RAVs are resistance associated variants. RAVs occur during (viral breakthrough) and after treatment (relapse) with direct acting antiviral medications (inhibitors—protease, polymerase, NS5A). In other words, someone is treated and not cured.
This can lead to a particular class of drugs (protease, polymerase, NS5A inhibitors) not working as well because a person has developed drug resistance.
In clinical trials of the direct acting antiviral medications, approximately 1% to 7% of the trial participants were not cured. In real world settings it is likely higher because of many issues such as missed doses, LIFE, and various health and other issues not addressed in clinical trials.
In this month’s Snapshots, I wrote about a couple of studies that addressed re-treatment. To overcome the RAVs and other negative predictors of treatment response (previous treatment non-response, cirrhosis, etc.,) ribavirin was added to both re-treatment groups. As a result, 75%-100% of the patients were cured. There are drugs being developed that have a high barrier to resistance that will replace ribavirin. Thankfully we have ribavirin now to help people in need of re-treatment and cure and, importantly, to prevent further hepatitis C disease progression.
The approach to retreatment of RAVs is rapidly evolving. Some physicians are beginning to test for RAVs, but it is far from being a routine test. Talk with your medical provider if you have questions.
If you are being re-treated with a direct acting antiviral medication, it is important to find an expert to consult with about the best HCV treatment regime for you.
Labels: direct-acting antiviral agents, NS5As, polymerase, protease, RAVs, retreatment, ribavirin, Treatment