ASP 2151

China [CN]

I. Basic Information

Item | Details

English Name | ASP2151 (Amenamevir)

Chinese Name | Amenamevir

CAS Number | 841301-32-4

Chemical Name | N-(2,6-dimethylphenyl)-N-(2-{[4-(1,2,4-oxadiazol-3-yl)phenyl]amino}-2-oxoethyl)-1,1-dioxothiophene-4-carboxamide

Molecular Formula | C₂₃H₂₃N₅O₆S

Molecular Weight | 497.53

Target | Herpesvirus helicase-primase complex (inhibits a key step in DNA replication)

Developer | Astellas

Market Launch | 2017 (Japan); Not yet approved in China

Dosage Form and Strength | Film-coated tablets: 100mg/tablet, 200mg/tablet

II. Physicochemical Properties

Parameter | Data

Appearance | White to off-white crystalline powder

Solubility | Slightly soluble in water (approximately 0.1 mg/mL, 25℃), readily soluble in dimethyl sulfoxide, soluble in methanol/ethanol

Dissociation Constant (pKa) | 7.8 (predicted value)

Stability | Stable for 36 months at 25℃/60% RH, stored in a sealed, cool, and dry place; avoid strong light, high temperature, and humidity

Chiral Characteristics | Contains 2 chiral centers, the pharmaceutical form is a single configurational isomer, optical purity > 99.5%

Partition Coefficient (logP) | 4.2 (predicted value)

III. Mechanism of Action (Core Advantage)

Viral DNA Replication Blockade: Specifically binds to the herpesvirus helicase-primase complex, inhibiting its ATPase, helicase, and primase activities, preventing viral DNA synthesis without affecting host cell DNA replication. Broad-spectrum anti-herpes activity:  It exhibits low EC₅₀ values ​​(0.038-0.10 μM) against HSV-1, HSV-2, and VZV, with significantly superior anti-VZV activity compared to acyclovir (EC₅₀ 1.3-27 μM).

Effective against resistant strains: It remains effective against HSV strains resistant to acyclovir and valacyclovir (due to thymidine kinase or DNA polymerase mutations), addressing the clinical challenge of drug resistance.

Convenient oral administration with long-lasting effects: It has good oral absorption and a half-life of approximately 16 hours, allowing for once-daily dosing and high patient compliance.