(Adds details, forecast)
Aug 1 (Reuters) - Pfizer Inc reported quarterly revenue on Tuesday that missed Wall Street estimates, driven by lower demand for its rheumatoid arthritis treatment Enbrel and pneumonia vaccine Prevnar.
Revenue fell to $12.9 billion in the second quarter from $13.15 billion, below analysts' estimates of $13.08 billion, according to Thomson Reuters I/B/E/S.
Sales of Enbrel, which Pfizer sells outside the United States and Canada, were hurt by competition from biosimilars.
Enbrel sales tumbled about 19.5 percent to $617 million in the quarter, while Prevnar sales declined 8.2 percent to $1.15 billion.
However, net income attributable to the largest U.S. drugmaker rose to $3.07 billion, or 51 cents per share, from $2.05 billion, or 33 cents per share, a year earlier.
Excluding items, Pfizer earned 67 cents per share, beating the average analysts' estimate by a cent.
The drugmaker also narrowed its 2017 adjusted earnings forecast to a range of $2.54 per share to $2.60 per share. It had previously forecast a range of $2.50 per share to $2.60 per share. (Reporting by Natalie Grover in Bengaluru; Editing by Arun Koyyur)