A phase I/II trial of a polysaccharide extract from Grifola frondosa (Maitake mushroom) in breast cancer patients

3024 Background: A polysaccharide extract from Grifola frondosa (Maitake extract) has shown immunomodulatory effects in preclinical studies and potentials for anticancer immunotherapy. However whether its oral administration in human is associated with measurable immunological change is unknown. Methods: In a phase I/II dose escalation trial, thirty postmenopausal breast cancer patients free of disease after initial treatment were enrolled sequentially into five cohorts of six patients each. Maitake extract was taken orally at 0.1, 0.5, 1.5, 3, or 5 mg/kg twice daily for three weeks. Peripheral blood was collected at day -7, 1 (prior to the first dosing), 7, 14, and 21 for ex vivo analyses. The primary endpoint was safety and tolerability. Results: No dose-limiting toxicity was encountered. Pharmacodynamic activities of the study agent did not follow a linear dose curve, as often seen with immunomodulatory agents. The following correlative endpoints showed significant changes compared to baseline. Quadrat...