Starting from the phase II clinical FGFR inhibitor lucitanib (2), we conducted a medicinal chemistry approach by opening the central quinoline skeleton coupled with a scaffold hopping process thus leading to a series of novel 2-benzamide-4-(6-oxy-N-methyl-1-naphthamide)-pyridine derivatives. Compound 25a was identified to show selective and equally high potency against FGFR1/2 and VEGFR2 with IC50 values less than 5.0 nM. Significant antiproliferative effects on both FGFR1/2 and VEGFR2 aberrant cancer cells were observed. In the SNU-16 xenograft model, compound 25a showed tumor growth inhibition rates of 25.0% and 81.0% at doses of 10 mg/kg and 50 mg/kg, respectively, with 5% and 10%body weight loss. In view of the synergistic potential of FGFs and VEGFs in tumor angiogenesis observed in preclinical studies, the FGFR/VEGFR2 dual inhibitor 25a may achieve better clinical benefits. (C) 2018 Elsevier Masson SAS. All rights reserved.

PI3Kδ is a key component in the aberrant signaling transduction in B cell malignancy, therefore specific targeting PI3Kδ has become an attractive molecularly targeted therapy for chronic lymphocytic leukemia (CLL). Herein, we describe the discovery and optimization of a series of 5-alkynyl substituted PI3Kδ inhibitors based on the first FDA-approved inhibitor idelalisib. Compound 8d bearing the 1-morpholinohex-5-yn-1-one moiety as the C5-substituent was identified to have high potency against PI3Kδ (3.82 nM) and SU-DHL-6 cells (7.60 nM), respectively. It was 154-fold selective over PI3Kα, 133-fold selective against PI3Kβ, and 24-fold selective against PI3Kγ. Treatment of MOLT-4 and SU-DHL-6 cells with compound 8d for 1 h resulted in reduction of phosphorylation of both Akt (S473) and its downstream S6k1 (T389) in a concentration-dependent manner. Compound 8d showed potent anti-proliferative activity as well against T lymphoblast MOLT-4, suggesting its potential activity in T-cell leukemia.

Aberrant fibroblast growth factor receptor (FGFR) activation is found across a diverse spectrum of malignancies, especially those lacking effective treatments. SOMCL-085 is a novel FGFR-dominant multi-target kinase inhibitor. Here, we explored the FGFR-targeting anticancer activity of SOMCL-085 both in vitro and in vivo . Among a panel of 20 tyrosine kinases screened, SOMCL-085 potently inhibited FGFR1, FGFR2 and FGFR3 kinase activity, with IC 50 values of 1.8, 1.9 and 6.9 nmol/L, respectively. This compound simultaneously inhibited the angiogenesis kinases VEGFR and PDGFR, but without obvious inhibitory effect on other 12 tyrosine kinases. In 3 representative human cancer cell lines with different mechanisms of FGFR activation tested, SOMCL-085 (20–500 nmol/L) dose-dependently inhibited FGFR1-3 phosphorylation and the phosphorylation of their key downstream effectors PLCγ and Erk. In 7 FGFR aberrant human cancer cell lines, regardless of the mechanistic complexity of FGFR over-activation, SOMCL-085 potently inhibited FGFR-driven cell proliferation by arresting cells at the G 1 /S phase. In the FGFR1-amplified lung cancer cell line H1581 xenograft mice and FGFR2-amplified gastric cancer cell line SNU16 xenograft mice, oral administration of SOMCL-085 (25, 50 mg·kg −1 ·d −1 ) for 21 days substantially suppressed tumor growth without affecting their body-weight. These results suggest that SOMCL-085 is a potent multi-target FGFR inhibitor that inhibits the FGFR-dependent neoplastic phenotypes of human cancer cells in vitro and in vivo.

Chronic lymphocytic leukemia (CLL) remains the most incurable leukemia. Early chemotherapeutic treatments, including alkylating agents, purine nucleoside derivatives, and immunotherapeutic antibodies, only show limited benefits for patients but severe off-target related side effects. Recent advances in understanding of the critical molecular pathways of regulating proliferation and survival of B-CLL cells have spurred a new therapeutical strategy by selectively targeting phosphoinositide 3-kinase delta (PI3Kδ). Idelalisib, a first-in-class PI3Kδ-selective small molecule has received the FDA's fast-track approval in July of 2014 as a new treatment of CLL, indolent B-cell non-Hodgkin's lymphoma, and relapsed small lymphocytic lymphoma. Undoubtedly, the success of idelalisib has provided a solid support in the development of PI3Kδ-specific inhibitors and reformed the concept of treating CLL. However, the number of reported selective inhibitors of PI3Kδ is very limited and very few have advanced into clinical trials. The mechanism of their actions remains elusive. More profound understanding on the modes of action of new PI3Kδ inhibitors will further validate the PI3Kδ-targeting strategy, and help to identify biomarkers capable of stratifying patients who will most likely benefit from the therapy.