The company said more patients had resumed interacting with their doctors in the third quarter than earlier in the health crisis, but prescribing volumes remained "modestly below" pre-pandemic levels.

Prescriptions for drugs including rheumatology medicine Enrbel will continue to be affected by the pandemic and Amgen has factored COVID-19 into revenue guidance for the fourth quarter and the beginning of next year, it said on its quarterly call.

The company raised its full-year adjusted earnings forecast to $15.80 to $16.15 per share, from a previous range of $15.10 to $15.75, and narrowed its revenue estimate. It now expects revenue of $25.1 billion to $25.5 billion versus it prior forecast of $25.0 billion to $25.6 billion.

The company reported a third-quarter adjusted profit $4.37 per share, beating the average estimate of $3.81 per share, as compiled by Refinitiv.

Revenue for the quarter rose 12% to $6.4 billion, in line with analyst estimates of $6.38 billion.

Sales of Prolia rose 11% to $701 million, ahead of the average analyst estimate of $688 million.

Psoriasis drug Otezla, acquired from Celgene Corp in November, had sales of $538 million for the quarter. Amgen said Otezla is expected to maintain its double-digit year-on-year volume growth trend, adding that as an oral pill, it is less affected by COVID-19.

Sales of Amgen's older arthritis drug Enbrel fell 3% year-on-year to $1.3 billion as the drug continued to lose market share in the quarter.

Amgen posted net income of $2.02 billion, or $3.43 per share, compared with a profit of $1.97 billion, or $3.27 a share, a year ago.

(Reporting By Deena Beasley and Carl O'Donnell; additional reporting by Shivani Singh in Bengaluru; Editing by Bill Berkrot and Sam Holmes)

By Deena Beasley and Carl O'Donnell