April 25 (Reuters) - Gilead Sciences reported a first-quarter loss on Thursday after taking a $3.9 billion charge for its recent acquisition of liver drug developer CymaBay Therapeutics, while revenue rose 5% on higher HIV, oncology and liver disease treatment sales.

For full-year 2024, Gilead said it still expects product sales of $27.1 billion to $27.5 billion, but lowered its earnings outlook to include the recent charge as well as incremental expenses related to the CymaBay deal.

The company said it now expects 2024 adjusted profit of $3.45 to $3.85 a share, down from a previous range of $6.85 to $7.25.

Wall Street analysts currently project Gilead's 2024 earnings at $3.94 a share on revenue of $27.5 billion, according to LSEG data.

The California-based drugmaker's first-quarter revenue totaled $6.69 billion, ahead of the average analyst projection of $6.34 billion.

Gilead posted an adjusted quarterly loss of $1.32 a share, which was better than the $1.48 per share loss forecast by analysts.

On a net basis, which included a $2.4 billion writedown of assets acquired from Immunomedics in 2020, Gilead reported a quarterly loss of $3.34 per share.

HIV product sales increased 4% from a year earlier to $4.3 billion. Quarterly sales of HIV drug Biktarvy rose 10% to $2.9 billion, which was in line with analyst estimates.

Gilead's oncology sales rose 18% to $789 million.

"We had a really strong quarter as reflected in both our commercial performance and clinical execution," Gilead CEO Daniel O'Day said in an interview.

He noted that Gilead expects to have results from trials of several key programs this year, including cancer drug Trodelvy.

(Reporting By Deena Beasley Editing by Bill Berkrot)