Table 8. Topical microbicide candidates that could prevent cell-associated HIV transmission by genital leukocytes.
| Class | Examples | Potential mechanisms |
|---|---|---|
| Membrane disrupters | C31 (Savvy)c Sodium lauryl sulfate (Invisible Condom) Nonoxynol-9c Ethanol in emollient gel |
Kill infected leukocytes, inactivate nascent HIV. However, nonspecific cytotoxicity could induce inflammation and enhance HIV transmission. |
| Acidifying agents | Carbopol 974Pc (BufferGel) AcidForm (Amphora) |
Kill/immobilize infected leukocytes; inactivate nascent HIV. |
| Entry inhibitors | ||
| Anionic polymers | Naphthalene sulfonate (PRO2000) Carrageenana,c (Carraguard) Cellulose sulfatec (Ushercell)) Cellulose acetate phthalate (CAP) Dendrimers [SPL7013 (Vivagel)] |
Negative charge could interfere with infected leukocyte: target cell interactions, entry of nascent HIV. |
| CCR5 blockers | PSC-RANTES CMPD167 Maraviroc Anti-CCR5 monoclonal antibodies |
Block chemotaxis of infected leukocytes and of target cells toward infected leukocytes; block binding of nascent HIV to target cells. |
| Fusion inhibitors | Cyanovirin-N | May interfere with infected leukocyte: target cell interactions, entry of nascent HIV. |
| Reverse transcriptase inhibitors | Tenofovir (PMPA)b Dapivirine (TMC 120) UC781 TMC120 MIV-150a |
Inhibit HIV replication in infected leukocytes and target cells. |
Alliances for Microbicide Development (www.microbicide.org). Cutler and Justman [317].
a
PC815 is co-formulation of Carrageenan and MIV-150.
b
Co-formulated with emtricitabine (FTC) in preclinical studies.
c
Not being studied at the present time in HIV prevention trials.