Calcium-release activated calcium (CRAC) channel inhibitors represent a new class of oral immunomodulatory agents with a potential safety profile suitable for chronic dosing to treat autoimmune disorders. Calcium entry through CRAC channels is a critical step in the functional responses of T cells and mast cells. Patients with mutations in CRAC channels are known to have a form of severe combined immunodeficiency, wherein the adaptive immune response is suppressed without major impairment of other organ systems. CalciMedica has discovered several novel small molecules that selectively inhibit CRAC channels, and is currently developing the first of these inhibitors, CM2489, for the treatment of psoriasis. We describe here the properties of CM3457, another selective CRAC channel inhibitor that is structurally distinct from CM2489. CM3457 potently inhibits CRAC channels, Th1, Th2 and Th17-derived cytokine production, T cell proliferation, and mast cell degranulation. Once-daily oral dosing of CM3457 significantly inhibits inflammation and joint histopathology in a rat collagen-induced arthritis model. CM3457 also inhibits lung inflammation and eosinophilia, as well as improves lung function, in a rat OVA-induced asthma model. These data provide evidence that CM3457 may be an effective therapeutic in the treatment of autoimmune disorders and asthma.