April 30 (Reuters) - U.S. drugmaker Merck & Co Inc reported an 8 percent increase in quarterly sales on Tuesday, as sales of its blockbuster lung cancer immunotherapy Keytruda rose.
Merck said net income rose to $2.92 billion, or $1.12 per share, for the first quarter from $736 million, or 27 cents per share, a year earlier.
The company had taken a $1.4 billion charge in the comparable quarter related to a collaboration with Japan's Eisai Co Ltd.
Sales rose to $10.81 billion, above analysts' average estimate of $10.48 billion. (Reporting by Manas Mishra in Bengaluru; Editing by Anil D'Silva)