New interferon shows fewer side effects and better treatment rate

April 17, 2011

Promising early results from the EMERGE study of the new drug peg-interferon lambda show that people tolerate it better than the current peg-interferon alpha. The lambda version also appears to suppress hepatitis C (HCV) to undetectable levels in more people than the alpha drug.

As one of the two drugs used in current standard treatment, peg-interferon (pIFN) alpha can cause troublesome side effects, including severe flu-like symptoms such as muscle aches and pains, nausea, fever, headache, tiredness and dry skin, as well as anxiety and depression. This newer version appears to cause far fewer side effects, and may even offer people a better option to standard treatment.

The study followed 526 people who started HCV treatment for the first time. Four groups took ribavirin with either pIFN-alpha or one of three doses of pIFN-lambda. Among those with the hardest-to-treat genotypes 1 and 4, 56% of those on pIFN-lambda reached undetectable HCV compared to 38% on pIFN-alpha after 12 weeks of treatment. Among those with types 2 and 3, response rates were closer, with 84% on pIFN-lambda and 97% on pIFN-alpha becoming undetectable.

Low levels of a certain white blood cell called neutrophils, or neutropenia, rarely occurred in those on pIFN-lambda while about 15% on pIFN-alpha had the condition. Anemia occurred up to 21% of those taking pIFN-lambda while 44% of those on pIFN-alpha experienced the condition. As for other side effects, up to 13% of those on pIFN-lambda reported more general side effects compared to 47% of those on pIFN-alpha.

This is good news for people who face HCV treatment. Many don’t start because of the possible troublesome side effects from standard treatment, while others stop after a time on the drugs. A safer, more tolerable and more effective version of pIFN would be a welcome addition to the drugs used for curing hepatitis C.