Current state on tryptophan 2,3-dioxygenase inhibitors: a patent review

Area of Science:

• Biochemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Tryptophan-2,3-dioxygenase (TDO2) is an enzyme that degrades tryptophan.
• TDO2 is expressed in the liver and brain, and is implicated in cancer and neuropsychiatric diseases.
• Initial research focused on TDO2 inhibitors for depression therapy before their link to cancer immunotherapy.

Purpose of the Study:

• To review patent literature on Tryptophan-2,3-dioxygenase inhibitors.
• To categorize compounds by chemical structure and present representative examples.
• To explore structure-activity relationships and inhibitory activities of TDO2 inhibitors.

Main Methods:

• Review of patent literature on TDO2 inhibitors.
• Categorization of compounds based on chemical structure.
• Integration of peer-reviewed literature to supplement patent data.

Main Results:

• Few selective and potent TDO2 inhibitors have been reported to date.
• No TDO2 inhibitors are currently in clinical trials.
• Representative examples of TDO2 inhibitors are presented with their activities and SARs.

Conclusions:

• TDO2 inhibitors hold promise for cancer immunotherapy and neurodegenerative diseases.
• Discovery of selective and potent TDO2 inhibitors remains challenging but is an active research area.
• Further research is needed to advance TDO2 inhibitors into clinical applications.