FOSTER CITY, Calif. (TheStreet) -- Gilead Sciences (GILD) - Get Report will not be blamed for a cooling of the biotech bull market, if any such thing exists. Second-quarter earnings and revenue topped Street expectations, bolstered by really strong hepatitis C drug sales. Gilead raised product sales guidance for the remainder of the year.

Biogen's (BIIB) - Get Report second-quarter earnings miss and the resulting cut to 2015 guidance last Friday may have shaken investor confidence in large-cap biotech stocks, but Gilead's "beat and raise" shouldn't draw such complaints. 

Ahead of Tuesday's earnings, Gilead shares closed 2% higher to $113.0. The stock is trading up another 3% to $116.75 in the after-hours session. 

Worldwide sales of Gilead's hepatitis C drugs Harvoni and Sovaldi were $4.89 billion in the June quarter ($3.44 billion U.S. and $1.45 billion international), besting the $4.3 billion consensus estimate and even beating first-quarter sales of $4.5 billion, which wasn't supposed to happen. Domestic and international were both stronger than expected, the former being a bigger surprise given what looked like slowing prescriptions. 

Total revenue in the June quarter rose 26% year over year to $8.2 billion. 

On an adjusted basis, Gilead earned $3.15 per share in the June quarter, an increase of 33% from the prior year. 

The company raised guidance on 2015 product sales to the range of $29-30 billion from $28-29 billion.

Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.