Phase III CASSINI study of Xarelto failed to meet endpoint in venous thromboembolism.- Janssen.

The Janssen Pharmaceutical Companies of Johnson & Johnson announced new data from the Phase III CASSINI study on the use of oral anticoagulant Xarelto (rivaroxaban) in the management and prevention of VTE (or blood clots) in high-risk patients with cancer. The composite primary endpoint of VTE occurrence did not reach statistical significance during the full study period. However, use of Xarelto resulted in a clinically meaningful and nominally significant 60 percent reduction of VTE events compared to placebo during the time patients were actively receiving treatment. Bleeding rates were low, though higher with Xarelto.

In the intent to treat (ITT) population, the primary efficacy composite endpoint occurred during the study period in 8.79 percent of patients in the placebo group and in 5.95 percent of patients treated with Xarelto 10 mg once daily; however, this result was not statistically significant. Approximately 62.4 percent of patients completed the double-blind trial period from randomization through the end of the study's 180-day observation period, regardless of whether they discontinued the study medication. Withdrawal of consent and death were the primary reasons for discontinuation.

Researchers also examined the primary efficacy composite endpoint in all randomized patients, during the time they were actively taking treatment, known as the 'on-treatment' period. For this pre-specified analysis, Xarelto was associated with a statistically significant 60 percent reduction in VTE events compared to placebo (2.62 percent vs. 6.41 percent). The primary safety outcome, ISTH major bleeding, during the on-treatment period was low across both treatment arms and occurred in 4/404 (0.99 percent) patients treated with placebo and 8/405 (1.98 percent) patients treated with Xarelto; this result was not statistically significant, though the study was not powered to detect a significant difference. These late-breaking results were presented at the 60th American Society of Hematology (ASH) Annual Meeting.