|
Ledipasvir
Ledipasvir is a drug for the treatment of hepatitis C that was developed by Gilead Sciences. 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. Ledipasvir is an inhibitor of NS5A, a hepatitis C virus 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 ribavirin 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 ribavir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ledipasvir/sofosbuvir
Ledipasvir/sofosbuvir, sold under the trade name Harvoni among others, is a medication used to treat hepatitis C. It is a fixed-dose combination of ledipasvir and sofosbuvir. Cure rates are 94% to 99% in people infected with hepatitis C virus (HCV) genotype 1. Some evidence also supports use in HCV genotype 3 and 4. It is taken daily by mouth for 8–24 weeks. It is generally well tolerated. Common side effects include muscle pains, headache, nausea, rash, and cough. It is unclear if use in pregnancy is safe for the baby. Ledipasvir works by decreasing the activity of NS5A and sofosbuvir works by decreasing the activity of NS5B polymerase. Ledipasvir/sofosbuvir was approved for medical use in the United States, in the European Union, and in Canada in 2014. It is on the World Health Organization's List of Essential Medicines. Medical uses Cure rates are 94% to 99% in people infected with genotype 1 (46% of HCV cases). It has also been evaluated for the treatment of infection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ledipasvir/sofosbuvir
Ledipasvir/sofosbuvir, sold under the trade name Harvoni among others, is a medication used to treat hepatitis C. It is a fixed-dose combination of ledipasvir and sofosbuvir. Cure rates are 94% to 99% in people infected with hepatitis C virus (HCV) genotype 1. Some evidence also supports use in HCV genotype 3 and 4. It is taken daily by mouth for 8–24 weeks. It is generally well tolerated. Common side effects include muscle pains, headache, nausea, rash, and cough. It is unclear if use in pregnancy is safe for the baby. Ledipasvir works by decreasing the activity of NS5A and sofosbuvir works by decreasing the activity of NS5B polymerase. Ledipasvir/sofosbuvir was approved for medical use in the United States, in the European Union, and in Canada in 2014. It is on the World Health Organization's List of Essential Medicines. Medical uses Cure rates are 94% to 99% in people infected with genotype 1 (46% of HCV cases). It has also been evaluated for the treatment of infection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sofosbuvir
Sofosbuvir, sold under the brand name Sovaldi among others, is a medication used to treat hepatitis C. It is taken Oral administration, by mouth. Common side effects include fatigue, headache, nausea, and trouble sleeping. Side effects are generally more common in interferon-containing regimens. Sofosbuvir may reactivate hepatitis B in those who have been previously infected. In combination with ledipasvir, daclatasvir or simeprevir, it is not recommended with amiodarone due to the risk of an bradycardia, abnormally slow heartbeat. Sofosbuvir is in the nucleotide analog family of medications and works by blocking the hepatitis C NS5B protein. Sofosbuvir was discovered in 2007 and approved for medical use in the United States in 2013. It is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. Medical uses Initial HCV treatment In 2016, the American Association for the Study of Liver Diseases and the Infectious Diseases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 people often have mild or no symptoms. Occasionally a fever, dark urine, abdominal pain, and yellow tinged skin occurs. The virus persists in the liver in about 75% to 85% of those initially infected. Early on, chronic infection typically has no symptoms. Over many years however, it often leads to liver disease and occasionally cirrhosis. In some cases, those with cirrhosis will develop serious complications such as liver failure, liver cancer, or dilated blood vessels in the esophagus and stomach. HCV is spread primarily by blood-to-blood contact associated with injection drug use, poorly sterilized medical equipment, needlestick injuries in healthcare, and transfusions. Using blood screening, the risk from a transfusion is less than one per two million. It may also be spread from an infected mother to her ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discovery And Development Of NS5A Inhibitors
Nonstructural protein 5A (NS5A) inhibitors are direct acting antiviral agents (DAAs) that target viral proteins, and their development was a culmination of increased understanding of the viral life cycle combined with advances in drug discovery technology. However, their mechanism of action is complex and not fully understood. NS5A inhibitors were the focus of much attention when they emerged as a part of the first curative treatment for hepatitis C virus (HCV) infections in 2014. Favorable characteristics have been introduced through varied structural changes, and structural similarities between NS5A inhibitors that are clinically approved are readily apparent. Despite the recent introduction of numerous new antiviral drugs, resistance is still a concern and these inhibitors are therefore always used in combination with other drugs. Hepatitis C virus HCV is a positive-sense single-stranded RNA virus that has been demonstrated to replicate in the hepatocytes of both humans and chi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discovery And Development Of NS5A Inhibitors
Nonstructural protein 5A (NS5A) inhibitors are direct acting antiviral agents (DAAs) that target viral proteins, and their development was a culmination of increased understanding of the viral life cycle combined with advances in drug discovery technology. However, their mechanism of action is complex and not fully understood. NS5A inhibitors were the focus of much attention when they emerged as a part of the first curative treatment for hepatitis C virus (HCV) infections in 2014. Favorable characteristics have been introduced through varied structural changes, and structural similarities between NS5A inhibitors that are clinically approved are readily apparent. Despite the recent introduction of numerous new antiviral drugs, resistance is still a concern and these inhibitors are therefore always used in combination with other drugs. Hepatitis C virus HCV is a positive-sense single-stranded RNA virus that has been demonstrated to replicate in the hepatocytes of both humans and chi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 COVID-19, including ledipasvir/sofosbuvir and sofosbuvir. Gilead is a member of the NASDAQ Biotechnology Index and the S&P 500. Gilead was founded in 1987 under the name Oligogen by Michael L. Riordan. The original name was a reference to oligomers, small strands of DNA used to target genetic sequences. Gilead held its IPO in 1992, and successfully developed drugs like Tamiflu and Vistide that decade. In the 2000s, Gilead received approval for drugs including Viread and Hepsera, among others. It began evolving from a biotechnology company into a pharmaceutical company, acquiring several subsidiaries, though it still relied heavily on contracting to manufacture its drugs. The company continued its growth in the 2010s, but came under heavy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NS5B
Nonstructural protein 5B (NS5B) is a viral protein found in the hepatitis C virus (HCV). It is an RNA-dependent RNA polymerase, having the key function of replicating HCV's viral RNA by using the viral positive RNA strand as a template to catalyze the polymerization of ribonucleoside triphosphates (rNTP) during RNA replication. Several crystal structures of NS5B polymerase in several crystalline forms have been determined based on the same consensus sequence BK (HCV-BK, genotype 1). The structure can be represented by a right hand shape with fingers, palm, and thumb. The encircled active site, unique to NS5B, is contained within the palm structure of the protein. Recent studies on NS5B protein genotype 1b strain J4's (HC-J4) structure indicate a presence of an active site where possible control of nucleotide binding occurs and initiation of de-novo RNA synthesis. De-novo adds necessary primers for initiation of RNA replication. Drugs targeting NS5B Several drugs are either on the ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 nucleic acids, the others being adenosine, thymidine, cytidine and guanosine. The five nucleosides are commonly abbreviated to their symbols, U, A, dT, C, and G, respectively. However, thymidine is more commonly written as 'dT' ('d' represents 'deoxy') as it contains a 2'-deoxyribofuranose moiety rather than the ribofuranose ring found in uridine. This is because thymidine is found in deoxyribonucleic acid (DNA) and usually not in ribonucleic acid (RNA). Conversely, uridine is found in RNA and not DNA. The remaining three nucleosides may be found in both RNA and DNA. In RNA, they would be represented as A, C and G whereas in DNA they would be represented as dA, dC and dG. Biosynthesis Uridine is widely produced in nature as uridine monophosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breakthrough Therapy
Breakthrough therapy is a United States Food and Drug Administration designation that expedites drug development that was created by Congress under Section 902 of the 9 July 2012 Food and Drug Administration Safety and Innovation Act. The FDA's "breakthrough therapy" designation is not intended to imply that a drug is actually a "breakthrough" or that there is high-quality evidence of treatment efficacy for a particular condition; rather, it allows the FDA to grant priority review to drug candidates if preliminary clinical trials indicate that the therapy may offer substantial treatment advantages over existing options for patients with serious or life-threatening diseases. The FDA has other mechanisms for expediting the review and approval process for promising drugs, including fast track designation, accelerated approval, and priority review. Requirements A breakthrough therapy designation can be assigned to a drug if "it is a drug which is intended alone or in combination with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Imidazoles
Imidazole (ImH) is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non-adjacent nitrogen atoms in meta-substitution. Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. This ring system is present in important biological building blocks, such as histidine and the related hormone histamine. Many drugs contain an imidazole ring, such as certain antifungal drugs, the nitroimidazole series of antibiotics, and the sedative midazolam. When fused to a pyrimidine ring, it forms a purine, which is the most widely occurring nitrogen-containing heterocycle in nature. The name "imidazole" was coined in 1887 by the German chemist Arthur Rudolf Hantzsch (1857–1935). Structure and properties Imidazole is a planar 5-membered ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclopropanes
Cyclopropane is the cycloalkane with the molecular formula (CH2)3, consisting of three methylene groups (CH2) linked to each other to form a ring. The small size of the ring creates substantial ring strain in the structure. Cyclopropane itself is mainly of theoretical interest but many of its derivatives are of commercial or biological significance. History Cyclopropane was discovered in 1881 by August Freund, who also proposed the correct structure for the substance in his first paper. Freund treated 1,3-dibromopropane with sodium, causing an intramolecular Wurtz reaction leading directly to cyclopropane. The yield of the reaction was improved by Gustavson in 1887 with the use of zinc instead of sodium. Cyclopropane had no commercial application until Henderson and Lucas discovered its anaesthetic properties in 1929; industrial production had begun by 1936. In modern anaesthetic practice, it has been superseded by other agents. Anaesthesia Cyclopropane was introduced into clin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_-_en.svg "Click for more on -> Hepatitis C")
