Faculty Bibliography

BACKGROUND: The maximum tolerated dose (MTD) and efficacy of weekly 1-hour paclitaxel with 3 days of high dose oral estramustine were evaluated in patients with hormone-refractory prostate carcinoma. METHODS: Patients enrolled in cohorts of three received two cycles of six weekly treatments with 1 week of rest: Cohort I received paclitaxel 40 mg/m2 and estramustine 600 mg/m2, and Cohorts II-IV received paclitaxel 60 mg/m2, 75 mg/m2, or 90 mg/m2, respectively, and estramustine 900 mg/m2. Toxicity was assessed weekly, and response was measured by serum prostate specific antigen (PSA), abdominal computed tomography scans, and bone scans at Week 13. RESULTS: Eighteen patients were enrolled, with 12 in Cohorts III and IV. Four patients did not complete treatment. Grade 3 toxicity included one patient with nausea and diarrhea in Cohort III and one patient each with neutropenia and edema followed by Grade 4 thromboembolism in Cohort IV. Grade 1-2 anemia or myelotoxicity were not observed; 3 patients had neuropathy, 5 patients had hair loss, and 8 patients had gastrointestinal symptoms. A decline in the serum PSA level > or = 50% occurred in none of three patients, one of three patients, four of six patients, and four of six patients in Cohorts I-IV, respectively. An intent-to-treat analysis showed responses in 9 of 18 patients (50%) in Cohorts I-IV, with 9 of 15 responders (60%) in Cohorts II-IV. Seven patients achieved declines in serum PSA levels > 75%. The median duration of PSA response was 16.7 weeks. Response was observed in one of three patients with measurable disease. CONCLUSIONS: The MTD for 1-hour weekly paclitaxel was 90 mg/m2 with 3 days of 900 mg/m2 estramustine. Hematologic and neurotoxicity were reduced markedly, and gastrointestinal symptoms were ameliorated, but thromboembolic events were unaffected. PSA response rates were within the expected 60% range for these agents

Estramustine is nornitrogen mustard linked to estradiol. It binds to tubulin and to microtubule-associated proteins, depolymerizes cytoplasmic microtubules, and disrupts the nuclear matrix. It has limited clinical activity as a single agent, but preclinical studies suggest that it is an effective modulator of antitubulins. This paper reviews the rationale for the combination of estramustine with antitubulins and the clinical toxicity profile of estramustine. Also discussed are data from phase II studies in hormone-resistant prostate cancer and in taxane-resistant breast cancer that suggest that the modulation of antitubulins by estramustine that has been demonstrated in vitro is indeed clinically relevant. Finally, current approaches to improving the tolerability of estramustine are described

After two decades of work in liposomal formulations for clinical use, two preparations containing doxorubicin (Doxil, ALZA, Pablo Alto, CA; and Evacet, The Liposome Company, Princeton, NJ), and one containing daunorubicin (DaunoXome; Gilead Sciences, Foster City, CA) have been undergoing widespread clinical study. Results have lived up to the promise that liposomal encapsulation may lead to toxicity attenuation, while retaining or even enhancing the efficacy of the parent anthracyclines. The eventual role of these agents in clinical practice is being defined in a number of studies that are reviewed herein. Already, approved indications have been achieved for doxorubicin against Kaposi's sarcoma and ovarian cancers, and for daunorubicin against Kaposi's sarcoma. The three compounds vary widely in their pharmacology, and these differences may contribute to their preferential localization into certain tumors. Additional indications for these liposomal encapsulated anthracyclines are likely to be established in the ensuing years

BACKGROUND: Pegylated liposomal doxorubicin is a new formulation with activity against epithelial ovarian carcinoma (EOC). The authors sought to determine patient characteristics that may predict for response to this treatment and favorable time to failure as well as survival. METHODS: Eight patients in a Phase I study and 44 patients in two consecutive Phase II studies who were treated with pegylated liposomal doxorubicin (40-60 mg/m2 every 3 weeks for the first two cycles and 40 mg/m2 every 4 weeks thereafter) after failing initial platinum-based chemotherapies for ovarian carcinoma were analyzed. Associations were sought for response, time to failure (TTF), and survival after the treatment and various pretreatment characteristics. RESULTS: Treatment with pegylated liposomal doxorubicin yielded 23% objective responses in measurable disease and 31% overall responses, including serum CA 125-defined responses. The median TTF was 5.2 months (95% confidence interval, 4.1-6.9 months) in all patients, and the median response duration in all responders was 13.2 months (95% confidence interval, 11.9-18.5 months). The overall median survival was 15 months (95% confidence interval, 11-40 months). The main predictive factors were tumor size and baseline hemoglobin level for TTF, and these plus Karnofsky performance status were the main predictive factors for survival. CONCLUSIONS: Pegylated liposomal doxorubicin is an effective drug when it is given as secondary therapy to patients with EOC. Lack of bulky disease is the major predictor for a favorable response, TTF, and survival. The role of this treatment in combination with other effective drugs should be explored in both previously treated and untreated patients with ovarian carcinoma.