Pharmaceutical giant GlaxoSmithKline Plc (GSK, GSK.L) on Monday said initial results from a late-stage study showed that investigational integrase inhibitor dolutegravir was not inferior to raltegravir, thus meeting the primary objective of the trial.
The results were announced by Shionogi-ViiV Healthcare LLC, a joint venture between ViiV Healthcare Ltd and Shionogi & Co., Ltd. ViiV Healthcare is an HIV company established by GlaxoSmithKline and Pfizer, Inc. (PFE).
Dolutegravir is an investigational integrase inhibitor, or INI, currently in development by Shionogi-ViiV Healthcare LLC for the treatment of HIV. It is currently the only once-daily, unboosted INI in late-stage clinical development. Integrase inhibitors block HIV replication by preventing the viral DNA from integrating into the genetic material of human immune cells.
The SPRING-2 Phase III study with dolutegravir was conducted in treatment-naïve adults with HIV-1. The primary objective was non-inferiority of dolutegravir to raltegravir.
The study was designed to compare the efficacy and safety of dolutegravir 50 mg administered once-daily to raltegravir 400 mg administered twice daily, both with two nucleoside reverse transcriptase inhibitors. Four hundred and eleven treatment-naïve study participants were randomised in each arm.
The primary endpoint of the study was the proportion of study participants with undetectable HIV-1 RNA through 48 weeks. Through 48 weeks, 88 percent of study participants on dolutegravir were virologically suppressed compared to 85 percent of participants on raltegravir.
The tolerability of dolutegravir was similar to that of raltegravir. Rates of adverse events led to withdrawal at 2 percent in both arms.
Drug-related nausea was reported by 10 percent of patients in each arm. No other adverse events related to study medication were reported by over 5 percent of participants in any arm.
SPRING-2 is the first of four Phase III studies due to be reported this year. Data from the clinical trials SINGLE, VIKING-3 and SAILING will be received in 2012, thus allowing further determination of the profile of dolutegravir.
"The SPRING-2 findings indicate that once daily unboosted dolutegravir may offer people living with HIV an additional treatment option in the future. These are the first large-scale safety and efficacy data in naïve patients, and we look forward to seeing further data in 2012 to build a more comprehensive picture of the role of dolutegravir," said Dr John Pottage, Chief Medical Officer, ViiV Healthcare.
Full results of the study, including the full results of the secondary endpoints, will be presented at an upcoming scientific meeting.
GSK.L is currently trading at 1,400.50 pence, up 4 pence or 0.29 percent, on a volume of 465,981 shares.
by RTT Staff Writer
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