Synthesis of deuterated S-217622 (Ensitrelvir) with antiviral activity against coronaviruses including SARS-CoV-2

S-217622 (Ensitrelvir) is a reversible severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 3-chymotrypsin-like protease (3CL^pro) inhibitor which obtained emergency regulatory approval in Japan for the treatment of SARS-CoV-2 infection on Nov 22, 2022. Herein, analogs of S-271622 with deuterium-for-hydrogen replacement were synthesized for comparison of the antiviral activities and pharmacokinetic (PK) profiles. Compared to the parent compound, C11-d2-S-217622 compound YY-278 retained in vitro activity against 3CL^pro and SARS-CoV-2. X-ray crystal structural studies showed similar interactions of SARS-CoV-2 3CL^pro with YY-278 and S-271622. The PK profiling revealed the relatively favorable bioavailability and plasma exposure of YY-278. In addition, YY-278, as well as S-217622, displayed broadly anti-coronaviral activities against 6 other coronaviruses that infect humans and animals. These results laid the foundation for further research on the therapeutic potential of YY-278 against COVID-19 and other coronaviral diseases.

Recent Updates on the Development of Deuterium-Containing Drugs for the Treatment of Cancer

Cancer is one of the deadliest diseases in the world. In 2020, 19.3 million cancer cases and 10 million deaths were reported in the world. It is supposed that the prevalence of cancer cases will rise to 28.4 million by 2040. Chemotherapy-based regimens have a narrow therapeutic index, severe adverse drug reactions, and lack metabolic stability. Besides, the metabolism of anticancer produces several non-active and toxic metabolites that reduce exposure of the target site to the parent drug. Therefore, developing better-tolerated and effective new anticancer drugs and modification of the existing anticancer drugs to minimize toxicity and increase efficacy has become a very urgent need. Deuterium incorporation reduces the metabolism of certain drugs that are breakdown by pathways involving hydrogen-carbon bond scission. For example, CYP450 mediated oxidative metabolism of drugs that involves the breakdown of a hydrogen-carbon bond affected by deuteration. Deuterium incorporation into the drug increases the half-life and reduces the dose, which provides better safety and efficacy. Deutetrabenazine is the first deuterated form of tetrabenazine approved to treat chorea associated with Huntington’s disease and tardive dyskinesia. The study revealed that Deutetrabenazine has fewer neuropsychiatric side effects with favorable safety than tetrabenazine. The current review highlights the deuterium kinetic isotope effect on drug metabolism, deuterated compound pharmacokinetic property, and safety profile. Besides, this review explains the deuterated anticancer drug development update status.