Abstract: The disclosure relates to novel compounds for use in the treatment or prophylaxis of cancers and other proliferative conditions that are for example characterized by cells that express cytochrome P450 1B1 (CYP1B1) and allelic variants thereof. Also provided are pharmaceutical compositions comprising one or more such compounds for use in medical therapy, for example in the treatment of prophylaxis of cancers or other proliferative conditions, as well as methods for treating cancers or other conditions in human or non-human animal patients. Provided are methods for identifying novel compounds for use in the treatment of prophylaxis of cancers and other proliferative conditions that are for example characterized by cells that express CYP1B1 and allelic variants thereof. Finally, provided is a method for determining the efficacy of a compound as described herein in treating cancer.