Enfuvirtide

Enfuvirtide is a 36-amino-acid peptide that copies a segment of HIV's own gp41 protein. By occupying that region it stops the virus from folding its envelope into the cell membrane - the fusion step. It was the first entry inhibitor approved (Fuzeon), and its niche is HIV that has failed other classes.

1. 1

   Binds the HR1 region of HIV gp41 as the virus engages CD4 and a co-receptor.

2. 2

   Prevents the conformational change that drives fusion of viral and cell membranes.

3. 3

   Blocks entry, so the virus never gets into the cell.

4. 4

   Acts outside the cell, independently of reverse transcriptase or protease.

5. 5

   Resistance arises through changes in the gp41 HR1 sequence.

• Greater viral load reduction and CD4 gain than optimised background therapy alone at 48 weeks in TORO
• Injection-site reactions in nearly all patients
• No oral formulation - twice-daily subcutaneous injections are a large burden
• Bacterial pneumonia occurred more often than in controls

1. 01Lalezari et al., Enfuvirtide, an HIV-1 fusion inhibitor, for drug-resistant HIV infection (TORO 1), NEJM 2003
2. 02European Medicines Agency - Fuzeon product information

References link to published literature, regulator pages or literature indexes. Where a link points to a search, it collects the peer-reviewed work on that molecule rather than a single study.