Mesothelioma is a type of cancer. It originates in cells that line human body cavities. Most people have advanced disease when they are diagnosed. Researchers want to see if a combination of drugs can help.

Objective:

To find a safe dose of LMB-100 in combination with ipilimumab when LMB-100 is injected into tumors.

Eligibility:

Adults ages 18 and older with malignant pleural or peritoneal mesothelioma that cannot be cured with surgery and has not responded to standard first-line treatments for mesothelioma.

Design:

Participants will be screened with:

Tumor biopsy or effusion, if needed
Medical history
Physical exam
Blood and urine tests
Imaging scans
Heart and lung function tests
Pregnancy test, if needed
Some screening tests will be repeated during the study.

Participants will get LMB-100 on Days 1 and 4 for up to 2 cycles. Each cycle lasts 21 days. They will stay in the hospital for about 8 days each time they get LMB-100. It will be injected into their tumor with needles.

Participants will get ipilimumab through a tube that is put in a vein. It will be given on Day 2 of the first 2 cycles and Day 1 of the next 2 cycles.

Participants will be assessed for how well they do daily activities. They will give blood and tissue samples for research.

Participants will have a safety visit 4 to 6 weeks after the last dose of the study drugs. Then they will have scans every 6 weeks until their disease gets worse. If their tumor gets bigger, they will have phone, video, or email follow-ups every 12 weeks.

Participants will be on this study for life....