Clinical updates at ROI meeting on GSK's dolutegravir and Medivir's simeprevir

UK pharma giant GlaxoSmithKline (LSE: GSK) and Japanese drug major Shionogi (TYO: 4507) reported interim results from the Phase III SAILING study (n=715) showing that about 79% of patients receiving once-daily dolutegravir regimen achieved virological suppression (hepatitis C virus RNA < 50 c/mL) versus 70% of patients on twice-daily raltegravir regimen (95% CI: 3.4% to 15.9%, p=0.003). These findings were presented at the 20th Retroviruses and Opportunistic Infections conference in Atlanta, Georgia, USA.

In addition, data showed that fewer subjects failed therapy with dolutegravir (n=2) compared to Merck & Co's Isentress (raltegravir, n=10, p=0.016). Overall, the tolerability of dolutegravir was similar to raltegravir. At 24 weeks, 2% of subjects on the dolutegravir discontinued due to adverse events versus 4% on the raltegravir. The drug-related adverse events were similar for both arms including diarrhoea (20% DTG, 17% RAL) and upper respiratory tract infection (11% DTG, 8% RAL).

Commenting on the results, analysts at EP Vantage, say: "With superiority to Isentress demonstrated in the trial, dolutegravir should have a good chance at challenging Merck & Co’s dominance in the integrase inhibitor class. With approval decisions on both sides of the Atlantic due in the second half of 2013, dolutegravir’s progress will be closely watched."