Treatment of Bolivian mucosal leishmaniasis with miltefosine.

BACKGROUND: Although mucosal leishmaniasis is a prominent disease, it has been studied only to a limited extent. It is classically treated with parenteral antimony or, as a last resort, amphotericin B. METHODS: We treated Bolivian mucosal leishmaniasis due to Leishmania braziliensis with the oral agent miltefosine, 2.5 mg/kg/day for 28 days, and followed-up for 12 months. RESULTS: Seventy-two patients were evaluable. The cure rate for the 36 patients who had "mild" disease (i.e., affecting nasal skin and nasal mucosa) was 83%. The cure rate for the 36 patients who had more extensive disease (involving the palate, pharynx, and larynx) was 58%. Patients refused to be randomized to parenteral agents, but the cure rate for an almost contemporary group who was receiving amphotericin B (45 mg/kg over 90 days) was 7 (50%) of 14. CONCLUSIONS: In this unrandomized trial, oral miltefosine was at least as effective as heroic doses of parenteral amphotericin B. The cure rate for miltefosine was approximately equivalent to historical cure rates using parenteral pentavalent antimony for mild and extensive disease in neighboring Peru. Although gastrointestinal side reactions do occur with miltefosine, its toxicity profile is superior to that of antimony and far superior to that of amphotericin B--in part because of the inherent attractiveness of oral versus parenteral agents. Our results suggest that miltefosine should be the treatment of choice for mucosal disease in North and South America.

Miltefosine: issues to be addressed in the future.

Future issues that need to be addressed for miltefosine are efficacy against non-Indian visceral leishmaniasis, efficacy in HIV-coinfected patients, efficacy against the many forms of cutaneous and mucosal disease, effectiveness under clinical practice conditions, generation of drug resistance and the need to provide a second antileishmanial agent to protect against this disastrous event, and the ability to maintain reproductive contraceptive practices under routine clinical conditions.

Development of miltefosine as an oral treatment for leishmaniasis.

Miltefosine was originally formulated and registered as a topical treatment for cutaneous cancers. For this indication and in subsequent development for leishmaniasis, a large body of non-clinical data has been generated. The gastrointestinal organ is the main site of toxicity, in both animal and in human studies. The testis and retina were identified as target organs in rats, although corresponding changes were not observed in clinical studies in humans. In terms of pharmacokinetics, the terminal elimination half-life is long (84h and 159h in rats and dogs respectively). Miltefosine is widely distributed in body organs and not metabolized by cytochrome P450 enzymes in vitro. The drug is embryotoxic and fetotoxic in rats and rabbits, and teratogenic in rats but not in rabbits. It is therefore contraindicated for use during pregnancy, and contraception is required beyond the end of treatment in women of child-bearing age.

Miltefosine for new world cutaneous leishmaniasis.

The oral agent miltefosine has demonstrated a >95% cure rate in Indian visceral leishmaniasis. We performed a large, placebo-controlled study of miltefosine therapy (2.5 mg/kg per day orally for 28 days) against cutaneous leishmaniasis in Colombia and Guatemala. In regions in Colombia where Leishmania vianna panamensis is common, the per-protocol cure rates for miltefosine and placebo were 91% (40 of 44 patients) and 38% (9 of 24). These values are similar to historic values for the antimony standard of care and placebo. In regions in Guatemala where L. v. braziliensis and L. mexicana mexicana are common, the per-protocol cure rates were 53% (20 of 38) for miltefosine and 21% (4 of 19) for placebo. The miltefosine rate was lower than historic antimony cure rates of >90%. Miltefosine was well tolerated. Miltefosine is a useful oral agent against cutaneous leishmaniasis due to L. v. panamensis in Colombia but not against leishmaniasis due to L. v. braziliensis in Guatemala.

Miltefosine (Impavido): the first oral treatment against leishmaniasis.

Miltefosine is a novel antileishmanial drug that has significant selectivity in both in vitro and in vivo models. Clinical efficacy was demonstrated for the treatment of visceral leishmaniasis with the advantage of oral administration over the currently recommended antileishmanial drugs that require parenteral administration. Miltefosine produces high cure rates also in patients resistant to the standard antimonial therapy.

Phase II study of miltefosine 6% solution as topical treatment of skin metastases in breast cancer patients.

Topical treatment of skin metastases with a cytotoxic agent is attractive for its easy self-administration and absence of major systemic interference. Miltefosine exerts its cytotoxicity by acting on cell membrane phospholipids and can be administered topically. Twenty breast cancer patients with progression of skin metastases were treated with a 6% solution of miltefosine, which was topically administered once daily during the first week and twice daily thereafter. Sixteen out of 20 patients also had metastatic disease at other sites. Concomitant systemic treatment when ongoing for at least 2 months prior to study entry was permitted, and consisted of chemotherapy and hormonal therapy in seven and nine patients, respectively. Prior palliative cytotoxic and hormonal therapy had been administered to 11 and 19 patients, respectively. No grade 3 and 4 toxicity occurred. Miltefosine therapy was discontinued in two patients due to nausea and in one patient due to skin toxicity. Grade 1 and 2 adverse skin reactions, and nausea and vomiting were seen in 11 and two patients, respectively. In 18 patients evaluable for response, four partial responses were noted (response rate 22%), while seven patients had stable disease. Three partial responses were observed in patients in whom the skin lesions were smaller than 1.5 cm2. Median duration of response was 2.5 months and median time to progression for all patients was 1.9 months. In this study topically applied miltefosine for metastatic skin lesions of breast cancer showed modest activity in a relatively heavily pretreated patient population, without serious systemic toxicity.

Phase II trial of topically applied miltefosine solution in patients with skin-metastasized breast cancer.

Skin deposits from breast cancer can present serious therapeutic problems, especially when resistant to conventional therapy. Topical application of a cytotoxic drug may represent an attractive new treatment modality devoid of major systemic toxicity. Miltefosine was selected because of its efficacy in breast cancer models. A mixture of alkylated glycerols of various chain lengths and water was used as the pharmaceutical vehicle to dissolve and to further facilitate tissue penetration of miltefosine. In our Institute a phase II study was performed to determine the efficacy and tolerability of topically applied miltefosine in patients with cutaneous metastases from breast cancer. Thirty-three patients in total entered the trial. A 6% miltefosine solution was applied once daily in the first week and twice daily in the following weeks. The planned minimum treatment duration was 8 weeks. We found an overall response rate of 43% for 30 evaluable patients, composed of 23% complete response and 20% partial response. The median response duration was 18 weeks, range 8-68. Toxicity consisted mainly of localized skin reactions, which could be controlled by a paraffin-based skin cream and, where appropriate, by dose modification. No systemic toxicities were observed. We conclude that topical miltefosine is an effective treatment modality in patients with skin metastases from breast cancer.

Topical administration of hexadecylphosphocholine in patients with cutaneous lymphomas: results of a phase I/II study.

BACKGROUND: Hexadecylphosphocholine is a new antineoplastic drug that inhibits tumor cell growth directly and, in addition, might have immunoregulatory properties. OBJECTIVES: We investigated the topical application of this phospholipid in patients with cutaneous lymphoma. METHODS: Twenty-four patients with histologically documented cutaneous lymphoma were treated for 8 weeks. Lesions that responded to treatment were biopsied and evaluated histologically. RESULTS: Of 15 patients with cutaneous T-cell lymphomas, 12 were evaluable. Two complete remissions, four partial remissions, and one minor remission were observed. Of seven patients with B-cell lymphomas, six were evaluable. One complete remission, three partial remissions, one case of stable disease, and one case of progressive disease were seen. However, histologic monitoring demonstrated only a partial clearing of infiltrating lymphocytes in lesions that showed a partial or complete response clinically. Both patients with lymphomatoid papulosis had complete clearing of the lesions clinically. An objective response rate (partial and complete response) of 56% (10/18) was achieved in the patients with cutaneous lymphoma who were treated in this study. CONCLUSION: Hexadecylphosphocholine appears to be effective topically in the treatment of some cases of cutaneous lymphomas.

Hexadecylphosphocholine in the topical treatment of skin metastases in breast cancer patients.

Widespread local recurrence of breast cancer, untreatable by surgery or radiation therapy, can present a serious therapeutic problem predominantly in patients refractory to systemic therapy. In a phase I trial hexadecylphosphocholine, a new agent with high membrane affinity and antineoplastic activity was applied topically to affected skin areas of breast cancer patients. The results provide evidence that hexadecylphosphocholine may be an active agent in the topical treatment of skin metastases.

Bone marrow purging with mafosfamide--a critical survey.

Autologous bone marrow transplantation (ABMT) is increasingly used to consolidate remissions, primarily in hematological disease. Various purging strategies have been developed to minimize the risk of reimplantation of tumor cells with the bone marrow autotransplant. Pharmacological purging with the oxazaphosphorine derivative mafosfamide has been studied extensively, and recent clinical data suggest that purging with mafosfamide may translate into superior remission duration if compared to nonpurged ABMT in acute leukemia. Chemical and experimental data relevant to mafosfamide-purging and clinical results are reviewed, with special emphasis on safety aspects.

Basis and new developments in the field of oxazaphosphorines.

All the research results summarized herein were gained in the attempt to improve selectivity in cancer chemotherapy: "Chemotherapeutic agents are not only ends in themselves, they are also beginnings,. . . Selectivity must be our goal and understanding its basis our guide to the future" (138). The development of the OAP cytostatics CP, IFO, TRO, and SUFO derives from the idea of applying the principle of transport form/active form to the highly reactive nitrogen mustard compounds. The desired conversion of the reactive nitrogen mustard into an inactive transport form (latentiation) was performed by chemical synthesis. The requirement for an enzymatic activation of the transport form to give the active form in the target organ cancer cell was met and has been shown to occur in a sequence of various metabolic reactions. The goal of a substantial increase in the therapeutic range of alkylating agents has been achieved with the development of the OAP cytostatics. The higher cancerotoxic selectivity is closely correlated with the cytotoxic specificity of their activated primary metabolites. A further increase in the cancerotoxic selectivity in OAPs was achieved by the development of mesna as a regional uroprotector. Mesna eliminates the danger of therapy-limiting urotoxic side effects of OAPs, allowing administration of higher dosages and more safely optimizing their therapeutic efficacy and partly overcoming resistance phenomena. The stabilization of the primary OAP metabolites (MAFO), opens up new possibilities in clinical therapy and in preclinical tests, for examination in the clonogenic stem cell test, for in vitro purging in ABMT, and for the regional therapy of tumors. A completely new type of therapy is emerging for OAP, specifically for low-dosage MAFO, as an immunomodulator, under certain circumstances, in combination with further substances, from the biological response modifier group.

The renal clearance of albumin following intravenous loading of homologous albumin in conscious rats.

Tubular reabsorption of albumin was studied in conscious rats by measuring the renal excretion at various plasma concentrations. The plasma albumin concentration was raised by loading the animals with homologous serum albumin. By using this procedure an average plasma concentration of 54 g/l could be reached, which is about twice the physiological plasma albumin concentration in untreated rats. Throughout the experiments the glomerular filtration rate was determined by the total plasma slope clearance of 51Cr-EDTA. Following the albumin load, the 51Cr-EDTA clearance remained at 54.8 +/- 12.2 ml/min/m2 body surface. By correlating renal albumin excretion and plasma albumin concentration, the sieving coefficient of albumin, phi, of 2.35 x 10(-4), the renal albumin threshold of 38 +/- 5 g/l, and the maximal tubular transport rate of albumin of 9.6 +/- 2.6 micrograms/min/g kidney weight could be calculated (mean +/- SD). There were some variations among the animals, resulting in a fairly large standard deviation. However, these values are in agreement with recent micropuncture data.

Escherichia coli single-strand deoxyribonucleic acid binding protein: stability, specificity, and kinetics of complexes with oligonucleotides and deoxyribonucleic acid.

The complex formation between the single-strand DNA binding protein (ssB protein) from Escherichia coli and oligonucleotides and single-stranded DNA has been studied by using fluorescence titrations, ultracentrifugation measurements, and fast kinetic techniques. Determination of the stoichiometries of oligo(dT)--ssB complexes shows that each of the four subunits of the ssB protein represents a binding site for an oligonucleotide about eight residues long. Occupation of all four binding sites with oligo(dT) or poly(dT) leads to 80% quenching of the intrinsic protein fluorescence. The binding sites are nearly equivalent and independent. For d(pT)16, the intrinsic binding constant is 6 X 10(5) M-1, and for d(pT)30-40, which is long enough to extend continuously over the ssB tetramer, the binding constant is higher than 5 X 10(8) M-1. Oligoadenylates bind about 2 orders of magnitude weaker than the corresponding oligo(dT) species. The binding of oligo(dT) is very weakly dependent on ionic strength, in contrast to the oligo(dA)--ssB complex formation. For d(pT)8, d(pT)16, and d(pT)30-40, the complex formation can be described by a simple one-step reaction. The strength of the interaction is mainly expressed in the rate constant of dissociation. In the cooperative complexes with poly(dT) or poly(dA), all four binding sites on the ssB tetramer are also occupied. It is concluded that single-stranded DNA is coiled around the ssB molecule. Fluorescence melting experiments of the complexes show that the conformation of the single-stranded DNA has a strong influence on the stability of the complexes.

Renal handling of albumin: clearance studies with bovine and rat serum albumin in conscious rats.

The reabsorption capacity of albumin was determined by a clearance technique following a single load of bovine or rat serum albumin in conscious rats. The maximum reabsorption capacity of both albumin amounted to 5.6--6.2 micrograms/min . 100 g BW and there seemed to be a nonselective mechanism for the two albumins. The tubular reabsorption capacity was reached at normal physiological plasma albumin concentration. The renal excretion threshold of both albumins amounted to 31.8 mg/ml, the sieving coefficient phi was calculated to be 2.0 . 10(-4). The glomerular filtration rate, controlled by the total plasma slope clearance of 51Cr-EDTA, remained unchanged following a load of rat serum albumin (54.8 +/- 12.2 ml/min . m2 body surface) but decreased significantly after the administration of bovine serum albumin.