1.Discovery of BI 224436, a Noncatalytic Site Integrase Inhibitor (NCINI) of HIV-1.
Fader LD1, Malenfant E1, Parisien M1, Carson R1, Bilodeau F1, Landry S1, Pesant M1, Brochu C1, Morin S1, Chabot C1, Halmos T1, Bousquet Y1, Bailey MD1, Kawai SH1, Coulombe R1, LaPlante S1, Jakalian A1, Bhardwaj PK1, Wernic D1, Schroeder P1, Amad M1, Edwar ACS Med Chem Lett. 2014 Jan 22;5(4):422-7. doi: 10.1021/ml500002n. eCollection 2014.
An assay recapitulating the 3' processing activity of HIV-1 integrase (IN) was used to screen the Boehringer Ingelheim compound collection. Hit-to-lead and lead optimization beginning with compound 1 established the importance of the C3 and C4 substituent to antiviral potency against viruses with different aa124/aa125 variants of IN. The importance of the C7 position on the serum shifted potency was established. Introduction of a quinoline substituent at the C4 position provided a balance of potency and metabolic stability. Combination of these findings ultimately led to the discovery of compound 26 (BI 224436), the first NCINI to advance into a phase Ia clinical trial.
2.Preclinical profile of BI 224436, a novel HIV-1 non-catalytic-site integrase inhibitor.
Fenwick C1, Amad M2, Bailey MD2, Bethell R2, Bös M2, Bonneau P2, Cordingley M2, Coulombe R2, Duan J2, Edwards P2, Fader LD1, Faucher AM2, Garneau M2, Jakalian A2, Kawai S2, Lamorte L2, LaPlante S2, Luo L2, Mason S2, Poupart MA2, Rioux N2, Schroeder P2, Si Antimicrob Agents Chemother. 2014 Jun;58(6):3233-44. doi: 10.1128/AAC.02719-13. Epub 2014 Mar 24.
BI 224436 is an HIV-1 integrase inhibitor with effective antiviral activity that acts through a mechanism that is distinct from that of integrase strand transfer inhibitors (INSTIs). This 3-quinolineacetic acid derivative series was identified using an enzymatic integrase long terminal repeat (LTR) DNA 3'-processing assay. A combination of medicinal chemistry, parallel synthesis, and structure-guided drug design led to the identification of BI 224436 as a candidate for preclinical profiling. It has antiviral 50% effective concentrations (EC50s) of <15 nM against different HIV-1 laboratory strains and cellular cytotoxicity of >90 μM. BI 224436 also has a low, ∼2.1-fold decrease in antiviral potency in the presence of 50% human serum and, by virtue of a steep dose-response curve slope, exhibits serum-shifted EC95 values ranging between 22 and 75 nM. Passage of virus in the presence of inhibitor selected for either A128T, A128N, or L102F primary resistance substitutions, all mapping to a conserved allosteric pocket on the catalytic core of integrase.