Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0854467 (myelosuppression)
 5,932 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The sodium salt of pyrazine-2-diazohydroxide (PZDH; NSC 361456) was identified as an active congener of the antitumor lead pyridine-2-diazotate with enhanced chemical stability under physiological conditions. In a phase I trial of PZDH administered as a single i.v. bolus injection, 19 patients with refractory solid tumors received 44 courses of therapy at dose levels ranging from 50 to 350 mg/m2. No objective responses to PZDH were noted. Myelosuppression characterized by prolonged, delayed onset leukopenia and thrombocytopenia was the dose limiting toxicity. A maximum tolerated dose of 350 mg/m2 was identified for this treatment schedule. Nonhematological toxicity was limited to severe nausea and vomiting, experienced by all patients treated at the lower doses, although reasonably well controlled when antiemetics were given prior to chemotherapy. The plasma pharmacokinetics of PZDH was evaluated following a single course of therapy in 16 patients. Drug levels were monitored using a specific capillary gas chromatographic assay with a 1-ng/ml lower limit of quantitation. In patients treated with doses greater than 50 mg/m2, the concentration of PZDH in plasma declined in a distinctly triexponential manner and remained above 1.5 ng/ml for at least 8 h. However, the initial decay phase, characterized by a harmonic mean half-life of 3.9 +/- 3.5 (SD) min (range, 2.2-6.3 min), was the primary determinant of drug disposition, as indicated by its 85.5-93.1% contribution to the area under the plasma concentration-time profiles from time zero to infinity. The harmonic mean terminal half-life increased with escalations in dose from 2.7 +/- 0.8 h (n = 2) at 100 mg/m2 to 8.5 +/- 3.0 h at 350 mg/m2 (n = 6). Total plasma drug clearance was very similar in patients treated with doses of 50-250 mg/m2, exhibiting a mean value of 42.5 +/- 7.8 liters/h/m2 (n = 10); however, it was significantly lower at the 350 mg/m2 dose level, 27.2 +/- 6.6 liters/h/m2 (n = 6; P < 0.002), denoting a departure from linear pharmacokinetic behavior. The rather low steady state apparent volume of distribution, which ranged from 6.0 +/- 1.5 (50 mg/m2, n = 2) to 12.7 +/- 8.0 (350 mg/m2, n = 6) liters/m2, was indicative of limited distribution of the drug into body tissue. The absence of objective antitumor effects should not discourage continued evaluation of PZDH against solid tumors selected for probable sensitivity as indicated by preclinical testing. A dose of 250 mg/m2 on a single i.v. bolus schedule is recommended for these phase II trials.
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PMID:Phase I evaluation and pharmacokinetic study of pyrazine-2-diazohydroxide administered as a single bolus intravenous injection in patients with advanced solid tumors. 840 71

Pyrazine diazohydroxide (PZDH) is a novel antitumor agent that forms DNA adducts via the reactive pyrazine diazonium ion. In a recent Phase I study of PZDH, we identified a recommended Phase II dose of 100 mg/m2/day x 5, given as a 5-min i.v. bolus with the cycles repeated every 42 days (N. J. Vogelzang, et al, Cancer Res., 54: 114-119, 1994). There was a moderate negative correlation between serum chloride concentration and logarithm platelet nadir, suggesting the hypothesis that PZDH is activated in an acidic environment, leading to more toxicity in acidotic patients. Therefore, the University of Chicago Phase II cooperative network conducted two Phase II studies of PZDH in renal cancer (15 patients, 2 with liver metastases) and in 5-fluorouracil-refractory colorectal cancer (14 patients, 13 with liver metastases) to determine efficacy in each disease and to correlate safety and tolerance of the drug with PZDH pharmacokinetics/pharmacodynamics and with arterial blood gas measurements. There were no responses seen in either tumor type. The primary toxicity of PZDH was myelosuppression with neutropenia (absolute neutrophil count, < 1000/microl) and thrombocytopenia (<50,000 cells/microl), seen in 41 and 24% of all cycles, respectively. Other grade 3 and 4 toxicities were rare. Pharmacodynamic analysis revealed no significant correlation between plasma levels at 5, 60, and 120 min; WBCs; absolute neutrophil and platelet count nadirs; and initial serum chloride or blood pH levels. The colorectal patients experienced significantly more thrombocytopenia than did the renal cancer patients (median platelet nadir after cycle 1 was 151 x 10(3)/microl for renal patients versus 76 x 10(3)/microl for colon patients; P = 0.04), suggesting either that prior 5-fluorouracil and leucovorin reduced bone marrow reserve or that colorectal patients with liver metastases experienced more PZDH toxicity. Regression analyses revealed a possible relationship (P = 0.06) between serum pH and thrombocytopenia (i.e., for each increase of 0.03 in pH, there was a 34% increase in the platelet nadir), but there was no relationship between serum chloride and thrombocytopenia. Curiously, an increase in alkaline phosphatase was associated with an increase in the platelet nadir (P = 0.02). If PZDH continues to be developed as an antineoplastic agent, further studies of these relationships are suggested.
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PMID:Phase II and pharmacodynamic studies of pyrazine diazohydroxide (NSC 361456) in patients with advanced renal and colorectal cancer. 956 86

CI-980, (ethyl (S)-(5-amino-1,2-dihydro-2-methyl-3-phenylpyrido[3,4-b] pyrazine-7-yl) carbamate 2-hydroxyethansulfonate (1:1)), is a water-soluble mitotic inhibitor. It acts by binding to the colchicine-binding site on tubulin, a site different from that of the vinca alkaloids, inhibiting tubulin polymerization. Cells exposed to CI-980 accumulate in M phase and die. In preclinical tumor models, CI-980 showed a broad spectrum of activity, including in multi-drug resistant tumor cell lines, with activity at least equal to that of vincristine. Extensive small cell lung cancer, despite its responsiveness to chemotherapy, is usually an incurable disease with survival in patients of less than one year. Due to the preclinical activity of CI-980 and its similar mechanism of action to drugs effective in small cell lung cancer, a phase II trial in extensive small cell lung cancer was initiated by The Ohio State University Phase II Research Consortium. A "window of opportunity" design was chosen where a short six-week trial of the drug was given unless there was significant objective response. Twelve patients were entered in the study and underwent a total of 16 cycles of chemotherapy. The median age of the patients was 54 years old (range 34-71) and performance status was ECOG 0 (four patients), ECOG 1 (seven patients), and ECOG 2 (one patient). The patients were treated with a 72-hr infusion at a dose of 4.5 mg/m2/day. Toxicity was predominantly myelosuppression with granulocytopenia (nine episodes), and anemia (seven episodes). There were no objective responses with 11 patients being removed from study due to progressive disease. Evaluation of leukocyte microtubule structure in peripheral blood revealed microtubule depolymerization, which was seen after treatment (t = 72 hr) and was reversible within 24 hr of stopping the drug. We conclude that despite antitumor activity demonstrated in preclinical studies, CI-980 does not have biological activity in previously untreated small cell lung cancer at this dose and infusion protocol.
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PMID:A phase II study of CI-980 in previously untreated extensive small cell lung cancer: an Ohio State University phase II research consortium study. 1190 39