Pfizer Reduces Xeljanz Doses After Trial Signals Clotting Dangers

Pfizer is reducing Xeljanz (tofacitinib) doses for patients in an arthritis trial after investigators discovered that the higher dose may be causing blood clots in the lung and even deaths.

In a safety alert, the FDA said that an external data safety monitoring committee found an increased occurrence of blood clots in the lungs and death in patients treated with tofacitinib 10 milligrams twice daily compared to patients treated with tocafitinib 5 milligrams twice daily or a necrosis factor inhibitor.

Xeljanz has been on the market since at least 2012 but the FDA required a clinical trial among rheumatoid arthritis patients to test the risk of heart problems, cancer and opportunistic infections. The agency says the safety trial will continue.