Restorative effect of MDP-Lys (L18) on leukopenia of cancer patient treated with radiotherapy

Twenty-eight cancer patients developing leukopenia ( ≤ 3,000/mm3) during radiotherapy were given either 200 μg of MDP-Lys (L18) 10 times consecutively (Group I) or 400 μg 6 times every other day (Group II). Mean number of leukocytes was 2,409/mm3 before the beginning of administration (Day 0), and 3,394/mm3 at the completion of administration (Day 14) in both groups. Overall, MDP-Lys was evaluated as effective in 14 (61 %) of analyzable 23 patients by the attending physician. Regarding the sequential mean number of leukocytes and the rate of efficacy, there was no significant difference between the groups. Fever was the most common side effects, occuring in 41 % of Group I and 64 % of Group II. The other side effects were local reaction or pain at the injected site and joint pain. There seemed to be positive correlations between fever and the increase in leukocytes. An increase in band form leukocytes was prominent in patients with associated fever. There was a trend towards slightly higher T4/T8 ratio in both groups. MDP-Lys was effective for irradiation-induced leukopenia. In view of efficacy and safety, it was useful in Group I rather than in Group II. (Namekawa, K.)