Astellas Pharma has pulled its filing in Japan for its oral Factor Xa inhibitor darexaban after regulators said they needed to see more data.

The Tokyo-based drugmaker says it has withdrawn a market authorisation application for darexaban, also known as YM150, which was submitted to Japan's Ministry of Health, Labour and Welfare in September. Astellas was seeking approval for the drug for the prevention of venous thromboembolism in patients at risk, such as those undertaking orthopaedic surgical procedures in the lower limbs.

However, the country's Pharmaceuticals and Medical Devices Agency has told Astellas that it needs toconduct additional clinical studies to supplement the current application package in order to achieve approval. Following a discussion with the PMDA, Astellas has decided to withdraw the application.

Nevertheless, it may not be all over for darexaban as the company says it is "considering the appointment of a partner" for the prevention of VTE in the USA and Europe, as well as stroke prevention in atrial fibrillation globally. Astellas added that it expects to decide the way forward for the drug, including the indication of VTE in Japan, based on the aforementioned partnership discussion.

Darexaban belongs to the same class of anticoagulants as Bayer/Johnson & Johnson's Xarelto (rivaroxaban), which is approved in Europe, and Pfizer/Bristol-Myers Squibb's apixaban.