Pyrido[2,3-d]pyrimidin-5-ones: a novel class of antiinflammatory macrophage colony-stimulating factor-1 receptor inhibitors.

A series of pyrido[2,3-d]pyrimidin-5-ones has been synthesized and evaluated as inhibitors of the kinase domain of macrophage colony-stimulating factor-1 receptor (FMS). FMS inhibitors may be useful in treating rheumatoid arthritis and other chronic inflammatory diseases. Structure-based optimization of the lead amide analogue 10 led to hydroxamate analogue 37, which possessed excellent potency and an improved pharmacokinetic profile. During the chronic phase of streptococcal cell wall-induced arthritis in rats, compound 37 (10, 3, and 1 mg/kg) was highly effective at reversing established joint swelling. In an adjuvant-induced arthritis model in rats, 37 prevented joint swelling partially at 10 mg/kg. In this model, osteoclastogenesis and bone erosion were prevented by low doses (1 or 0.33 mg/kg) that had minimal impact on inflammation. These data underscore the potential of FMS inhibitors to prevent erosions and reduce symptoms in rheumatoid arthritis.

Discovery and SAR of novel Naphthyridines as potent inhibitors of spleen tyrosine kinase (SYK).

The discovery of novel 5,7-disubstituted[1,6]naphthyridines as potent inhibitors of Spleen Tyrosine Kinase (SYK) is discussed. The SAR reveals the necessity for a 7-aryl group with preference towards para substitution and that this in combination with 5-aminoalkylamino substituents further improved the potency of the compounds. The initial SAR as well as a survey of the other positions is discussed in detail.