DAA Non-Adherence Results in Lower Virologic Response Rates

Issue: June 2016

SAN DIEGO — Non-adherence to novel direct-acting antiviral therapies resulted in a 19% reduction in sustained virologic response at 12 weeks, according to findings presented at Digestive Disease Week 2016.

Amber R. Altstadt, PharmD, of the department of pharmacy at Froedtert and The Medical College of Wisconsin in Milwaukee, said that WHO estimated 50% of people do not take chronic medications as prescribed. “This has been documented in literature,” she said. “Our aim was to analyze missed doses of DAA medications and their impact on SVR12.”

The retrospective chart review was conducted in patients treated with novel DAA therapies between January 2014 and June 2015 at a single clinic in the U.S. The clinic employs a pharmacist, nurses and medical providers to care for patients in a team-based approach. The clinic pharmacist contacts patients every 2 to 4 weeks to assess DAA treatment adherence, tolerability, and interactions. The researchers defined more than one missed dose per month on average or more than five total missed doses as non-adherence.

Results indicated that 24 patients were non-adherent and 113 were adherent. SVR12 rates were 67% in the non-adherent group (an additional 8% with HCV RNA quantification <12 IU/mL) and 86% in the adherent group (an additional 10% with HCV RNA quantification <12 IU/mL; P = .037). “There was a 19% lower rate of SVR12 achievement in patients who had documented non-adherence vs. those with documented adherence,” Altstadt said.

“I do want to note that there was some HCV lab heterogeneity,” she said in reference to the HCV RNA <12 IU/mL results, which will be assessed for SVR24 achievement in a study extension. She added that despite lab heterogeneity, there was a clear 25% relapse rate in the non-adherent group vs. only 4% in the adherent group.

Psychiatric illness, female gender, and African American race were significantly associated with non-adherence. Cirrhosis demonstrated a non-significant association with non-adherence.

Adverse events were reported, including fatigue, headache, nausea, diarrhea, anorexia, and rash. None of these factors significantly impacted adherence. “Nausea did come close,” Altstadt said.

Altstadt concluded that more proactive efforts targeting adherence may benefit individual and population health.

Reference:

Altstadt AR, et al. Abstract #601. Presented at: Digestive Disease Week; May 21-24, 2016; San Diego.

Disclosures: Altstadt reports no relevant financial disclosures.