Therapeutic modulators of peroxisome proliferator-activated receptors (PPAR): a patent review (2008-present)

Introduction: Peroxisome proliferator-activated receptors (PPAR) are ligand-activated transcription factors belonging to the nuclear receptor superfamily. The three known subtypes PPAR alpha, PPAR gamma and PPAR delta have different tissue distribution and play a key role as regulators of glucose and lipid homeostasis as well as in cell proliferation, differentiation and inflammatory responses. They have gained a lot of interest as pharmaceutical targets over the last years and with the antidiabetic thiazolidindiones (TZDs) and the hypolipidemic fibrates, two classes of drugs had entered the market. Early observations of severe adverse events changed the situation in the recent past. Areas covered: Herein the authors summarize recent (2008-present) patent applications concerning PPAR ligands claimed for the use in metabolic disorders as well as patents indicating new applications for modulators of the PPAR subtypes. Expert opinion: Looking at the recent patent activity regarding novel compounds, there have not been real innovations. As major applications for therapeutic PPAR ligands cancer therapy, skin-related disorders and systemic anti-inflammatory therapies might arise in the mid-term future. The known PPAR targeting drugs might see a repurposing for novel indications.