Bi‐weekly chlorambucil treatment of chronic lymphocytic leukemia

Abstract

Because the lymphocytes of chronic lymphocytic leukemia (CLL) are known to proliferate slowly, it was postulated that intermittent therapy might have a cumulative inhibitory effect on tumor cells while permitting normal cells to recuperate between doses. Sixty‐two evaluable patients with CLL were treated with chlorambucil given orally as a single pulse every 2 weeks. The initial dose was 0.4 mg/kg; subsequent doses were increased by 0.1 mg/kg until toxicity or disease control was achieved. Responses were obtained in 6 of 8 (75%) previously untreated patients with indolent disease, in 18 of 31 (61%) previously untreated patients with active disease, in 7 of 14 (50%) previously treated patients not shown to be resistant to alkylating agents, and in 2 of 9 (22%) patients resistant to prolonged daily chlorambucil therapy. The over‐all effectiveness in patients with CLL not previously resistant to chlorambucil was 31 of 53 (58%), with five complete remissions (9%). Hematologic toxicity was usually mild and never life‐threatening. Gastrointestinal toxicity, which occurred in 23 of 62 patients, was usually mild and easily controlled with anti‐emetics. It is concluded that bi‐weekly oral administration of chlorambucil is effective therapy for CLL with response rates similar to daily continuous chlorambucil. Hematologic toxicity is considerably less than with daily treatment. Copyright © 1974 American Cancer Society