Download MendeleyDiscovery of a Novel Series of Potent, Selective, Orally Available, and Brain-Penetrable C1s Inhibitors for Modulation of the Complement Pathway.
Ikeda, Z., Kamei, T., Sasaki, Y., Reynolds, M., Sakai, N., Yoshikawa, M., Tawada, M., Morishita, N., Dougan, D.R., Chen, C.H., Levin, I., Zou, H., Kuno, M., Arimura, N., Kikukawa, Y., Kondo, M., Tohyama, K., Sato, K.(2023) J Med Chem 66: 6354-6371
- PubMed: 37120845
- DOI: https://doi.org/10.1021/acs.jmedchem.3c00348
- Primary Citation of Related Structures:
8GMN - PubMed Abstract:
A novel series of non-amidine-based C1s inhibitors have been explored. Starting from high-throughput screening hit 3 , isoquinoline was replaced with 1-aminophthalazine to enhance C1s inhibitory activity while exhibiting good selectivity against other serine proteases. We first disclose a crystal structure of a complex of C1s and a small-molecule inhibitor ( 4e ), which guided structure-based optimization around the S2 and S3 sites to further enhance C1s inhibitory activity by over 300-fold. Improvement of membrane permeability by incorporation of fluorine at the 8-position of 1-aminophthalazine led to identification of ( R )-8 as a potent, selective, orally available, and brain-penetrable C1s inhibitor. ( R )-8 significantly inhibited membrane attack complex formation induced by human serum in a dose-dependent manner in an in vitro assay system, proving that selective C1s inhibition blocked the classical complement pathway effectively. As a result, ( R )-8 emerged as a valuable tool compound for both in vitro and in vivo assessment.
Organizational Affiliation:
Research, Takeda Pharmaceutical Company Ltd., 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
