Discovery of Novel Allosteric EGFR L858R Inhibitors for the Treatment of Non-Small-Cell Lung Cancer as a Single Agent or in Combination with Osimertinib.

Addressing resistance to third-generation EGFR TKIs such as osimertinib via the EGFRC797S mutation remains a highly unmet need in EGFR-driven non-small-cell lung cancer (NSCLC). Herein, we present the discovery of the allosteric EGFR inhibitor 57, a novel fourth-generation inhibitor to overcome EGFRC797S-mediated resistance in patients harboring the activating EGFRL858R mutation. 57 exhibits an improved potency compared to previous allosteric EGFR inhibitors. To our knowledge, 57 is the first allosteric EGFR inhibitor that demonstrates robust tumor regression in a mutant EGFRL858R/C797S tumor model. Additionally, 57 is active in an H1975 EGFRL858R/T790M NSCLC xenograft model and shows superior efficacy in combination with osimertinib compared to the single agents. Our data highlight the potential of 57 as a single agent against EGFRL858R/C797S and EGFRL858R/T790M/C797S and as combination therapy for EGFRL858R- and EGFRL858R/T790M-driven NSCLC.

Discovery of benzoylisoindolines as a novel class of potent, selective and orally active GlyT1 inhibitors.

Benzoylisoindolines were discovered as a novel structural class of GlyT1 inhibitors. SAR studies and subsequent lead optimization efforts focused primarily on addressing hERG liability and on improving in vivo efficacy resulted in the identification of potent GlyT1 inhibitors displaying excellent selectivity and in vivo PD and PK profiles.

Novel dihydrofolate reductase inhibitors. Structure-based versus diversity-based library design and high-throughput synthesis and screening.

Novel 2,4-diaminopyrimidines bearing N,N-disubstituted aminomethyl residues at the 5-position were designed as dihydrofolate reductase (DHFR) inhibitors. These compounds were obtained by treatment of 1-[(2,4-diamino-5-pyrimidinyl)methyl]pyridinium bromide with secondary amines in a polar solvent and in the presence of triethylamine at room temperature. The procedure was found to be very efficient and suitable for application in high-throughput synthesis. In addition, we found that high-throughput screening for enzymatic and in vitro antibacterial activity could be performed on crude reaction mixtures, thus avoiding any purification step. Over 1200 proprietary secondary amines were selected for high-throughput synthesis, based on structural and diversity-related criteria, and the resulting products were submitted to high-throughput screening. A greater number of hits, and significantly more active compounds, were obtained through structure-based library design than through diversity-based library design. Different classes of inhibitors of DHFR were identified in this way, including compounds derived from di-, tri-, and tetracyclic amines. In general, these products showed high activity against the enzymes derived from both TMP-sensitive and TMP-resistant Streptococcus pneumoniae. Some compounds possessed appreciable selectivity for the bacterial over the human enzyme, whereas other compounds were not at all selective. In most cases, active enzyme inhibitors also displayed antibacterial activity.

Selective GlyT1 inhibitors: discovery of [4-(3-fluoro-5-trifluoromethylpyridin-2-yl)piperazin-1-yl][5-methanesulfonyl-2-((S)-2,2,2-trifluoro-1-methylethoxy)phenyl]methanone (RG1678), a promising novel medicine to treat schizophrenia.

The GlyT1 transporter has emerged as a key novel target for the treatment of schizophrenia. Herein, we report on the optimization of the 2-alkoxy-5-methylsulfonebenzoylpiperazine class of GlyT1 inhibitors to improve hERG channel selectivity and brain penetration. This effort culminated in the discovery of compound 10a (RG1678), the first potent and selective GlyT1 inhibitor to have a beneficial effect in schizophrenic patients in a phase II clinical trial.

Novel ketolide antibiotics with a fused five-membered lactone ring--synthesis, physicochemical and antimicrobial properties.

In an effort to find novel semisynthetic macrolides with extended antibacterial spectrum and improved activity we prepared a series of compounds based on commercially available clarithromycin, a potent and safe antimicrobial agent of outstanding clinical and commercial interest. According to the literature, improvement of antibacterial activity of erythromycin type antibiotics can be achieved by introduction of fused heterocycles such as cyclic carbonates or carbamates at positions 11 and 12 (such as in telithromycin). In the course of the work presented here, a similar, hitherto unprecedented set of compounds bearing a five-membered lactone ring fused to positions 11 and 12 was prepared based on carbon-carbon bond formation via intramolecular Michael addition of a [(hetero)arylalkylthio]acetic acid ester enolate to an alpha,beta-unsaturated ketone as the key step. Some of the ketolide compounds described in this paper were highly active against a representative set of erythromycin sensitive and erythromycin resistant test strains. The best compound showed a similar antimicrobial spectrum and comparable activity in vitro as well as in vivo as telithromycin. Furthermore, some physicochemical properties of these compounds were determined and are presented here. On the basis of these results, the novel ketolide lactones presented in this paper emerged as valuable lead compounds with comparable properties as the commercial ketolide antibacterial telithromycin (Ketek).