Up to 20 participants will be enrolled into two sequential cohorts. Cohort 1 will consist of 10 participants who will receive simtuzumab every other week for a total of 3 infusions. Participants in Cohort 2 (10 subjects) will also receive simtuzumab every other week for a total of 3 infusions; the dose will depend on the safety and tolerability of simtuzumab seen in Cohort 1.