CRM1/chromosome region maintenance 1

KPT-276 significantly prolongs survival of leukemic mice and reduces leukemic burden in a xenograft AML mouse model. KPT-276 significantly suppresses tumor growth in an MCL-bearing severe combined immunodeficient mouse model without severe toxicity. KPT-276 reduces monoclonal spikes in the Vk*MYC transgenic MM mouse model, and inhibits tumor growth in a xenograft MM mouse model.

Overexpression of the cellular nuclear exportin 1, more commonly called chromosomal region maintenance 1 (CRM1), has been associated with malignant progression and mortality. Therefore, activation of nuclear export can play a significant etiologic role in some forms of human neoplasia and serve as a novel target for the treatment of these cancers. Mantle cell lymphoma (MCL) is an aggressive histotype of B-cell non-Hodgkin lymphoma that remains incurable. The objective of this study was to investigate the functional significance of CRM1 in MCL by evaluating the therapeutic efficacy of CRM1 inhibition in MCL in vitro and in vivo. Our results showed that CRM1 is highly expressed in MCL cells and is involved in regulating growth and survival mechanisms through the critical nuclear factor-κB survival pathway, which is independent of p53 status. Inhibition of CRM1 by two novel selective inhibitors of nuclear export (SINE), KPT-185 and KPT-276 , in MCL cells resulted in significant growth inhibition and apoptosis induction. KPT-185 also induced CRM1 accumulation in the nucleus, resulting in CRM1 degradation by the proteasome. Oral administration of KPT-276  significantly suppressed tumor growth in an MCL-bearing severe combined immunodeficient mouse model, without severe toxicity. Our data suggest that SINE CRM1 antagonists are a potential novel therapy for patients with MCL, particular in relapsed/refractory disease.[2]

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RNA interference screening identified XPO1 (exportin 1) among the 55 most vulnerable targets in multiple myeloma (MM). XPO1 encodes CRM1, a nuclear export protein. XPO1 expression increases with MM disease progression. Patients with MM have a higher expression of XPO1 compared with normal plasma cells (P<0.04) and to patients with monoclonal gammopathy of undetermined significance/smoldering MM (P<0.0001). The highest XPO1 level was found in human MM cell lines (HMCLs). A selective inhibitor of nuclear export compound KPT-276  specifically and irreversibly inhibits the nuclear export function of XPO1. The viability of 12 HMCLs treated with KPT-276  was significantly reduced. KPT-276  also actively induced apoptosis in primary MM patient samples. In gene expression analyses, two genes of probable relevance were dysregulated by KPT-276 : cell division cycle 25 homolog A (CDC25A) and bromodomain-containing protein 4 (BRD4), both of which are associated with c-MYC pathway. Western blotting and reverse transcription-PCR confirm that c-MYC, CDC25A and BRD4 are all downregulated after treatment with KPT-276 . KPT-276  reduced monoclonal spikes in the Vk*MYC transgenic MM mouse model, and inhibited tumor growth in a xenograft MM mouse model. A phase I clinical trial of an analog of KPT-276  is ongoing in hematological malignancies including MM[3].

MV4-11 xenograft mouse model[1]
Spleen cells (0.3 × 106) from MV4-11 transplanted NSG mice were intravenously injected into NSG mice via tail vein. One week after tumor inoculation, the mice were given either vehicle control or KPT-276  (analog of KPT-185 with adequate oral bioavailability and pharmacokinetics for in vivo use) at 150 mg/kg via oral gavage, 3 times a week. Mice were monitored closely for clinical signs of leukemia, such as weight loss and hindlimb paralysis. Expected median survival for untreated animals in this model is 28 days. Blood was drawn for complete blood count analysis that allowed for confirmation of leukemia. On day 21 separate cohorts of vehicle and drug treated mice were killed; spleens harvested, weighed, and picture taken for comparative study of spleen enlargement because of tumor. Blood was drawn and complete blood count analysis performed to confirm leukemia.

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Dissolved in DMSO; ~150 mg/kg; Oral administration

Human leukemia (MV4-11) xenografts are established in mice.

[1]. Preclinical activity of a novel CRM1 inhibitor in acute myeloid leukemia. Blood. 2012 Aug 30;120(9):1765-73.

[2]. Novel selective inhibitors of nuclear export CRM1 antagonists for therapy in mantle cell lymphoma. Exp Hematol. 2013 Jan;41(1):67-78.e4.

[3]. Genome-wide studies in multiple myeloma identify XPO1/CRM1 as a critical target validated using the selective nuclear export inhibitor KPT-276. Leukemia. 2013 Dec;27(12):2357-65.

Chromosome maintenance protein 1 (CRM1) is a nuclear export receptor involved in the active transport of tumor suppressors (e.g., p53 and nucleophosmin) whose function is altered in cancer because of increased expression and overactive transport. Blocking CRM1-mediated nuclear export of such proteins is a novel therapeutic strategy to restore tumor suppressor function. Orally bioavailable selective inhibitors of nuclear export (SINE) that irreversibly bind to CRM1 and block the function of this protein have been recently developed. Here we investigated the antileukemic activity of KPT-SINE (KPT-185 and KPT-276) in vitro and in vivo in acute myeloid leukemia (AML). KPT-185 displayed potent antiproliferative properties at submicromolar concentrations (IC50 values; 100-500 nM), induced apoptosis (average 5-fold increase), cell-cycle arrest, and myeloid differentiation in AML cell lines and patient blasts. A strong down-regulation of the oncogene FLT3 after KPT treatment in both FLT3-ITD and wild-type cell lines was observed. Finally, using the FLT3-ITD-positive MV4-11 xenograft murine model, we show that treatment of mice with oral KPT-276 (analog of KPT-185 for in vivo studies) significantly prolongs survival of leukemic mice (P < .01). In summary, KPT-SINE are highly potent in vitro and in vivo in AML. The preclinical results reported here support clinical trials of KPT-SINE in AML.[1]

C16H10F8N4O

426.26

426.072

C, 45.08; H, 2.36; F, 35.66; N, 13.14; O, 3.75

1421919-75-6

71496742

White to off-white solid powder

1.6±0.1 g/cm3

477.2±55.0 °C at 760 mmHg

242.4±31.5 °C

0.0±1.2 mmHg at 25°C

1.530

3.41

0

11

3

29

620

0

FC1(C([H])([H])N(C(/C(/[H])=C(\[H])/N2C([H])=NC(C3C([H])=C(C(F)(F)F)C([H])=C(C(F)(F)F)C=3[H])=N2)=O)C1([H])[H])F

JCHAWRDHMUSLMM-UPHRSURJSA-N

InChI=1S/C16H10F8N4O/c17-14(18)6-27(7-14)12(29)1-2-28-8-25-13(26-28)9-3-10(15(19,20)21)5-11(4-9)16(22,23)24/h1-5,8H,6-7H2/b2-1-

(Z)-3-[3-[3,5-bis(trifluoromethyl)phenyl]-1,2,4-triazol-1-yl]-1-(3,3-difluoroazetidin-1-yl)prop-2-en-1-one

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2 mg/mL (4.69 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2 mg/mL (4.69 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 20.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 3: 30% PEG400+0.5% Tween80+5% Propylene glycol: 5 mg/mL

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 (Please use freshly prepared in vivo formulations for optimal results.)