Debio 0932 (also known as CUDC-305) is a novel, potent and orally bioactive HSP90 (heat shock protein 90) inhibitor with IC50s of 100 and 103 nM for HSP90α and HSP90β, respectively. HSP90 that has been isolated from erlotinib-resistant NSCLC cells binds CUDC-305 firmly (IC50 70 nmol/L). This outcome is in good agreement with the strong antiproliferative activity in erlotinib-resistant non-small cell lung cancer cell lines (IC50 120-700 nmol/L) that has been previously documented. Additionally, it shows long-lasting inhibition of several oncoproteins and induces apoptosis in NSCLC cells resistant to erlotinib. Under subcutaneous xenograft models of H1975 and A549, which carry EGFR T790M mutations or K-ras mutations resulting in acquired and primary erlotinib resistance, respectively, CUDC-305 potently inhibits tumor growth. Moreover, CUDC-305 considerably increases animal survival in orthotopic lung tumor models of H1975 and A549; this effect may be partly explained by the compound's preferred exposure in lung tissue. Moreover, in an H1975 brain metastatic model, CUDC-305 can prolong animal survival, providing additional evidence of its blood-brain barrier-crossing capacity. CUDC-305 causes apoptosis in vivo while concurrently inducing the degradation of receptor tyrosine kinases and downstream signaling molecules of the PI3K/AKT and RAF/MEK/ERK pathways, which is consistent with its effects in different tumor models. In the H1975 tumor model, CUDC-305 improved the antitumor activity of a standard-of-care medication in a combination study. These findings imply that CUDC-305 may be useful in the management of NSCLC patients who have developed either primary or secondary resistance to EGFR inhibitor therapy.

Physicochemical Properties

Molecular Formula	C22H30N6O2S
Molecular Weight	442.5776
Exact Mass	442.215
Elemental Analysis	C, 59.70; H, 6.83; N, 18.99; O, 7.23; S, 7.25
CAS #	1061318-81-7
PubChem CID	44156921
Appearance	White to off-white solid powder
Density	1.3±0.1 g/cm3
Boiling Point	654.8±65.0 °C at 760 mmHg
Flash Point	349.8±34.3 °C
Vapour Pressure	0.0±2.0 mmHg at 25°C
Index of Refraction	1.659
LogP	4.32
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	8
Rotatable Bond Count	8
Heavy Atom Count	31
Complexity	591
Defined Atom Stereocenter Count	0
SMILES	S(C1=C([H])C2=C(C([H])=C1N(C([H])([H])[H])C([H])([H])[H])OC([H])([H])O2)C1=NC2C(N([H])[H])=NC([H])=C([H])C=2N1C([H])([H])C([H])([H])N([H])C([H])([H])C(C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]
InChi Key	RVJIQAYFTOPTKK-UHFFFAOYSA-N
InChi Code	InChI=1S/C22H30N6O2S/c1-22(2,3)12-24-8-9-28-14-6-7-25-20(23)19(14)26-21(28)31-18-11-17-16(29-13-30-17)10-15(18)27(4)5/h6-7,10-11,24H,8-9,12-13H2,1-5H3,(H2,23,25)
Chemical Name	2-[[6-(dimethylamino)-1,3-benzodioxol-5-yl]sulfanyl]-1-[2-(2,2-dimethylpropylamino)ethyl]imidazo[4,5-c]pyridin-4-amine
Synonyms	CUDC305; CUDC-305; CUDC 305; Debio0932; Debio-0932; Debio 0932
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	HSP90α ( IC50 = 100 nM ); HSP90β ( IC50 = 103 nM )
ln Vitro	Debio 0932 is an oral HSP90 inhibitor that has IC50 values of 103 nM for HSP90β and 100 nM for HSP90α, respectively. With a mean IC50 of 48.8 nM, Debio 0932 (CUDC-305) binds to the tumor HSP90 complex. In cancer cell lines, Debio 0932 (1 μM) stimulates the degradation of several HSP90 client proteins. Additionally, Debio 0932 exhibits inhibitory activities against 40 cancer cell lines (mean IC50, 220 nM) with an IC50 ranging from 40 to 900 nM (containing 34 solid and 6 hematologic tumor-derived lines)[1]. The HSP90 complex derived from cancer is strongly bound by Debio 0932, with an IC50 of 61.2 nM in H1975 cells and 74.2 nM in H1993 cells, respectively. In NSCLC cell lines harboring mutations that may confer resistance to erlotinib, Debio 0932 (CUDC-305, 1 μM) persistently induces oncoprotein degradation[3].
ln Vivo	Debio 0932 (CUDC-305, 30 mg/kg, p.o.) shows good pharmacokinetic profiles in tumor-bearing nude mice. In several animal models of U87MG glioblastoma, Debio 0932 (160 mg/kg, p.o.) degrades HSP90 client proteins, inhibits tumor growth, and also increases survival time. By administering Debio 0932 at intervals of every other day (q2d), it also inhibits tumor growth in the U87MG s.c. tumor model in a dose-dependent manner[1]. By day 11, Debio 0932 (80 mg/kg, p.o.) considerably reduces psoriasis and lowers epidermal thickness in a model of psoriasis xenograft transplantation[2]. Additionally, Debio 0932 (CUDC-305) can pass through the blood-brain barrier. In the H1975 subcutaneous tumor model, Debio 0932 (80, 120, and 160 mg/kg, p.o.) inhibits tumor growth in a dose-dependent manner. In the erlotinib-resistant H1975 subcutaneous tumor model, Debio 0932 (160 mg/kg, p.o.) also enhances antitumor activity[3].
Cell Assay	In 96-well plates, human cancer cell lines are plated with culture medium at a density of 5,000 to 10,000 per well. After that, the cells are incubated for 120 hours at different concentrations of the compounds (Debio 0932). Using the ATPlite kit, an ATP content assay is used to evaluate growth inhibition. To lyse cells and stabilize ATP, a 25-μL cell lysis solution is added to each well's 50-μL phenol red-free culture medium. After adding 25 microliters of substrate solutions to each well, the luminescence is measured using a TopCount liquid scintillation analyzer. The percentage of values obtained in untreated controls is used to express the values. Sigmoidal dose-response curve fitting is used with PRISM software to calculate IC50 values[1].
Animal Protocol	Animals with appropriate tumor sizes are randomly assigned to different groups once their tumors have grown after implantation. Based on the body weight of the individual animal, Debio 0932 is administered orally in a 30% Captisol formulation. The same dosage paradigm is applied to the control group, which receives vehicle (30% Captisol). In combination studies, i.p. injections of 0.9% normal saline diluted with either paclitaxel or camptothecin-11 are administered twice a week[1].
References	[1]. CUDC-305, a novel synthetic HSP90 inhibitor with unique pharmacologic properties for cancer therapy. Clin Cancer Res. 2009 Jun 15;15(12):4046-57 [2]. Debio 0932, a new oral Hsp90 inhibitor, alleviates psoriasis in a xenograft transplantation model. Acta Derm Venereol. 2014 Nov;94(6):672-6. [3]. Targeting heat shock protein 90 with CUDC-305 overcomes erlotinib resistance in non-small cell lung cancer. Mol Cancer Ther. 2009 Dec;8(12):3296-306.
Additional Infomation	Hsp90 Inhibitor Debio 0932 is an orally active and small molecule inhibitor of heat shock protein 90 (Hsp90) with potential antineoplastic activity. Hsp90 inhibitor Debio 0932 specifically blocks Hsp90, thereby inhibiting its chaperone function and promoting the degradation of its client proteins, many of which are oncogenic signaling proteins involved in tumor cell proliferation and survival. This may lead to an inhibition of tumor cell proliferation. Hsp90, a chaperone protein upregulated in a variety of tumor cells, regulates the folding, stabilization and degradation of many oncogenic signaling proteins.

Solubility Data

Solubility (In Vitro)

DMSO: ~75 mg/mL (~169.5 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.65 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (5.65 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. Solubility in Formulation 3: ≥ 2.5 mg/mL (5.65 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	2.2595 mL	11.2974 mL	22.5948 mL
	5 mM	0.4519 mL	2.2595 mL	4.5190 mL
	10 mM	0.2259 mL	1.1297 mL	2.2595 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.