Sofosbuvir

Isopropyl (2S)-2-[[[(2R,3R,4R,5R)-5-(2,4-dioxopyrimidin-1-yl)-4-fluoro-3-hydroxy-4-methyl-tetrahydrofuran-2-yl]methoxy-phenoxy-phosphoryl]amino]propanoate

http://www.ama-assn.org/resources/doc/usan/sofosbuvir.pdf  –for cas no

Jun. 7, 2013– Gilead Sciences, Inc. today announced that the U.S. Food and Drug Administration (FDA) has granted priority review to the company’s New Drug Application (NDA) for sofosbuvir, a once-daily oral nucleotide analogue inhibitor for the treatment of chronic hepatitis C virus (HCV) infection. The FDA grants priority review status to drug candidates that may offer major advances in treatment over existing options. Gilead filed the NDA for sofosbuvir on April 8, 2013, and FDA has set a target review date under the Prescription Drug User Fee Act (PDUFA) of December 8, 2013.

The data submitted in this NDA support the use of sofosbuvir and ribavirin (RBV) as an all-oral therapy for patients with genotype 2 and 3 HCV infection, and for sofosbuvir in combination with RBV and pegylated interferon (peg-IFN) for treatment-naïve patients with genotype 1, 4, 5 and 6 HCV infection.

Sofosbuvir is an investigational product and its safety and efficacy have not yet been established.

About Gilead Sciences

Gilead Sciences is a biopharmaceutical company that discovers, develops and commercializes innovative therapeutics in areas of unmet medical need. The company’s mission is to advance the care of patients suffering from life-threatening diseases worldwide. Headquartered in Foster City, California, Gilead has operations in North America, Europe and Asia Pacific.

Sofosbuvir (formerly PSI-7977 or GS-7977) is an experimental drug candidate for the treatment of hepatitis C.^[1] It was discovered at Pharmasset and then acquired for development by Gilead Sciences. It is currently in Phase III clinical trials.^[2]

Sofosbuvir is a prodrug that is metabolized to the active antiviral agent 2′-deoxy-2′-α-fluoro-β-C-methyluridine-5′-monophosphate.^[3]

Sofosbuvir is a nucleotide analogue inhibitor of the hepatitis C virus (HCV) polymerase.^[4] The HCV polymerase or NS5B protein is a RNA-dependent RNA polymerase critical for the viral cycle.

Sofosbuvir is being studied in combination with pegylated interferon and ribavirin, with ribavirin alone, and with other direct-acting antiviral agents.^[5] It has shown excellent clinical efficacy when used either with pegylated interferon/ribavirin or in interferon-free combinations. In particular, combinations of sofosbuvir with NS5A inhibitors, such as daclatasvir or GS-5885, have shown sustained virological response rates of up to 100% in people infected with HCV.^[6]

Data from the ELECTRON trial showed that a dual interferon-free regimen of sofosbuvir plus ribavirin produced a 24-week post-treatment sustained virological response (SVR24) rate of 100% for previously untreated patients with HCV genotypes 2 or 3.^[7][8]

Data presented at the 20th Conference on Retroviruses and Opportunistic Infections in March 2013 showed that a triple regimen of sofosbuvir, ledipasvir (formerly GS-5885), 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.^[9]Gilead has developed a sofosbuvir + ledipasvir coformulation that is being tested with and without ribavirin.

1. Sofia, M. J.; Bao, D.; Chang, W.; Du, J.; Nagarathnam, D.; Rachakonda, S.; Reddy, P. G.; Ross, B. S. et al. (2010). “Discovery of a β-d-2′-Deoxy-2′-α-fluoro-2′-β-C-methyluridine Nucleotide Prodrug (PSI-7977) for the Treatment of Hepatitis C Virus”. Journal of Medicinal Chemistry 53 (19): 7202–7218. doi:10.1021/jm100863x. PMID 20845908. edit
2.  “PSI-7977″. Gilead Sciences.
3.  Murakami, E.; Tolstykh, T.; Bao, H.; Niu, C.; Steuer, H. M. M.; Bao, D.; Chang, W.; Espiritu, C. et al. (2010). “Mechanism of Activation of PSI-7851 and Its Diastereoisomer PSI-7977″. Journal of Biological Chemistry 285 (45): 34337–34347.doi:10.1074/jbc.M110.161802. PMC 2966047. PMID 20801890. edit
4.  Alejandro Soza (November 11, 2012). “Sofosbuvir”. Hepaton.
5.  Tom Murphy (November 21, 2011). “Gilead Sciences to buy Pharmasset for $11 billion”. Bloomberg Businessweek.
6.  http://www.gilead.com/pr_1757156
7.  AASLD: PSI-7977 plus Ribavirin Can Cure Hepatitis C in 12 Weeks without Interferon. Highleyman, L. HIVandHepatitis.com. 8 November 2011.
8.  Nucleotide Polymerase Inhibitor Sofosbuvir plus Ribavirin for Hepatitis C. Gane, E et al. New England Journal of Medicine 368:3444. January 3, 2013.
9.  CROI 2013: Sofosbuvir + Ledipasvir + Ribavirin Combo for HCV Produces 100% Sustained Response. Highleyman, L. HIVandHepatitis.com. 4 March 2013.