Phase I study of TH-302, investigational hypoxia-targeted drug, in combination with sunitinib.

e15557 Background: Tumors often consist of highly hypoxic subregions known to be resistant to chemotherapy and radiotherapy. TH-302 is an investigational hypoxia-targeted drug with a 2-nitroimidazole trigger designed to release the DNA alkylator bromo-isophosphoramide mustard (Br-IPM) when reduced in severe hypoxia. Preclinical models demonstrate that treatment with sunitinib increased the tumor hypoxic fraction, the therapeutic target of TH-302. Initiating TH-302 following sunitinib significantly increased the efficacy of sunitinib in these models. In this phase 1 dose escalation study, TH-302 was combined with standard dose sunitinib. Methods: Eligible patients (pts) for the study (NCT01381822) had advanced RCC, GIST or PNET tumors, evaluable disease by RECIST, ECOG ≤2 and acceptable hematologic, hepatic and renal function. Pts received TH-302 in combination with standard full doses of 50 mg PO sunitinib daily from Day 1 to Day 28 of a 6 week cycle. TH-302 was administered IV on Days 8, 15 and 22. TH-30...