UPDATE 1-Roche says new data confirm Mabthera, Actemra work

*Roche presents data on arthritis drugs

*MabThera study shows multiple courses help treatment

*MabThera well tolerated over the long term

*Fifth Phase III Actemra study confirms disease remission (Adds details)

ZURICH, Oct 27 (Reuters) - Swiss drugmaker Roche(ROG.VX) said on Monday new data showed its drug MabThera continued to improve patient response in rheumatoid arthritis with multiple courses of treatment and that it was well tolerated over the long term.

The group said patients in the study had not responded adequately to another class of rheumatoid arthritis drug known as tumour necrosis factor (TNF) inhibitors, which is the most commonly prescribed first-line biologic therapy.

"Prolonged treatment with MabThera clearly demonstrates an improvement in symptoms for patients with rheumatoid arthritis who do not respond adequately to TNF inhibitor therapy," said Professor Edward Keystone, Rheumatology Department at the University of Toronto, Canada.

In a separate statement, Roche said a fifth Phase III study had confirmed a "significant rate of disease remission" in patients treated with Actemra and that the drug can stop structural damage to joints as well as improve patients' physical function after one year of treatment.

Earlier in October Roche said it was still discussing what additional information is required for approval of Actemra with U.S. regulators after the U.S. Food and Drug Administration requested more information related to the manufacturing of the drug.

Roche is presenting the data at the American College of Rheumatology's annual meeting in San Francisco. (Reporting by Katie Reid; Editing by Greg Mahlich)