SAN FRANCISCO — Despite continued drug use, hepatitis C reinfection rarely occurred in a cohort of patients with HCV who received opioid agonist therapy and were treated for HCV, according to findings presented at The Liver Meeting 2018.
Jason Grebely, PhD, of The Kirby Institute at the UNSW Sydney, Australia, and colleagues, aimed to further analyze HCV reinfection patterns as they associate with injection drug use risk behavior in a cohort of patients who completed the Co-STAR Part A study.
“The Co-STAR Part B trial design was a 3-year observational study open to all participants who got greater than or equal to one dose of elbasvir and grazoprevir [Zepatier, Merck] in Part A of the study,” Grebely said. “Participants with genotype 1, 4, and 6 infection were included.”
Grebely noted that the overall SVR in Co-STAR Part A was 91%.
In Part B of the analysis, researchers followed up patients at 6, 12, 18, 24 and 30 months to determine rates of HCV RNA reinfection. Clinicians also genotyped and sequenced patients, performed urine drug screening, and surveyed them about drug use behaviors at each visit. Among 199 patients enrolled in Part B of the study, 148 made it to final follow-up at 30 months.
“Overall, retention was reasonably good in this study,” Grebely said.
A slightly higher proportion of patients who reported positive drug screenings continued through to Part B from Part A of the study, according to Grebely.
Results from the 6-month visit showed that 50% of patients reported using drugs within the last month. This trend persisted through 12 months (47%), 18 months (49%), 24 months (44%), and 30 months (44%). Regarding injection drug use, 21% reported using at 6 months, 19% at 12 months, 17% at 18 months, 15% at 24 months, and 16% at 30 months. Sharing of injection equipment ranged from 5% at 6 months to 3% at 30 months.
“As you can see, injection drug use remained consistent,” Grebely said.
Self-reporting data showed that 45% of the cohort had used non-injection drugs at 6 months, which also remained relatively stable through the 30-month time point (39%). “This was demonstrating little change in drug user over time, at least by self-reporting,” Grebely said.
There were 10 patients who experienced reinfections, eight of whom had persistent reinfections, according to Grebely. Overall, reinfections occurred in 1.8 patients per 100 person-years, according to Grebely. The rate was 2.8 infections per 100 person-years among those reporting injection drug use.
“We saw a higher rate of reinfection in early follow-up,” Grebely said. “That may be attributed to more frequent visits early in the follow-up period.”
Four of those patients were retreated outside of the parameters of the trial, while two reported spontaneous clearance. – by Rob Volansky
Grebely J, et al. Abstract 52. Presented at: The Liver Meeting 2018; Nov. 9-13, 2018; San Francisco.
Disclosure: Grebely reports no relevant financial disclosures.