Inclusion Criteria:  Must have histologically confirmed relapsed or refractory sarcoma. Must have measurable disease by RECIST criteria at study enrollment Performance status of Karnofsky/Lansky ≥50%  Must have normal organ and marrow function as defined below:  Absolute neutrophil count ≥1,000/mcL Platelet count ≥ 100,000/mcL Total bilirubin within normal institutional limits AST (SGOT) ≤ 2.5 X institutional upper limit of normal ALT (SGPT) ≤ 2.5 X institutional upper limit of normal Serum Creatinine ≤1.5X institutional limit of normal Must be able to swallow pills or consume the contents of the DSF and Capsules sprinkled on food. Participants, or parent/guardians for participants <18 years old (yo), must have the ability to understand and the willingness to sign a written informed consent document. Must abstain from alcohol during study. Prior treatment toxicities must have stabilized or resolved to ≤ Grade 1 according to NCI CTCAE Version 5.0 except alopecia, neuropathy and hematologic criteria (must meet normal organ and marrow function criteria above). Participants ≥18yo must agree to pre-and post-treatment core needle tumor biopsies. For participants <18yo biopsies are optional. Biopsies will not be performed if deemed unsafe by interventional radiologists that will be performing the procedure and is not part of the study team to avoid bias. Must abstain from sexual intercourse or used appropriate, highly-effective birth control measures.  Exclusion Criteria:  Has active, uncontrolled bacterial, viral, or fungal infection(s) requiring systemic therapy Has a history of allergy or hypersensitivity to any of the study drugs, their pharmaceutical class or any of their excipients. The participant exhibits any of the events outlined in the Contraindications or Special Warnings and Precautions sections of Liposomal Doxorubicin Prescribing Information package inserts or on the Investigator's Brochure for DSF/Cu. Has a concomitant serious medical or psychiatric illness that, in the opinion of the investigator, could compromise the participant's safety or the study data integrity. Is currently enrolled in any other clinical protocol or investigational trial involving administration of antineoplastic compounds for the treatment of their sarcoma. Is unwilling or unable to comply with study procedures. Know condition preventing safe administration of copper such as a copper allergy or Wilson's Disease. Investigator feels participation in this study would be harmful or of no benefit to the potential participant