Pre-surgery treatment with the novel drug vidutolimod and the PD-1 checkpoint inhibitor nivolumab led to tumor control in 55% of patients with stage 3 cutaneous melanoma, according to the results of a single-arm phase 2 clinical trial led by the University of Pittsburgh, UPMC Hillman Cancer Center and the National Cancer Institute (NCI). The findings, published in Cancer Cell , support the development of vidutolimod for treating cutaneous melanoma and provide important insights that could advance research on this drug for use in other cancers. "This is the first and only clinical trial so far to test the novel combination of nivolumab and the experimental drug vidutolimod in the neoadjuvant setting," said lead author Diwakar Davar, M.
D., associate professor at the Pitt School of Medicine and UPMC Hillman. "It's exciting that we saw a response rate of 55%, which is on par with currently approved immunotherapy combinations .
" Vidutolimod, which has not yet been approved by the U.S. Food and Drug Administration (FDA), targets the TLR9 pattern recognition receptor, which is a protein that plays a critical role in the initiation of innate immune responses to foreign threats.
TLR9-targeting agents are often included in drugs and vaccines because of their immune-augmenting effects, but less is known about how they work in combination with other cancer therapies. For this phase 2 clinical trial, 31 patients with high-risk stage 3 resectable melanoma received seven injections of vidut.