UPDATE 1-Pfizer's biosimilar of Roche's Rituxan succeeds in study

(Adds details on Rituxan)

Jan 24 (Reuters) - Pfizer Inc said on Wednesday its biosimilar of Roche's Rituxan was as effective as the original drug in treating patients with a type of follicular lymphoma, meeting the main goal of a study.

The success of Pfizer's biosimilar comes as Rituxan's U.S. patent is set to expire later this year. The drug had raked in sales of about 7.30 billion Swiss francs ($7.70 billion) in 2016.

Rituxan, which is also Roche's best-selling drug, is used in treating several types of blood cancer as well as rheumatoid arthritis.

Roche and Biogen Inc co-market Rituxan in the United states. The drug is sold under the brand name MabThera by Roche in other markets, except Japan where its is co-marketed by Chugai and Zenyaku Kogyo Co Ltd.

Rituxan first received the U.S. Food and Drug Administration's approval in 1997 to treat a type of blood cancer.

Pfizer's shares were up marginally in morning trading on Wednesday. (Reporting by Manas Mishra and Akankshita Mukhopadhyay in Bengaluru; Editing by Anil D'Silva)