RecruitingDrug trialDose Escalation/Expansion Study of Mavrostobart (PT199), an Anti-CD73 mAb, Administered Alone and in Combination With a PD-1 Inhibitor or Chemotherapy (the MORNINGSTAR Study)This is a first-in-human, Phase 1/2, open-label, study designed to evaluate the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy of Mavrostobart (PT199) alone and in combination with a PD-1 inhibitor or chemotherapy.