Amrubicin (SM-5887) is a DNA topozyme II. Amrubicin (SM-5887) (2.5 μg/mL) enhances radiation response in human lung adenocarcinoma A549 cells [1]. Amrubicin inhibits LX-1, A549, A431 and BT-474 cell lines at IC50s of 1.1, 2.4, 0.61, and 3.0 μg/mL, respectively [2]. Amrubicin tuff U937 cells exhibit cell cycle features with an IC50 of 5.6 μM. Amrubicin (SM-5887) (20 μM) causes duct induction in U937 cells, activates caspase-3/7, and lowers mitochondrial membrane potential (Δψm) [3].

Amrubicin (SM-5887) (25 mg/kg, intravenous injection) demonstrates strong anticancer effect against SCLC tumors Lu-24 and Lu-134; T/C values (which compare the treatment group's mean tumor growth rate to Article 14 of those tumors) were 17% and 9%, respectively, for those tumors on a daily basis. Amrubicin (SM-5887) (25 mg/kg, iv) in combination with ciprofloxacin and irinotecan effectively decreased tumor formation in mice with produced LX-1 cells, as compared to Amrubicin alone. In human cancer xenograft models, amrubicin (SM-5887) either by itself or in conjunction with Tegaf and Urinary End Base suppresses tumor growth [2].

Absorption, Distribution and Excretion
Peak plasma concentrations of the active metabolite _amrubicinol_ were observed from immediately after administration of amrubicin to 1h after administration. Plasma concentrations of amrubicinol were low compared with amrubicin plasma concentrations. The plasma amrubicinol AUC (area under the curve) was approximately 10-fold lower than the amrubicin plasma AUC. Concentrations of amrubicinol were higher in RBCs as compared with plasma. Amrubicinol AUCs ranged from 2.5-fold to 57.9-fold higher in red blood cells (RBCs) compared to plasma. Because amrubicinol distributes itself into RBCs more than amrubicin, the concentrations of amrubicinol and amrubicin in RBCs were quite similar. The AUC of amrubicinol in RBCs was approximately twofold lower than the amrubicin RBC AUC. In one study, after repeated daily amrubicin administration, amrubicinol accumulation was observed in plasma and RBCs. On day 3, the amrubicinol plasma AUC was 1.2-fold to 6-fold higher than day 1 values; the RBC AUC was 1.2-fold to 1.7-fold higher than day 1 values. After 5 consecutive daily doses, plasma and RBC amrubicinol AUCs were 1.2-fold to 2.0-fold higher than day 1 values.
In one study, urinary excretion of amrubicin and amrubicinol after ingestion of amrubicin accounted for 2.7% to 19.6% of the administered dose. The amount of excreted amrubicinol was approximately 10-fold greater than excreted amrubicin. Excretion of amrubicin and its metabolites is primarily hepatobiliary. Enterohepatic recycling was demonstrated in rats.
Moderate volume of distribution (1.4 times total body water).
The plasma pharmacokinetics of amrubicin in cancer patients are characterized by low total clearance (22% of total liver blood flow).

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Metabolism / Metabolites
The primary metabolite (amrubicinol) in rats and dogs is a product of reduction by cytoplasmic carbonyl reductase at the C-13 carbonyl group. Other enzymes participating in the metabolism of amrubicin and amrubicinol were nicotinamide adenine dinucleotide phosphate, reduced form (NADPH)–P450 reductase and nicotinamide adenine dinucleotide [phosphate] (NAD[P]H)-quinone oxidoreductase. Twelve additional metabolites were detected in vivo and in vitro in one study. Peak plasma concentrations of the active metabolite amrubicinol were observed from immediately after dosing to 1 hour after dosing. These included four aglycone metabolites, two amrubicinol glucuronides, deaminated amrubicin, and five highly polar unknown metabolites. In vitro cell growth inhibitory activity of the minor metabolites was substantially lower than that of amrubicinol. Excretion of amrubicin and its metabolites is primarily hepatobiliary. Enterohepatic recycling was demonstrated in rats.

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Biological Half-Life
20-30 h In a study of dogs, Amrubicin plasma concentrations followed a biphasic pattern with peak concentrations observed immediately after dosing followed by α and β half-lives (t1/2) ± SD of 0.06 ± 0.01 and 2.0 ± 0.3 hours, respectively.

Protein Binding
A study was performed on the plasma protein binding of amrubicin in both patients with hepatic impairment and those with normal liver function. In those with liver impairment, the plasma protein binding was found to be 91.3–97.1% and in those with normal hepatic function, 82.0–85.3%.

[1]. Enhancement of radiosensitivity by topoisomerase II inhibitor, amrubicin and amrubicinol, in human lung adenocarcinoma A549 cells and kinetics of apoptosis and necrosis induction. Int J Mol Med. 2006 Nov;18(5):909-15.

[2]. Amrubicin, a novel 9-aminoanthracycline, enhances the antitumor activity of chemotherapeutic agents against human cancer cells in vitro and in vivo. Cancer Sci. 2007 Mar;98(3):447-54.

[3]. Amrubicin induces apoptosis in human tumor cells mediated by the activation of caspase-3/7 preceding a loss of mitochondrial membrane potential. Cancer Sci. 2006 Dec;97(12):1396-403. Epub 2006 Sep 21.

Amrubicin is a synthetic anthracycline antibiotic with molecular formula C25H25NO9. A specific inhibitor of topoisomerase II, it is used (particularly as the hydrochloride salt) in the treatment of cancer, especially lung cancer, where it is a prodrug for the active metabolite, ambrucinol. It has a role as a topoisomerase II inhibitor, an antineoplastic agent and a prodrug. It is a quinone, a member of tetracenes, a methyl ketone, an anthracycline antibiotic and a primary amino compound.
Amrubicin is a third-generation synthetic anthracycline currently in development for the treatment of small cell lung cancer. Pharmion licensed the rights to Amrubicin in November 2006. In 2002, Amrubicin was approved and launched for sale in Japan based on Phase 2 efficacy data in both SCLC and NSCLC. Since January 2005, Amrubicin has been marketed by Nippon Kayaku, a Japanese pharmaceutical firm focused on oncology, which licensed Japanese marketing rights from Dainippon Sumitomo, the original developer of Amrubicin.
Amrubicin is a synthetic 9-amino-anthracycline with antineoplastic activity. Amrubicin intercalates into DNA and inhibits the activity of topoisomerase II, resulting in inhibition of DNA replication, and RNA and protein synthesis, followed by cell growth inhibition and cell death. This agent has demonstrated a higher level of anti-tumor activity than conventional anthracycline drugs without exhibiting any indication of the cumulative cardiac toxicity common to this class of compounds.

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Drug Indication
Investigated for use/treatment in lung cancer.

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Mechanism of Action
As an anthracycline, amrubicin has antimitotic and cytotoxic activity through a variety of mechanisms of action. Amrubicin is found to form complexes with DNA via intercalation between base pairs, and it inhibits topoisomerase II enzyme activity by stabilizing the DNA-topoisomerase II complex, which prevents the re-ligation portion of the ligation-religation reaction that topoisomerase II normally catalyzes. Topoisomerase II is an enzyme located in the nucleus that regulates DNA structure through double-strand breakage and re-ligation, therefore modulating DNA replication and transcription. Inhibition of the enzyme leads to inhibition of DNA replication and halt cell growth with an arrest of the cell cycle occurring at the G2/M phase. The mechanism by which amrubicin inhibits DNA topoisomerase II is believed to be through stabilization of the cleavable DNA–topo II complex, ending in re-ligation failure and DNA strand breakage. DNA damage triggers activation of caspase-3 and -7 and cleavage of the enzyme PARP (Poly ADP ribose polymerase), leading to apoptosis and a loss of mitochondrial membrane potential. Amrubicin, like all anthracyclines, intercalates into DNA and produces reactive oxygen free radicals via interaction with NADPH, which causes cell damage. Compared with doxorubicin, another member of the anthracycline drug class, amrubicin binds DNA with a 7-fold lower affinity and therefore, higher concentrations of amrubicin are necessary to promote DNA unwinding.

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Pharmacodynamics
The _anthracycline glycoside_ group of antibiotics, which includes amrubicin, represent a group of potent anticancer agents with potent activity against both solid tumors and hematological malignancies. They are the principal subjects of a large number of studies for the treatment of adult and childhood neoplastic diseases. Amrubicin is a 9-aminoanthracycline derivative and promotes cell growth inhibition by stabilizing protein – DNA complexes followed by double-stranded DNA breaks, which are mediated by topoisomerase-II enzyme. Anthracyclines have been observed to have a variety molecular effects (for example, DNA intercalation, inhibition of topoisomerase II, and stabilization of topoisomerase IIα cleavable complexes). Amrubicin shows decreased DNA intercalation when compared with doxorubicin. The decreased DNA interaction likely influences the intracellular distribution because amrubicin and its metabolite, _amrubicinol_. Amrubicin showed 20% distribution into the nucleus of P388 cells compared with the 80% nuclear distribution shown by doxorubicin (another anthracycline drug). The cell growth inhibitory effects of amrubicin appear to be mainly due to the inhibition of topoisomerase II.

C₂₅H₂₅NO₉

483.47

483.152

110267-81-7

92395-36-3 (HCl);110267-81-7;110311-30-3;

3035016

Pink to red solid powder

1.6±0.1 g/cm3

717.8±60.0 °C at 760 mmHg

172-174ºC

387.9±32.9 °C

0.0±2.4 mmHg at 25°C

1.720

2.64

5

10

3

35

881

5

CC(=O)[C@]1(C[C@@H](C2=C(C1)C(=C3C(=C2O)C(=O)C4=CC=CC=C4C3=O)O)O[C@H]5C[C@@H]([C@@H](CO5)O)O)N

VJZITPJGSQKZMX-XDPRQOKASA-N

InChI=1S/C25H25NO9/c1-10(27)25(26)7-13-18(16(8-25)35-17-6-14(28)15(29)9-34-17)24(33)20-19(23(13)32)21(30)11-4-2-3-5-12(11)22(20)31/h2-5,14-17,28-29,32-33H,6-9,26H2,1H3/t14-,15+,16-,17-,25-/m0/s1

(7S,9S)-9-acetyl-9-amino-7-[(2S,4S,5R)-4,5-dihydroxyoxan-2-yl]oxy-6,11-dihydroxy-8,10-dihydro-7H-tetracene-5,12-dione

SM-5887; AMR; SM-5887; SM5887; SM 5887; Amirubicin Hydrochloride; Foreign brand name: Calsed

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)

DMSO : ≥ 30 mg/mL (~62.05 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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