The epipodophyllotoxin derivatives VM26 and VP16: Experimental and clinical aspects

VM26, teniposide, and VP16, etoposide, are semisynthetic derivatives of podophyllotox‐in, a derivative of podophyllin. Podophyllin is the crude extract from the roots of two related plants, the American mandrake or may apple (podophyllum peltatum) and podophyllum emodi from India, which have been used in folk medicine throughout the ages in both American and Asian cultures. VM26 and VP16 were introduced almost simultaneously clinically in the early 1970's but the subsequent development has differed greatly (1,2,3,4,5). VP16 has been widely studied alone and in combination in the majority of common tumour types and is highly effective in several, notably testicular and small cell lung cancers, lymphomas and acute leukaemias. Early indications of this activity focused investigator interest almost exclusively on VP16, with the result that clinical research on VM26 has lagged far behind. VM26 has tended to be used in paediatric oncology, especially for neuroblastoma, but is also active in acute leukaemias, lymphomas and in small cell carcinoma.