Radiotherapy is a regular care for metastatic solid tumors or lymphoma, and it can induce immunogenic death of tumor cells and a stronger immune response. Sometimes, tumor regression would be observed at sites distant to an irradiated field because of the radiotherapy-induced anticancer immune responses, so-called abscopal response. Manganese has been confirmed to activate innate immune and function as anticancer immunoadjuvant in pre-clinical studies. This study is designed to assess the abscopal response and safety of combined therapy of manganese and radiotherapy in patients with metastatic solid tumors or lymphoma.

Inclusion Criteria:

1. Subjects must have histologically proven metastatic solid tumors or lymphoma.
2. Subjects must have at least two distinct measurable sites of disease (≥1 cm).
3. ≥ 18 years old.
4. Life expectancy of at least 6 months.
5. Eastern Cooperative Oncology Group performance status 0-2.
6. Subjects must have stable or progressing disease to the ongoing systemic therapy.
7. Multiple lines of previous chemo-immunotherapy were permitted.
8. Patients with known brain metastases were included in the trial but brain lesions were not eligible as target or non-target lesions.
9. Adequate organ function.
10. Female participants of childbearing potential must be willing to use an adequate method of contraception for the course of the study through 120 days after the last dose of study drug.
11. Male participants of childbearing potential must agree to use an adequate method of contraception, starting with the first dose of study drug through 120 days after the last dose of study drug.

Exclusion Criteria:

1. Subjects with any autoimmune disease or history of syndrome that requires corticosteroids or immunosuppressive medications.
2. Serious uncontrolled medical disorders or active infections, pulmonary infection especially.
3. Prior organ allograft.
4. Women who are pregnant or breastfeeding.
5. Women with a positive pregnancy test on enrollment or prior to investigational product administration.
6. Subjects who are compulsorily detained for treatment of either a psychiatric or physical (eg, infectious disease) illness.
7. Subjects with previous or concurrent other malignancies.