Glaxo warns of anemia risk with transplant drug

* Follows similar warning for Roche's CellCept

* Some cases reversible if drug stopped or dose lowered

LOS ANGELES, Sept 3 (Reuters) - GlaxoSmithKline PLC (GSK.L) and U.S. regulators said on Thursday they had notified healthcare professionals that a type of anemia has been reported in some patients treated with transplant drug Myfortic.

The warning involves cases of pure red cell aplasia (PRCA), a type of anemia that can cause fatigue, lethargy or abnormal paleness of the skin.

PRCA was found to be reversible in some cases when the drug dose was lowered or the drug was stopped, Glaxo said. In transplant patients, however, reduced immunosuppression may put the transplanted organ at risk.

The Food and Drug Administration and Roche Holding AG (ROG.VX) last month revised the label of transplant drug CellCept to include a new warning about cases of PRCA.

Both Myfortic, known generically as mycophenolic acid, and CellCept, mycophenolate mofetil, are used to suppress the immune system to prevent patients' bodies from rejecting a transplanted organ. (Reporting by Deena Beasley; Editing by Tim Dobbyn)