A Phase 1/2a, Open-Label, Dose-Escalation and Dose-Expansion First-In-Human Study of the Safety, Tolerability, Activity, and Pharmacokinetics of REGN10597 (Anti PD-1-IL2RA-IL2 Fusion Protein) in Patients With Advanced Solid Organ Malignancies

Key Inclusion Criteria:

Dose-escalation cohorts:

1. Histologically or cytologically confirmed diagnosis of malignancy (locally advanced or metastatic) with confirmed progression on standard-of-care therapy
2. Participants are required to submit archival tissue with optional fresh biopsy

Dose-expansion cohorts:

1. Histologically of cytologically confirmed diagnosis of Melanoma or ccRCC tumors with criteria, as defined in the protocol
2. Participants are required to submit fresh pretreatment biopsy during screening

Key Exclusion Criteria:

1. Prior treatment with Interleukin 2 (IL2)/IL15/IL7
2. Prior treatment with anti PD-1/PD-L1, or an approved systemic therapy or any previous systemic non-immunomodulatory biologic therapy within 4 weeks, as defined in the protocol
3. Has received radiation therapy or major surgery within 14 days prior to first dose of study drug or has not yet recovered from AEs
4. Has had prior anti-cancer immunotherapy within 2 months prior to study therapy
5. Has ongoing immune-related AEs prior to initiation of study drug, as defined in the protocol
6. Has known allergy or hypersensitivity to components of the study drug
7. Has any condition requiring ongoing/continuous corticosteroid therapy (>10 mg prednisone/day or anti-inflammatory equivalent) within 1-2 weeks to the first dose of study drug
8. Has ongoing or recent (within 5 years) evidence of significant autoimmune disease or any other condition that required treatment with systemic immunosuppressive treatments