PubChem CID 9934746 Formula C26H31N5O4 Molar mass 477.554 g/mol | ChemSpider 8110374 3D model (Jmol) Interactive image | |
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Synonyms 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(N-carbamoyl-2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one | ||
RPL-554 (LS-193,855) is a drug candidate for respiratory diseases. It is an analog of trequinsin, and like trequinsin, is a dual inhibitor of the phosphodiesterase enzymes PDE-3 and PDE-4. As of October 2015, inhaled RPL-554 delivered via a nebulizer was in development for COPD and had been studied in asthma.
PDE3 inhibitors act as bronchodilators, while PDE4 inhibitors have an anti-inflammatory effect.
RPL554 was part of a family of compounds invented by Sir David Jack, former head of R&D for GlaxoSmithKline, and Alexander Oxford, a medicinal chemist; the patents on their work were assigned to Vernalis plc.
In 2005, Rhinopharma Ltd, acquired the rights to the intellectual property from Vernalis. Rhinopharma was a startup founded in Vancouver, Canada in 2004 by Michael Walker, Clive Page, and David Saint, to discover and develop drugs for chronic respiratory diseases, and intended to develop RPL-554, delivered with an inhaler, first for allergic rhinitis, then asthma, then for COPD. RPL554 was synthesized at Tocris, a contract research organization, under the supervision of Oxford, and was studied in collaboration with Page's lab at King’s College, London. In 2006 Rhinopharma recapitalized and was renamed Verona Pharma plc.