UPDATE 1-US FDA warns Shire, Eisai on promotions

* US FDA warns Eisai on blood disorder drug

* Shire warned on kidney drug

WASHINGTON, Nov 13 (Reuters) - U.S. regulators have warned Shire PLC (SHP.L) and Eisai Co Ltd (4523.T) about drug promotions that minimized the medicines' risks and overstated benefits, letters released on Friday said.

The Food and Drug Administration said a promotional card for patients developed by Eisai "presents numerous claims that misleadingly overstate the efficacy" of Dacogen, a drug for treating blood disorders known as myelodysplastic syndromes.

Eisai's promotion also "omits material risks associated with Dacogen treatment," the FDA said in a Nov. 6 letter.

Eisai officials could not immediately be reached for comment.

In a separate Nov. 5 letter to Shire, the FDA said a company brochure for kidney drug Fosrenol chewable tablets left out risk information and made unsubstantiated claims that the drug worked better than rival treatments.

Shire spokesman Matt Cabrey said the company had received the letter and was reviewing it.

The FDA posted the letters on its website here. (Reporting by Lisa Richwine, editing by Leslie Gevirtz)