Effects of lonidamine alone or combined with hyperthermia in some experimental cell and tumour systems.

Lonidamine or 1-[(2, 4-dichlorophenyl) methyl]-1H-indazole-3-carboxylic acid, studied in a battery of in vitro and in vivo tests currently used for the screening of anti-tumour agents affecting cell division, has been shown to have a narrow spectrum of anti-tumour activity. The significance of this finding is discussed in the light of previous investigations suggesting that lonidamine affects mitochondrial function and not cell replication. Hyperthermia has been shown to sensitize tumour cells to lonidamine. This observation indicates that in combination with hyperthermia lonidamine has some potential for the treatment of cancer; moreover, it suggests that hyperthermia might reproduce a metabolic condition occurring in some stages of the disease. The blood levels corresponding to the anti-tumour action of lonidamine in animals are in the range of those detected in patients treated with the drug.