism (VTE) commonly occur in patients with cancer. However, because of the National Health Insurance regulations, available dosage forms, and clinical conditions, the prescribed dose of rivaroxaban may not be consistent with its recommended dose.

OBJECTIVE

To evaluate the 6-month recurrence rate of VTE and safety of rivaroxaban for patients with cancer.

METHODS

Patients with new cancer diagnosis or recurrence from 2014 to 2018 who initiated rivaroxaban for VTE from January 2015 to January 2019 were included. We set the rivaroxaban initiation date as the index date and followed up the patients for 180 days. We collected information regarding the starting and maintenance dose/frequency and the treatment duration. The efficacy outcome was the recurrence of VTE within 180 days. The safety outcome included the major bleeding rate and clinically relevant nonmajor bleeding (CRNMB) rate.

RESULTS

Approximately, 46.2% of the 65 included patients received a standard starting dose, and 45% of patients received a maintenance dose above 15 mg (median: 23.9 and 13.1 mg per day, respectively). Two-thirds of the patients stopped treatment within 180 days. Recurrent VTE occurred in 2 (3.1%) patients within 6 months. The major bleeding rate was 7.7%, and the CRNMB rate was 3.1%.

CONCLUSION AND RELEVANCE

The 6-month recurrence rate of VTE and safety profile were similar between the lower and standard dose of rivaroxaban. This result may be applied to the institutions with dosage availability limited by formulary regulation and patients who cannot use full dose because of clinical considerations.

Long-term VTE treatment with rivaroxaban: Results from the DRESDEN NOAC REGISTRY

Data on long-term effectiveness and safety of venous thromboembolism (VTE) treatment with rivaroxaban are scarce and not available from randomized clinical trials. To supplement the positive results of phase III VTE treatment trials with rivaroxaban, we used data from the ongoing, prospective, non-interventional DRESDEN NOAC REGISTRY to evaluate long-term management patterns and clinical outcomes. Between December 1st 2011 and September 30th 2020, 812 patients with acute VTE (575 DVT; 237 PE) and rivaroxaban treatment were prospectively followed. During treatment (median rivaroxaban exposure 1.1 years IQR 0.3-5.0 years; median follow-up 6.1 years IQR 4.7-7.8 years) rates of recurrent VTE and ISTH major bleeding were 0.7/100 pt. years (95% CI 0.4-1.1) and 2.1/100 pt. years; 95% CI 1.5-2.8, respectively. Of the 427 patients still taking rivaroxaban at 12 months, 276 and 202 were still taking rivaroxaban at 3 and 5 years, respectively. "Scheduled end of treatment" was the leading discontinuation reason also beyond 12 months. When exposure days were divided by the number of major clinical outcomes (recurrent VTE + other major cardiovascular + ISTH major bleeding), continued rivaroxaban treatment had the longest "exposure per event" period (6398 days/event) compared to patients switching to alternative treatments (4658 days/event) or stopping anticoagulation completely (4337 days/event). Our results confirm low thrombotic and major bleeding rates for long-term VTE treatment with rivaroxaban. Beyond 12 months, scheduled treatment discontinuations still occur. Although 3-5% of patients planned for indefinite rivaroxaban therapy switched to other anticoagulants each year, the overall persistence to rivaroxaban was high.

Rivaroxaban for cancer-associated venous thromboembolism

All cancers can increase the risk of developing venous thromboembolism (VTE), and anticoagulants should be considered as an optimal treatment for patients suffering from cancer-associated VTE. However, there is still a debate about whether the new oral anticoagulant, rivaroxaban, can bring better efficacy and safety outcomes globally. Thus, this systematic review and meta-analysis was conducted to evaluate the efficacy and safety of rivaroxaban. We searched PubMed, Cochrane Central Register of Controlled Trials, Web of Science, and China National Knowledge Infrastructure for relevant published papers before 1 September 2019, with no language restrictions. The primary outcomes are defined as the recurrence of VTE. The secondary outcomes are defined as clinically relevant non-major bleeding, adverse major bleeding events, and all-cause of death. The data were analyzed by Stata with risk ratio (RR) and 95% confidence interval (CI). Four trials encompassing 1996 patients were included. Rivaroxaban reduced recurrent VTE with no significant difference (RR = 0.68, 95% CI = 0.43-1.07). Similarly, there were no significant differences in adverse major bleeding events (RR = 0.86, 95% CI = 0.37-2.00), clinically relevant non-major bleeding (RR = 1.24, 95% CI = 0.73-2.12) and all-cause mortality (RR = 0.76, 95% CI = 0.40-1.44). In a selected study population of cancer patients with VTE, rivaroxaban is as good as other anticoagulants. Further, carefully designed randomized controlled trials should be performed to confirm these results.