Two semisynthetic derivatives of the plant genus Podophyllum have received high marks in clinical trials on patients with small-cell lung cancer.
One of the two chemically similar compounds, etoposide (VP16), has recently been recommended for approval as an anti-cancer agent by the Food and Drug Administration's oncology advisory committee. The other, teniposide (VM26), has shown promise in limited trials.
Podophyllum extracts have a long history of medical use. Hundreds of years ago, Native Americans made cathartics from aqueous extracts of the roots of one particular Podophyllum species, the American mayapple. American colonists subsequently used another extract, podophyllin, as an emetic, and it was included in the first United States Pharmacopoeia in 1820. Currently, podophyllin is used as a topical caustic agent in treating condyloma acuminatum.
Over the last 10 years, VP16 and VM26 have undergone extensive clinical evaluation in the treatment of cancer patients. Three years ago, they were approved