To compare OS for INT230-6 vs US Standard of Care (SOC) in participants with unresectable or metastatic liposarcoma, undifferentiated pleomorphic sarcoma or leiomyosarcoma who have disease progression prior to study enrollment following no more than 2 standard therapies, which must have included an anthracycline-based regimen, unless contraindicated, and then a maximum of 1 additional regimen.

The primary objective is to assess the safety and tolerability of single and multiple intratumoral doses of INT230-6 in subjects with advanced or recurrent malignancies. This will be assessed by the rate of ≥ grade 3 AE's attributed to INT230-6 and not the underlying disease. NCI Common Terminology Criteria for Adverse Events (CTCAE v.4.03) (Scale 1 (least severe) to 5 (most severe)) All recorded adverse events will be listed and tabulated by system organ class, preferred term, and dose and coded according to the most current version of MedDRA. The incidence of adverse events will be tabulated and reviewed for potential significance and clinical importance. Adverse Events will be summarized for all reported data and by study period: a) up to and including 28 days post last dose of initial treatment, and b) from first dose of re-initiation of treatment, for subjects who re-initiate study therapy while in follow-up, up to 28 days post-dose of the last re-treatment dose.