UPDATE 1-Genentech revises Rituxan warning after death

(Adds Genentech comment, details)

WASHINGTON, Sept 11 (Reuters) - Genentech Inc DNA.N has revised a warning on the drug Rituxan to reflect the case of a rheumatoid arthritis patient, who was treated with the medicine and died from a brain infection, U.S. health officials said on Thursday.

Genentech also sent a letter to doctors about the fatal case of progressive multifocal leukoencephalopathy (PML), according to a notice on the Food and Drug Administration's Web site. PML is a brain infection and had already been noted on Rituxan's label as a possible risk.

Biogen Idec (BIIB.O), which co-markets Rituxan, reported the fatal case of PML in July.

Doctors treating patients with Rituxan should consider PML in any patient with new neurological symptoms, the FDA's notice said. Genentech's letter advised stopping Rituxan in patients who develop PML and noted there is no adequate treatment for the often-fatal infection.

Genentech spokeswoman Tara Cooper said the company and the FDA agreed on the language in the letter to doctors explaining the case.

Rituxan also is approved for treating non-Hodgkin's lymphoma.

(Reporting by Lisa Richwine and Deena Beasley; Editing by Leslie Gevirtz, Bernard Orr)