Study of IDO Inhibitor in Combination With Checkpoint Inhibitors for Adult Patients With Metastatic Melanoma

The incidence of melanoma is increasing. Based upon data obtained between 2004 and 2006, the lifetime probability of developing melanoma in the United States is estimated to be 1 in 37 for men and 1 in 56 for women. In the United States, melanoma is the fifth leading cancer in men and the seventh in women. Locally confined, fully-resectable disease may be curable with current therapy; but Stage IV metastatic disease (or relapsed/recurrent disease) is highly refractory to therapy. Thus, experimental clinical trials provide an accepted treatment option for metastatic or relapsed/refractory melanoma. The current study is designed as a prospective trial to evaluate the combination of indoximod and checkpoint inhibitors in adult patients with metastatic melanoma. Ipilimumab, pembrolizumab and nivolumab will be used at the recommended approved doses for this indication. The current trial will be done in two phases: a Phase 1b dose escalation of indoximod in combination with ipilimumab, starting at half the recommended single-agent dose, to establish the recommended Phase 2 dose for the combination. This will be followed by a three arm expansion study testing a fixed dose of indoximod (at the recommended Phase 2 dose) combined with standard-dose ipilimumab, pembrolizumab or nivolumab. Treatment will be administered on an outpatient basis. No investigational or commercial cancer directed agents or therapies other than those described below may be administered. Safety assessment will follow the guidelines provided in the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE) Version.4.03. Patients will be followed both clinically and radiographically starting 12 weeks after initiation of treatment then every 8 weeks for tumor evaluation. Post-treatment scans will be compared to the baseline scan and responses will be assessed based using mWHO and immune related response criteria (irRC) described by Wolchok et al. (Wolchok et al., 2009).