Engagement and Retention
Co-infections and Related Conditions (CRC)
This study will examine the feasibility of switching antiretroviral therapies (ART) followed by antiviral treatment for hepatitis C for co-infected people receiving methadone as opioid substitution therapy in Regina, Saskatchewan. Specifically, participants will switch to E/C/F/TAF (elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide) and then receive SOF/VEL (sofosbuvir/velpatasvir), followed by a switch to B/F/TAF (bictegravir-emtricitabine-tenofovir alefenamide fumerate).
Injection drug use is the primary risk factor for HIV in Saskatchewan, a province where incidence rates of HIV are double those of the rest of Canada. In 2011, over three quarters of HIV cases in Saskatchewan were due to injection drug use, compared to only one in five in the rest of the country. A significant number of people in this population are also living with hepatitis C virus (HCV) and many are current receiving opioid substitution therapy (OST), including methadone.
For people receiving methadone, regular trips to community pharmacies can help to improve adherence to other medications, like HIV and HCV antiviral therapies. The regimens used in this study are once daily and one pill each, characteristics which will help to optimize and monitor treatment adherence in this group. Although E/C/F/TAF and SOL/VEL have been tested independently, they have not been adequately studied in combination or in persons receiving OST. The logic behind the final switch to B/F/TAF is that it is a smaller pill size, has excellent tolerability, and a reduced risk of interactions with other medications.
As a feasibility study, the primary goal of the study is to assess how willing people are to switch their antiviral regimen and how adherent people were once they switched. The researchers are also interested in assessing the safety and success of this regimen in this specific population (HIV/HCV positive and receiving methadone treatment), information which may provide justification for this approach in the future. The data gathered in this study will also inform the feasibility of future clinical trials that aim to evaluate new or under-studied treatment strategies in non-traditional patient populations such as those on OST and those who use injection drugs.
On the first study visit, participants will undergo a regular clinical assessment as well as bone and kidney health testing. Participants will switch to E/C/F/TAF and be monitored for 12 weeks. Following this period, the HCV antiviral regimen (SOF/VEL) will be added to the regimen for a further 12 weeks — all study drugs will be dispensed during daily visits to community pharmacies. After completion of the SOF/VEL treatment, study participants will visit their physicians for assessments at 12- and 24-weeks post-treatment. Finally, participants will switch to B/F/TAF for a further 48 weeks. At the end of the study, participants and their physician will decide whether to remain on B/F/TAF, switch to a different ART regimen, or resume a previous ART regimen.
If you would like more information on this clinical study, please refer to clinicaltrials.gov.