This study is open to men and women over the age of 18 who have Kaposi Sarcoma (KS). Kaposi Sarcoma is a cancer related to a viral infection, known as the Kaposi sarcoma-associated herpesvirus, or KSHV.

Several anti-cancer drugs work well in treating Kaposi Sarcoma, but there is no curative treatment. The standard treatment approach is chemotherapy, radiation, and/or medication applied on the skin.
   
The purpose of this study is to test the effectiveness of the study drug pomalidomide to see if it shrinks the cancer. This study will also confirm if a 4 mg dose has the same effect as the 5 mg dose.

Pomalidomide is approved by the U.S. Food and Drug Administration (FDA) to treat multiple myeloma (a type of blood cancer). Pomalidomide has also been granted accelerated FDA approval for Kaposi Sarcoma in both people living with HIV and not living with HIV. This approval was based on a small clinical trial and this clinical trial is being done to confirm pomalidomide’s efficacy in a larger group of volunteers.
   
Participants will take pomalidomide capsules by mouth and will continue to take the medication as long as the side effects can be managed and the cancer is not getting worse.

All participants will also be asked to complete a study diary to record the time they took the pomalidomide and if any doses were missed for each of the cycles of treatment. Participants will need to bring the study diary, medication container, and any unused capsules to each visit.