Domatinostat With Sirolimus for Relapsed, Refractory Sarcoma and Osteosarcoma

Inclusion Criteria:

* Age ≥12 and ≤40 years.
* Histologically confirmed relapsed or refractory sarcoma (Phase 1) or osteosarcoma (Phase 2).
* At least one prior standard systemic therapy regimen.
* Not candidates for available therapies known to provide survival benefit.
* Karnofsky/Lansky performance score ≥60.
* Life expectancy ≥16 weeks.
* Adequate organ function: ANC ≥1,000/mcL, Platelets ≥100,000/uL, Hemoglobin ≥8 g/dL, Adequate hepatic and renal function.
* Ability to swallow tablets.
* Negative pregnancy test for females of childbearing potential.
* Agreement to use effective contraception.
* Ability to provide informed consent/assent.

Exclusion Criteria:

* Receiving another investigational agent.
* Receiving concurrent anticancer therapy.
* Known hypersensitivity to domatinostat or sirolimus.
* Bone marrow-only disease.
* CNS metastatic disease.
* Major surgery within 2 weeks prior to treatment.
* Active malignancy within the previous 3 years (with protocol-specified exceptions).
* History of solid organ transplantation.
* Significant recent cardiac disease.
* Concurrent prohibited CYP3A4/P-gp interacting medications.
* Uncontrolled infection or other serious uncontrolled illness.
* Pregnancy or breastfeeding.
* HIV infection on antiretroviral therapy.
* Weight \<40 kg.
* Inability to comply with study requirements.