(Reuters) - AbbVie Inc's ABBV.N said it would be cautious with drug pricing, especially for Humira, the world's biggest selling drug, sending its shares down 2 percent, despite the drugmaker's quarterly profit narrowly beating estimates.

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

Abbvie CEO Richard Gonzalez said on Friday the company would continue to be “careful and conservative” about pricing, even though the drugmaker has already concluded negotiations with insurers for coverage of its Humira drug in 2017 and 2018.

“I’d say even in this last cycle, we have been even a little more conservative than we have been in the past because this (drug pricing) has become such a heated topic in the United States,” Gonzalez said.

AbbVie had in January pledged to limit drug price hikes to under 10 percent and once a year, as political and payer scrutiny into drug pricing intensified in United States.

Overall sales of Humira, which is used to treat autoimmune disorders and has a list price of $4,441 for a two-pen pack, rose 13.7 percent to $4.72 billion, beating analysts’ average estimate of $4.64 billion, according to Barclays.

The drug’s U.S. sales rose 18 percent, driven by pricing as well as low double-digit prescription growth, AbbVie executives said.

However, the blockbuster drug faces looming competition from copycat versions in the United States.

AbbVie has been trying to block the launch of Amgen's AMGN.O Humira knock-off.

Earlier this year, the U.S. patent office ruled in favor of Coherus Biosciences' CHRS.O Humira copy, in a move that analysts say could advance its U.S. launch by a year.

AbbVie's cancer drug Imbruvica, which it jointly owns with Johnson & Johnson JNJ.N, raked in sales of $626 million, above the consensus estimate of $609 million.

Sales of its hepatitis C treatment, Viekira Pak, came at $225 million, well below the consensus estimate of $257 million, as rival products from Gilead Sciences Inc GILD.O and Merck & Co Inc MRK.N ate into sales.

AbbVie said regulatory decisions on its next-generation hepatitis C treatment, Maviret, are expected in the coming weeks. If approved, the company expects to see a meaningful impact to sales only in 2018.

Excluding items, the company earned $1.42 per share, beating analysts’ estimates by 2 cents, according to Thomson Reuters I/B/E/S.

AbbVie’s net revenue rose to $6.94 billion, edging past estimates of $6.93 billion.

Shares of the company, which maintained its adjusted profit forecast for 2017, were down at $70.34 in afternoon trading.