BI 224436

BI 224436 is a first-in-class investigational small molecule developed as a non-catalytic site integrase inhibitor (NCINI) for the treatment of HIV infection. Unlike traditional integrase strand transfer inhibitors (INSTIs), which bind to the catalytic site of HIV-1 integrase, BI 224436 targets a conserved allosteric pocket on the enzyme's catalytic core. This unique mechanism disrupts viral replication by inhibiting integration of viral DNA into the host genome through an allosteric effect rather than direct competition at the active site. The compound demonstrated potent antiviral activity in vitro with EC50 values below 15 nM against various HIV-1 laboratory strains and retained efficacy against viruses harboring resistance mutations to existing INSTIs. It also showed favorable pharmacokinetic and ADME properties in preclinical models, including good oral bioavailability and low cytochrome P450 inhibition. Despite promising preclinical results, clinical development was discontinued before completion of Phase 1 trials[1][3][4][5][6].