Effects of biological response modifiers on childhood ALL being in remission after chemotherapy

Of 125 children with acute lymphoblastic leukemia (ALL), who had been in continuous remission for three years on chemotherapy, 108 patients received biological response modifiers (BRM) such as Bestatin, N-CWS, OK-432 and/or PSK in order to prevent relapse after treatment suspension. From 20 patients who were treated with PSK, 6 relapsed within 13 months. This relapse rate was quite similar to the rate observed with those children who were off therapy (4 relapses in 17 patients within 13 months). In contrast to these 37 patients, only 3 out of 31 patients who received Bestatin (p less than 0.05) and 8 out of 57 patients who received N-CWS or OK-432 relapsed. Based on these findings, BRMs used in the present study seems to be effective to prevent relapse of leukemia among childhood ALL who have electively stopped chemotherapy.