&NA;CGS 27023A is a nonpeptide matrix metalloprotease inhibitor which is showing potential in phase I studies as a therapy for solid tumours, and in preclinical studies as a therapy for osteoarthritis and rheumatoid arthritis. It is undergoing phase I studies with Novartis for the treatment of solid tumours in the UK, the Netherlands and Switzerland. CGS 27023A appears well to be tolerated at doses greater than 300mg twice daily, with biologically relevant plasma levels. No tumour regressions have been observed to date.It has been developed by Novartis to target the matrix metalloprotease stromelysin, which is found in elevated levels in cartilage and synovial fluid of patients with osteoarthritis. Novartis has selected the compound as a candidate for clinical development for osteoarthritis and rheumatoid arthritis.