ZIO-101 (S-dimethylarsino-glutathione): Phase I/II trials in advanced/progressive multiple myeloma

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Background: ZIO-101(S-dimethylarsino-glutathione), a novel organic arsenic, is active against multiple cancers including myeloma in vitro and in animal models. In vitro, it is active at low concentrations in cancers resistant to arsenic trioxide. Anti-cancer activity is multifaceted and is mediated by disrupted mitochondrial function, increased reactive oxygen species (ROS) production, modified signal transduction and anti-angiogenesis. Methods: (1) Phase I/II study to determine maximum tolerated dose (MTD), dose- limiting toxicity (DLT), safety-profile and preliminary efficacy in patients with advanced/progressive myeloma receiving ZIO-101 daily for 5 consecutive d every 4 w; (2) comparison of this schedule at MTD with a schedule of 420 mg/me2/d twice/w for 3 w every 4 w. Results: (1) phase I/ II: 19 patients have been treated so far. Median age is 61 y (range, 41–84 y). Median N prior therapies was 8 (range, 4–10). ZIO-101 was well-tolerated; MTD was 420 mg/me2/d for the 5 d schedule, and DLT was transient confusion /ataxia. No clinically- important biochemical, bone marrow, or cardiac toxicities were seen and there was neither neuropathy nor QTc-prolongation. Pain during peripheral infusion was reported in some patients. Anemia was the only adverse event = grade-3 in 25% of subjects. 6 of 14 evaluable subjects had stable disease (SD) =8 w and 2, SD > 6 mo. Accrual to the phase II portion continues. Conclusions: ZIO-101 was well- tolerated. In the daily for 5 consecutive d every 4 w schedule, the MTD is 420 mg/me2/d and DLT, transient confusion /ataxia. There was SD in 43% of patients with advanced/progressive myeloma, of whom half are beyond 6 months. Accrual into the phase II part of this study continues.

No significant financial relationships to disclose.

Inoculation of field-established mulberry and papaya with arbuscular mycorrhizal fungi and a mycorrhiza helper bacterium

The effects of soil inoculation with arbuscular mycorrhizal (AM) fungi and a mycorrhiza helper bacterium (MHB) were investigated on mulberry and papaya plants already established in the field. Ten-year-old mulberry plants (var. M5) were inoculated with Glomus fasciculatum and 1.5-year-old papaya plants (var. Solo) were inoculated with a mixed culture of G. mosseae and G. caledonium with or without Bacillus coagulans at two levels of P fertilizer. Growth, P uptake, yield and AM colonization levels were monitored. Leaf yield in mulberry and fruit yield in papaya were minimal in uninoculated plants given 50% recommended P. However, crop yields of both mulberry and papaya inoculated with AM fungi alone or together with the bacterium and given 50% recommended P were statistically on a par with that of uninoculated plants given 100% recommended P. As inoculation of B. coagulans increased mycorrhiza levels in AM fungal-inoculated plants, this may be included in the class of MHB. Thus, mulberry and papaya already established in the field may respond to AM inoculation and MHB may increase symbiosis development by efficient AM fungi.