Inclusion Criteria:

        Participants are eligible to be included in the study only if all the following criteria
        apply:

          1. Subject has voluntarily agreed to participate by giving written informed consent in
             accordance with ICH/GCP guidelines and applicable local regulations.

          2. Subject must have a histologically confirmed diagnosis of an unresectable, locally
             advanced or metastatic ovarian cancer, or primary peritoneal cancer or fallopian tube
             cancer.

          3. Subjects must be refractory or intolerant to existing therapy(ies) known to provide
             clinical benefit for their condition. Subject must have received platinum-based
             therapies, and should not be eligible for further platinum therapy, or should be
             intolerant to such therapy. Subjects with HRD positive disease may participate if they
             have received prior polyadenosine diphosphate ribose polymerase (PARP) inhibitor
             therapy given alone or with bevacizumab.

          4. Subjects should not be primary platinum refractory as defined by progressing during or
             within 1 month of upfront platinum therapy.

          5. Has measurable disease by RECIST v1.1 using radiologic assessment.

          6. Subject age is 18 years and older.

          7. Has an Eastern Cooperative Oncology Group (ECOG) Performance Status of 0 or 1.

          8. Has life expectancy of greater than 12 weeks.

          9. Has adequate organ function.

         10. Females of childbearing potential (FCBP) must have a negative serum or urine pregnancy
             test within 72 hours of D1 of IP.

         11. Recovery from prior anti-cancer treatments including surgery, radiotherapy,
             chemotherapy or any other anti-cancer therapy to baseline or ≤ Grade 1.

         12. Willing to consent to mandatory pre-treatment and on-treatment tumor biopsy(ies),
             unless there is excessive risk as determined by the investigator.

        Exclusion Criteria:

        Participants are excluded from the study if any of the following criteria apply:

          1. Prior treatment with an anti-CD47 or anti-SIRPα targeting agent or a CD40 agonist.

          2. Any anti-cancer therapy within the washout period prior to first dose (D1) of
             SL-172154.

          3. Concurrent chemotherapy, immunotherapy, biologic or hormonal/hormonal suppression
             therapy for cancer treatment is prohibited. Concurrent use of hormones for non-cancer
             related conditions is acceptable.

          4. Use of corticosteroids or other immunosuppressive medication, current or within 14
             days of D1 of SL-172154 treatment.

          5. Receipt of live attenuated vaccine within 28 days of D1 of IP.

          6. Active or documented history of autoimmune disease. Exceptions include controlled Type
             I diabetes, vitiligo, alopecia areata or hypo/hyperthyroidism.

          7. Hypersensitivity to the active drug substance or to any of the excipients for the
             agent to be administered or subjects with known hypersensitivity to Chinese hamster
             ovary cell products.

          8. Active pneumonitis (i.e. drug-induced, idiopathic pulmonary fibrosis,
             radiation-induced, etc.).

          9. Ongoing or active infection (e.g., no systemic antimicrobial therapy for treatment of
             infection within 5 days of D1 of IP).

         10. Symptomatic peptic ulcer disease or gastritis, active diverticulitis, other serious
             gastrointestinal disease associated with diarrhea within 6 months of D1 of IP.

         11. Clinically significant or uncontrolled cardiac/thromboembolic disease.

         12. Untreated central nervous system or leptomeningeal metastases.

         13. Women who are breast feeding.

         14. Psychiatric illness/social circumstances that would limit compliance with study
             requirements and substantially increase the risk of AEs or compromised ability to
             provide written informed consent.

         15. Another malignancy that requires active therapy and that in the opinion of the
             investigator and Sponsor would interfere with monitoring of radiologic assessments of
             response to IP.

         16. Has undergone allogeneic stem cell transplantation or organ transplantation.

         17. Known history or positive test for human immunodeficiency virus, or positive test for
             hepatitis B.