oblimersen and Acute-Disease

Topics: Acute Disease; Antineoplastic Agents; Antineoplastic Combined Chemotherapy Protocols; Benzamides; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Drug Evaluation; Gene Expression Regulation, Neoplastic; Genes, bcl-2; Humans; Imatinib Mesylate; Leukemia, Myeloid; Piperazines; Protein-Tyrosine Kinases; Pyrimidines; Quinolones; Thionucleotides

The acute myeloid leukemias (AML) are often fatal disorders with a range of clinical, morphologic, cytogenetic, and molecular features and a consequent need for a diverse array of therapies. This need for tailored therapy for subsets of patients with AML is exemplified in those with acute promyelocytic leukemia, the subject of a separate article in this issue (Tallman and Nabhan). Unfortunately, we tend to examine novel agents in patients with very advanced disease, in which prior therapies have inevitably altered the tumor. Of a myriad of possible exciting novel agents, a few, including PS-341, Genasense (Genta, Berkeley Heights, NJ), decitabine, 5-azacytidine, clofarabine, and troxacitabine, are briefly reviewed with an emphasis on their mechanisms of action from a perspective that suggests possible synergistic therapeutic interventions. With the growing appreciation of the pivotal role of angiogenesis in AML, angiogenesis modulators are a good example of a core class of drugs upon which future noncytotoxic combinations may be built. Those agents targeting vascular endothelial growth factor are also briefly reviewed.

Topics: Acute Disease; Adenine Nucleotides; Angiogenesis Inhibitors; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antimetabolites, Antineoplastic; Antineoplastic Agents; Arabinonucleosides; Azacitidine; Bevacizumab; Boronic Acids; Bortezomib; Clofarabine; Cytosine; Decitabine; Dioxolanes; Humans; Indoles; Leukemia, Myeloid; Phthalazines; Pyrazines; Pyridines; Pyrroles; Thionucleotides

To develop and validate an ultrasensitive and specific hybridization-based enzyme-linked immunosorbent assay method for quantification of two phosphorothioate oligonucleotides (PS ODNs) (G3139 and GTI-2040) in biological fluids.. This assay was based on hybridization of analytes to the biotin-labeled capture ODNs followed by ligation with digoxigenin-labeled detection ODN. The bound duplex was then detected by anti-digoxigenin-alkaline phosphatase using Attophos (Promega, Madison, WI, USA) as substrate. S1 nuclease and major factors such as the hybridization temperature, concentration of capture probe, and the use of detergent were evaluated toward assay sensitivity, selectivity, and accuracy.. The method is selective to the parent drugs with minimal cross-reactivity (<6%) with 3'-end deletion oligomers for both G3139 and GTI-2040. A linear range of 0.05 to 10 nM (r2 > 0.99) was observed for GTI-2040 in a variety of biological matrices. For both G3139 and GTI-2040, the within-day precision and accuracy values were found to be <20% and 90-110%, respectively; the between-day precision and accuracy were determined to be <20% and 90-120%. Addition of S1 nuclease combined with washing step greatly improved the assay linearity and selectivity. The utility of this assay was demonstrated by simultaneous determination of GTI-2040 in plasma and its intracellular levels in treated acute myeloid leukemia patients.. The validated hybridization enzyme-linked immunosorbent assay method is specific for quantitation of PS ODNs in biological samples to picomolar level. This method provides a powerful technique to evaluate plasma pharmacokinetics and intracellular uptake of PS ODNs in patients and shows its utility in clinical evaluations.

Topics: Acute Disease; Animals; DNA Probes; Enzyme-Linked Immunosorbent Assay; Erythrocytes; Humans; K562 Cells; Leukemia, Myeloid; Leukocytes, Mononuclear; Mice; Nucleic Acid Hybridization; Oligodeoxyribonucleotides; Oligonucleotides, Antisense; Rats; Reproducibility of Results; Single-Strand Specific DNA and RNA Endonucleases; Temperature; Thionucleotides

Oblimersen selectively targets Bcl-2 mRNA and has been shown to enhance the apoptotic activity of various antileukemic agents, including gemtuzumab ozogamicin (GO), in preclinical studies. We evaluated the efficacy and safety of oblimersen combined with GO in patients > or =60 years of age in first relapse with CD33+ acute myeloid leukemia. Oblimersen 7 mg/kg/day was given as a continuous intravenous infusion on days 1-7 and 15-21. GO 9 mg/m2 was given intravenously on days 4 and 18. Twelve of 48 patients (25%) achieved a major response (five, complete response and seven, complete response without platelet recovery). Ten of the 12 patients who achieved a major response survived >6 months compared with six of 36 non-responders. Serious adverse events for the oblimersen/GO combination were qualitatively similar to those reported for GO alone. Oblimersen can be safely combined with GO. Assessment of incremental benefit will require a randomized trial.

Topics: Acute Disease; Aged; Aminoglycosides; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antineoplastic Combined Chemotherapy Protocols; Cytogenetic Analysis; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug-Related Side Effects and Adverse Reactions; Female; Follow-Up Studies; Gemtuzumab; Humans; Infusions, Intravenous; Leukemia, Myeloid; Male; Maximum Tolerated Dose; Recurrence; Risk Factors; Survival Rate; Thionucleotides; Treatment Outcome

Overexpression of Bcl-2 is a potential mechanism for chemoresistance in acute leukemia and has been associated with unfavorable clinical outcome. We hypothesized that down-regulation of Bcl-2 would restore chemosensitivity in leukemic cells. To test this hypothesis, we performed a phase 1 study of G3139 (Genasense, Genta, Berkeley Heights, NJ), an 18-mer phosphorothioate Bcl-2 antisense, with fludarabine (FL), cytarabine (ARA-C), and granulocyte colony-stimulating factor (G-CSF) (FLAG) salvage chemotherapy in patients with refractory or relapsed acute leukemia. Twenty patients with refractory or relapsed acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL) were enrolled. G3139 was delivered by continuous infusion on days 1 to 10. FLAG chemotherapy was administered on days 5 to 10. Common side effects of this combination included fever, nausea, emesis, electrolyte imbalance, and fluid retention that were not dose limiting. Plasma pharmacokinetics of G3139 demonstrated steady-state concentration (Css) within 24 hours. Of the 20 patients, 9 (45%) had disease response, 6 (5 AML, 1 ALL) with complete remission (CR) and 3 (2 AML and 1 ALL) with no evidence of disease but failure to recover normal neutrophil and/or platelet counts or to remain in remission for at least 30 days (incomplete remission). Bcl-2 mRNA levels were down-regulated in 9 of the 12 (75%) evaluable patients. This study demonstrates that G3139 can be administered safely with FLAG chemotherapy and down-regulate its target, Bcl-2. The encouraging clinical and laboratory results justify the current plans for a phase 3 study in previously untreated high-risk AML (ie, age at least 60 years).

Topics: Acute Disease; Adolescent; Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Cytarabine; Down-Regulation; Female; Genes, bcl-2; Granulocyte Colony-Stimulating Factor; Humans; Leukemia; Male; Middle Aged; Oligonucleotides, Antisense; Remission Induction; Salvage Therapy; Thionucleotides; Vidarabine

Down-regulation of Bcl-2 by the antisense G3139, currently under clinical evaluations, could restore chemosensitivity in otherwise resistant malignant cells. To date, the mechanism of intracellular accumulation of G3139 following in vivo administration remains to be elucidated. This study aimed to assess whether detectable intracellular concentrations of G3139 are achievable in vivo and how these relate to Bcl-2 down-regulation.. Cellular uptake of G3139 was studied in leukemia myeloid cell lines and blasts collected from treated patients using a newly developed, novel, and highly sensitive ELISA-based assay. Real-time reverse transcription-PCR was used to quantify Bcl-2 mRNA changes in treated cells.. The assay was fully validated and showed a limit of quantification of 50 pmol/L. When exposed to 0.33 to 10 mumol/L G3139, K562 cells exhibited intracellular concentrations in the range of 2.1 to 11.4 pmol/mg protein. When G3139 was delivered with cationic lipids, a 10- to 25-fold increase of the intracellular concentrations was observed. There was an accumulation of G3139 in the nuclei, and the ratio of nucleus to cytoplasm was increased 7-fold by cationic lipids. Intracellular concentrations of G3139 were correlated with Bcl-2 mRNA down-regulation. Robust intracellular concentrations of G3139 were achieved in vivo in bone marrow (range, 3.4-40.6 pmol/mg protein) and peripheral blood mononuclear cells (range, 0.47-19.4 pmol/mg protein) from acute myeloid leukemia patients treated with G3139.. This is the first evidence that measurable intracellular levels of G3139 are achievable in vivo in acute myeloid leukemia patients and that Bcl-2 down-regulation is likely to depend on the achievable intracellular concentrations rather than on plasma concentrations.

Topics: Acute Disease; Base Sequence; Cell Line, Tumor; Chromatography, High Pressure Liquid; Enzyme-Linked Immunosorbent Assay; Humans; K562 Cells; Leukemia, Myeloid; Oligonucleotides, Antisense; Proto-Oncogene Proteins c-bcl-2; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thionucleotides; Time Factors

Topics: Acute Disease; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Small Cell; Clinical Trials, Phase I as Topic; Humans; Leukemia, Myeloid; Lung Neoplasms; Middle Aged; Multicenter Studies as Topic; Oligonucleotides, Antisense; Thionucleotides