Janssen-Cilag Ltd has announced that NHS England (NHSE) will provide crucial funding for its once-daily, fixed-dose combination of darunavir and the pharmacoenhancer, cobicistat, called REZOLSTA® (darunavir/cobicistat). Darunavir/cobicistat is indicated for use in combination with other antiretroviral medications, for treating adults with human immunodeficiency virus-1 (HIV-1) whose virus does not carry darunavir resistance-associated mutations.1
This means that across England, clinicians will be able to routinely prescribe darunavir – the UK’s most prescribed protease inhibitor2 – combined with a ‘booster’ – in only one tablet to adults living with HIV-1.
With fewer than 2 out of 3 HIV patients in the UK reporting 100% adherence after 8 months of treatment,3 experts believe that the fixed-dose combination of darunavir/cobicistat could help improve adherence by reducing the number of pills that a patient needs to take.4 This is important given that optimal adherence is generally considered to be above 95%, the level required to prevent HIV becoming resistant to medication.5
Dr Rozlyn Bekker, Medical Director, Janssen UK, commented: “Significant progress in HIV treatment means that HIV can now be managed as a chronic disease with potentially normal life expectancy, provided that patients are able to adhere to treatment. By funding treatment, NHS England is making available a treatment option for individuals who require darunavir to effectively control the HIV, but who would potentially also benefit from the convenience of fewer tablets to support their adherence to treatment.”
The data have demonstrated that once-daily darunavir/cobicistat, in combination with 2 nucleotide/nucleoside reverse transcriptase inhibitors, offers effective virological suppression; the virologic response rates (HIV-1 viral load <50 copies/ml) over 48 weeks were 81% overall and 83% in treatment-naïve patients.6 Only 5% of patients discontinued treatment due to adverse events, the most common of which were diarrhea (27%) and nausea (23%), which were grade 1 or 2 in severity.6
Darunavir is a protease inhibitor used for the treatment of human immunodeficiency virus-1 (HIV-1) infection and can be taken with either ritonavir (indicated for use in adults and paediatric patients from the age of 3) or cobicistat (indicated for use in adults only). Darunavir received initial approval in Europe in 2007 for use in HIV-1 infected highly pre-treated patients, with later approvals for treatment-naïve and less experienced adult patients, and then for use in paediatric patients. Darunavir/ritonavir is approved for use in paediatric patients aged 3-17.7
Tybost (cobicistat 150 mg tablets) is a cytochrome P450 3A (CYP3A) inhibitor. It boosts blood levels of atazanavir or darunavir by inhibiting CYP3A, an enzyme that metabolises these drugs in the body. Cobicistat acts only as a pharmacokinetic enhancer and has no antiviral activity. Cobicistat was developed by Gilead Sciences Inc. and is a pharmacokinetic enhancer or boosting agent used with the protease inhibitors darunavir and atazanavir and also the integrase inhibitor elvitegravir, for the treatment of HIV. Gilead Sciences Inc. is responsible for the manufacture, development and commercialization of Tybost® (cobicistat) as a stand-alone product.8