Inclusion Criteria:

          -  Histologically or cytologically confirmed metastatic or unresectable solid malignancy
             within one of the following indications:

               1. Soft tissue sarcoma

               2. Colorectal carcinoma

               3. Non-small cell lung carcinoma

               4. Head and neck squamous cell carcinoma

               5. Breast carcinoma

               6. Ovarian carcinoma

               7. Exocrine pancreatic adenocarcinoma

               8. Gastric carcinoma

               9. Melanoma

          -  Relapsed, refractory, or progressive disease with no appropriate standard therapy
             available at the time of enrollment

          -  ECOG performance status of 0 or 1

          -  Measureable disease per the Response Evaluation Criteria in Solid Tumors (RECIST) v1.1
             at baseline

          -  Patients of childbearing potential may not be pregnant, must agree not to become
             pregnant until at 30 days after last dose of study drug, and must use 2 effective
             means of birth control.

          -  Patients who can father children must use 2 effective means of birth control and must
             agree not to donate sperm until at least 60 days after last dose of study drug.

        Exclusion Criteria:

          -  History of another malignancy within 3 years prior to first dose of study drug
             (exceptions for malignancies with negligible risk of metastasis)

          -  Previous exposure to CD47 or SIRPα targeted therapy

          -  Chemotherapy, systemic radiotherapy, biologics, other anti-neoplastic or
             investigational agents, and/or other antitumor treatment with immunotherapy that is
             not completed 4 weeks prior to first dose of SGN-CD47M. Focal radiotherapy that is not
             completed 2 weeks prior to the first dose of SGN-CD47M

          -  Known active central nervous system metastases

          -  Positive for hepatitis B, active hepatitis C infections, positive for human
             immunodeficiency virus (HIV), or known active or latent tuberculosis

          -  History of sickle cell anemia, auto-immune hemolytic anemia, or idiopathic
             thrombocytopenic purpura

          -  Carcinomatous meningitis

          -  Red blood cell transfusion within 4 weeks prior to enrollment or platelet transfusion
             within 2 weeks prior to enrollment

          -  Any active Grade 3 or higher viral, bacterial, or fungal infection within 2 weeks
             prior to first dose

          -  History of a cerebral vascular event, unstable angina, myocardial infarction, or
             cardiac symptoms consistent with New York Heart Association Class III-IV within 6
             months prior to first dose

          -  Condition requiring systemic treatment with corticosteroids or other immunosuppressive
             medications within 2 week prior to first dose

          -  Active autoimmune disease, autoimmune-related toxicity from prior
             immuno-oncology-based therapy

          -  Estimated life expectancy of less than 12 weeks