[Phase I study of Bestatin: (I) A clinical study on determination of an optimal dose of Bestatin].

Bestatin is a low toxic peptide discovered by Umezawa et al. and animal experiments have revealed that Bestatin enhances the immune response to activate the defense mechanism of the living organism, and thus suppresses the growth and metastasis of cancer. Recently we performed a phase I study of Bestatin to determine an optimal dose. Analysis of changes in immunological parameters at all the tested dosages of Bestatin led to the presumption that its optimal dose was in the low dosage ranging from 10 to 100 mg daily. Because the effects of a single administration of Bestatin on immunological parameters disappeared at day 7, 2 or 3 times administration per week or even daily seemed to be required. Hematology, hepatic and renal function tests revealed no apparent adverse reactions which were considered to be derived from Bestatin administration.