Paclitaxel pharmacology and other tumor types

At this juncture in the development of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), knowledge about the agent's pharmacologic behavior and clinical antitumor activity in less common neoplasms is being elucidated. The recent information about paclitaxel's pharmacologic behavior, particularly pertaining to its interactions with other agents, may help explain some of the reasons for its failure and success in certain clinical settings, as well as its unique toxicities when it is administered in combination chemotherapy regimens. Not only has the prototypical taxane demonstrated substantial activity in common malignancies such as carcinoma of the lung (both non-small cell and small cell), breast, and ovary, but the agent has demonstrated notable activity in less common tumor types that also exhibit significant problems in terms of morbidity, mortality, and lack of effective therapies. Substantial antitumor activity has been confirmed in patients with advanced carcinomas of the head and neck, bladder, testes, esophagus, and endometrium, and unknown primary type. Additionally, modest activity has been noted in Kaposi's sarcoma, lymphoma, and carcinomas of the stomach and cervix, which is significant in view of the lack of alternative therapeutic options. This summary will discuss recent developments in the pharmacology of paclitaxel and give an overview of the clinical status of paclitaxel in less common tumor types.