JNJ-4178 (adafosbuvir, odalasvir, and simeprevir) in Japanese patients with chronic hepatitis C virus genotype 1 or 2 infection with or without compensated cirrhosis: the Phase IIa OMEGA-3 study

Treatment progress and expansion in Japan: From interferon to direct-acting antiviral

Hepatitis C virus (HCV) was first discovered in 1989, and patients infected with HCV were initially treated with interferon (IFN) monotherapy. In the 2000s, pegylated IFN combined with ribavirin was the mainstay of therapy for infected patients, but the sustained virologic response (SVR) rate was less than 50% for patients with HCV genotype 1. To further improve the therapeutic effect, direct-acting antiviral (DAA) was developed, and combination therapy with DAA and IFN has been available since 2011. In addition, IFN-free DAA therapy became available in 2014, and SVR was achieved in more than 95% of patients with chronic hepatitis and compensated cirrhosis. Thus, in just 30 years since the discovery of HCV, we aim to eliminate HCV in almost all patients. However, there are remaining issues to be addressed. Many of the patients who achieved SVR with DAA therapy had advanced liver fibrosis, and it is necessary to verify to what extent DAA therapy improves their prognosis in terms of liver function, hepatocellular carcinoma occurrence, and mortality. Resistance-associated substitutions can cause failure of DAA therapy, and the search for an effective therapy for high-level resistant viruses such as P32 deletion is particularly important. DAA therapy was approved for use in patients with decompensated cirrhosis in Japan in 2019, which is an unmet need so far. It is also important to verify the efficacy and safety in real-world settings. The World Health Organization aims to eliminate HCV by 2030, and Japan must tackle its remaining issues to achieve this goal.

Advances in Nucleoside and Nucleotide Analogues in Tackling Human Immunodeficiency Virus and Hepatitis Virus Infections

Nucleoside and nucleotide analogues are structurally similar antimetabolites and are promising small-molecule chemotherapeutic agents against various infectious DNA and RNA viruses. To date, these analogues have not been documented in-depth as anti-human immunodeficiency virus (HIV) and anti-hepatitis virus agents, these are at various stages of testing ranging from pre-clinical, to those withdrawn from trials, or those that are approved as drugs. Hence, in this review, the importance of these analogues in tackling HIV and hepatitis virus infections is discussed with a focus on the viral genome and the mechanism of action of these analogues, both in a mutually exclusive manner and their role in HIV/hepatitis coinfection. This review encompasses nucleoside and nucleotide analogues from 1987 onwards, starting with the first nucleoside analogue, zidovudine, and going on to those in current clinical trials and even the drugs that have been withdrawn. This review also sheds light on the prospects of these nucleoside analogues in clinical trials as a treatment option for the COVID-19 pandemic.

Therapeutic potential of uracil and its derivatives in countering pathogenic and physiological disorders

Uracil is one of the most notable pharmacophores in medicinal chemistry as the pyrimidine nucleobase forms an integral part of many commercial drugs. Though the name uracil is usually associated with cancer drugs, there are many uracil-based compounds which can treat different diseases when they are employed. So far, there has been no in-depth review concerning uracil drugs in the market, or in the different stages of clinical trials, including those approved or discontinued. The current work focuses on the importance of uracil and its derivatives in treating different diseases. The use of uracil compounds in treating viral infections, cancer, diabetic, thyroid and autosomal recessive disorders are discussed in the review. The mechanism of action of each uracil drug with emphasis on their structure and properties are discussed in detail. The targeted action of these drugs on sites or on the different stages of a disorder/pathogenic life cycle are also discussed. This review encompasses uracil drugs approved as well as those in development from the 1950's onwards. The utility of uracil in drug discovery and its association with a wide range of diseases is brought forth within this review to demonstrate its potential to a wider audience.