Navelbine (Vinorelbine) is under study by Burroughs Wellcome as a mitotic inhibitor of the vinca alkaloid family. Compared with vinblastine given for adult solid tumors, it shows greater activity with less toxicity. It is also active when taken orally. It has shown promise against drug-resistant breast cancer and has also shown antitumor effects against lung cancer, for which drug approval has just been obtained.
Taxotere is a more potent and water soluble derivative of taxol . It has been under study by Rhone Poulenc in Europe and very recently in the U.S. As with taxol, antitumor responses have been noted in ovarian, breast and lung cancers. The drug has an advantage over taxol in that it requires less premedication and is easily administered as a one-hour infusion . On the other hand, skin toxicity, edemas and pleural effusions have complicated its administration. Patients who did not respond to taxol would not be expected to benefit from taxotere, but this point has not been extensively studied.
Topotecan is a semisynthetic, water-soluble derivative of camptothecin, a plant product first tested in 1970. It is of great interest since it does not share the unpredictable toxicities of the parent compound and is active against a number of cancers in animals that are resistant to standard chemotherapeutic agents. It is currently undergoing early clinical trials in humans in a number of dosage schedules. Activity has been reported for a number of solid tumors.
