A Study to Evaluate the Safety, Pharmacokinetics, and Antitumor Activity of AK117 as Monotherapy or in Combination With AK104

All subjects will receive 4 weekly infusions (Days 1, 8, 15, and 22) of AK117 in each 28-day treatment cycle until unacceptable toxicity, documentation of confirmed progressive disease (PD), or subject withdrawal.

All Subjects will receive 3 weekly infusions of AK117 (Days 1, 8, and 15) and 1 infusion of AK104 (on Day 1) as combination therapy in each 21-day treatment cycle until unacceptable toxicity, documentation of confirmed PD, or subject withdrawal.