This study is a first-in-human (FIH), Phase 1, multicenter, open-label study to evaluate the safety, tolerability, and PK of IGM-7354 in participants with relapsed and/or refractory tumors. The study design consists of a dose-escalation stage and dose-expansion stage. Study participation will consist of a 28-day screening period, a treatment period, and a safety follow-up period 90-days after the last dose.

Patients will be enrolled in two stages: a dose-escalation stage and an expansion stage. The escalation stage will investigate single agent IGM-7354 safety and tolerability in patients with relapsed and/or refractory solid tumors. The dose expansion serial biopsy cohort will assess the intra-tumoral PD changes related to the activity of IGM-7354.

IGM-7354 will be administered intravenously (IV).

Key Inclusion Criteria:

• Age > 18 years at time of signing ICF
• ECOG Performance Status of 0 or 1
• Histologic or cytologic documentation of incurable, locally advanced or metastatic solid tumors for which standard therapies are not available, are no longer effective, are not tolerated, or have been declined by the participant
• Participants with either measurable or evaluable disease
• Adequate organ function
• At least 2 weeks prior to Day 1 or 5 half-lives, whichever is shorter, must have elapsed from the use of anti-tumor therapy, including chemotherapy, biologic, experimental, or hormonal therapy
• Participants must be willing to have pre-treatment and on-treatment tumor biopsies for biomarker evaluation

Key Exclusion Criteria:

• Inability to comply with study and follow-up procedures
• Prior IL-15, IL-2, synthetic IL-2, or IL-2v based therapy
• History of severe allergic or anaphylactic reactions to monoclonal antibody therapy
• Palliative radiation to bone metastases within 2 weeks prior to Day 1
• Major surgical procedure within 4 weeks prior to Day 1
• Untreated or active central nervous system (CNS) metastases. Patients with a history of treated CNS metastases are eligible.
• Active autoimmune disease that has required systemic treatment in the past 2 years.
• Diagnosis of immunodeficiency
• Current Grade >1 toxicity from prior therapy. Participants with current Grade 2 chronic toxicities that are well-controlled by medications may be enrolled after discussion with medical monitor