 Preliminary efficacy and toxicity data from another phase II trial of 22 ER-positive or ER-negative patients were reported at the same conference. In that study, patients could have had 1 previous chemotherapy regimen or were experiencing disease progression while on tamoxifen and were given 500 mg of ZD1839 daily. Two patients had a partial response and 10 had stable disease at 4 weeks. In both trials the toxicity profile was identical to that seen in patient with NSCLC. 