US biotechnology group Gilead enjoyed a strong second quarter this year, with net earnings leaping 34% to $265.2 million, or $0.56 a share, on accelerating sales of its HIV franshise.

Total revenues leapt 38% to $685.3 million, with growth mainly down to a stellar performance by the HIV drug Truvada (emtricitabine and tenofovir disoproxil fumarate), which sky rocketed 143% to $299.3 million, and royalties from the flu treatment Tamiflu (oseltamivir), which rose to $73.3 million from $36.2 million last year. Also driving growth was the chronic hepatitis B treatment Hepsera (adefovir dipivoxil), up 24% to $56.8 million.

Sales of Viread (tenofovir disoproxil fumarate), dropped 20% to $167.4 million, reflecting a higher number of patients switching from a Viread-based regimen to one containing Truvada where available. In the same vein, turnover of Emtriva (emtricitabine) tumbled 29% to $8.7 million.

The robust results, as well as the recent US nod for its triple combo pill Atripla, have led the firm to lift its full year target for the HIV portfolio to $1.95-$2 billion, up from the earlier goal of $1.83-$1.88 billion, according to media reports.

Atripla, which incorporates B-MS’ Sustiva (efavirenz) and Gilead's Emtriva (emtricitabine) and Viread (tenofovir) in a single pill, received US approval earlier this month, becoming the first once-daily triple therapy for HIV on the market. The drug has been designed to increase convenience for the patient, and better compliance with therapy to provide tighter control of the virus and hold back the development of resistant strains.