In:
Cancer Research, American Association for Cancer Research (AACR), Vol. 71, No. 8_Supplement ( 2011-04-15), p. 4435-4435
Abstract:
NK012 is a micelle-forming macromolecular prodrug of SN-38, an active metabolite of irinotecan (CPT-11). It accumulates in tumor tissue and gradually releases SN-38 in an enzyme-independent manner. We previously reported that NK012 showed stronger antitumor activity in a broad range of human solid tumor xenograft models than CPT-11 (2006 AACR Annual Meeting, #3062). Currently, phase II clinical trials of NK012 in patients with triple-negative breast cancer, small cell lung cancer, and colorectal cancer are ongoing in the United States and Japan. In this study, we evaluated the antitumor activity of NK012 in an orthotopic multiple myeloma model that shows typical infiltration of human myeloma cells into murine bone marrow tissue. A suspension of 2 × 106 cells of CD138 positive U266 human myeloma cells was injected into immunodeficient NOG (NOD/Shi-scid, IL-2Rγnull) mice via tail vein. The transplanted mice produced plasma M protein (human IgE) and developed lytic bone lesions. In addition, hind-leg paralysis caused by myeloma progression in spinal cord was observed. These symptoms were similar to complications observed in the patients with multiple myeloma. The intravenous administration of NK012 at 3.75, 7.5, and 15 mg/kg/day by q4d × 3 suppressed M protein concentration in plasma and proliferation of myeloma cells in bone marrow in a dose-dependent manner. Also observed were decrease in the area of osteolytic lesions and recovery of decreased total bone mineral density in the tibias. To examine the efficacy of NK012 in survival time, the myeloma-transplanted mice were treated with 9.4 mg/kg/day (28.2 mg/m2/day), q7d × 6, equivalent to the clinical recommended dose of 28 mg/m2/day as a single dose. NK012 significantly prolonged survival time of the mice compared with control group (78.5 days vs. 40 days, P & lt;0.001). We next examined the combination effect of NK012 with bortezomib, which is commonly used for multiple myeloma treatment. The combined treatment of NK012 (9.4 mg/kg/day, q7d × 3) with bortezomib (0.5 mg/kg/day, 2 times/week × 2, i.v.) exhibited increase in median survival time over bortezomib alone (83.5 days vs. 68 days). In conclusion, these results suggested NK012 is a promising candidate for human multiple myeloma treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4435. doi:10.1158/1538-7445.AM2011-4435
Type of Medium:
Online Resource
ISSN:
0008-5472
,
1538-7445
DOI:
10.1158/1538-7445.AM2011-4435
Language:
English
Publisher:
American Association for Cancer Research (AACR)
Publication Date:
2011
detail.hit.zdb_id:
2036785-5
detail.hit.zdb_id:
1432-1
detail.hit.zdb_id:
410466-3
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