Harvoni is the latest hepatitis C drug created by Gilead Sciences. It is widely known as the most effective chronic hep C treatment.
How Harvoni works depends on its pharmaceutically active ingredients. Harvoni is a pill made of 90 mg of ledipasvir and 400 mg of sofosbuvir. Sofosbuvir, which is a completely new substance, having a reputation of the new wonder (though expensive) drug. It manages on itself to cure roughly 90% of hepatitis C patients. Harvoni, sofosbuvir mixture with ledipasvir, cure rate is 99%.
Sofosbuvir mechanism of action is simple enough. Hepatitis C is a virus disease, and virus needs to reproduce in order to survive. Sofosbuvir inhibits viral reproduction by being built in the new virus as an inhibiting building block. Virus needs RNA molecule to reproduce, and sofosbuvir prevents this RNA molecule from forming. You can read more about sofosbuvir mechanism of action.
What makes Harvoni more effective is addition of molecule ledipasvir to sofosbuvir. How Harvoni works is largerly based on how sofosbuvir works; but the additional 9% in cure rate is because of ledipasvir mechanism of action.
This is ledipasvir molecule.
It might seem like much and it truly is quite useful. It's mechanism of action is similar to sofosbuvir's. Ledipasvir targets a piece inside hepatitis C virus. This piece is called phosphoprotein NS5A. It is responsible for virus replication and construction. By targeting and inhibiting this protein, hepatitis C virus is powerless to replicate. Our immune system is thus given a chance to kill it of, which in most cases does very well.
It is also noteworthy that treatment with Harvoni does not need interferon; which in needed is some treatment cases with Sovaldi (drug only with sofosbuvir). This means that patients don't have to use needlees for interferon administration on daily basis.
Sofosbuvir and ledipasvir work synergetically to weaken hepatitic C replication. In such a way, virus is weakened. Immune system does the rest.
In bottomline, how Harvoni works in not unlike how Sovaldi works, Harvoni just does it better.