U.S. FDA says Roche cancels heart transplant study

(Adds details on cancellation of study, background)

WASHINGTON, Feb 22 (Reuters) - Roche Holding AG (ROG.VX) had ended its study of heart transplant patients sooner than anticipated after a higher than expected rate of acute organ rejection, U.S. health regulators said on Thursday.

The Food and Drug Administration (FDA) said patients in the trial were switched from a regimen of calcineurin inhibitor and the company's immunosuppressant drug CellCept to the immunosuppressant drug sirolimus and CellCept 12 weeks after transplantation.

Sirolimus is sold by Wyeth WYE.N under the brand name Rapamune.

Immunosuppressant drugs aim to prevent organ rejection in people who have undergone transplant surgery.

"The safety and efficacy of CellCept in combination with sirolimus following withdrawal of initial calcineurin inhibitor therapy has not been established," the FDA said in a statement on its Web site.

Roche said in a Feb. 1 letter to doctors the trial known as Heart Spare The Nephron had been designed to investigate whether kidney function would improve if the inhibitor therapy was withdrawn and sirolimus introduced.

The company said it would continue to monitor the safety of CellCept through other means.

Representatives for Roche could not be immediately reached for comment.

The FDA posted the notice and the company's letter on it's web site here#CellCept

((Reporting by Susan Heavey, editing by Toni Reinhold; Reuters Messaging: susan.heavey.reuters.com@reuters.net, Phone: 202-354-5848)) Keywords: ROCHE CELLCEPT/

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