More than 75% of breast cancers are estrogen receptor alpha (ERα) positive (ER+), and resistance to current hormone therapies occurs in one-third of ER+ patients. Tumor resistance is still ERα-dependent, but mutations usually confer constitutive activation to the hormone receptor, rendering ERα modulator drugs such as tamoxifen and aromatase inhibitors ineffective. Fulvestrant is a potent selective estrogen receptor degrader (SERD), which degrades the ERα receptor in drug-resistant tumors and has been approved for the treatment of hormone-receptor-positive metastatic breast cancer following antiestrogen therapy.
View Article and Find Full Text PDFFrom a HTS campaign, a new series of pyrimidone anilides exemplified by compound 1 has been identified with good inhibitory activity for the PI3Kβ isoform. The structure of compound 1 in PI3Kγ was solved revealing a binding mode in agreement with the SAR observed on PI3Kβ. These compounds displayed inhibition in the nanomolar range in the biochemical assay and were also potent p-Akt inhibitors in a PTEN-deficient PC3 prostate cancer cell line.
View Article and Find Full Text PDFMost of the phosphoinositide-3 kinase (PI3K) kinase inhibitors currently in clinical trials for cancer treatment exhibit pan PI3K isoform profiles. Single PI3K isoforms differentially control tumorigenesis, and PI3Kβ has emerged as the isoform involved in the tumorigenicity of PTEN-deficient tumors. Herein we describe the discovery and optimization of a new series of benzimidazole- and benzoxazole-pyrimidones as small molecular mass PI3Kβ-selective inhibitors.
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