Clin Cancer Res
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Fenretinide (4-HPR) is a retinoid analogue with antitumor and chemopreventive activities. In addition to 4-HPR, there are several other new phenylretinamides bearing hydroxyl, carboxyl, or methoxyl residues on carbons 2, 3, and 4 of the terminal phenylamine ring [N-(2-hydroxyphenyl)retinamide (2-HPR), N-(3-hydroxyphenyl)retinamide, N-(2-carboxyphenyl)retinamide, N-(3-carboxyphenyl)retinamide, N-(4-carboxyphenyl)retinamide, and N-(4-methoxyphenyl)retinamide (4-MPR) ]. It is hypothesized that these agents can act independent of the nuclear retinoid receptor pathway. ⋯ The induction of differentiation and G(1) accumulation was only observed in the F9-WT cells, indicating that this effect is receptor-dependent. 4-MPR, a major metabolite of 4-HPR, lacks a charged group on the terminal phenylamine ring and did not induce retinoid receptor-dependent effects, but did induce cell growth inhibition. Thus, 4-MPR may play a role in the clinical activity of 4-HPR. This study further reveals the mechanism of action of these novel phenylretinamides and supports continued investigation into their development as chemopreventive drugs.
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A Phase I study in patients with advanced cancer was conducted to determine the safety, pharmacokinetics, and maximum tolerated dose of Triapine, a new, potent small-molecule inhibitor of ribonucleotide reductase. ⋯ Triapine administered at a dose of 96 mg/m(2) by 2-h i.v. infusion daily for 5 days on an every-other-week schedule demonstrates an acceptable safety profile. Serum concentrations that surpass in vitro tumor growth-inhibitory concentrations are achieved for brief periods of time each day and are sufficient to produce myelosuppression, the expected consequence of ribonucleotide reductase inhibition. Phase II trials are indicated but will proceed with a daily-for-4-days schedule to reduce the incidence of grade 4 leukopenia. The safety profile also supports the initiation of Phase I combination trials with other anticancer agents.
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Diflomotecan (BN80915) is an E-ring modified camptothecin analogue that possesses greater lactone stability in plasma compared with other topoisomerase I inhibitors, a potential advantage for antitumor activity. As with other camptothecins, oral administration has pharmacological and clinical advantages. This Phase I study was performed to assess the feasibility of the administration of oral diflomotecan, to determine the maximum-tolerated, dose its bioavailability, and to explore the pharmacokinetics. ⋯ The recommended oral diflomotecan dose for Phase II studies is 0.27 mg/day x 5 every 3 weeks. This regimen is convenient and generally well tolerated with a favorable pharmacokinetic profile and high but variable bioavailability.
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There is increasing evidence that the chimeric monoclonal antibody G250 (cG250) can be internalized by G250 antigen-expressing renal cell carcinoma (RCC) cells. Thus, accumulation in tumors of cG250 labeled with residualizing radionuclides might be higher than that of nonresidualizing (131)I-cG250. Here, we present a study comparing intrapatiently the accumulation of (131)I-cG250 and (111)In-cG250 in RCC metastases. ⋯ (111)In-ITC-DTPA-cG250 outperformed (131)I-cG250 for visualization of metastatic RCC lesions, not just because of the superior gamma camera characteristics of (111)In, but more importantly, also because higher tumor:blood ratios were obtained. The higher activities of (111)In-ITC-DTPA-cG250 in metastatic lesions might be caused by internalization and subsequent intracellular retention of the radiolabel, implying that in future radioimmunotherapy trials with cG250 in RCC patients, the use of a residualizing radionuclide should be considered.
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Randomized Controlled Trial Clinical Trial
Approval summary for zoledronic acid for treatment of multiple myeloma and cancer bone metastases.
This article summarizes data submitted to the United States Food and Drug Administration for marketing approval of zoledronic acid (Zol; Novartis Pharmaceuticals, East Hanover, NJ), a bisphosphonate drug for treating patients with bone metastases. ⋯ In prostate cancer, both the proportions analysis and time-to-SRE analysis showed significantly less bone morbidity on Zol (4 mg) than placebo, but no significant difference between Zol (8 mg) and placebo in either analysis. In the solid tumor study, the time to SRE analysis but not the proportions analysis showed significantly less skeletal morbidity on Zol (4 mg) than placebo, and Zol (8 mg) was significantly better than placebo in both analyses. The breast cancer and myeloma study demonstrated noninferiority of Zol compared with Pam, with Zol retaining at least 49.3% of the Pam treatment effect previously demonstrated in placebo-controlled trials. Zol was approved on February 22, 2002, by the United States Food and Drug Administration for the "treatment of patients with multiple myeloma and documented bone metastases from solid tumors, in conjunction with standard antineoplastic therapy. Prostate cancer should have progressed after treatment with at least one hormonal therapy." The recommended dose and schedule is 4 mg of Zol infused over 15 min every 3-4 weeks. Increased Zol doses and shorter infusions are not recommended because of potential renal toxicity.