Adherence was also reported to be high, yet variable, with use of wireless pillboxes and video-based observed therapy.
Findings from a new study indicated high sustained virologic response (SVR) rates among individuals with Hepatitis C Virus (HCV) infection and active drug/alcohol use.
Furthermore, these patients demonstrated high, but variable, adherence to ledipasvir/sofosbuvir using wireless pillboxes and video-based observed therapy.
These results suggest further potential for expanding HCV treatment in a population that is often subject to adherence and reinfection concerns.
Kristina Brooks, PharmD, and colleagues at the University of Colorado Anschutz Medical Campus, conducted a prospective, open-label study of ledipasvir/sofosbuvir in persons who use drugs or alcohol in order to assess treatment outcomes and adherence predictors.
Patients were randomized to wireless or video-based directly observed therapy and were assessed every 2 weeks for 12 weeks total.
Brooks and team examined SVR by intention-to-treat and as-treat. Additionally, they used generalized linear models to determine risk factors associated with poor adherence, defined as missing ≥1 dose(s) between visits.
Overall, they assessed a total of 60 participants, all of whom received ≥1 dose of treatment. Of the total, 78% were male and 22% were Black. Further, 25% were cirrhotic and 78% had comorbid HIV.
The investigators noted that 94% of the 343 person-visits were positive with current drug use—which was assessed through self-report or urine toxicology screen. The most common substances were marijuana (60%), alcohol (56%), methamphetamine (37%), opioids (22%), cocaine (17%), and injection drug (20%).
By intention-to-treat, 86.7% of the 60 patients achieved SVR (95% CI, 75.4-94.1). Furthermore, there was no observed significant difference between the type of therapy.
In the as-treated population—or those with results available 12 weeks after treatment completion—94.5% (95% CI, 84.8-98.9) were considered cured.
As for intention-to-treat therapy adherence, median total adherence was 96% (IQR, 83-99) overall. Wireless pillboxes and video therapy did not differ significantly by total (P = .08) or 84-day adherence (P = .09).
Further, between-visit adherence was 100% (IQR, 86-100%).
According to univariable models, risk factors associated with poor adherence included HIV coinfection (OR, 2.94; 95% CI, 1.37-6.32; P = .006), black race (OR, 4.09; 95% CI, 1.42-11.74; P = .009), methamphetamine use (OR, 2.51; 95% CI, 1.44-4.37; P = .001), and cocaine use (OR, 2.12; 95% CI, 1.08-4.18; P = 0.03).
However, these odds decreased with marijuana use (OR, O.34; 95% CI, 0.17-0.70; P = 0.003) and video-based directly observed therapy (OR, 0.43; 95% CI, 0.21-0.87; P = 0.02).
And finally, the investigators reported that any adverse events possibly related to study medication (n = 55) were mild or moderate in severity. The most common events included fatigue (12.1%), diarrhea (17.2%), headache (12.1%), and other gastrointestinal issues (10.3%). There was 1 participant who discontinued treatment due to nausea and vomiting at week 11 but nonetheless achieved SVR.
“Though overall adherence and SVR rates were high, risk factors for missed doses between study visits were identified, notably the use of methamphetamine, cocaine, Black race, and having HIV,” the investigators wrote.
They indicated that larger studies evaluating these factors in greater detail are warranted so as to ensure all persons actively using drugs with HCV are successfully and properly treated.
“Our findings support expanding DAA treatment to PWUD to eradicate HCV, and the use of technology-based measures to facilitate treatment uptake in this population,” the team concluded.
The study, “Adherence to Direct-Acting Antiviral Therapy in People Actively Using Drugs and Alcohol: The INCLUD Study,” was published online in Oxford Academic: Open Forum Infectious Diseases.