A phase II trial of pyrazine diazohydroxide in patients with disseminated malignant melanoma and no prior chemotherapy--Southwest Oncology Group study

Palladium(II)-Stabilized Pyridine-2-Diazotates: Synthesis, Structural Characterization, and Cytotoxicity Studies

Well-defined diazotates are scarce. Here we report the synthesis of unprecedented homoleptic palladium(II) diazotate complexes. The palladium(II)-mediated nitrosylation of 2-aminopyridines with NaNO₂ results in the formation of metal-stabilized diazotates, which were found to be cytotoxic to human ovarian cancer cells.

New potentially active pyrazinamide derivatives synthesized under microwave conditions

A series of 18 N-alkyl substituted 3-aminopyrazine-2-carboxamides was prepared in this work according to previously experimentally set and proven conditions using microwave assisted synthesis methodology. This approach for the aminodehalogenation reaction was chosen due to higher yields and shorter reaction times compared to organic reactions with conventional heating. Antimycobacterial, antibacterial, antifungal and photosynthetic electron transport (PET) inhibiting in vitro activities of these compounds were investigated. Experiments for the determination of lipophilicity were also performed. Only a small number of substances with alicyclic side chain showed activity against fungi which was the same or higher than standards and the biological efficacy of the compounds increased with rising lipophilicity. Nine pyrazinamide derivatives also inhibited PET in spinach chloroplasts and the IC₅₀ values of these compounds varied in the range from 14.3 to 1590.0 μmol/L. The inhibitory activity was connected not only with the lipophilicity, but also with the presence of secondary amine fragment bounded to the pyrazine ring. Structure-activity relationships are discussed as well.

N-substituted 5-amino-6-methylpyrazine-2,3-dicarbonitriles: microwave-assisted synthesis and biological properties

In this work a series of 15 N-benzylamine substituted 5-amino-6-methyl-pyrazine-2,3-dicarbonitriles was prepared by the aminodehalogenation reactions using microwave assisted synthesis with experimentally set and proven conditions. This approach for the aminodehalogenation reaction was chosen due to its higher yields and shorter reaction times. The products of this reaction were characterized by IR, NMR and other analytical data. The compounds were evaluated for their antibacterial, antifungal and herbicidal activity. Compounds 3 (R = 3,4-Cl), 9 (R = 2-Cl) and 11 (R = 4-CF₃) showed good antimycobacterial activity against Mycobacterium tuberculosis (MIC = 6.25 µg/mL). It was found that the lipophilicity is important for antimycobacterial activity and the best substitution on the benzyl moiety of the compounds is a halogen or trifluoromethyl group according to Craig’s plot. The activities against bacteria or fungi were insignificant. The presented compounds also inhibited photosynthetic electron transport in spinach chloroplasts and the IC₅₀ values of the active compounds varied in the range from 16.4 to 487.0 µmol/L. The most active substances were 2 (R = 3-CF₃), 3 (R = 3,4-Cl) and 11 (R = 4-CF₃). A linear dependence between lipophilicity and herbicidal activity was observed.

A Phase II trial of vinorelbine tartrate in patients with disseminated malignant melanoma and one prior systemic therapy

BACKGROUND

Single-agent chemotherapy with dacarbazine continues to be the standard of care for the treatment of metastatic melanoma. However, there is a large population of patients who have failed first-line therapy and might benefit from additional treatment. In the current study, the authors evaluated the antitumor effects and toxicity of vinorelbine therapy in patients who had failed one prior systemic therapy.

METHODS

Patients were required to have a histologic diagnosis of melanoma and be of Stage IV with measurable disease, a Southwest Oncology Group (SWOG) performance status (PS) of 0-2, no evidence of brain metastases, and adequate bone marrow and liver function. Treatment was comprised of vinorelbine given at a dose of 30 mg/m(2)/week by intravenous bolus.

RESULTS

Twenty-four patients were registered to the study, 3 of whom were determined to be ineligible. The 21 eligible patients had a median age of 58 years with a SWOG PS of 0 in 7 patients, 1 in 13 patients, and 2 in 1 patient. There were no complete or partial responses observed, for a response rate of 0 of the 21 patients studied (95% confidence interval [95% CI], 0-16%); the study closed after the first stage of accrual. The estimated median progression-free survival was 2 months (95% CI, 1.5-3.3 months) and the estimated median overall survival was 6 months (95% CI, 3.7-8.3 months). There was one death due to febrile neutropenia reported, with six patients experiencing one or more Grade 4 toxicities, including neutropenia/granulocytopenia, leukopenia, dyspnea, and fatigue.

CONCLUSIONS

Despite impressive preclinical activity against melanoma, vinorelbine does not appear to have enough clinical activity to be of interest in previously treated patients with disseminated melanoma. The progression-free and overall survival results noted in previously treated patients in the current study were similar to results reported in prior SWOG Phase II trials in untreated patients. The group of previously treated patients may be used to evaluate new agents for the treatment of disseminated melanoma.