IDO thwarts antitumor T cell responses; plus Lumen, Loki, Genentech and more

NanoString Technologies Inc. (NASDAQ:NSTG) and University of Chicago scientists showed in Science Translational Medicine that epacadostat, an IDO1 inhibitor from Incyte Corp. (NASDAQ:INCY), reduced rather than enhanced T cell function in tumor biopsies from ovarian cancer patients. Combining epacadostat with purinergic receptor antagonists, to counteract epacadostat-mediated increases in nicotinamide adenine dinucleotide (NAD+), rescued T cell proliferation and increased survival in a mouse model of ovarian cancer.

Enthusiasm for IDO as an immuno-oncology target cratered after epacadostat, in combination with Keytruda pembrolizumab, failed to meet the primary endpoint of progression-free survival in the Phase III ECHO-301 trial, and did not show statistical difference in overall survival, its secondary endpoint, versus Keytruda monotherapy...