(Reuters) - AbbVie Inc ABBV.N reported quarterly adjusted revenue that missed analysts' estimates as weaker-than-expected sales of its hepatitis C treatment and cancer therapy overshadowed strong U.S. demand for its flagship drug, Humira.

A screen displays the share price for pharmaceutical maker AbbVie on the floor of the New York Stock Exchange July 18, 2014. REUTERS/Brendan McDermid

The company’s shares were down 2.57 percent at $59.7 in afternoon trading on Friday, wiping out $2.55 billion of its market value.

AbbVie has sharpened its focus on oncology to reduce its reliance on Humira. The company bought Pharmacyclics and its half-ownership of the leukemia drug, Imbruvica, for $21 billion in 2015.

Sales of the drug, which is also sold by Johnson & Johnson JNJ.N, fell short of fourth-quarter expectations, partly due to an inventory issue, analysts said.

However, AbbVie said it expects 2017 Imbruvica sales of $2.4 billion, up from $1.83 billion last year.

Sales of Abbvie's hepatitis C treatment, Vikiera Pak, also missed estimates, hurt by competition from Gilead Sciences Inc GILD.O and Merck & Co Inc MRK.N.

The company forecast full-year Vikiera sales of $1 billion, below the $1.52 billion the drug raked in last year.

The sales expectations come when investors are already jittery about looming biosimilar competition for Humira, the world’s top-selling drug.

U.S. sales of the autoimmune treatment came in well ahead of analysts’ estimate in the fourth quarter, but international revenue was hit by indirect biosimilar competition in Europe and a strong dollar, analysts said.

AbbVie, which is trying to block the U.S. launch of a Humira biosimilar developed by Amgen Inc AMGN.O, said it expects biosimilar launches in the vast majority of countries in 2018.

Chief Financial Officer Bill Chase said the company expected mid-to-high teens growth for Humira in the United States for 2017.

“I don’t see anything on the horizon ... that would give me pause as to the fundamental trajectory of Humira,” Chief Executive Officer Richard Gonzalez said on a post-earnings call.

AbbVie has already negotiated with U.S. insurers for Humira coverage in 2017 and 2018.

The company earlier this month said it would limit price hikes to once a year and keep them under 10 percent, as political and payer scrutiny into drug pricing intensifies.

AbbVie has already hiked prices on a majority of its products for 2017, the company said on the call.

The company has raised Humira’s gross price by 8.4 percent, according to Evercore ISI.

Adjusted quarterly revenue of $6.78 billion came in below analysts’ average estimate of $6.91 billion, according to Thomson Reuters I/B/E/S/.

AbbVie said it expected 2017 adjusted earnings of $5.44 to $5.54 per share, compared with analysts’ estimate of $5.47.