Phase III trial of nonpegylated liposomal doxorubicin in combination with trastuzumab and paclitaxel in HER2-positive metastatic breast cancer.

BACKGROUND: Nonpegylated liposomal doxorubicin liposomal doxorubicin, (Myocet™; Sopherion Therapeutics, Inc Canada, and Cephalon, Europe) (NPLD; Myocet(®)) in combination with trastuzumabHerceptin(®) (Hoffmann-La Roche) has shown promising activity and cardiac safety. We conducted a randomized phase III trial of first-line NPLD plus trastuzumab and paclitaxel (Pharmachemie B.V.) (MTP) versus trastuzumab plus paclitaxel (TP) in patients with human epidermal growth factor 2 receptor (HER2)-positive metastatic breast cancer. PATIENTS AND METHODS: Patients were randomly assigned to NPLD (M, 50 mg/m(2) every 3 weeks for six cycles), trastuzumab (T, 4 mg/kg loading dose followed by 2 mg/kg weekly), and paclitaxel (P, 80 mg/m(2) weekly) or T + P at the same doses until progression or toxicity. The primary efficacy outcome was progression-free survival (PFS). RESULTS: One hundred and eighty-one patients were allocated to receive MTP, and 183 to TP. Median PFS was 16.1 and 14.5 months with MTP and TP, respectively [hazard ratio (HR) 0.84; two-sided P = 0.174]. In patients with estrogen receptor (ER)- and progesterone receptor (PR)-negative tumors, PFS was 20.7 and 14.0 months, respectively [HR 0.68; 95% confidence interval (CI) 0.47-0.99]. Median overall survival (OS) was 33.6 and 28.9 months with MTP and TP, respectively (HR 0.79; two-sided P = 0.083). In ER- and PR-negative tumors, OS was 38.2 and 27.9 months, respectively (HR 0.63; 95% CI 0.42-0.93). The frequency of adverse events was higher with MTP, but there was no significant difference in cardiac toxicity between treatment arms. CONCLUSION(S): The trial failed to demonstrate a significant clinical improvement with the addition of M to TP regimen. The clinical benefit observed in an exploratory analysis in the ER- and PR-negative population deserves consideration for further clinical trials. CLINICAL TRIAL NUMBER: NCT00294996.

The effect of space flight on the production of actinomycin D by Streptomyces plicatus.

The effect of space flight on production of the antibiotic actinomycin D by Streptomyces plicatus WC56452 was examined onboard the US Space Shuttle mission STS-80. Paired space flight and ground control samples were similarly prepared using identical hardware, media, and inoculum. The cultures were grown in defined and complex media under dark, anaerobic, thermally controlled (20 degrees C) conditions with samples fixed after 7 and 12 days in orbit, and viable residuals maintained through landing at 17 days, 15 h. Postflight analyses indicated that space flight had reduced the colony-forming unit (CFU) per milliliter count of S. plicatus and increased the specific productivity (pg CFU(-1)) of actinomycin D. The antibiotic compound itself was not affected, but its production time course was altered in space. Viable flight samples also maintained their sporulation ability when plated on agar medium postflight, while the residual ground controls did not sporulate.

Production, isolation and structure determination of novel fluoroindolocarbazoles from Saccharothrix aerocolonigenes ATCC 39243.

Saccharothrix aerocolonigenes ATCC 39243 produces an indolocarbazole antitumor agent rebeccamycin under submerged fermentation conditions. Adding DL-6-fluorotryptophan to culture of S. aerocolonigenes ATCC 39243 induces the formation of two novel indolocarbazoles, fluoroindolocarbazoles A and B. Feeding DL-5-fluorotryptophan to culture of S. aerocolonigenes ATCC 39243 induces the production of a novel indolocarbazole, fluoroindolocarbazole C. These fluoroindolocarbazoles have been isolated from culture broth and purified to homogeneity by vacuum liquid chromatography and column chromatography. All three fluoroindolocarbazoles are more potent than rebeccamycin against P388 leukemia by ip route in murine model.

The effects of space flight on the production of monorden by Humicola fuscoatra WC5157 in solid-state fermentation.

The effect of space flight on the production of the antibiotic monorden on two types of agar media, T8 and PG, by Humicola fuscoatra WC5157 was examined on board the US Space Shuttle mission STS-77 in May 1996. Paired space-flight and ground control samples were prepared using identical hardware, protocol, media, and inoculum. Inoculation occurred simultaneously for both groups 2.5 after launch. The flight and ground samples were allowed to grow for the entire 10-day mission in a dark, thermally controlled (22 degrees C) environment. Post-flight HPLC analysis of the flight and ground sample extracts indicated that the production of monorden by H. fuscoatra WC5157 in the flight samples was higher than in the ground samples in both agar media. In the T8 medium, the production of monorden in the flight and ground samples was 11.6 +/- 3.5 micrograms and 8.9 +/- 1.1 micrograms respectively (30% increase). In the PG medium, the production of monorden in the flight and ground samples was 23.8 +/- 3.3 micrograms and 8.2 +/- 2.2 micrograms respectively (190% increase). The production of monorden in the flight and ground control samples was confirmed by HPLC-MS analysis.

The effect of carbon source, temperature and aeration on the production of ascosteroside, a novel antifungal agent, by Ascotricha amphitricha.

This paper describes the optimization of production of ascosteroside, a novel antifungal agent with an alpha-linked glycoside of a lanosterone-type triterpenoid structure. Glucose, sorbose and inositol were determined to be the best carbon sources for the production of ascosteroside. Temperature affected levels of ascosteroside, with production being highest at 16 degrees C with 1% glucose, and lowest at 32 degrees C. Dissolved oxygen levels were found to be critical in the production of ascosteroside in fermenter cultures. In order for production of ascosteroside to occur in fermenter cultures, the threshold level of dissolved oxygen was found to be above 26%.

Pyrrolosporin A, a new antitumor antibiotic from Micromonospora sp. C39217-R109-7. I. Taxonomy of producing organism, fermentation and biological activity.

Strain C39217-R109-7 (ATCC 53791) is an actinomycete strain isolated from a soil sample collected at Puerto Viejo, Peru. It produces a new antitumor antibiotic, designated pyrrolosporin A. Taxonomic studies on its morphological, cultural and physiological characteristics identified this producing strain as Micromonospora sp. C39217-R109-7. Pyrrolosporin A shows antimicrobial activity against Gram-positive bacteria and it is weakly active against Gram-negative bacteria. Pyrrolosporin A prolongs the life span of mice inoculated with P388 leukemia cells.

BMS-182123, a fungal metabolite that inhibits the production of TNF-alpha by macrophages and monocytes.

A fungal metabolite, BMS-182123, which inhibited bacterial endotoxin-induced production of tumor necrosis factor (TNF-alpha) in murine macrophages and human peripheral blood monocytes (in vitro), was isolated from the culture broth of Penicillium chrysogenum strain V39673. The effective BMS-182123 concentration (IC50) resulting in 50% inhibition of lipopolysaccharide-induced TNF-alpha production in murine macrophages and human monocytes was 600 ng/ml and 4.0 microgram/ml, respectively. BMS-182123 suppressed the lipopolysaccharide-induced TNF-alpha promoter activity and did not affect the stability of posttranscriptional mRNA. Addition of hydrophobic resin, Amberlite XAD-8 (1%), to the fermentation enhanced the production of BMS-182123 by 5.5 fold. A total of 577 mg pure BMS-182123 was recovered from a 250-liter fermentation supplemented with 1% Amberlite XAD-8.

Tubulin polymerization by paclitaxel (taxol) phosphate prodrugs after metabolic activation with alkaline phosphatase.

Paclitaxel (taxol) phosphate derivatives BMY46366, BMY-46489, BMS180661 and BMS180820 were used to determine the ability of alkaline phosphatase to convert these water-soluble potential prodrugs to tubulin-polymerizing metabolites (i.e., paclitaxel). Compounds were treated up to 180 min with an in vitro metabolic activation system composed of 10% bovine alkaline phosphatase in 0.2 M tris, pH 7.4, or in 0.2 M glycine, pH 8.8, plus 0.05 M MgCl2. Samples were tested (either by direct addition or after methylene chloride extraction/dimethyl-sulfoxide resuspension) in spectrophotometric tubulin polymerization assays utilizing bovine-derived microtubule protein. Pretreatment of 2'- and 7-phosphonoxyphenylpropionate prodrugs BMS180661 and BMS180820 with alkaline phosphatase for 30 to 120 min yielded relative initial slopes of about 20 to 100% at test concentrations equimolar to paclitaxel. High-performance liquid chromatography/mass spectrometry of BMS180661 treated with alkaline phosphatase confirmed the production of paclitaxel from the prodrug. In contrast, 2'- and 7-phosphate analogs BMY46366 and BMY46489 treated with alkaline phosphatase were not active in tubulin assays. None of the paclitaxel phosphate prodrugs polymerized tubulin in the absence of metabolic activation. The differences in tubulin polymerization with metabolic activation may be related both to accessibility of the phosphate group to the enzyme and to anionic charge effects. These results demonstrate that certain paclitaxel phosphate prodrugs can be metabolized by alkaline phosphatase to yield effective tubulin polymerization.

Korkormicins, novel depsipeptide antitumor antibiotics from Micromonospora sp C39500: fermentation, precursor directed biosynthesis and biological activities.

Micromonospora sp C39500, isolated in our laboratory from a soil sample, produced a complex of seven novel depsipeptide antitumor antibiotics, designated korkormicins. The major component of the complex, korkormicin A, has a MW of 1452 and a molecular formula of C66H84N16O22. Korkormicin A exhibits potent in vivo antitumor activity against P388 leukemia and M109 lung carcinoma implanted intraperitoneally (ip) in mice, with effective doses of 0.05-0.20 mg kg-1 injection-1, for five or three ip injections, respectively. It is also active against Gram-positive bacteria but inactive against Gram-negative bacteria. The production of korkormicin A was enhanced by 3-fold when 0.1% L-valine was added to the production culture at 48 h. A titer of 401.0 micrograms ml-1 was achieved in the fermenter culture supplemented with 0.1% L-valine.

Large scale production and semi-purification of kedarcidin in a 1000-L fermentor.

Actinomycete strain ATCC 53650 was grown in a 1000-L fermentor containing 680 L of medium and the production of kedarcidin was monitored by HPLC. The titers of kedarcidin in the fermentor cultures were 0.49-0.53 mg ml-1. A quick and efficient purification method involving the use of anion exchange resin DE23 (batch adsorption-desorption) and an ultrafiltration system yielded high recovery (65% yield) of kedarcidin from the fermentor culture. Over 200 grams of lyophilized kedarcidin of 70% purity was recovered from each of two 1000-L fermentor cultures using this process.

Inhibition of antibacterial activity of himastatin, a new antitumor antibiotic from Streptomyces hygroscopicus, by fatty acid sodium salts.

Himastatin, a cyclohexadepsipeptide antibiotic, had in vivo antitumor activity against localized P388 leukemia and B16 melanoma but had no distal site antitumor activity. An in vitro Bacillus subtilis well-agar diffusion assay was employed to test the hypothesis that himastatin was enzymatically inactivated. The activity of himastatin against B. subtilis was inhibited when himastatin was mixed with mouse liver S9 fraction and microsomes. However, subsequent investigations demonstrated that the markedly decreased antibacterial activity was not enzymatic in nature but was related to the presence of certain fatty acid salts. Saturated fatty acid sodium salts with a carbon chain number of 8 or more reduced the antimicrobial activity of himastatin 50 to 100 times. If antibiotics such as ampicillin, bacitracin, chloramphenicol, and tunicamycin were used in place of himastatin, no meaningful reduction in antibacterial activity occurred. However, the antibacterial activity of the membrane-active peptide antibiotic polymyxin B, but not that of polymyxin E (colistin), was reduced in a manner similar to that of himastatin. Importantly, the activity of himastatin against HCT-116 colon adenocarcinoma cells in soft agar was markedly reduced in the presence of sodium palmitate as the reference fatty acid salt. The data indicate that himastatin may be trapped in micelles in vitro. It may be speculated that the lack of distal site antitumor activity resulted from similar complex formation between himastatin and lipids in vivo. The results also suggest that the cancer cytotoxic and antimicrobial effects of himastatin may result from interactions with the cell membrane.

The effect of cerulenin on the production of esperamicin A1 by Actinomadura verrucosospora.

Addition of cerulenin (0.25-1.0 mM) to cultures of Acinomadura verrucosospora before the onset of esperamicin synthesis inhibited the production of esperamicin A1 by the microorganism. This result indicates that esperamicin A1 is biosynthesized in part by the polyketide pathway. Addition of cerulenin to the cultures during the active production phase led to a net decrease in esperamicin A1 production. The 14C-acetate labeling pattern of esperamicin A1 in the cultures with or without addition of cerulenin at the active production phase also demonstrated the instability of esperamicin A1 in the fermentation. This suggests that esperamicin A1 is unstable and degradation occurs during the active production phase. Addition of the neutral resin Diaion HP-20 (1%) to the fermentation enhanced the production of esperamicin A1 by 53%.

Improved processes for the production and isolation of dynemicin A and large-scale fermentation in a 10,000-liter fermentor.

Supplementing the culture of Micromonospora chersina sp. nov. No. M956-1 with NaI (0.5 mg/l) enhanced the production of dynemicin A by 35-fold in shake flask culture. Homogeneous dynemicin A was obtained from the whole broth extract by Dicalite chromatography, Sephadex LH-20 chromatography and vacuum liquid chromatography. Gram quantities of dynemicin A were obtained from the fermentation of M. chersina sp. nov. No. M956-1 in a 10,000-liter fermentor.

Isolation of a bromo analog of rebeccamycin from Saccharothrix aerocolonigenes.

When grown in a defined medium containing 0.05% KBr, Saccharothrix aerocolonigenes ATCC 39243 produces a novel bromo analog of rebeccamycin. This new analog, designated bromorebeccamycin, has been isolated from the culture broth and purified by vacuum liquid chromatography and column chromatography. Spectroscopic data demonstrated that bromorebeccamycin has the same structure as rebeccamycin, except for the replacement of the two chlorine atoms by bromine atoms in the molecule. Bromorebeccamycin and rebeccamycin have a similar potency and activity against P388 leukemia in the murine model.

Kedarcidin, a new chromoprotein antitumor antibiotic. I. Taxonomy of producing organism, fermentation and biological activity.

Strain L585-6 (ATCC 53650) is an actinomycete isolated from a soil sample collected in Maharastra State, India. It produces a new chromoprotein antitumor antibiotic, designated kedarcidin. Taxonomic studies demonstrated that strain L585-6 is an unidentified and unknown actinomycete. Kedarcidin shows potent antitumor activity against implanted P388 leukemia (3.3 micrograms/ml/kg) and B16 melanoma (2 micrograms/kg) in mice. Kedarcidin also shows potent antimicrobial activity against Gram-positive bacteria but no activity against Gram-negative bacteria.

Maduropeptin, a complex of new macromolecular antitumor antibiotics.

Maduropeptin, a complex of new macromolecular antitumor antibiotics, is a metabolite of Actinomadura madurae H710-49. The active components maduropeptins A1, A2 and B are acidic chromopeptides with MW of around 22,500 and composed of 14 types of amino acids and an unstable chromophore. The antibiotics are active in vitro against Gram-positive bacteria and highly cytotoxic to tumor cells. They produced significant prolongation of survival time of mice implanted with P388 leukemia and B16 melanoma.

Identification of indolepyruvic acid as an intermediate of rebeccamycin biosynthesis.

Experimental evidence is presented to demonstrate that indolepyruvic acid is an intermediate in the rebeccamycin biosynthetic pathway. [3-14C]Indolepyruvic acid was prepared and efficiently incorporated (8%) into rebeccamycin by Saccharothrix aerocolonigenes.

Himastatin, a new antitumor antibiotic from Streptomyces hygroscopicus. I. Taxonomy of producing organism, fermentation and biological activity.

Strain C39108-P210-51 (ATCC 53653), an actinomycete isolated from a soil sample collected in India, was found to produce a new antitumor antibiotic, designated himastatin. Taxonomic studies on its morphological, cultural and physiological characteristics identified this producing strain as Streptomyces hygroscopicus C39108-P210-51. Himastatin shows antimicrobial activity against Gram-positive bacteria but it is inactive against Gram-negative bacteria. Himastatin prolongs the life span of mice inoculated with P388 leukemia and B16 melanoma cells.