• 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.