The US Food and Drug Administration (FDA) has approved a new antiviral drug to treat chronic cases of hepatitis C which functions by attacking hepatitis C virus (HCV) strains. In its press release on June 28, 2016, FDA stated the new HCV drug, Epclusa, will be a pioneer drug in this field.
Manufactured and marketed by Gilead Sciences, Inc, of Forster City California, Epclusa is a fixed-dose drug which is a combination of two drugs, sofosbvir and velpatasir, used in a 4:1 volume. Following the drug approval, the stocks of Gilead Sciences, Inc saw a rise which is likely to attract investors as well.
The orally administered tablet is recommended for adult patients of HCV with and without advanced liver disease, known as cirrhosis. However, Epclusa is recommended to be used in combination with another HCV drug ribavirin for patients who suffer from decompensated cirrhosis which is characterized by moderate to severe cirrhosis. .
The cure rate of 90% is hoped to further improve with the use of Epclusa as it penetrates six HCV viral genomes to hinder their activity. In this regard, Edward Cox, MD, director of the Office of Antimicrobial Products in the FDA’s Center for Drug Evaluation and Research commented, “This approval offers a management and treatment option for a wider scope of patients with chronic hepatitis C.”
Amongst the targeted viral strains, FDA discovered about 75% American patients of HCV have contracted HCV genotype 1, for about 20-25% patients genotypes 2 and 3 come into play while in a very small population of patients, viral genotype 4, 5 and 6 are present. With the approval of Epclusa, even rarely occurring strains of HCV will be targeted.
Hepatitis C is classified as one of the leading causes of liver dysfunction which affects 130-150 million people globally. The virus that leads to serious hepatitis C virus-related liver problems such as cirrhosis and liver cancer claims about 500,000 lives annually. It is a bloodborne disease which spreads from one person to another through unscreened blood transfusion, sharing of injection syringes and the use of non-sterilized medical equipment. Although the virus can lead to serious symptoms; if antiviral medication is taken on time, the condition can be cured in 90% of cases.
Epclusa works efficiently against Hepatitis C by making use of the action mechanisms of sofosbuvir and velpatasvir, simultaneously. Sofosbuvir inhibits the activity of HCV NS5B RNA-dependent RNA polymerase which is crucial for viral replication. It also adds uridine analog triphosphate to the viral RNA which acts at a chain terminator for the viral nucleotide sequence. On the other hand, velpatasvir is an inhibitor of HCV NS5A protein which is important for viral genome replication.
Prior to gaining FDA approval, the drug safety and efficacy was observed in three Phase 3 clinical trials with 1,558 participants who took the drug for 12 weeks for their condition. The results were very successful, as 95-99% of the blood tests taken after 12 weeks detected no traces of the virus.
Additionally, 267 patients out of all patients suffered from decompensated cirrhosis. Of these 267 patients, 87 participants were given Epclusa in combination with ribavirin for 12 weeks. Amongst them, 94% cases showed no presence of the virus in the blood test.
Despite significant findings in favor of the drug, FDA has also pointed out a few side effects of Epclusa such as headache and signs of fatigue. For patients who have disease comorbidity, some precautions were also highlighted. The combination of Epclusa and ribavirin is not recommended for patients who show side effects with the use of ribavirin alone. Epclusa is also associated with the slowing down of the heart rate (Bradycardia). Patients who take beta blockers or amiodarone for underlying heart conditions can also have serious episodes of bradycardia.
To counteract these adverse effects, co-administration of amiodarone with Epclusa is discouraged. Some other drugs may also reduce the efficacy of Epclusa. Therefore it is important, particularly for patients who have cardiac co-morbidities or other advanced liver diseases, to visit their doctors and receive a personalized drug prescription in accordance with the individual’s medical needs.