Ledipasvir is a drug for the treatment of

hepatitis C Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver; it is a type of viral hepatitis. During the initial infection period, people often have mild or no symptoms. Early symptoms can include ...

that was developed by

Gilead Sciences Gilead Sciences, Inc. () is an American biopharmaceutical company headquartered in Foster City, California, that focuses on researching and developing antiviral drugs used in the treatment of HIV/AIDS, hepatitis B, hepatitis C, influenza, and CO ...

. After completing Phase III clinical trials, on February 10, 2014, Gilead filed for U.S. approval of a ledipasvir/sofosbuvir fixed-dose combination tablet for genotype 1 hepatitis C. The ledipasvir/sofosbuvir combination is a direct-acting antiviral agent that interferes with HCV replication and can be used to treat patients with genotypes 1a or 1b without PEG-interferon or

ribavirin Ribavirin, also known as tribavirin, is an antiviral medication used to treat illness caused by respiratory syncytial virus (RSV) and hepatitis C virus (HCV) infections, as well as some viral hemorrhagic fevers. For HCV, it is used in combi ...

. Ledipasvir is an

inhibitor Inhibitor or inhibition may refer to: Biology * Enzyme inhibitor, a substance that binds to an enzyme and decreases the enzyme's activity * Reuptake inhibitor, a substance that increases neurotransmission by blocking the reuptake of a neurotransmi ...

of NS5A, a

hepatitis C virus The hepatitis C virus (HCV) is a small (55–65 nm in size), enveloped, positive-sense single-stranded RNA virus of the family ''Flaviviridae''. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer ( hepatoc ...

protein. Data presented at the 20th Conference on Retroviruses and Opportunistic Infections in March 2013 showed that a triple regimen of the nucleotide analog inhibitor sofosbuvir, ledipasvir, and

produced a 12-week post-treatment sustained virological response (SVR12) rate of 100% for both treatment-naive patients and prior non-responders with HCV genotype 1. The sofosbuvir/ledipasvir coformulation is being tested with and without ribavirin. In February 2014 Gilead filed for United States

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...

(FDA) approval of ledipasvir/sofosbuvir oral treatment, without interferon and ribavirin. On 10 October 2014 the FDA approved the combination product ledipasvir/sofosbuvir called ''Harvoni''.

Medical uses

Ledipasvir is most commonly used in combination with sofosbuvir for treatment in chronic hepatitis C genotype 1 patients. This drug has been tested and shown efficacy in treatment-naive and treatment experienced patients.

Adverse effects

According to clinical trials, ledipasvir/sofosbuvir has been very well tolerated with the most common side effects being fatigue and headache.

Interactions

Most drug-drug interactions with Harvoni involve Pgp-inducers such as St. John’s wort or

rifampicin Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), ''Mycobacterium avium'' complex, leprosy, and Legionnaires' disease. It is almost always used tog ...

. Concomitant use will decrease the blood concentration of Harvoni and thus, have reduced therapeutic effects.

Mechanism of action

Ledipasvir inhibits an important viral phosphoprotein, NS5A, which is involved in viral replication, assembly, and secretion. Sofosbuvir, on the other hand, is metabolized to a

uridine Uridine (symbol U or Urd) is a glycosylated pyrimidine analog containing uracil attached to a ribose ring (or more specifically, a ribofuranose) via a β-N1- glycosidic bond. The analog is one of the five standard nucleosides which make up nuc ...

triphosphate mimic, which acts as a

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

chain terminator when incorporated into RNA by NS5B polymerase.

Cost

Similar to sofosbuvir, the cost of Harvoni has been a controversial topic. It costs $1,125 per pill in the US, translating to $63,000 for an 8-week treatment course, $94,500 for a 12-week treatment course, or $189,000 for a 24-week treatment course. Gilead justifies the cost by outweighing the benefit of curing hepatitis C over the cost of spending double on liver transplants or temporarily treating liver diseases. Gilead has provided a ledipasvir/sofosbuvir assistance program for eligible underserved or underinsured hepatitis C patients who cannot afford the costs of treatment. In July 2015 Gilead modified the eligibility criteria to receive Support Path benefits for HCV patients in the United States.

References