oxadiazoles and Herpes-Zoster

Acyclovir, valacyclovir, and famciclovir are used for the treatment of herpes simplex virus (HSV) and varicella-zoster virus (VZV) infections. Helicase-primase inhibitors (HPIs) inhibit replication fork progression that separates double DNA strands into two single strands during DNA synthesis. The HPIs amenamevir and pritelivir have novel mechanisms of anti-herpetic action, and their once-daily administration has clinical efficacy for genital herpes. Among HPIs, amenamevir has anti-VZV activity. The concentrations of HSV-1 and VZV required for the 50% plaque reduction of amenamevir were 0.036 and 0.047 μM, respectively. We characterized the features of amenamevir regarding its mechanism, resistance, and synergism with acyclovir. Its antiviral activity was not influenced by the viral replication cycle, in contrast to acyclovir. A clinical trial of amenamevir for herpes zoster demonstrated its non-inferiority to valacyclovir. To date, amenamevir has been successfully used in over 1,240,000 patients with herpes zoster in Japan. Post-marketing surveillance of amenamevir in Japan reported side effects with significant potential risk identified by the Japanese Risk Management Plan, including thrombocytopenia, gingival bleeding, and palpitations, although none of these were serious. The clinical efficacy and safety profiles of amenamevir were established in patients with herpes zoster. Therefore, amenamevir as an HPI opens a new era of anti-herpes therapy.

Topics: Animals; Antiviral Agents; Clinical Trials as Topic; DNA Helicases; DNA Primase; Herpes Genitalis; Herpes Zoster; Herpesvirus 1, Human; Humans; Mice; Oxadiazoles

In July 2017, Japan's Ministry of Health, Labor and Welfare issued a marketing authorization valid throughout Japan for N-(2,6-dimethylphenyl)-N-(2-{[4-(1,2,4-oxadiazol-3-yl)phenyl]amino}-2-oxoethyl)-1,1-dioxothiane-4-carboxamide (amenamevir) for the first time worldwide. The decision was based on the favorable opinion of the Pharmaceuticals and Medical Device Agency (PMDA) recommending a marketing authorization of amenamevir for treatment of herpes zoster (HZ). Amenamevir has a different action mechanism from previously approved synthetic nucleoside compounds for the treatment of HZ including acyclovir, valacyclovir and famciclovir. The usual adult dose is 400 mg amenamevir p.o. once daily for 7 days. The benefit is its ability to cure HZ as well as preventing postherpetic neuralgia. The most common side-effects are increase of urine N-acetyl-β-D-glucosaminidase and α1-microglobulin levels. However, based on the detailed evaluation of the submitted clinical studies, there seems to be no serious safety concerns about amenamevir regarding the kidney of both renally normal and impaired patients. The objective of this article is to summarize the scientific review of the application. The detailed scientific assessment report and product information, including the summary of product characteristics, are available on the PMDA website (www.pmda.go.jp/PmdaSearch/iyakuSearch/).

Topics: Adult; Antiviral Agents; Herpes Zoster; Humans; Japan; Oxadiazoles; Pharmaceutical Preparations

The discovery of acyclovir and penciclovir has led to the development of a successful systemic therapy for treating herpes simplex virus infection and varicella-zoster virus infection, and the orally available prodrugs, valacyclovir and famciclovir, have improved antiviral treatment compliance. Acyclovir and penciclovir are phosphorylated by viral thymidine kinase and are incorporated into the DNA chain by viral DNA polymerase, resulting in chain termination. Helicase-primase plays an initial step in DNA synthesis to separate the double strand into two single strands (replication fork) and is a new target of antiviral therapy. The helicase-primase inhibitors (HPIs) pritelivir and amenamevir have novel mechanisms of action, drug resistance properties, pharmacokinetic characteristics, and clinical efficacy for treating genital herpes. The clinical study of amenamevir in herpes zoster has been completed, and amenamevir has been submitted for approval for treating herpes zoster in Japan. The clinical use of HPIs will be the beginning of a new era of anti-herpes therapy.

Topics: Acyclovir; Animals; Antiviral Agents; Clinical Trials as Topic; Guanine; Herpes Simplex; Herpes Zoster; Herpesvirus 3, Human; Humans; Oxadiazoles; Simplexvirus

Valacyclovir and famciclovir enabled successful systemic therapy for treating herpes simplex virus (HSV) and varicella zoster virus (VZV) infection by their phosphorylation with viral thymidine kinase. Helicase-primase inhibitors (HPIs) inhibit the progression of the replication fork, an initial step in DNA synthesis to separate the double strand into two single strands. The HPIs amenamevir and pritelivir have a novel mechanism of action, once-daily administration with nonrenal excretory characteristics, and clinical efficacy for genital herpes. Amenamevir exhibits anti-VZV and anti-HSV activity while pritelivir only has anti-HSV activity. A clinical trial of amenamevir for herpes zoster has been completed, and amenamevir has been licensed and successfully used in 20,000 patients with herpes zoster so far in Japan. We have characterized the features of the antiviral action of amenamevir and, unlike acyclovir, the drug's antiviral activity is not influenced by the viral replication cycle. Amenamevir is opening a new era of antiherpes therapy.

Topics: Animals; Antiviral Agents; DNA Helicases; DNA Primase; Drug Resistance, Viral; Herpes Zoster; Herpesvirus 3, Human; Humans; Oxadiazoles; Pyridines; Sulfonamides; Thiazoles; Viral Proteins

Amenamevir is a potent helicase-primase inhibitor and a novel class of antiviral agent other than nucleoside compounds, such as aciclovir, valaciclovir and famciclovir. This study is the first randomized, double-blind, valaciclovir-controlled phase 3 study to evaluate the efficacy and safety of amenamevir in Japanese patients with herpes zoster when treated within 72 h after onset of rash. A total of 751 patients were randomly assigned to receive either amenamevir 400 mg or 200 mg p.o. once daily or valaciclovir 1000 mg three times daily (daily dose, 3000 mg) for 7 days. The primary efficacy end-point was the proportion of cessation of new lesion formation by day 4 ("day 4 cessation proportion"). The day 4 cessation proportions for amenamevir 400 and 200 mg and valaciclovir were 81.1% (197/243), 69.6% (172/247) and 75.1% (184/245), respectively. Non-inferiority of amenamevir 400 mg to valaciclovir was confirmed by a closed testing procedure. Days to cessation of new lesion formation, complete crusting, healing, pain resolution and virus disappearance were evaluated as secondary end-points. No significant differences were observed in any of the treatment groups. Amenamevir 400 and 200 mg were well tolerated as well as valaciclovir. The proportions of patients who experienced drug-related adverse events were 10.0% (25/249), 10.7% (27/252) and 12.0% (30/249) with amenamevir 400 and 200 mg and valaciclovir, respectively. In conclusion, amenamevir 400 mg appears to be effective and well tolerated for treatment of herpes zoster in immunocompetent Japanese patients.

Topics: Acyclovir; Aged; Antiviral Agents; Double-Blind Method; Female; Herpes Zoster; Humans; Male; Middle Aged; Oxadiazoles; Treatment Outcome; Valacyclovir; Valine

Amenamevir (ASP2151) is a nonnucleoside antiherpesvirus compound available for the treatment of varicella-zoster virus infections. In this article we summarize the findings of four phase 1 studies in healthy participants.. Four randomized phase 1 studies investigated the safety and pharmacokinetics of single and multiple doses of amenamevir, including the assessment of age group effect (nonelderly vs elderly), food effect, and the relative bioavailability of two formulations. Amenamevir was administered orally at various doses as a single dose (5-2400 mg) or daily (300 or 600 mg/day) for 7 days.. Following single and multiple oral doses, amenamevir demonstrated a less than dose proportional increase in the pharmacokinetic parameters area under the plasma drug concentration versus time curve from time zero to infinity (AUC. Amenamevir had less than dose proportional pharmacokinetic characteristics. Age may have an influence on amenamevir pharmacokinetics; however, the effect was considered minimal. The pharmacokinetics of amenamevir were affected by food, with AUC. Astellas Pharma.. ClinicalTrials.gov identifiers NCT02852876 (15L-CL-002) and NCT02796118 (15L-CL-003).

Topics: Adult; Aged; Antiviral Agents; Cross-Over Studies; Dose-Response Relationship, Drug; Female; Healthy Volunteers; Herpes Zoster; Humans; Japan; Male; Middle Aged; Oxadiazoles

Amenamevir (ASP2151) is a nonnucleoside human herpesvirus helicase-primase inhibitor that was approved in Japan for the treatment of herpes zoster (shingles) in 2017. This article reports the results of two clinical trials that investigated the effects of renal and hepatic impairment on the pharmacokinetics of amenamevir.. These studies were phase 1, open-label, single-dose (oral 400 mg), parallel-group studies evaluating the pharmacokinetics, safety, and tolerability of amenamevir in healthy participants and participants with moderate hepatic impairment and mild, moderate, and severe renal impairment.. In the hepatic impairment study, the pharmacokinetic profile of amenamevir in participants with moderate hepatic impairment was generally similar to that of participants with normal hepatic function. In the renal impairment study, the area under the amenamevir concentration versus time curve from the time of dosing up to the time of the last sample with extrapolation to infinity of the terminal phase was increased by 78.1% in participants with severe renal impairment. There was a positive relationship between creatinine clearance and oral and renal clearance for amenamevir in the renal impairment study. In both studies, amenamevir was safe and well tolerated.. The findings of the hepatic impairment study indicate that no dosing adjustment is required in patients with moderate hepatic impairment. In the renal impairment study, systemic amenamevir exposure was increased by renal impairment. However, it is unlikely that renal impairment will have a significant effect on the safety of amenamevir given that in previous pharmacokinetic and safety studies in healthy individuals amenamevir was safe and well tolerated after a single dose (5-2400 mg, fasted condition) and repeated doses for 7 days (300 or 600 mg, fed condition), and the amount of amenamevir exposure in the renal impairment study was covered by those studies. These findings suggest that amenamevir does not require dosage reduction in accordance with the creatinine clearance FUNDING: Astellas Pharma.

Topics: Adolescent; Adult; Aged; Antiviral Agents; Female; Herpes Zoster; Humans; Japan; Liver Diseases; Male; Middle Aged; Oxadiazoles; Renal Insufficiency; Young Adult

Topics: Aged; Cytochrome P-450 Enzyme System; Drug-Related Side Effects and Adverse Reactions; Herpes Zoster; Humans; Male; Oxadiazoles

We herein report the case of a 78-year-old woman who was diagnosed as having disseminated herpes zoster (DHZ) complicated with probable varicella-zoster pneumonia during maintenance therapy for microscopic polyangiitis. Because the patient had severe renal dysfunction, amenamevir administration was started to avoid any neurotoxicity of acyclovir, which is suggested to be optimal for treatment. It ameliorated her symptoms without any adverse events. This is the first report suggesting the efficacy of amenamevir in the treatment of severe herpes zoster infection with coexisting DHZ and probable varicella-zoster pneumonia. Amenamevir could thus be a treatment option for severe varicella zoster virus infections.

Topics: Acyclovir; Aged; Antiviral Agents; Chickenpox; Female; Herpes Zoster; Herpesvirus 3, Human; Humans; Immunocompromised Host; Oxadiazoles; Pneumonia; Varicella Zoster Virus Infection

Amenamevir has been approved for the treatment of herpes zoster (HZ); however, its therapeutic efficacy against central nervous system (CNS) infection may be insufficient due to its low spinal fluid permeability. We herein report a case of aseptic meningitis in a 91-year-old Japanese man treated with amenamevir for HZ in the trigeminal nerve region. Several cases of CNS infection have been reported in patients receiving amenamevir treatment for HZ. Patients with CNS complications often have skin rashes near the trigeminal region. Thus, we should be alert for signs of CNS infection when administering amenamevir to patients with such rashes.

Topics: Aged, 80 and over; Antiviral Agents; Exanthema; Herpes Zoster; Herpesvirus 3, Human; Humans; Male; Meningitis, Aseptic; Oxadiazoles; Trigeminal Nerve

Varicella-zoster virus (VZV) resistance to current antiviral drugs, that all target the viral DNA polymerase, represents a growing concern, notably among immunocompromised patients. Amenamevir, a novel antiviral that inhibits the VZV helicase-primase (HP) complex, is approved in Japan for the treatment of herpes zoster. In this study, we describe the low natural polymorphism of VZV HP complex (interstrain identity >99.7% both at nucleotide and amino acid levels) among 44 VZV clinical isolates. This work enabled to settle the maps of natural polymorphisms of VZV HP complex and to provide the genotypic tools for the monitoring of the emergence of VZV resistance to amenamevir in patients.

Topics: Antiviral Agents; DNA Primase; Drug Resistance, Viral; Female; Herpes Zoster; Herpesvirus 3, Human; Humans; Immunocompromised Host; Japan; Male; Middle Aged; Oxadiazoles

A 78-year-old woman was diagnosed with herpes zoster in the first branch of the trigeminal nerve and was treated with amenamevir. Subsequently, she was hospitalized for postherpetic neuralgia. Fever and unconsciousness were observed, and a diagnosis of varicella-zoster virus meningoencephalitis and vasculitis was made. In addition to the antithrombotic therapy, she was treated with intravenous acyclovir and steroid pulse therapy; however, her unconsciousness persisted. Amenamevir was not transferrable to the spinal fluid and resulted in an incomplete treatment of herpes zoster in the cerebral nerve region, suggesting that this case may be related to the severe course of the disease.

Topics: Acyclovir; Aged; Antiviral Agents; Female; Herpes Zoster; Humans; Infusions, Intravenous; Magnetic Resonance Imaging; Meningoencephalitis; Methylprednisolone; Oxadiazoles; Pulse Therapy, Drug; Severity of Illness Index; Trigeminal Nerve; Vasculitis

Topics: Acyclovir; Antiviral Agents; Herpes Zoster; Humans; Oxadiazoles

Amenamevir (ASP2151), a herpesvirus helicase-primase inhibitor, is currently used for the treatment of herpes zoster in Japan. Amenamevir is mainly metabolized in the liver, and urinary excretion of amenamevir is approximately 10% in healthy adults. The increase of systemic exposure in non-dialysis patients with severe renal impairment was much less than that associated with nucleoside antiviral agents. The aim of this study was to evaluate the pharmacokinetics and dialyzability of a single oral dose (400 mg) of amenamevir in hemodialysis patients.. This was a single-arm, open-label, multicenter clinical pharmacology study. Nine patients aged 20-80 years with end-stage kidney disease and undergoing maintenance hemodialysis three times weekly were enrolled. Pharmacokinetics and dialyzability were investigated by serial collection of blood samples until 48 h post-dose during the study.. The maximum plasma concentration and time to reach maximum plasma concentration during 24 h post-dose were 1585 ng/mL and 6.2 h, respectively. The area under the plasma concentration-time curve (AUC) from time zero to 24 h was 23,890 ng h/mL. The median terminal elimination half-life within 24 h before, during, and after hemodialysis was 14.7, 15.2, and 12.4 h, respectively. The AUC in hemodialysis patients was approximately double that in healthy adults. This increase in AUC was much less than that reported in nucleoside antiviral agents. The hemodialysis clearance, elimination fraction percentage, and amount of amenamevir removed were 37.8 mL/min, 28.1%, and 132.0 μg, respectively. The amount of amenamevir removed by hemodialysis was minimal. None of the hemodialysis parameters were associated with serum albumin. This study revealed no clinically relevant safety concerns.. There were no clinically relevant safety concerns when 400 mg of amenamevir was administered as a single dose to hemodialysis patients without dose adjustment and/or modification of the dosing schedule.. JapicCTI-184242.

Topics: Administration, Oral; Adult; Aged; Aged, 80 and over; Antiviral Agents; Female; Herpes Zoster; Humans; Japan; Male; Middle Aged; Oxadiazoles; Renal Dialysis; Renal Insufficiency; Young Adult

A 76-year-old Japanese female who was treated with long-term use of prednisolone at 10 mg/day for interstitial pneumonia developed acute right-dominant lower limb paralysis and then upper limb paralysis with herpes zoster eruptions on the right C7-Th1 dermatomes. On admission, right predominant quadriplegia was observed with sensory symptoms; Hughes functional grade was level 4; the hand grip power was right, 0, and left, 7 kg, the deep tendon reflexes were abolished throughout without pathologic reflexes. Twenty days after the onset of the symptoms, the cerebrospinal fluid (CSF) revealed mild increases of lymphocytes (13 cells/μl) and protein content (73 mg/dl). Varicella-zoster virus (VZV) PCR was negative in the CSF, but an enzyme immunoassay for VZV was positive in her serum and CSF, and the high titers were prolonged. Peripheral nerve conduction and F wave studies suggested right-dominant demyelinating polyradiculoneuropathy. A T

Topics: Acyclovir; Aged; Antibodies, Viral; Antiviral Agents; Biomarkers; Diffusion Magnetic Resonance Imaging; Female; Guillain-Barre Syndrome; Herpes Zoster; Herpesvirus 3, Human; Humans; Immunocompromised Host; Immunoglobulins, Intravenous; Oxadiazoles; Polyradiculoneuropathy; Quadriplegia; Varicella Zoster Virus Infection

Topics: Acyclovir; Adult; Antiviral Agents; DNA, Viral; Drug Resistance, Viral; Drug Substitution; Female; Herpes Zoster; Herpesvirus 3, Human; Humans; Immunocompromised Host; Oxadiazoles; Treatment Outcome

ASP2151 (amenamevir) is a helicase-primase complex inhibitor with antiviral activity against herpes simplex virus HSV-1, HSV-2, and varicella-zoster virus (VZV). To assess combination therapy of ASP2151 with existing antiherpes agents against HSV-1, HSV-2, and VZV, we conducted in vitro and in vivo studies of two-drug combinations. The combination activity effect of ASP2151 with nucleoside analogs acyclovir (ACV), penciclovir (PCV), or vidarabine (VDB) was tested via plaque-reduction assay and MTS assay, and the data were analyzed using isobolograms and response surface modeling. In vivo combination therapy of ASP2151 with valaciclovir (VACV) was studied in an HSV-1-infected zosteriform spread mouse model. The antiviral activity of ASP2151 combined with ACV and PCV against ACV-susceptible HSV-1, HSV-2, and VZV showed a statistically significant synergistic effect (P<0.05). ASP2151 with VDB was observed to have additive effects against ACV-susceptible HSV-2 and synergistic effects against VZV. In the mouse model of zosteriform spread, the inhibition of disease progression via combination therapy was more potent than that of either drugs as monotherapy (P<0.05). These results indicate that the combination therapies of ASP2151 with ACV and PCV have synergistic antiherpes effects against HSV and VZV infections and may be feasible in case of severe disease, such as herpes encephalitis or in patients with immunosuppression.

Topics: Animals; Chlorocebus aethiops; Disease Models, Animal; Drug Synergism; Female; Herpes Zoster; Herpesvirus 1, Human; Herpesvirus 2, Human; Herpesvirus 3, Human; Humans; Mice; Microbial Sensitivity Tests; Nucleosides; Oxadiazoles; Treatment Outcome; Vero Cells; Viral Plaque Assay