Preclinical profile of a potent gamma-secretase inhibitor targeting notch signaling with in vivo efficacy and pharmacodynamic properties.

Abstract

Notch signaling is an area of great interest in oncology. RO4929097 is a potent and selective inhibitor of gamma-secretase, producing inhibitory activity of Notch signaling in tumor cells. The RO4929097 IC50 in cell-free and cellular assays is in the low nanomolar range with >100-fold selectivity with respect to 75 other proteins of various types (receptors, ion channels, and enzymes). RO4929097 inhibits Notch processing in tumor cells as measured by the reduction of intracellular Notch expression by Western blot. This leads to reduced expression of the Notch transcriptional target gene Hes1. RO4929097 does not block tumor cell proliferation or induce apoptosis but instead produces a less transformed, flattened, slower-growing phenotype. RO4929097 is active following oral dosing. Antitumor activity was shown in 7 of 8 xenografts tested on an intermittent or daily schedule in the absence of body weight loss or Notch-related toxicities. Importantly, efficacy is maintained after dosing is terminated. Angiogenesis reverse transcription-PCR array data show reduced expression of several key angiogenic genes. In addition, comparative microarray analysis suggests tumor cell differentiation as an additional mode of action. These preclinical results support evaluation of RO4929097 in clinical studies using an intermittent dosing schedule. A multicenter phase I dose escalation study in oncology is under way.

• Authors: Leopoldo Luistro, Wei He, Melissa Smith, Kathryn Packman, Maria Vilenchik, Daisy Carvajal, John Roberts, James Cai, Windy Berkofsky-Fessler, Holly Hilton, Michael Linn, Alexander Flohr, Roland Jakob-Røtne, Helmut Jacobsen, Kelli Glenn, David Heimbrook, John F Boylan
• Journal: Cancer research (Cancer Res) Vol. 69 Issue 19 Pg. 7672-80 (Oct 01 2009) ISSN: 1538-7445 [Electronic] United States
• PMID: 19773430 (Publication Type: Journal Article)

Chemical References

• Benzazepines
• Protease Inhibitors
• RNA, Messenger
• Receptors, Notch
• Amyloid Precursor Protein Secretases
• 2,2-dimethyl-N-(6-oxo-6,7-dihydro-5H-dibenzo(b,d)azepin-7-yl)-N'-(2,2,3,3,3-pentafluoropropyl)malonamide

Topics

• Amyloid Precursor Protein Secretases (antagonists & inhibitors)
• Animals
• Benzazepines (pharmacology)
• Carcinoma, Non-Small-Cell Lung (drug therapy, enzymology, metabolism)
• Cell Line, Tumor
• Hair Follicle (drug effects, metabolism)
• Humans
• Lung Neoplasms (drug therapy, enzymology, metabolism)
• Mice
• Neoplasms (drug therapy, enzymology, metabolism)
• Protease Inhibitors (pharmacology)
• RNA, Messenger (genetics, metabolism)
• Rats
• Receptors, Notch (antagonists & inhibitors, metabolism)
• Signal Transduction (drug effects)
• Transcription, Genetic (drug effects)
• Xenograft Model Antitumor Assays