Global pharmaceutical giant AbbVie (ABBV -0.93%) reported another quarter of steady growth in Q1 this morning, with the current best-selling drug in the world, Humira, once again leading the way.

For the quarter, AbbVie reported revenue of $4.56 billion, a 5.4% increase from the year-ago period and inclusive of a negative 1.3% effect from currency translation. Humira, the company's rheumatoid arthritis blockbuster, delivered 17.5% worldwide sales growth to $2.64 billion for the quarter, putting it on pace for more than $10 billion in annual sales. U.S. sales provided much of the spark with revenue domestically up 24.7%.

Also boosting AbbVie's topline was low testosterone therapy AndroGel, which grew sales by 6% to $254 million; hypothyroidism drug Synthroid, whose sales jumped an impressive 31.5% to $157 million; and Creon, an exocrine pancreatic insufficiency medication, which delivered an 18.4% increase in sales to $107 million.

Profit for the quarter improved by a modest 4.4% to an adjusted $0.71 per share, largely due to Humira's higher sales, but partially offset by higher research and development, as well as selling, general and administrative expenses. Nonetheless, adjusted gross margin expanded 220 basis points to 78.4%.

Looking forward, AbbVie reaffirmed its previously issued full-year guidance which calls for $3-$3.10 in adjusted EPS on revenue of approximately $19 billion. This forecast excludes any potential revenue benefit it could receive from its direct-acting antiviral candidate for hepatitis C were it to be approved and hit pharmacy shelves before the year is out. AbbVie submitted the new drug application for its DAA HCV drug earlier this week.