TAXOIDS - A NEW CLASS OF CYTOTOXIC AGENTS

Taxoids (paclitaxel and docetaxel) are a new class of cytotoxic agents . Their mechanism of action (enhanced polymerization of tubulin and in hibition of its depolymerization) acts thereby as mitotic spindle inhi bitors. Significant experimental antitumor activity, although more mar ked with docetaxel, has been observed with both agents. Their main sid e-effects are reversible non cumulative neutropenia and alopecia; sign ificant hypersensitivity reactions using cortico-steroids antiHT1/2 pr emedication are seen in < 5% of patients receiving paclitaxel as a pul sed (3 h) infusion; neurotoxicity, appears dose-related; docetaxel can induce a peculiar skin toxicity often associated with edema. Paclitax el at the recommended dose of 175 mg/m2 achieves responses in 20-30% o f patients with relapsed ovarian carcinoma; its activity in advanced b reast cancer although significant is clearly dose-related with an opti mal dose still debatable; responses are observed in almost-equal-to 30 % of patients with non small cell lung cancer (NSCLC). Docetaxel (100 mg/2) is active in first line treatment of advanced breast cancer (50- 72% RR) as well as 2nd line treatment (> 40% RR); an activity in the r ange of that observed with paclitaxel is reported in NSCLC.