Abstract: This disclosure relates to new phthalimide and isoindolinone derivatives and other PFKFB3 inhibitors for use in the treatment of diseases. The invention further relates to pharmaceutical compositions containing such PFKFB3 inhibitors, methods of preparation thereof, methods for their use as therapeutic agents, and methods of preparation of a medicament for use in therapy, as well as kits and other inventions comprising such PFKFB3 inhibitors. These PFKFB3 inhibitors are useful for the treatment and prophylaxis of cancer, neurodegenerative diseases, autoimmune diseases, inflammatory disorders, multiple sclerosis, metabolic diseases, inhibition of angiogenesis and other diseases and conditions, where the modulation of PFKFB3 and/or PFKFB4 has beneficial effect as well as neuroprotection.