The reduced apixaban is found to be effective in preventing the recurrence of blood clots in cancer patients

The reduced apixaban is found to be effective in preventing the recurrence of blood clots in cancer patients

Patients with active cancer who developed a blood clot or venous thromboembolism (VTE) and were treated with blood-thinning medications for at least six months, followed by an additional 12 months of low-dose apixaban, experienced similar VTE recurrences and fewer bleeding events as similar patients who received a full dose of the oral blood-thinning medications over the same period of time. These results from the API-CAT trial were presented at the American College of Cardiology Annual Scientific Meeting (ACC.25).

VTEs are a common complication of cancer and the second leading cause of death in cancer patients after cancer itself. Cancer cells release substances that make it easier for blood clots to form. Cancer treatment can also cause inflammation of blood vessels and increase the risk of blood clots. In addition, the limited mobility of patients and the use of invasive devices also explains the risk of VTE.

For patients with cancer who develop VTE, international guidelines recommend treatment with anticoagulants or blood-thinning medications for at least six months and as long as the cancer is active or cancer treatment continues. However, studies have shown that there is a significant risk of recurrent VTE after six months of anticoagulant treatment. However, studies also show that anticoagulant treatment can increase patients' risk of bleeding.

The best way to prevent VTE recurrence after six months of anticoagulant treatment was not clear. “

Isabelle Mahé, MD, PhD, professor of internal medicine at Université Paris Cité, head of internal medicine at Paris auxiliary public hospitals and principal investigator for the study

The aim of the API-CAT study was to assess whether the lower dose of apixaban was comparable to the full dose in preventing recurrence of VTE in patients with active cancer who had completed at least six months of treatment with a blood-depressant medication for VTE. Study researchers also examined whether the low dose resulted in a reduced risk of bleeding compared to a full dose.

In this randomized, international, double-linked study, a total of 1,766 patients were prospectively enrolled in 11 countries. Their average age was 67 years and 57% were women. All had active cancer (breast cancer, 22.7%; colorectal cancer, 15.3%; prostate cancer, 9.3%; other cancers, 41.4%); 65.8% had metastatic cancer (cancer that had spread from where it started to other parts of the body), and 81.2% were receiving concurrent cancer treatment at inclusion. The median time since VTE for patients was eight months. At enrollment, all patients had completed at least six months of anticoagulant treatment.

Patients were randomly assigned to receive 5 mg (2.5 mg twice daily; the reduced dose group) or 10 mg twice daily. Neither patients nor their doctors knew what dose patients received until the end of the study. All deaths, suspected VTE recurrences and suspected bleeding events during the study were reviewed by an independent group of physicians who were also unaware of which treatment patients were receiving. The primary endpoint of the study was VTE recurrence or death from VTE during the treatment period. The key secondary endpoint was a composite of major bleeding and any bleeding requiring medical attention.

At 12 months, 18 patients in the reduced-dose group and 24 in the full-dose group had recurrent VTE (12-month cumulative incidence of 2.1% and 2.8%, respectively), a difference that was statistically significant for failure to receive the reduced dose compared to the full dose. Clinically significant bleeding requiring medical attention occurred in 102 patients in the reduced-dose group compared to 136 patients in the full-dose group (12-month cumulative incidence of 12.1% and 15.6%, respectively), a statistically significant reduction in favor of the reduced dose. Mortality rates were similar in the two groups (17.7% in the reduced-dose group, 19.6% in the full-dose group).

“We can say that the underdosed apixaban is both effective and safer than the full dose,” Mahé said, adding that the results should lead to a guideline update recommending extended treatment with a reduced-dose anticoagulant in this patient group.

Study limitations include a lack of guidance on how long anticoagulant treatment should extend beyond the study's 12-month follow-up period. Second, Mahé said, the study does not provide information about possible differences in effectiveness or safety between racial and ethnic groups because France does not allow the collection of data on patients' race and ethnicity. In addition, patients with brain tumors were excluded from the study, so the results do not apply to them.

Mahé and her colleagues plan to publish a follow-up analysis of the results according to the type of cancer patients and study the determinants of bleeding.

The study was funded by the BMS-Pfizer Alliance. Bristol-Myers Squibb made Apixaban available free of charge. This was an Investigator-sponsored study coordinated by ASSERHEIT PUST PUBLIQUE des Hôpitaux de Paris (AP-HP). The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report.

This study was simultaneously published online in theNew England Journal of MedicineAt the time of presentation.

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