Faculty Bibliography

Pegylated liposomal doxorubicin (Doxil) and 99mTc-HYNIC PEG liposomes (HPL) were reported earlier to cause hypersensitivity reactions (HSRs) in a substantial percentage of patients treated i.v. with these formulations. Here we report that (1) Doxil, HPL, pegylated phosphatidylethanolamine (PEG-PE)-containing empty liposomes matched with Doxil and HPL in size and lipid composition, and phosphatidylglycerol (PG)-containing negatively charged vesicles were potent C activators in human serum in vitro, whereas small neutral liposomes caused no C activation. (2) Doxil and other size-matched PEG-PE and/or PG-containing liposomes also caused massive cardiopulmonary distress with anaphylactoid shock in pigs via C activation, whereas equivalent neutral liposomes caused no hemodynamic changes. (3) A clinical study showed more frequent and greater C activation in patients displaying HSR than in non-reactive patients. These data suggest that liposome-induced HSRs in susceptible individuals may be due to C activation, which, in turn, is due to the presence of negatively charged PEG-PE in these vesicles

Impressive responses to pegylated liposomal doxorubicin (Doxil/Caelyx) in pretreated ovarian cancer patients during phase I studies led to a phase II study in platinum and taxane failures. A 26% objective response rate was obtained in this trial and this was confirmed by further phase II studies. The stage was set for a phase III trial in comparison with topotecan, the drug that had become standard in the salvage treatment of patients who were platinum-refractory or -resistant. The completed trial indicates equivalence of results in terms of response rates, time to treatment failure and survival. Differences exist in the toxicity spectrum and in subset analysis according to platinum resistance. On this basis, Caelyx is being positioned as part of chemotherapeutic regimens in first-line phase III trials

PURPOSE: Neoadjuvant chemotherapy for breast cancer creates new possibilities for the analysis of biological factors in the tumor and/or host, which may play a role in the response to treatment. In this study we analyzed whether changes in local antitumor immunity take place after neoadjuvant paclitaxel therapy and if they correlate with response to treatment. Experimental Design: Neoadjuvant chemotherapy (paclitaxel, 200 mg/m2 q2w, 4 treatments) was followed by definitive surgical management. Histological sections from the pre- and post-treatment surgical specimens of 25 patients were analyzed for the extent of lymphocytic infiltration and presence of tumor infiltrating lymphocytes (TILs). The cumulative apoptotic response in the tumor after the first dose of paclitaxel was also studied in 10 of 25 patients. RESULTS: Pretreatment lymphocytic infiltrate in the tumor was minimal in the majority of patients and showed no relationship with clinical response. In the patients without TILs before treatment, development of TILs after treatment was noted in 0/3 (0%) patients with stable disease, 3/12 (25%) patients with clinical partial response, and 4/6 (67%) patients with clinical complete response and pathological residual disease. These correlated with the tumor cell apoptotic response to the first dose of paclitaxel. CONCLUSIONS: These results suggest that development of TILs after treatment correlates with clinical response to neoadjuvant paclitaxel therapy. The possible mechanism(s) whereby neoadjuvant chemotherapy may lead to induction of antitumor T cells is discussed. Immunological processes may influence the response of breast cancer patients to neoadjuvant treatment

Preclinical data suggests that the action of fluoropyrimidines may be enhanced by the addition of hydroxyurea. We developed a phase I trial to determine the maximum tolerated dose and pharmacokinetics of i.v. hydroxyurea (HU) in combination with i.p. 5-fluoro-2'-deoxyuridine (FUdR) and leucovorin (LV). Eligible patients had metastatic carcinoma confined mostly to the peritoneal cavity, and adequate hepatic, renal and bone marrow function. Patients were treated with a fixed dose of FUdR (3 g) and LV (640 mg) administered on days 1--3. HU was administered as a 72-h infusion starting simultaneously with i.p. therapy on day 1. The following dose levels were studied: 2.0, 2.5, 3.0 and 3.6 g/m(2)/day. Pharmacokinetics were studied in blood and peritoneal fluid. Twenty-eight patients were accrued. Steady-state plasma and peritoneal fluid HU levels increased with increasing dose, and steady state was achieved within 12 h of continuous dosing. The steady-state HU plasma:peritoneal fluid concentration ratio ranged from 1.06 x 10(3) to 1.25 x 10(3) and the plasma HU clearance ranged from 4.63 to 5.81 l/h/m(2). Peritoneal fluid AUC = 137,639 +/- 43,914 microg/ml x min, t(1/2) = 100.9 +/- 56.4 min and Cl = 25.29 +/- 10.88 ml/min. Neutropenia represented the dose-limiting toxicity. We conclude that i.p. FUdR and LV in combination with i.v. HU is well tolerated. The addition of systemic HU increased the incidence of myelosuppression.