Inclusion Criteria:

          -  Any advanced/metastatic, non-hematological, extracranial solid tumor malignancy with
             disease progression after at least one line of standard therapy or for which standard
             therapy known to prolong survival does not exist

          -  Patients must have at least two sites of non-osseous disease that are ≥10mm in
             diameter, one of which must be accessible for intratumoral injection and tumor
             biopsies and the other of which must be accessible for needle biopsies by
             interventional radiology. (Sites have to be deemed safe for repeated access upon IR
             review, based on anatomic location, size, shape, and accessibility). Liver lesions may
             not be used as the injection site even if otherwise deemed safe for access.

          -  Patients must have at least one additional site of measurable disease by Response
             Evaluation Criteria in Solid Tumors (RECIST) criteria, other than the sites selected
             for intratumoral injection and tumor biopsies

          -  All patients with tumor types for which anti-PD-1 or anti PD-L1 therapy has been
             approved should have received such therapy prior to enrollment, with evidence of
             progression on at least two scans (ie, with pseudoprogression ruled out). Patients
             with validated driver mutations should have received and progressed on appropriate
             targeted therapy

          -  Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1

          -  Life expectancy of at least three months

          -  Total bilirubin < 1.5 x upper limit of normal (ULN) (unless patient has history of
             Gilbert?s disease)

          -  Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) < 3 x upper limit
             of normal (ULN)

          -  Creatinine < 1.5 x ULN or measured or calculated creatinine clearance (glomerular
             filtration rate [GFR] can also be used in place of creatinine or creatinine [CrCl]) >=
             60 mL/min for subject with creatinine levels > 1.5 x ULN

          -  Absolute neutrophil count (ANC) >= 1,500/mcL

          -  Hemoglobin >= 9 g/dL without transfusion within the past 4 weeks

          -  Platelets >= 100,000/mcL

          -  Prothrombin time (PT)/international normalized ratio (lNR) within normal limits

          -  Written informed consent obtained from subject

          -  Patients who have previously received an immune checkpoint inhibitor prior to
             enrollment must have any immune related toxicities resolved to =< grade 1 or baseline
             (prior to the checkpoint inhibitor) to be eligible. Patients who developed endocrine
             adverse events on checkpoint inhibitor are eligible to enter regardless of the Common
             Terminology Criteria for Adverse Events (CTCAE) Grade resolution as long as the
             patient is well controlled on endocrine replacement

          -  Women of childbearing potential must have a urine or serum pregnancy test within 24
             hours prior to the first dose of trial treatment. If the urine test is positive or
             cannot be confirmed as negative, then a serum test will need to be negative

          -  Women of childbearing potential must practice a highly effective method of birth
             control during treatment and for 160 days after treatment completion. Women of
             childbearing potential who chose complete abstinence must agree to have a urine or
             serum pregnancy tests within 24h of each dose of study treatment. If the urine test is
             positive or cannot be confirmed as negative, then a serum test will need to be
             negative

          -  Men who are sexually active with women of childbearing potential must agree to follow
             instructions for methods of contraception while being treated on the study, and for
             165 days after treatment completion. Men must agree to not donate sperm during this
             time period

        Exclusion Criteria:

          -  History of grade 2 or higher hypersensitivity reaction to either SD-101 or BMS-986178

          -  Patients who require immediate treatment or cytoreduction, as deemed by their
             physician or the study investigators

          -  Treatment with other anticancer therapy (chemotherapy, small molecule, or radiation
             therapy) within the past 3 weeks prior to study entry or within the past 6 weeks prior
             to study entry for immunotherapies

          -  Use of investigational agent within the past 3 weeks prior to study enrollment

          -  Major surgery within 4 weeks of enrollment, or a wound that has not fully healed

          -  Vaccinated with live, attenuated vaccines within 4 weeks of enrollment

          -  Symptomatic central nervous system (CNS) metastases

          -  Known bleeding disorder that is deemed to place the patient at unacceptable risk for
             bleeding complications from intratumoral injection. Patients on anticoagulants and
             anti-platelet agents other than aspirin are excluded

          -  Any uncontrolled bacterial, fungal, viral, or other infection

          -  Active autoimmune disease requiring systemic treatment within the past 2 years, with
             the exception of patients well controlled on physiologic endocrine replacement

          -  Treatment with corticosteroids (> 10 mg per day prednisone or equivalent) or other
             immune suppressive drugs within 14 days prior to initiation of study drug. Steroids
             for topical ophthalmic, inhaled, or nasal administration are allowed. Patients
             requiring courses of systemic steroids for 14 consecutive days or less for an acute
             condition (not for a chronic autoimmune illness) may receive study drug 14 days after
             steroid therapy

          -  Prior history of cancer that is unlikely to interfere with the ability to give study
             treatment or affect the primary outcome or interpretation of the primary outcome of
             the study. For a history of malignancy treated with curative intent, enrollment should
             occur at least 2 years after such therapy.

          -  Significant cardiac disease (New York Heart Association [NYHA] class IV congestive
             heart failure, or unstable angina or myocardial infarction within the past 6 months)

          -  Human immunodeficiency virus (HIV) positive (+) patients or patients with active
             hepatitis B or C infection

          -  Patients who are pregnant or breastfeeding

          -  Any other medical history, including laboratory results, deemed by the investigator
             likely to interfere with their participation in the study, or to interfere with the
             interpretation of the results