Safety, Tolerability, and Efficacy of Doxorubicin and Pembrolizumab for Sarcoma

Inclusion Criteria

• Be willing and able to provide written informed consent for the trial.
• Must have a histologically confirmed diagnosis of unresectable or metastatic soft tissue sarcoma not amenable to curative treatment with surgery or radiotherapy. Patients with Ewings sarcoma, osteosarcoma, chondrosarcoma, Kaposis sarcoma, gastrointestinal stromal tumors (GIST), clear cell sarcoma, alveolar soft part sarcoma and any other soft tissue or bone sarcoma felt to be chemotherapy resistant in the opinion of the Sponsor-Investigator will be excluded.
• Must not have received prior treatment with an anthracycline chemotherapy (eg, doxorubicin) and/or anti-PD-1/PD-L1 therapy.
• May have had any number of prior systemic cytotoxic therapies for unresectable/metastatic disease.
• Must have at least one radiologically measurable lesion as per RECIST 1.1 defined as a lesion that is 10mm in longest diameter or lymph node that is 15mm in short axis imaged by CT scan or MRI. Tumors with previously irradiated field will be designated as nontarget lesions unless progression is documented or a biopsy is obtained to confirm persistence of at least 90 days following completion of radiotherapy.
• All subjects with accessible tumor will be asked to provide a fresh tumor biopsy if they can be safely biopsied in the opinion of the investigator. Recently obtained archived core or excisional biopsy of a tumor lesion (obtained up to 12 months prior to Cycle 1 Day 1) may be substituted only if the subject is unwilling or unable (e.g. inaccessible or subject safety concern) to undergo a fresh tumor biopsy. Subjects who are unwilling or unable to have a fresh tumor biopsy and do not have recently obtained archived tissue available may submit an archived specimen (obtained > 12 months prior to Cycle 1 Day 1) only upon approval from the Sponsor-Investigator.
• Be at least 12 years of age on day of signing informed consent. Assent will be obtained in appropriately aged subjects per institutional guidelines.
• ECOG performance status 0 or 1.
• Life expectancy of at least 3 months per the Investigator.
• Have adequate organ function as indicated by the laboratory values in Table 1 of protocol. All screening labs should be performed within 10 days of treatment initiation. PT/INR and PTT must be performed within 7 days of study treatment initiation for subjects on anti-coagulants such as coumadin/heparin.
• The subject has left ventricular ejection fraction (LVEF) greater than or equal to 50% assessed within 21 days prior to study regimen initiation.
• Subjects must not be expecting to conceive or father children within the timeframe referenced below. Subjects of childbearing potential must be willing to adhere to the contraception requirement as described in Section 3.3.2 from the day of the screening visit (or 14 days prior to the initiation of study treatment for oral contraception) throughout the study period up to 120 days after the last dose of pembrolizumab and/or up to 180 days after the last dose of doxorubicin. If there is any question that a subject of childbearing potential will not reliably comply with the requirements for contraception, that subject should not be entered into the study.
• Female subjects of childbearing potential must have a negative urine or serum pregnancy test at screening (within 72 hours of first dose of study treatment). If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required. The serum pregnancy test must be negative for the subject to be eligible.
• Subject has voluntarily agreed to participate by giving written informed consent for the trial. The subject may also provide consent for Optional and Future Studies-Biospecimen Collection. However, the subject may participate in the main trial without participating in Optional and Future Studies.

Exclusion Criteria

• Currently participating and receiving study therapy or have participated in a study of