Amgen joined several drugmakers that have vowed to limit or delay price increases under intensifying pressure from the Trump administration to cut health care costs for U.S. consumers.

The world's largest biotechnology company also announced replacements for its head of research and development and retiring global commercial operations chief.

The company said on a conference call that it decided in May to forego list price increases it had planned for July, although it did not say which drugs it had targeted for price hikes.

"We have no plans to change that for the balance of the year," CEO Robert Bradway said.

Amgen posted adjusted earnings of $3.83 per share, topping analysts' average expectations by 29 cents, according to Thomson Reuters I/B/E/S.

Growth of newer drugs like cholesterol fighter Repatha and osteoporosis drug Prolia offset weakness in older products, the company said.

The company increased its 2018 earnings forecast to $13.30 to $14 per share, up from its previous view of $12.80 to $13.70.

Amgen shares rose 1 percent in extended trading to $196.

Overall revenue for the quarter revenue rose 4 percent to $6.06 billion.

Sales of rheumatoid arthritis drug Enbrel fell 11 percent to $1.3 billion.

Sales of the potent but expensive cholesterol drug Repatha have begun to take off, increasing 78 percent to $148 million. They have been held back since the drug's 2015 approval by an unwillingness of insurers and pharmacy benefit managers to authorize its use for most patients.

Prolia sales rose 21 percent to $610 million.

Amgen did not report early sales of Aimovig, the new migraine preventer that won U.S. approval in May. Amgen offered all new patients two free months of the medicine.

The company is trying to get around barriers large insurers are setting for patients prescribed the costly new headache treatment. Amgen said it had already negotiated contracts with payers covering around 30 percent of commercially-insured patients in the United States.

Amgen announced that longtime research chief Sean Harper is stepping down and will be replaced by David Reese, currently head of translational sciences and oncology at the company.

Murdo Gordon, who left his role as Bristol-Myers Squibb's chief commercial officer earlier this week, will replace Tony Hooper as executive vice president of global commercial operations in September, the company said.

(Reporting By Michael Erman and Robin Respaut; editing by Bill Berkrot)

By Michael Erman and Robin Respaut