Guidelines regarding the use of IFNL3 (formerly known as IL28B) genotypes in peginterferon alpha based therapies have been accepted for publication in the Clinical Pharmacology and Therapeutics by the Clinical Pharmacogenetics Implementation Consortium (CPIC).
Hepatitis C virus (HCV) infection affects more than 150 million people worldwide and is one of the leading causes
of cirrhosis and hepatocellular carcinoma. Treatment for chronic
HCV infection includes combination pegylated-interferon alpha 2a or 2b
(PEG-IFN α) and ribavirin (RBV) therapy as well as protease
inhibitors. The response rate varies greatly among patients and had been especially low for patients with HCV genotype 1 and 4. Currently IFNL3 (IL28B) variations (rs12979860 and
rs8099917) are the strongest baseline predictor of response to PEG-interferon-α
and ribavirin therapy in HCV genotype 1 patients. Patients with the favorable response genotype (rs12979860 CC) have increased likelihood of response (higher SVR rate) to PEG-IFN α and RBV therapy
as compared to patients with unfavorable response genotypes (rs12979860 CT or TT). With protease
inhibitor regimens, the IFNL3 genotype
predicts response and also predicts eligibility for the shorter durations of
therapy. The IFNL3 genotypes along with other clinical and genetic factors may guide patients
and clinicians in their treatment decisions.
For details, see the CPIC guideline, accepted article preview and supplement for IFNL3 (IL28B) and peginterferon alpha based regimens.
For other CPIC guidelines see the list of CPIC publications and guidelines in progress.