Brand name: Not yet established
Generic name: dolutegravir, or DTG
Class: Integrase inhibitor (integrase strand transfer inhibitor, or INSTI)
AWP: TBD; investigational drug at press time.
Standard Dose: One 50 mg tablet once a day chosen for Phase 3 research. Twice-daily dosing was shown to work better in people who have viral resistance to Isentress and the investigational elvitegravir in a short study, VIKING Cohort II, and a large ViiV Phase 3 trial will look at the twice-daily dose. Take missed dose as soon as possible, unless it is closer to the time of your next dose. Do not double up on your next dose.
Potential side effects and toxicity: Seen in clinical studies: nausea, diarrhea, headache, dizziness, fatigue, weakness, and upset stomach or indigestion. Lymphatic cancer occurred in one study participant, but there is no information yet about whether or not this was drug-related. Available data are limited due to investigational drug status.
Potential drug interactions: There is evidence that Aptivus/Norvir, Sustiva, and Intelence lower dolutegravir concentration. More drug interactions are anticipated, but data are limited right now due to investigational drug status. Tell your provider or pharmacist about all medications, herbs, and supplements you are taking or thinking of taking, prescribed or not.
More information: Still in clinical study, but expected to be available this year through expanded access (free medication to those in great need). Dolutegravir is a second-generation INSTI, meaning that it can work in people whose virus has developed resistance to Isentress and the investigational elvitegravir, but it will likely need to be dosed twice daily in these individuals. Does not require use with a booster medication like elvitegravir (see elvitegravir page). Development of a co-formulated single-tablet regimen with abacavir and lamivudine is in the works. It is being studied at a twice-daily dose with an optimized background regimen (the best regimen a medical provider can create for a study participant) in people with current or a history of treatment failure with an INSTI (basically, those for whom Isentress no longer works, but also those who experienced virologic failure on the investigational elvitegravir). Visit www.clinicaltrials.gov and search for VIKING-3 to learn about this study. It was found to be as safe and effective as Sustiva (efavirenz, the principle component of Atripla) at 48 weeks in the SPRING-1 study, with a faster time to undetectable viral load of less than 50 copies per mL and fewer side effects in people on HIV therapy for the first time. Both groups saw an increase of about 200 in their CD4+ T-cell counts, with no statistically significant difference. The three people with virologic failure on dolutegravir (2% of study participants) had no INSTI resistance mutations in their virus, a good sign and something you want to see in a new INSTI. This study had mostly young, white men as participants and these results may not be applicable to the general public. Another study indicates efficacy against virus that is resistant to Isentress and elvitegravir. Dolutegravir is being developed by ViiV Healthcare in collaboration with Shionogi. Providers may want to order a resistance test that can measure INSTI resistance (standard resistance tests cannot). See package insert, when available, for more complete information on potential side effects and interactions.
Dolutegravir is an investigational, once-daily integrase inhibitor that does not require boosting. Clinical trials suggest that the combination of dolutegravir plus two NRTIs is as effective as Atripla for initial therapy, with better tolerability. Resistance to dolutegravir has been uncommon so far, which may give it an advantage over Isentress and elvitegravir. Dolutegravir may have "second generation potential," since it can still be active against virus that's resistant to Isentress and elviteg-ravir, especially when it's given at a higher dose. Still, it's best to avoid extensive integrase inhibitor resistance by stopping integrase inhibitors that aren't working, since some mutations cause more cross-resistance than others.
-- Joel Gallant, M.D., M.P.H.
This new agent is a promising competitor to Isentress and another integrase inhibitor, elvitegravir. This second-generation drug doesn't need a booster (can you say Hallelujah!) and has a less likely and different resistance profile than others in this class. After speaking to a few lucky folks already on this one, they all report feeling just fine. Isentress finally has some competition to be worried about! I heard there might be a combo involving Epzicom [emtricitabine and abacavir], but I'm not sure if that would catch hold in the treatment-experienced world, with all the baggage abacavir has had in the past.
-- Joey Wynn