André Coune

Pilot study of amphotericin B entrapped in sonicated liposomes in cancer patients with fungal infections

A pilot study with amphotericin B incorporated in sonicated liposomes (ampholiposomes) made of egg phosphatidylcholine, cholesterol and stearylamine in a molar ratio 4:3:1 was performed in cancer patients with fungal infections. Fifteen patients received a total of 117 intravenous infusions of ampholiposomes. The total dose of amphotericin B administered per patient ranged from 20 to 1004 mg (mean 472 mg). The number of infusions per patient varied from 1 to 20 (mean 8) and the duration of treatment from 1 to 29 days (mean 10 days). Infusion of doses up to 1.8 mg/kg was well tolerated. None of the common side-effects of Fungizone, the colloidal suspension of amphotericin B, occurred; it was noteworthy that patients had no renal function impairment. Serum amphotericin B concentrations given as ampholiposomes were much higher than those obtained with Fungizone. With a daily treatment schedule, peak and trough serum amphotericin B concentrations, as measured by HPLC, were 10 to 20 micrograms/ml and 5 to 10 micrograms/ml respectively; while they did not exceed 2 micrograms/ml and 1 microgram/ml with Fungizone. Amphotericin B given as ampholiposomes had a prolonged serum beta half-life (25.3 +/- 16.0 h). Higher serum antifungal activity was observed with ampholiposomes as compared to Fungizone. We concluded that ampholiposomes have a better therapeutic index than Fungizone.

Intravenous infusion of high doses of liposomes containing NSC 251635, a water-insoluble cytostatic agent. A pilot study with pharmacokinetic data.

In patients with resistant malignant tumors, we performed a pilot trial of intravenous infusion of a water-insoluble cytostatic agent, NSC 251635, entrapped in large volumes of liposomes made of egg yolk lecithin, cholesterol, and stearylamine (4:3:1). Forty liposome infusions were given to 14 patients in 38 courses. The volume of liposomes (20 mg of lipids/mL) varied from 205 to 1,000 mL or 124 to 617 mL/m2 of body surface, and amounts of NSC 251635 varied from 82 to 456 mg/m2. Three patients received repeated single courses. Liposomal therapy was very well tolerated. Side effects observed during some infusions were mild sedation, fever, chills, lumbar pain, urticarial rash, and bronchospasm. In all patients investigated, an important activation of the complement system was observed. No objective regression of the tumors was observed. The limiting factor in the phase I study was not toxicity but the volume of liposomes that could be prepared at once because of the long time required for its preparation. Pharmacokinetic data showed that maximal serum phospholipid and NSC 251635 concentrations were obtained at the end of the liposome infusion. The drugs peak was followed by a decreasing phase leading to a kind of plateau and a prolonged presence of the drug in the blood until 120 hours after its administration. Comparison of the pharmacokinetics of phospholipids and NSC 251635 suggests a rather rapid dissociation of the drug from the liposome.

Liposomes as drug delivery system in the treatment of infectious diseases. Potential applications and clinical experience

SummaryLiposomes are microscopic, closed lipid vesicles able to entrap hydrophilic as well as lipophilic compounds. They constitute a versatile drug delivery system. When injected by the intravenous route, liposomes are taken up by macrophages in the liver and in the spleen. Investigation of several animal models of infections has shown that liposome-entrapped anti-infectious drugs are active against infections due to facultative intracellular bacteria, parasites such as Leishmania, viruses such as the one causing Rift valley fever. Liposomes of different lipid compositions, structures and sizes were used for intravenous administration of anti-infectious drugs without inducing toxicity in the tested animals. Clinical experience was obtained with two different liposomal preparations of amphotericin B in the treatment of systemic fungal diseases in cancer patients; these preparations were shown to be effective and very well-tolerated.ZusammenfassungLiposomen sind mikroskopisch kleine geschlossene Lipidvesikel mit der Fähigkeit, sowohl hydrophile als lipophile Wirkstoffe einzuschließen; sie stellen ein vielseitig nutzbares Arzneimittelfreisetzungssystem dar. Nach intravenöser Applikation erfolgt vorwiegend eine Aufnahme der Liposomen durch die Makrophagen in Leber und Milz. Untersuchungen an verschiedenen Infektionsmodellen bei Tieren haben ergeben, daß liposomal verkapselte antimikrobielle Pharmaka gegenüber Infektionen durch fakultativ intrazelluläre Erreger wie Bakterien, Parasiten (z. B. Leishmania), Viren (z. B. den Erreger des Rift valley fever) wirksam sind. Liposomen unterschiedlicher Lipidzusammensetzungen, Arten und Größen sind für die intravenöse Zufuhr von antimikrobiellen Arzneimitteln angewandt worden, ohne bei den Versuchstieren toxisch zu wirken. Klinische Erfahrungen beim Menschen konnten mit zwei verschiedenen Liposomenpräparationen von Amphotericin B in der Behandlung von systemischen Pilzinfektionen bei Krebskranken gewonnen werden. Diese Präparationen haben sich als wirksam und sehr gut verträglich erwiesen.

Successful treatment with liposomal amphotericin B in two patients with persisting fungemia.

Two granulocytopenic patients in whom fungemia persisted despite therapy with deoxycholate amphotericin B were subsequently successfully treated by daily intravenous administration of amphotericin B entrapped in sonicated liposomes made of egg yolk lecithin, cholesterol and stearylamine in a molar ratio of 4:3:1. High serum concentrations of amphotericin B could be maintained in both patients during therapy with liposomal amphotericin B and were associated with high in vitro antifungal activity. Liposomal amphotericin B was tolerated much better than the deoxycholate preparation. These findings suggest that the liposomal amphotericin B preparation is superior in the treatment of fungemia in granulocytopenic patients, and that randomized trials are warranted.

A phase II study evaluating CAVi (cyclophosphamide, adriamycin, vincristine) potentiated or not by amphotericin B entrapped into sonicated liposomes, as salvage therapy for small cell lung cancer

Abstract Two consecutive trials were conducted, testing the CAVi (cyclophosphamide 1 g/m 2 ; doxorubicin (adriamycin) 45 mg/m 2 ; vincristine 1.4 mg/m 2 ; all i.v. on day 1; every 3 weeks) combination as salvage therapy for small cell lung cancer (SCLC) after first line treatment with etoposide plus vindesine with or without cisplatin. In the first study, CAVi was used alone. In 45 evaluable patients, 6 objective responses were observed (13%; Confidence Limits (C.L.): 5.1–20.8). In the second study, CAVi was potentiated with 2 mg/kg of ampholiposomes given i.v., 24 h prior to chemotherapy. Ampholiposomes consisted of amphotericin B entrapped into sonicated liposomes made of egg lecithin, cholesterol and stearylamine in the molar ratio 4:3:1 (lipid concentration: 20 mg/ml). Among 11 evaluable patients, 6 objective responses were observed (55%; Confidence Limits: 23.4–83.3) and toxicity was not increased. These preliminary results suggest that ampholiposomes might overcome resistance to chemotherapy in SCLC and should encourage controlled studies.

Role of intensive care unit in a medical oncology department

Over a 4-year period, 912 patients were admitted to the ICU of the medical oncology service at the Institut Jules Bordet: 574 (63%) were admitted for medical emergencies and 338 (37%) for intensive treatment and/or monitoring. In the first group, the main causes of admission were hypercalcemia, thromboembolic disease, cardiac arhythmias, encephalopathies and pneumopathies. Overall mortality during the ICU stay was 23% (133/574). In the second group, patients were admitted primarily in order to receive, under optimal surveillance, anticancer treatment, either because they were at high risk of complications or because the approach was mainly investigational; several investigations, in the fields of supportive care and anticancer treatment, were successfully conducted within the ICU environment.

Amphotericin B as a potentiation agent to cytotoxic chemotherapy

DEVELOPMENT of tumor cells resistant to chemotherapeutic drugs prevents the successful eradication of most human disseminated malignancies. Known mechanisms of drug resistance are many: defective drug transport, defective drug metabolism to active species, altered intracellular nucleotide pools, increased drug inactivation, altered DNA repair, gene amplification and altered target protein. Resistance to a given drug can result from several unrelated mechanisms. Moreover, resistance to a specific agent belonging to the groups of antitumor antibiotics or plant alkaloids can confer cross-resistance to structurally dissimilar drugs with different mechanisms of action. The pathway by which this pleiotropic resistance is acquired by tumor cells appears to be at the level of membrane transport. In membranes of hamster, mouse and human tumor cell lines that display multiple resistance to drugs, increased expression of a 170,000 dalton surface antigen has been shown to be correlated with resistance. A P-glycoprotein of identical molecular size, sharing some immunogenic homology with this membrane component, has been demonstrated in colchicine-resistant Chinese hamster ovarian cells. In these cells the colchicine resistance, the pleiotropic resistance and a reduced drug accumulation in the cells have been shown to be due to the same genetic alteration. The Pglycoprotein marker for drug resistance has also been demonstrated in the membrane of cells directly derived from ovarian cancer in two pati-

The antitumoral activity of some derivatives of 6-aminochrysene

Abstract Twenty-two N-substituted derivatives of the carcinostatic 6-aminochrysene have been tested as potential carcinostatic agents (using 6-aminochrysene as a standard) on spontaneous mammary tumor in [C3H/020] F1 mice, and on the slow-growing transplanted rhabdomyosarcoma in inbred WAG/Rij rats. Many of these compounds displayed important activity against both types of tumor, and some of them merit further investigations. In contrast compounds active on these experimental tumors, were completely inactive on Ehrlich carcinoma and on Sarcoma 180.

Pharmacokinetics of Amphotericin B in Patients Receiving Repeated Intravenous High Doses of Amphotericin B Entrapped into Sonicated Liposomes

AbstractRepeated high doses (2-4 mg/kg/day) of amphotericin B entrapped in sonicated liposomes made of egg yolk lecithin, cholesterol, and stearylamine in the molar ratio 4:3:1 were given intravenously to cancer patients with fungal complications. High levels of the drug were measured in the serum. Pharmacokinetic analysis showed that amphotericin B distribution followed a nonlinear bicompartmental model incorporating a liposome-free drug subsystem. This model allowed us to define the Michaelis-Menten dissociation constant of uptake of the drug entrapped in the liposomes by the storage compartment, the maximal liberation rate and fractional liberation rate of free amphotericin B, and the number of binding sites in the ampholiposome storage compartment. the levels of free amphotericin B in the serum and the kinetics of saturation of the uptake of ampholiposomes by the storage compartment were also calculated.

Endocrine effects of trilostane: in vitro and in vivo studies

Trilostane (4-alpha-5-epoxy-17 beta-hydroxy-3-oxo-5-alpha-androstan-2-carbonitrile) is a modified steroidal molecule. In vitro and in vivo studies in rats have shown that it inhibits adrenal, ovarian and placental steroid synthesis. It seems to act by exerting a selective blockade on 3 beta-hydroxysteroid dehydrogenase. In this study, we investigated whether this molecule interacts with hormone receptors for estrogen, androgen or progesterone. We also tried to demonstrate the effect which Trilostane may have on cellular cultures of human mammary carcinoma (MCF-7 Evsa-T). We also studied hormonal modifications in a series of 12 patients treated with different doses of Trilostane, since this drug is supposed to inhibit the production by the adrenal glands of mineralocorticoids, of glucocorticoids and of the precursors of estrogens. Our results indicate that Trilostane does not react with any of the main hormonal sex steroid receptors, nor does it interfere with cultures of human mammary cancer cells either containing estrogen receptors and therefore allegedly hormone-dependent (MCF-7 line), or estrogen receptor-negative cells, presumably independent of hormonal manipulations (Evsa-T cell line). Finally, endocrine studies on postmenopausal women with advanced breast cancer show that Trilostane significantly reduces the plasma levels of estrone and of its major androgen precursor (androstenedione). However, the latter inhibition is no different from that exerted by hydrocortisone acetate administered alone at a dose of 40 mg/day. The results of clinical trials comparing hydrocortisone alone with hydrocortisone plus Trilostane are awaited.