NFAT Transcription Factor Regulator-1 (compound example 19) inhibits IL-2 synthesis with an IC ₅₀ of 182 nM. NFAT Transcription Factor Regulator-1 inhibits human and rat PBMC proliferation with IC ₅₀ s of 82 and 146 nM, respectively. NFAT Transcription Factor Regulator-1 is able to inhibit IL-4 and IL-5 production in human T-cell lines with similar potency to its effects on IL-2 release.

NFAT Transcription Factor Regulator-1 is found to have an inhibitory potency approximately 10-fold better than that of cyclosporine. Comparable inhibitory effects on T-cell IL-2 production are obtained with NFAT Transcription Factor Regulator-1 and cyclosporine at doses of 3.0 and 30 mg/kg, po, respectively. The efficacies achieved in monkeys in vivo for blocking T-cell cytokine production suggest that NFAT Transcription Factor Regulator-1 has potential similar to that of cyclosporine for use in transplantation.