MIV-150 is a tight-binding, allosteric inhibitor of reverse transcriptase that is active against HIV-1 and HIV-2. MIV-150 has been shown to inactivate viruses that are resistant to other antiviral drugs, including non-nucleoside reverse transcriptase inhibitors, nucleoside reverse transcriptase inhibitors, and protease inhibitors. MIV-150 effectively inactivated free virus. Combination of MIV-150 and Carraguard demonstrated an additive antiviral effect. Seminal fluid had no effect on the antiviral activity of MIV-150 or Carraguard. The average concentration that blocks 50% of infection (EC50) for PC-815 was approximately 10 times stronger than Carraguard for the different clinical isolates used in the study.