A Phase 1a/1b Study of ACTM-838 in Patients With Advanced Solid Tumors

Inclusion Criteria:

1. Advanced solid tumor for which there is no remaining standard curative therapy andno therapy with a demonstrated survival benefit, or they must be ineligible toreceive or refuse to receive such therapy

2. At least one measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST ) v1.1; amenable for biopsy, and radiographically apparent on computedtomography (CT) or magnetic resonance imaging (MRI )

3. Eastern Cooperative Oncology Group (ECOG) 0-1

4. Adequate hematologic, hepatic, pulmonary, and cardiac function

5. CD4 count >500/mL at screening

6. Additional protocol defined inclusion criteria may apply

Exclusion Criteria:

1. Active autoimmune disease requiring systemic treatment (i.e., with use of diseasemodifying agents, systemic corticosteroids or immunosuppressive drug) within thepast 6 months prior to dosing of investigational product.

2. History of permanent artificial implants (e.g., prosthetic joints, artificial heartvalves, pacemakers, orthopaedic screw[s], metal plate[s], bone graft[s], or otherexogenous implant[s]

3. Known history of cholelithiasis or urolithiasis

4. History of valvular disease, arterial aneurisms or arterial or venous malformation

5. Known active brain metastases

6. Documented active Salmonella infection or vaccination with Salmonella typhi within 6months prior to investigational product dosing

7. Additional protocol defined inclusion/exclusion criteria may apply