Enfuvirtide (T-20) Description Enfuvirtide is an antiretroviral drug that is used to treat HIV. Specifications Cas No. 159519-65-0 Product ID E5220 Product Name Enfuvirtide (T-20) Synonym T20; Fuzeon; Pentafuside; DP178. Formula Wt. 4462 Purity ≥95% Store Temp +4oC References Wikipedia. http:||wikipedia.com (accessed June, 2006).