Epacadostat (previously INCB24360) is an investigational drug for cancer. Epacadostat is an inhibitor of

indoleamine 2,3-dioxygenase-1 Indoleamine-pyrrole 2,3-dioxygenase (IDO or INDO ) is a heme-containing enzyme physiologically expressed in a number of Tissue (biology), tissues and Cell (biology), cells, such as the small intestine, lungs, female genital tract or placenta. In ...

(IDO1). Epacadostat inhibits IDO1 by competitively blocking it, without interfering with

IDO2 Ido () is a constructed language derived from Reformed Esperanto, and similarly designed with the goal of being a universal second language for people of diverse backgrounds. To function as an effective ''international auxiliary language'', ...

or tryptophan 2,3-dioxygenase (TDO). It has antitumor activity in some models, though is most effective when combined with other immunotherapy agents.

History and clinical trials

As of 2017, the combination of epacadostat with

pembrolizumab Pembrolizumab, sold under the brand name Keytruda, is a humanized antibody used in cancer immunotherapy that treats melanoma, lung cancer, head and neck cancer, Hodgkin lymphoma, stomach cancer, cervical cancer, and certain types of breast canc ...

(Keytruda) was being investigated by

Incyte Incyte is an American multinational pharmaceutical company with headquarters in Wilmington, Delaware, and Morges, Switzerland. The company was created in 2002 through the merger of Incyte Pharmaceuticals, founded in Palo Alto, California in 1991 ...

and Merck & Co. in several cancers, as was the combination of epacadostat with

nivolumab Nivolumab, sold under the brand name Opdivo, is a medication used to treat a number of types of cancer. This includes melanoma, lung cancer, malignant pleural mesothelioma, renal cell carcinoma, Hodgkin lymphoma, head and neck cancer, urotheli ...

(Opdivo) by Incyte and

Bristol Myers Squibb The Bristol Myers Squibb Company (BMS) is an American multinational pharmaceutical company. Headquartered in New York City, BMS is one of the world's largest pharmaceutical companies and consistently ranks on the ''Fortune'' 500 list of the lar ...

. In April 2018, Incyte announced they were halting the Phase III ECHO-301/KEYNOTE-252 (NCT02752074) trial of epacadostat with pembrolizumab for melanoma as the combination therapy missed the first

primary endpoint Clinical endpoints or clinical outcomes are outcome measures referring to occurrence of disease, symptom, sign or laboratory abnormality constituting a target outcome in clinical research trials. The term may also refer to any disease or sign tha ...

of improving

progression-free survival Progression-free survival (PFS) is "the length of time during and after the treatment of a disease, such as cancer, that a patient lives with the disease but it does not get worse". In oncology, PFS usually refers to situations in which a tumor is p ...

vs. pembrolizumab alone. The second primary endpoint of

overall survival Survival rate is a part of survival analysis. It is the proportion of people in a study or treatment group still alive at a given period of time after diagnosis. It is a method of describing prognosis in certain disease conditions, and can be use ...

is not yet determined.

References

{{Chemotherapeutic agents Experimental cancer drugs Sulfamides Oxadiazoles Bromoarenes Fluoroarenes