carrimycin

Carrimycin is a novel synthetic macrolide antibiotic with broad-spectrum antibacterial activity against both gram-positive and gram-negative bacteria. It was approved by the China Food and Drug Administration in 2019. The drug primarily consists of three components—Isovalerylspiramycin I, II, and III—and small amounts of other 4″-acylspiramycins. Carrimycin exerts its antibacterial effect by binding to the 50S ribosomal subunit of bacteria, thereby inhibiting protein synthesis. In addition to its antimicrobial properties, carrimycin has demonstrated immunomodulatory effects as well as anti-inflammatory and anti-tumor activities. In cancer cells, particularly squamous cell carcinoma and hepatocellular carcinoma models, the active component Isovalerylspiramycin I targets selenoprotein H (SelH), a nucleolar reactive oxygen species-scavenging enzyme. By accelerating SelH degradation, carrimycin induces oxidative stress in tumor cells' nucleoli, disrupts ribosomal biogenesis via inhibition of RNA polymerase I association with rDNA, impairs ribosomal RNA transcription/assembly, and promotes apoptosis. Carrimycin also exhibits antiviral activity against coronaviruses including SARS-CoV-2 by directly binding to the viral frameshift-stimulatory element (FSE) RNA pseudoknot. This action decreases programmed –1 ribosomal frameshifting efficiency required for viral replication complex formation. The drug has been evaluated in phase III clinical trials for severe COVID-19 treatment due to its combined antiviral effects (impeding coronavirus replication), immunomodulation (reducing pro-inflammatory cytokines such as IL-6/IL-8/IL-1β/IL-4), organ protection during systemic inflammation or sepsis models in animals, antipyretic effect, and overall safety profile[1][5][6][7].

Other names

isovalerylspiramycin Iisovalerylspiramycin IIisovalerylspiramycin III