Phase I study of docetaxel in combination with cyclophosphamide as first-line chemotherapy for metastatic breast cancer

This phase I was study conducted to establish the maximum tolerated dose, dose-limiting toxicity, and recommended dose of docetaxel in combination with cyclophosphamide as first-line chemotherapy for metastatic breast cancer. Twenty-six patients were treated with cyclophosphamide (600 mg m−2, intravenous bolus) followed by docetaxel (60, 75 or 85 mg m−2, 1-h intravenous infusion) every 3 weeks. The maximum tolerated dose was docetaxel 85 mg m−2 with cyclophosphamide 600 mg m−2, the dose-limiting toxicity being febrile neutropenia. Grade 4 neutropenia was experienced by all patients, but was generally brief. Otherwise, the combination was well tolerated with few acute and no chronic non-haematological toxicities of grade 3/4. Activity was observed at all dose levels and disease sites, and the overall response rate was 42% (95% confidence interval 22–61%). The pharmacokinetics of docetaxel were not modified by cyclophosphamide coadministration. These findings establish a recommended dose of docetaxel 75 mg m−2 in combination with cyclophosphamide 600 mg m−2 every three weeks for phase II evaluation

Antisense phosphorothioate oligonucleotides: selective killing of the intracellular parasite Leishmania amazonensis.

We targeted the mini-exon sequence, present at the 5' end of every mRNA of the protozoan parasite Leishmania amazonensis, by phosphorothioate oligonucleotides. A complementary 16-mer (16PS) was able to kill amastigotes--the intracellular stage of the parasite--in murine macrophages in culture. After 24 hr of incubation with 10 microM 16PS, about 30% infected macrophages were cured. The oligomer 16PS acted through antisense hybridization in a sequence-dependent way; no effect on parasites was observed with noncomplementary phosphorothioate oligonucleotides. The antisense oligonucleotide 16PS was a selective killer of the protozoans without any detrimental effect to the host macrophage. Using 16PS linked to a palmitate chain, which enabled it to complex with low density lipoproteins, improved the leishmanicidal efficiency on intracellular amastigotes, probably due to increased endocytosis. Phosphorothioate oligonucleotides complementary to the intron part of the mini-exon pre-RNA were also effective, suggesting that antisense oligomers could prevent trans-splicing in these parasites

Leishmanicidal activity of amino acid and peptide esters: an update

Institut Pasteur Unité d'ImmunoparasitologieUSP ICB II Departamento de ParasitologiaInstitut Pasteur Unité d'Immunophysiologie CellulaireInstitut Pasteur Unité de Microscopie ElectroniqueFriedrich Miescher InstitutEscola Paulista de Medicina Departamento de BiofisicaUNIFESP, EPM, Depto. de BiofisicaSciEL

A randomized phase II study of alternating and sequential regimens of docetaxel and doxorubicin as first-line chemotherapy for metastatic breast cancer

Background: This phase II study evaluated the feasibility and efficacy of alternating and sequential regimens of docetaxel and doxorubicin as first-line chemotherapy for metastatic breast cancer (MBC). Patients and methods: Women with MBC requiring first-line chemotherapy for progressive disease (n = 106) were randomized and received 3-weekly monotherapy with docetaxel (T, 100 mg/m(2), 1-h i.v. infusion) and doxorubicin (A, 75 mg/m(2), 20-30-min i.v. infusion) either on a cycle-by-cycle alternating basis (ATATATAT, n = 51) or sequentially each for four cycles (TTTTAAAA, n = 55). Results: For both regimens, the median number of cycles administered was the maximum of eight. The alternating and sequential groups achieved similar objective tumor response rates (60% and 67%, respectively) and similar median duration of response (47 and 44 weeks, respectively). With a median follow-up of 31 months, median survival times were estimated at 20 and 26 months in the alternating and sequential groups, respectively. No unexpected toxicities were reported. Compared with alternating therapy, patients receiving sequential therapy were more likely to complete the planned eight chemotherapy cycles (69% versus 63%), and had a lower incidence of febrile neutropenia (2% versus 14%). Conclusions: Alternating and sequential docetaxel-doxorubicin regimens are viable alternatives to simultaneous combination therapy in MBC, with sequential therapy achieving slightly higher response rates and improved tolerability compared with alternating therapy

Targeted Reduction in Expression of Trypanosoma cruzi Surface Glycoprotein gp90 Increases Parasite Infectivity

A previous study had shown that the expression of gp90, a stage-specific surface glycoprotein of Trypanosoma cruzi metacyclic trypomastigotes, is inversely correlated with the parasite's ability to invade mammalian cells. By using antisense oligonucleotides complementary to a region of the gp90 gene implicated in host cell adhesion, we investigated whether the selective inhibition of gp90 synthesis affected the capacity of metacyclic forms to enter target cells. Parasites were incubated for 24 h with 20 μM PS1, a phosphorothioate oligonucleotide based on a sequence of the gp90 coding strand; PS2, the antisense counterpart of PS1; or PO2, the unmodified version of PS2 containing phosphodiester linkages, and the expression of surface molecules was analyzed by flow cytometry and immunoblotting using specific monoclonal antibodies. PS2 but not PS1 or PO2 inhibited the expression of gp90. Inhibition by PS2 was dose dependent. Northern blot analysis revealed that steady-state gp90 mRNA levels were diminished in PS2-treated parasites compared to untreated controls. Treatment with PS2 did not affect the expression of other metacyclic stage surface glycoproteins involved in parasite-host cell interaction, such as gp82 and the mucin-like gp35/50. Expression of gp90 was also inhibited by other phosphorothioate oligonucleotides targeted to the gp90 gene (PS4, PS5, PS6, and PS7) but not by PS3, with the same base composition as PS2 but a mismatched sequence. Parasites treated with PS2, PS4, or PS5 entered HeLa cells in significantly higher numbers than untreated controls, whereas the invasive capacity of PS1- and PS3-treated parasites was unchanged, confirming the inverse association between infectivity and gp90 expression