Results from the study, known as AntiRetroviral Therapy with TMC114 examined in naïve subjects (ARTEMIS), were published in AIDS. The study compared the efficacy and safety of the protease inhibitors darunavir/ritonavir (r) and lopinavir/r in treatment-naïve adults with HIV (those who have never taken HIV medication before) [1].

ARTEMIS is an international ongoing, randomized, controlled, open-label non-inferiority Phase III trial that compares the efficacy and safety of darunavir/r with lopinavir/r in treatment-naïve HIV-1-infected adult patients with viral load greater than 5000 copies/mL [1].

At 48 weeks, the primary objective of ARTEMIS was reached when darunavir/r was demonstrated to be non-inferior to lopinavir/r for virologic response (confirmed HIV RNA < 50 copies/mL) [1]. The difference between the treatment arms was not significant at week 48 [1]. The pre-planned safety and efficacy analysis at 96 weeks was a secondary endpoint [1]. At 96 weeks, the study showed darunavir/r was non-inferior to lopinavir/r for virologic response [1]. The estimated difference in virologic response between the treatment groups was eight per cent and statistically significant (95 per cent confidence interval 1.9; 14.8) per data published in AIDS [1].

In the 96-week per-protocol analysis of 689 patients, darunavir/r 800/100mg once daily was shown to be non-inferior to lopinavir/r 800/200mg once daily or 400/100mg twice daily in treatment-naïve adults with HIV-1 [1]. In addition, in the intent-to-treat analysis, the study showed that:

• 79 per cent of patients in the darunavir/r arm reached an undetectable viral load (<50 copies/mL), versus 71 per cent of patients in the lopinavir/r arm, (p = 0.012) [1].
• In patients with a high baseline HIV-1 RNA (≥100,000 copies/ml; n = 237), virologic response rates were higher with darunavir/r than with lopinavir/r (76 versus 63%, respectively; P = 0.023) [1].
• Similarly, for those with a baseline CD4 cell count less than 200 cells/ml (n = 289), the response rate was higher in the darunavir/r arm than in the lopinavir/r arm (79 versus 65%, respectively; P = 0.009) [1].
• Response rates between arms were not significantly different for patients with HIV-1 RNA less than 100,000 copies/ml (darunavir/r: 81% versus lopinavir/r: 75%) or CD4 cell count at least 200 cells/ml (darunavir/r: 79% versus LPV/r: 75%) at baseline [1].

Incidence of grade 2–4 treatment-related diarrhoea reported in the darunavir/r arm was four per cent versus 11 per cent in the lopinavir/r arm [1]. Nausea was reported in two per cent versus three per cent, respectively [1]. Discontinuations due to adverse events were four per cent in the darunavir/r arm and nine per cent in the lopinavir/r arm [1].

There are an estimated 77,400 people living with HIV in the UK, and at least 7734 people were diagnosed with the virus in 2007 [2]. Although there is still no cure for HIV or AIDS, the combination of existing and more recent treatments known as highly active antiretroviral therapy (HAART) has drastically improved life expectancy for people living with HIV/AIDS and decreased the number of people who die from AIDS [3].

Darunavir is part of a group of anti-HIV treatments called protease inhibitors, which stop the replication of the HIV virus by attacking an enzyme in HIV, called protease. Nearly all the protease inhibitors used today are ’boosted’. This means they have their power increased by the addition of a small dose of a second protease inhibitor called ritonavir [4].

References

1 Mills, A. et al (2009) Once-daily darunavir/ritonavir vs. lopinavir/ritonavir in treatment-niave, HIV-1-infected patients: 96-week analysis. AIDS. (in press)
2 Health Protection Agency (2008) Record numbers living with HIV in the UK. Cited 12 Jan 2009.
3 AVERT.org. HIV and AIDS in the UK. Cited 13 Jan 2009.
4 NAM. HIV treatment. Cited 12 Jan 2009.