AbstractEighty‐seven patients with histologically or cytologically proven non‐small‐cell carcinoma of the lung were treated with 4′‐deoxydoxo‐rubicin (DxDx) 30 mg/m2every 3 weeks. Three responses (4%), all partial, were observed. All responses occurred in patients with large‐cell anaplastic lung cancer and none in squamous or adenocarcinoma histologies (P<0.01). The durations of partial response for these three responders were 70, 198+ and 209+ days. The side effects noted were predominantly neutropenia, anemia, and weight loss. In three patients, declines in cardiac ejection fraction of 7%, 12%, and 23% occurred after cumulative drug doses of 150 mg/m2, 150 mg/m2, and 233 mg/m2, respectively. 4′‐Deoxydoxorubicin had little activity in non‐small‐cell lung cancer at the do