Xoma-3E

This is a Phase I, single-center, double-blind, placebo-controlled dose escalation trial of three dose cohorts (A: 0.033 mg/kg, B: 0.165 mg/kg, and C: 0.33 mg/kg). The purpose of this study is to evaluate the safety and tolerability of NTM-1633 in healthy adults. This is a first-in-human study consisting of three cohorts of eight subjects each. Dosing for each cohort is as follows: Two sentinel subjects will be administered a single 1-hour infusion (one NTM-1633, one placebo). No more than two subjects per day thereafter (at least 24 hrs will elapse between the dosing of each two subjects) will be dosed in the same manner until all subjects are dosed. Dose escalation will not occur until safety data through Day 8 is reviewed by the Safety Review Committee (SRC). Objective dose-escalation criteria and safety evaluations will be utilized. The study duration will be for approximately 8 months. Subjects in Cohort A will participate for approximately 17 weeks and Subjects in Cohorts B and C will participate approximately 21 weeks. Primary Objective: To assess the safety and tolerability of escalating doses of NTM-1633 administered intravenously in healthy adults.