This is an open-label, non-randomized, multicenter, dose-escalation and expansion study in patients with selected solid tumors.

This study will determine the maximum tolerated dose of CDX-585 while also evaluating the safety, tolerability, and efficacy of CDX-585 in patients with cancer.

Eligible patients that enroll to the dose-escalation portion of the study will be assigned to one of several dose levels of CDX-585. The dose-escalation part of the study will test the safety profile of CDX-585 and determine which dose of CDX-585 will be studied in the expansion portions of the study.

All patients enrolled in the study will be closely monitored to determine if there is a response to the treatment as well as for any side effects that may occur.

The expansion portion of the study will further evaluate the safety of CDX-585 in selected tumor types at the dose level chosen during the escalation part of the study.

Key Inclusion Criteria:

1. Recurrent, locally advanced, or metastatic solid tumor cancer excluding primary central nervous system tumors (e.g., glioblastoma).
2. Receipt of standard therapy for the tumor type in the recurrent, locally advanced, or metastatic setting.
3. Measurable (target) disease by iRECIST.
4. If of childbearing potential (male or female), agrees to practice an effective form of contraception during study treatment and for at least 3 months following last treatment.
5. Willingness to undergo a pre-treatment and on-treatment biopsy, if required.

Key Exclusion Criteria:

1. History of severe hypersensitivity reactions to other monoclonal antibodies.
2. Previous treatment with any anti-ILT4 antibody.
3. Patients who have received more than 1 anti-PD-1 or anti-PD-L1 targeted therapy, including in the adjuvant setting.
4. Prior anti-PD-L1 based therapy within 12 weeks and prior anti-PD-1 based therapy within four weeks to the planned start of study treatment.
5. Other prior malignancy, except for adequately treated basal or squamous cell skin cancer or in situ cancers. For all other cancers, the patient must be disease-free for at least one year to be allowed to enroll.
6. Thrombotic events within the last six months prior to study treatment
7. Active, untreated central nervous system metastases.
8. Active autoimmune disease or documented history of autoimmune disease.
9. History of (non-infectious) pneumonitis or has current pneumonitis.

There are additional criteria your study doctor will review with you to confirm eligibility.