Background:

Enfuvirtide is an anti-HIV-1 fusion inhibitor peptide.

A cell-cell fusion assay reveals that the effective concentration for achieving 50% inhibition (IC50) of Enfuvirtide is 23 ± 6 nM[2]. IFN-λs (1, 2, or 3) or the antiretrovirals (AZT, Efavirenz, Indinavir, and Enfuvirtide) significantly inhibita the expression of HIV p24 antigen and Gag gene in macrophages. IFN-λs (1, 2, or 3) also enhanced the anti-HIV (Bal) effect of AZT, Efavirenz, Indinavir, and Enfuvirtide[3].

Enfuvirtide has a T1/2 of 3.8 h[2].

Reference:
[1]. Figueira TN, et al. Quantitative analysis of molecular partition towards lipid membranes using surface plasmon resonance. Sci Rep. 2017 Mar 30;7:45647.
[2]. Cao P, et al. The improved efficacy of Sifuvirtide compared with Enfuvirtide might be related to its selectivity for the rigid biomembrane, as determined through surface plasmon resonance. PLoS One. 2017 Feb 16;12(2):e0171567.
[3]. Wang X, et al. IFN-λ Inhibits Drug-Resistant HIV Infection of Macrophages. Front Immunol. 2017 Mar 6;8:210.