3 Min Read (Reuters) - U.S. biotech Amgen Inc on Tuesday provided a 2021 earnings forecast below Wall Street estimates and said it had paused or halted enrollment for clinical trials of three cancer drugs. Slideshow ( 2 images ) The company also said it expects net selling prices for its drugs to fall by a rate in the mid-single digits this year - after a drop of 6% in 2020 - and the COVID pandemic will continue to impact sales. Amgen shares, which closed at $240.49, were down $4.37, or 2%, at $236.12 after hours. For 2021, Amgen forecast adjusted earnings of $16.00 to $17.00 per share, putting the midpoint below analysts’ estimates of $17.03 per share, according to IBES data from Refinitiv. The full-year revenue forecast of $25.8 billion to $26.6 billion was more in line with analyst projections of $26.45 billion.