Nivolumab Alone or in Combination With Ipilimumab in Treating Patients With Advanced Uterine Leiomyosarcoma

Inclusion Criteria

• Patients must have histologically or cytologically confirmed advanced leiomyosarcoma of the uterus (ULMS); advanced ULMS is defined as metastatic ULMS or unresectable primary ULMS
• Patients must have measurable disease, defined as at least one lesion that can be accurately measured in at least one dimension (longest diameter to be recorded for non-nodal lesions and short axis for nodal lesions) as >= 20 mm (>= 2 cm) with conventional techniques or as >= 10 mm (>= 1 cm) with spiral computed tomography (CT) scan, magnetic resonance imaging (MRI), or calipers by clinical exam
• Patients must have received at least one prior line of chemotherapy, for ULMS (either in the adjuvant or metastatic setting)
• Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1
• Life expectancy of greater than 9 months
• Absolute neutrophil count >= 1,500/mcL
• Platelets >= 100,000/mcL
• Total bilirubin = = 50 mL/min (if using the Cockcroft-Gault formula)
• Patients with a requirement for steroid treatment or other immunosuppressive treatment: patients should be excluded if they have a condition requiring systemic treatment with either corticosteroids (> 10 mg daily prednisone equivalents) or other immunosuppressive medications within 14 days of study drug administration; inhaled or topical steroids and adrenal replacement doses > 10 mg daily prednisone equivalents are permitted in the absence of active autoimmune disease
• Women of child-bearing potential (WOCBP) must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation; WOCBP should use an adequate method to avoid pregnancy for 31 weeks after the last dose of investigational drug; women of childbearing potential must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of human chorionic gonadotropin [HCG]) within 24 hours prior to the start of nivolumab; women must not be breastfeeding; women who are not of childbearing potential (i.e., who are postmenopausal or surgically sterile) do not require contraception
• Women of childbearing potential (WOCBP) is defined as any female who has experienced menarche and who has not undergone surgical sterilization (hysterectomy or bilateral oophorectomy) or who is not postmenopausal; menopause is defined clinically as 12 months of amenorrhea in a woman over 45 in the absence of other biological or physiological causes; in addition, women under the age of 55 must have a documented serum follicle stimulating hormone (FSH) level less than 40 mIU/mL
• WOCBP receiving nivolumab will be instructed to adhere to contraception for a period of 31 weeks after the last dose of investigational product; these durations have been calculated using the upper limit of the half-life for nivolumab (25 days) and are based on the protocol requirement that WOCBP use contraception for 5 half-lives plus 30 days
• Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform the treating physician immediately
• Ability to understand and the willingness to sign a written informed consent document
• For enrollment in the first stage of Cohort B, patients must have accessible pre-treatment and post-treatment (4-6 weeks) tumor for biopsy

Exclusion Criteria

• Patients who have had chemotherapy or radiotherapy within 4 weeks (6 weeks for nitrosoureas or mitomycin C) prior to entering the study or those who have not recovered from adverse events (AEs) due to agents administered more than 3 weeks earlier; patients who have had prior pelvic radiation may be at increased risk for bowel perforation, and therefore may not have residual inflammatory disease of the bowel or residual bowel toxicity based on baseline imaging and clinical assessment; palliative (limited-field) radiation therapy is permitted, if all of the following criteria are met:
• Repeat imagi