The Food and Drug Administration (FDA) has approved a new drug that fights chronic hepatitis C infections (HCV).

"Today's approval represents a significant shift in the treatment paradigm for some patients with chronic hepatitis C," Edward Cox, M.D., director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research, said in an FDA news release.

Sovaldi is the second HCV-treating drug approved by the FDA in the past two weeks; the FDA approved the drug Olysio (simeprevir) on Nov. 22.

The drug is a nucleotide analog inhibitor, which blocks a protein that HVC needs to replicate. It is expected to be used in combination with other drugs.

Sovaldi was successful in six clinical trials that encompassed 1,947 that were infected with HCV and had either not been treated or did not respond to other medicines. The drug was shown to eliminate the virus within 12 weeks.

The drug will provide an option for patients who cannot handle an interferon-based treatment regimen or who are suffering from liver cancer and waiting for a transplant; these groups were previously unable to receive treatment.

The most common side effects of Sovaldi and ribavirin are fatigue and headache. The widely-seen side effects in those on a Sovaldi, ribavirin and peginterferon-alfa regimen were "fatigue, headache, nausea, insomnia and anemia," the news release reported.

Sovaldi was reviewed under the FDA's priority review program, which looks at drugs designed to treat serious conditions and would provide "significant improvement in safety or effectiveness" if approves.

"Sovaldi is the third drug with breakthrough therapy designation to receive FDA approval. The FDA can designate a drug as a breakthrough therapy at the request of the sponsor if preliminary clinical evidence indicates the drug may demonstrate a substantial improvement over available therapies for patients with serious or life-threatening diseases," the news release reported.