Pomalidomide is a derivative of thalidomide marketed by Celgene. It is anti-angiogenic and also acts as an immunomodulator. Pomalidomide directly inhibits angiogenesis and myeloma cell growth. This dual effect is central to its activity in myeloma, rather than other pathways such as TNF alpha inhibition, since potent TNF alpha inhibitors including rolipram and pentoxifylline do not inhibit myeloma cell growth nor angiogenesis. Up regulation of Interferon gamma, IL-2 and IL-10 as well as down regulation of IL-6 have been reported for pomalidomide. These changes may contribute to pomalidomide's anti-angiogenic and anti-myeloma activities. Because Pomalyst can cause harm to unborn babies when administered during pregnancy, women taking Pomalyst must not become pregnant. Women must produce two negative pregnancy tests and use contraception methods before beginning Pomalyst.