 This is a Phase I, open-label, multi-center, competitive enrollment and dose-escalation study of ALT-836 in combination with standard of care gemcitabine in participants who have locally advanced or metastatic solid tumors. The purpose of this study is to determine the maximum tolerated dose MTD, and to assess the safety and pharmacokinetic profile of ALT-836 given with gemcitabine. The clinical benefit, progression-free survival and overall survival of study participants will also be assessed. 