UPDATE 1-Roche seeks approval for rheumatoid arthritis drug

* Roche files to extend use of RoActemra in Europe

* Drug for inhibition of joint damage

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ZURICH, Sept 30 (Reuters) - Swiss drugmaker Roche Holding AG (ROG.VX) said it had filed to extend the use of RoActemra in Europe to inhibit the progression of joint damage and to improve physical function in patients with rheumatoid arthritis (RA).

The filing followed a study that showed parents receiving RoActemra in combination with methotrexate (MTX) had significantly less damage to their joints at two years than patients who received MTX alone, Roche said on Wednesday.

RoActemra, known as Actemra outside of the EU, is currently licensed in Europe for use in combination with MTX to treat adult patients with moderate to severe RA who responded inadequately to, or who were intolerant to, previous therapy.

MTX is used to reduce inflammation of the joints in RA patients, but it can also affect the immune system. (Reporting by Jason Rhodes, editing by Will Waterman)