This phase II trial tests whether atezolizumab in combination with selinexor works to shrink tumors in patients with alveolar soft part sarcoma and whether the study drugs are better than the usual approach in treating this type of cancer. The usual approach is defined as care most people get for alveolar soft part sarcoma if they are not part of a clinical study, which includes treatment with radiation, kinase inhibitor drugs, immunotherapy drugs, or chemotherapy drugs. Immunotherapy with monoclonal antibodies, such as atezolizumab, may help the body's immune system attack the cancer, and may interfere with the ability of tumor cells to grow and spread. Selinexor is in a class of medications called selective inhibitors of nuclear export (SINE). It works by blocking a protein called CRM1, which may help keep cancer cells from growing and may kill them. Giving atezolizumab in combination with selinexor may help shrink tumors and stabilize the cancer in patients with alveolar soft part sarcoma.
To be enrolled in the safety run-in, patients must have an advanced soft tissue sarcoma (not otherwise specified [NOS]). To be enrolled in the ASPS cohort, patients must have histologically or cytologically confirmed alveolar soft part sarcoma that is not curable by surgery
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) by chest x-ray or as ≥ 10 mm (≥ 1 cm) with CT scan, MRI, or calipers by clinical exam.
Patients with unresectable, metastatic and measurable ASPS that is resistant/refractory to ICI treatment will be eligible for the ASPS cohort of this study if they show clinical and/or radiological evidence of disease progression after receiving prior ICI therapy (including history and increasing physical symptoms). On-study documentation will include a physician's rationale that supports evidence of clinical disease progression (i.e., increasing tumor pain)
Age >= 12 years. Because no dosing or adverse event data are currently available on the use of atezolizumab in combination with selinexor in patients ˂ 18 years of age, children < 12 years of age are excluded from this study
Malabsorption syndrome or other conditions that would interfere with intestinal absorption
Hormone-replacement therapy or oral contraceptives
Herbal therapy > 1 week prior to cycle 1, day 1 (herbal therapy intended as anti-cancer therapy must be discontinued at least 1 week prior to cycle 1, day 1)
Palliative radiotherapy for bone metastases > 2 weeks prior to cycle 1, day 1