To learn if the study drug REC-617 can help to control LMS. The safety of REC-617 will also be studied.
Histologically confirmed leiomyosarcoma (any site of origin).
RB1-negative tumor, as assessed by immunohistochemistry (IHC) with a cutoff of 0% versus any expression Participants will have measurable diseases by RECIST 1.1. Previously ablated/ radiated/treated areas can only be counted towards measurable disease if there is unequivocal progression after directed therapy.
Participant will have tumor lesion(s) or metastases amenable to biopsy, excluding bone metastases, as confirmed by a radiologist, if appropriate, and as deemed safe by the Investigator. If there is only one target lesion per RECIST 1.1 which is accessible to biopsy, this lesion should be at least 2cm.
At least one prior line of systemic therapy. C. Participants Characteristics
Participants who are receiving any other investigational agents or have received any other investigational agent within 3 weeks prior to enrollment.
Current enrollment in another clinical study unless it is non-interventional or the follow-up period of an interventional study.
Prior treatment with radiotherapy (including radio-labeled spheres and/or cyberknife, hepatic arterial embolization (with or without chemotherapy) or cryotherapy/ablation) is allowed if these therapies did not affect the areas of measurable disease being used for this protocol.
Received medications known to prolong QTc within 5 half-lives before the first dose of the study treatment. List of medications that prolong QTc can be obtained from crediblemeds.org.