The addition of PSK to maintenance chemotherapy was found to improve the survival rate of patients with acute myelogenous leukaemia (AML)30 but this was short of statistical significance (p =0.105). However, patients who remained in remission for 270 days benefited for a further 418 days onPSK.

In another study, PSK was effective in preventing relapse in childhood acute lymphoblastic leukaemia following treatment with chemotherapy but the benefit was also not statistically significant31. Although showing no significant effect with PSK, adverse effects were not observed in this paediatric population.