ERα (IC50 = 26 nM); ERβ (IC50 = 99 nM)[1]

The GP130 D1 domain is bound by the small molecule GP130 inhibitor benzedoxifene [1]. When IL-6 and IL-11 trigger STAT3 phosphorylation in the GP130/STAT3 pathway signaling, benzedoxifene blocks this process [1]. In human pancreatic cancer cells, zedoxifene (10 μM–20 μM; 2 hours) suppresses the phosphorylation of STAT3 caused by cytokines [2]. Human pancreatic cancer cells undergo apoptosis when exposed to bezoxifene (5–20 μM) over night [2]. STAT3 nuclear translocation caused by IL-6 is inhibited by benzedoxifene [2]. By blocking GP130, benzedoxifene stops pancreatic cancer cells from migrating [2].

In an in vivo mouse model, benzedoxifene (5 mg/kg; ir; once daily for 18 days) suppresses the formation of Capan-1 tumors [2].

Ligand binding[1]
Interaction of bazedoxifene acetate (BZA) with human ERα and ERβ was assessed with a solid phase competitive radioligand binding assay using [3H]-17β- estradiol as previously described.

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STAT3 DNA binding assay[2]
BxPC-3 cells were seeded in a 10-cm plate and treated with Bazedoxifene (5–10 μmol/L) or DMSO for 24 hours. The Nuclear Extract Kit was used to prepare cell nuclear extracts following the manufacturer's protocol. Nuclear extracts were analyzed for STAT3 DNA–binding activity using a STAT3 DNA binding ELISA kit (Active Motif) with an ELISA-based method. Absorbance was read at 450 nm.

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STATs phosphorylation induced by cytokines or growth factors[2]
PANC-1, AsPC-1, and HPAF-II pancreatic cancer cells were seeded in 10-cm plates and allowed to adhere overnight. The following night, the cells were serum starved. The cells were then left untreated or were treated with Bazedoxifene (5–20 μmol/L) or DMSO. After 2 hours, the untreated and Bazedoxifene-treated cells were stimulated by IL6 (50 ng/mL), IL11 (50 ng/mL), OSM (50 ng/mL), or INFγ (50 ng/mL) for 30 minutes. The cells were harvested and analyzed by Western blot analysis for p-STAT3Y705 or p-STAT1Y701.

Western Blot Analysis[2]
Cell Types: AsPC-1 Cell
Tested Concentrations: 10 μM, 20 μM
Incubation Duration: 2 hrs (hours)
Experimental Results: Inhibition of STAT3 phosphorylation induced by IL-6, IL-11 or OSM (50 ng/mL).

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Apoptosis analysis [2]
Cell Types: Capan-1 cells, BxPC-3 cells, HPAF-II cells, HPAC cells
Tested Concentrations: 10 μM, 20 μM (Capan-1); 5μM, 10μM (BxPC-3); 10 μM, 20 μM (HPAF-II); 10 μM, 15 μM (HPAC)
Incubation Duration: Overnight
Experimental Results: Induction of apoptosis.

Animal/Disease Models: 6weeks old female athymic nude mice [2]
Doses: 5 mg/kg
Route of Administration: po (oral gavage), daily, for 18 days.
Experimental Results: Inhibited the growth of pancreatic cancer xenograft tumors and induced tumor cell apoptosis.

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Vasomotor instability (hot flush)[1]
Ovariectomized female (60 d) rats were obtained after surgery. The surgeries were performed minimally 7 d before initiation of any experiment. Vehicle and ethinyl estradiol (0.3 mg/kg) were included in each replicate. Bazedoxifene was administered orally in a saline, Tween-80, methylcellulose vehicle. A detailed description of methodology for evaluating vasomotor instability in rats has been published (21). Briefly, compound treatment (17β-estradiol, ethinyl estradiol, or bazedoxifene) is initiated, and on the third day of treatment each animal receives a morphine pellet sc. This is followed by two more pellets on the fifth day of treatment. On the eighth day, a thermistor is taped to the animal’s tail to measure tail skin temperature for 15 min (to obtain baseline temperature) followed by a sc injection of naloxone (1 mg/kg). Tail skin temperature readings continue for 1 h after naloxone injection.

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All animal studies were conducted in accordance with the principles and standard procedures approved by IACUC of the Research Institute at Nationwide Children's Hospital. Capan-1 (3 × 106) and HPAF-II (3 × 106) cells in Matrigel were injected subcutaneously into the both side of flank area of 6-week-old female athymic nude mice which were purchased from Harlan. After Capan-1 tumor development, which was 1 week after initial implantation, mice were divided into two treatment groups consisting of four mice (tumors: n = 8): DMSO vehicle control and gavage injection of Bazedoxifene (5 mg/kg/d). Mice bearing HPAF-II tumor were irrigated with Bazedoxifene(5 mg/kg/d) and/or injected via abdomen with paclitaxel (15 mg/kg, 2/w). Tumor growth was determined by measured the length (L) and width (W) of the tumor every other day with a caliper, and tumor volume was calculated on the basis of the following formula: volume = 0.52 × LW2. After 21 days of treatment, tumors were harvested, snap-frozen in dry ice, and stored at −80°C. Tumors tissue homogenates were lysed and separated by SDS-PAGE to examine the expression of STAT3 phosphorylation, P-ERK1/2, P-AKT (Ser473), and cleaved caspase-3.[2]

Absorption, Distribution and Excretion
Bazedoxifene is rapidly absorbed with a tmax of approximately 2 hours and exhibits a linear increase in plasma concentrations for single doses from 0.5 mg up to 120 mg and multiple daily doses from 1 mg to 80 mg. The absolute bioavailability of bazedoxifene is approximately 6%.
The major route of elimination of radio-labelled bazedoxifene is the faeces, and less than 1% of the dose is eliminated in urine.
Following intravenous administration of a 3 mg dose of bazedoxifene, the volume of distribution is 14.7 ± 3.9 l/kg.
The apparent oral clearance of bazedoxifene is approximately 4 to 5 l/h/kg.

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Metabolism / Metabolites
Glucuronidation is the major metabolic pathway. After peroral application, bazedoxifene is metabolized by UDP-glucuronosyltransferases (UGTs) to bazedoxifene-4'-glucuronide (M4) and bazedoxifene-5-glucuronide (M5).Little or no cytochrome P450-mediated metabolism is evident. The concentrations of this glucuronide are approximately 10-fold higher than those of unchanged active substance in plasma.

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Biological Half-Life
~30 hours.

Protein Binding
98-99%.

[1]. Bazedoxifene acetate: a selective estrogen receptor modulator with improved selectivity. Endocrinology. 2005 Sep;146(9):3999-4008.

[2]. Bazedoxifene as a Novel GP130 Inhibitor for Pancreatic Cancer Therapy. Mol Cancer Ther. 2016 Nov; 15(11): 2609–2619.

Bazedoxifene is a phenylindole.
Bazedoxifene is a third generation selective estrogen receptor modulator (SERM), developed by Pfizer following the completion of their takeover of Wyeth Pharmaceuticals. In late 2013, Pfizer received approval for bazedoxifene as part of the combination drug DUAVEE in the prevention (not treatment) of postmenopausal osteoporosis. It is approved in the European Union (marketed in Italy and Spain) and Japan as monotherapy. In 2013, the combination product containing conjugated estrogens and bazedoxifene was approved by the FDA for the treatment of moderate to severe vasomotor symptoms associated with menopause, as well as the prevention of postmenopausal osteoporosis in women.
Bazedoxifene is an Estrogen Agonist/Antagonist. The mechanism of action of bazedoxifene is as a Selective Estrogen Receptor Modulator.
Bazedoxifene is an indole derivative and third-generation selective estrogen receptor modulator (SERM) with potential antineoplastic activity. Upon administration, bazedoxifene specifically binds to estrogen receptors in responsive tissues, including liver, bone, breast, and endometrium. The resulting ligand-receptor complex is translocated to the nucleus where, depending on the tissue type, it either promotes or suppresses the transcription of estrogen-regulated genes. Bazedoxifene acts as an estrogen antagonist in uterine and breast tissue, thereby blocking the proliferative effects of estrogen-binding to ER-positive cells in these tissues. Bazedoxifene functions as an estrogen agonist in lipid metabolism, thereby decreasing total and LDL cholesterol levels. In bone, it decreases bone resorption and bone turnover and increases bone mineral density.

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Drug Indication
Indicated for following conditions alone or in combination with conjugated estrogens in women with a uterus: - Treatment of moderate to severe vasomotor symptoms associated with menopause - Prevention of postmenopausal osteoporosis
FDA Label
Conbriza is indicated for the treatment of postmenopausal osteoporosis in women at increased risk of fracture. A significant reduction in the incidence of vertebral fractures has been demonstrated; efficacy on hip fractures has not been established. When determining the choice of Conbriza or other therapies, including oestrogens, for an individual postmenopausal woman, consideration should be given to menopausal symptoms, effects on uterine and breast tissues, and cardiovascular risks and benefits.

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Mechanism of Action
Bazedoxifene belongs to a class of compounds known as selective estrogen receptor modulators (SERMs). Bazedoxifene acts as both an oestrogen-receptor agonist and/or antagonist, depending upon the cell and tissue type and target genes. Bazedoxifene decreases bone resorption and reduces biochemical markers of bone turnover to the premenopausal range. These effects on bone remodelling lead to an increase in bone mineral density (BMD), which in turn contributes to a reduction in the risk of fractures. Bazedoxifene functions primarily as an oestrogen-receptor antagonist in uterine and breast tissues.

C30H34N2O3

470.6

470.256

C, 76.57; H, 7.28; N, 5.95; O, 10.20

198481-32-2

Bazedoxifene acetate;198481-33-3;Bazedoxifene hydrochloride;198480-56-7;Bazedoxifene-d4;1133695-49-4;Bazedoxifene-d4 acetate;1795027-71-2

154257

White to yellow solid powder

1.2±0.1 g/cm3

694.4±55.0 °C at 760 mmHg

373.8±31.5 °C

0.0±2.3 mmHg at 25°C

1.622

6.59

2

4

7

35

623

0

UCJGJABZCDBEDK-UHFFFAOYSA-N

InChI=1S/C30H34N2O3/c1-22-28-20-26(34)12-15-29(28)32(30(22)24-8-10-25(33)11-9-24)21-23-6-13-27(14-7-23)35-19-18-31-16-4-2-3-5-17-31/h6-15,20,33-34H,2-5,16-19,21H2,1H3

1-(4-(2-(azepan-1-yl)ethoxy)benzyl)-2-(4-hydroxyphenyl)-3-methyl-1H-indol-5-ol

WAY-140424; WAY140424; WAY 140424; TSE 424; Bazedoxifene [INN]; 1H-Indol-5-ol, 1-[[4-[2-(hexahydro-1H-azepin-1-yl)ethoxy]phenyl]methyl]-2-(4-hydroxyphenyl)-3-methyl-; Bazedoxifene free base; Q16TT9C5BK; 1-(4-(2-(azepan-1-yl)ethoxy)benzyl)-2-(4-hydroxyphenyl)-3-methyl-1H-indol-5-ol; TSE424; TSE-424 Viviant.

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 : ~100 mg/mL (~212.49 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.31 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 25.0 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: ≥ 2.5 mg/mL (5.31 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.31 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 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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