In clinical trials of TBR-760 for the treatment of acromegaly, single-dose administration of TBR-760 resulted in significant, sustained suppression both of GH and PRL; however, with chronic, repeated administration the suppression of GH/insulin-like growth factor 1 gradually waned to become similar to that of SST agonists alone, whereas the suppression of PRL remained profound. The gene discussed is IGF1; the disease is acromegaly.