PDGFRA and systemic mastocytosis: Ripretinib (QINLOCKTM) is a novel type II, tyrosine switch control inhibitor designed to broadly inhibit activating and drug-resistant mutations in KIT and PDGFRA. It is being developed by Deciphera Pharmaceuticals for the treatment of KIT- and PDGFRA-driven cancers, including GIST, systemic mastocytosis and other solid tumours.