IPI-549 is an orally bioavailable, highly selective small molecule inhibitor of the gamma isoform of phosphoinositide-3 kinase (PI3K-gamma) with potential immunomodulating and antineoplastic activities. Upon administration, IPI-549 prevents the activation of the PI3K-gamma-mediated signaling pathways, which may lead to a reduction in cellular proliferation in PI3K-gamma-expressing tumor cells. In addition, this agent is able to modulate anti-tumor immune responses and inhibit tumor-mediated immunosuppression. Unlike other isoforms of PI3K, the gamma isoform is overexpressed in certain tumor cell types and immune cells; its expression increases tumor cell proliferation and survival. By selectively targeting the gamma isoform, PI3K signaling in normal, non-neoplastic cells is minimally or not affected, which results in a reduced side effect profile. Preclinical data in multiple solid tumor models have demonstrated that IPI-549 targets immune cells and alters the immune-suppressive microenvironment, promoting an anti-tumor immune response that leads to tumor growth inhibition. A Phase 1 study of IPI-549 in patients with advanced solid tumors is ongoing.

Geclosporin (Cyclosporine) is an immunosuppressive agent, that is used to prevent rejection of a transplanted organ by the body. Geclosporin is isolated from a fungus, Beauveria nivea, and was first discovered in 1970. By suppressing the immune system, this drug prevents white blood cells from rejecting the transplanted organ. Geclosporin primarily does this by suppressing T cells and T cell cytokine production, but also acts in other ways, for example by inhibiting growth and activation of B cells and antigen presenting cells, and by reducing antibody production. Geclosporin is usually combined with other compounds, and has been studied as potential treatment for a large range of disorders. It is used for the treatment of several other conditions, such as severe recalcitrant plaque psoriasis, severe active rheumatoid artritis, and to prevent rejection of donor cells as a result of bone marrow transplantation. Relapse after discontinuation of this compound is to be expected, and therefore, patients should receive maintenance therapy at the lowest effective dosage. The most common adverse events are hypertrichosis, gingival hyperplasia, and neurological and gastrointestinal effects. Renal dysfunction is also possible, but irreversible damage is rare.