Phase 4 Real-World Study Assesses Simeprevir for Hepatitis C

A phase 4 study examined how effective simeprevir (Olysio/Janssen) treatment is in a real-world setting for patients infected with chronic genotype 1 hepatitis C.

Conducted by Imtiaz Alam, MD, PA, of the Austin Hepatitis Center, and colleagues, the study is called Simeprevir ObservatioNal Effectiveness across practice seTtings (SONET). Trial and clinical study results can vary dramatically compared to those obtained in real-world settings. Therefore, Alam and team took a real-world approach to assess the medication, and found that it is common, well-tolerated, and effective.

Simeprevir was approved by the US Food and Drug Administration (FDA) in late 2013 after 80% of treatment-naïve patients achieved sustained virologic response (SVR) with a simeprevir, peginterferon-alfa, and ribavirin combination.

For this phase 4, observational study, the researchers included patients from 37 sites. SONET was conducted between February 2014 and November 2015. In addition to examining the effectiveness of simeprevir-based regimens, the researchers considered patient and practice characteristics, virologic response rates and associated factors, and safety outcomes.

Of the 315 patients, 291 completed the treatment and 275 completed the study.

“In total, 258/315 (81.9%) patients received 12 weeks of treatment; for patients without cirrhosis, 170/191 (89%) received treatment for 12 weeks,” the authors wrote in the Oxford University Press.

Further, 88 out of 124 patients with cirrhosis received 12 weeks of treatment, while 25 of them received 24 weeks. Academic medical centers, private practice clinics, integrated healthcare systems, and other clinics made up the practice settings involved in the study.

The main finding that came out of SONET is that more than 90% of the patients achieved SVR 12 weeks (SVR12) after finishing the simeprevir-based treatment regimen in a real-world setting. The authors add that their results also underscore “the challenge of patient follow-up outside of clinical trials.”

A total of 255 patients in the study were receiving simeprevir and sofosbuvir; only 17 patients were also receiving ribavirin. The researchers noted that a higher proportion of those receiving ribavirin achieved SVR12 than those receiving only simeprevir and sofosbuvir. However, due to the low numbers of patients taking ribavirin, the researchers could not formally evaluate those results.

The researchers recognized that one challenge was that they used an intent to treat (ITT) analysis in an observational study design is difficult because patients are lost to follow-up and then considered non-responders.

“The proportion of patients who had cirrhosis (30.4%) was higher than that seen in most clinical trials, suggesting that clinicians in the real world are treating patients with more advanced disease than those included in clinical studies,” the team continued.

A final challenge was that there was some difficulty in finding healthcare providers in particular practice settings, such as opiate dependency centers and community health centers. The lack of participation by such centers, where there may be more diversity, made assessing such factors as patient interaction with staff and socioeconomic status impossible.

Nevertheless, the regimen effectively treated patients with genotype 1 hepatitis C with few negative outcomes.

The study, “Real-World Effectiveness of Simeprevir-Containing Regimens Among Patients with Chronic Hepatitis C Virus: The SONET Study,” was published by the Oxford University Press on behalf of the Infectious Diseases Society of America.

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