(Reuters) - Amgen Inc AMGN.O on Tuesday said its second-quarter revenue fell 3% due to more competition for its older off-patent drugs, but rising sales of newer medicines helped its results exceed Wall Street forecasts.

FILE PHOTO: An Amgen sign is seen at the company's office in South San Francisco, California in this October 21, 2013 file photo. REUTERS/Robert Galbraith/Files

Amgen also said its experimental cancer drug AMG510 has shown activity in patients with colorectal and appendiceal cancer, helping to boost the company’s shares by nearly 3% to $181 in extended trading.

The U.S. biotechnology company, which presented data in June showing that AMG510 also appeared to be effective against lung cancer, said it may begin a trial later this year that could serve as the basis for a U.S. regulatory application seeking approval.

AMG510 is part of a growing trend of precision medicines that target gene mutations driving cancer regardless of in which organ the disease originated.

“I’m very impressed with the emerging safety profile that we are seeing with AMG510,” David Reese, Amgen’s head of research and development, said on a conference call on Tuesday.

Amgen said second-quarter adjusted earnings per share rose 4% to $3.97, topping analysts’ average expectations by 41 cents, according to IBES data from Refinitiv. A lower number of outstanding shares contributed to the earnings beat.

Total revenue of $5.87 billion, while lower than a year ago, topped analysts’ estimates of $5.66 billion.

“Amgen had a good quarter all around,” said Jefferies analyst Michael Yee. “They tightened up guidance to the higher end of the range, which is where the Street is at.”

The company raised the lower end of its full-year outlook and now expects adjusted earnings of $13.75 to $14.30 per share on revenue of $22.4 billion to $22.9 billion. It had previously forecast $13.25 to $14.30 per share on revenue of $22 billion to $22.9 billion.

Sales of potent cholesterol fighter Repatha rose 3% to $152 million, below Wall Street estimates of $157 million. Sales of Amgen's new migraine drug Aimovig, which competes with similar new treatments from Eli Lilly LLY.N and Teva TEVA.TA, totaled $83 million for the quarter, beating the $77.4 million projected by analysts.

But sales of Neulasta, which fights infections by boosting white blood cells, fell 25% to $824 million, while sales of kidney drug Sensipar plunged 71% to $122 million as competition from cheaper generics and biosimilars increased.

Amgen reported a net profit of $2.17 billion, or $3.57 per share, for the quarter, compared with a profit of $2.29 billion, or $3.50 per share, a year ago.