CDK9/cyc T2 (Ki = 0.626 nM); CDK9/CycT1 (Ki = 1.68 nM); CDK6/cycD1 (Ki = 2.92 nM); CDK4/Cyc D1 (Ki = 3.96 nM); CDK1/cycB (Ki = 5.4 nM); CDK1/cyc A (Ki = 9.1 nM)

Targeted downregulation of MCL-1 in ABC and GCB isoforms is shown with voruciclib hydrochloride (0.5–5 µM; 6 hours) [1]. The Ki values are 0.626 nM, 1.68 nM, 2.92 nM, respectively, for each target (e.g., CDK9/cyc T2, CDK9/cyc T1, CDK6/cyc D1, CDK4/cyc D1, CDK1/cyc B, and CDK1/cyc A for Voruciclib hydrochloride)[1].

Voruciclib hydrochloride (200 mpk; oral gavage) combined with venetoclax (10 mpk, 1 mpk, 50 mpk, 25 mpk in U2932, RIVA, SU-DHL-4, and NU-DHL-1, respectively) enhances tumor growth inhibition In the U2932, RIVA, SU-DHL-4 (6 days per week for 4 weeks) and NU-DHL-1 (5 days per week for 3 weeks) DLBCL models, compared with either drug alone [ 1].

Reaction Biology IC50 profiling[1]
Rank order of sensitivity of 48 kinases to voruciclib hydrochloride was determined at Reaction Biology Corp. Kinase activity was measured using a filter binding assay with radioactive γ-33P-ATP as phosphate donor. The ATP concentration was near the Km values for the respective kinases. For each kinase, an IC50 value was calculated from a 10-point concentration curve of the test article and converted to Ki values. The 48 kinases studied here had been identified in previous screening experiments as the most promising target candidates.

Western Blot Analysis[1]
Cell Types: U2932, RIVA, OCI-LY10 cells (ABC subtype), NU-DHL-1, SU-DHL-4, SU-DHL-6 cells (GCB subtype)
Tested Concentrations: 0.5 µM , 1 µM, 2 µM, 3 µM, 4 µM, 5 µM
Incubation Duration: 6 hrs (hours)
Experimental Results: Targeted downregulation of MCL-1 was shown in both ABC and GCB subtypes.

Animal/Disease Models: ABC isoforms (U2932, RIVA, OCI-LY10), GCB isoforms (SU-DHL-4, NU-DHL-1) xenografted into female NOD.CB17-Prkdcscid/NCrHsd mice [1]
Doses: 200 mpk
Doses: po (oral gavage); U2932, RIVA, SU-DHL-4 (6 days per week for 4 weeks), OCI-LY10 (6 days per week for 2 weeks), NU-DHL-1 ( 5 days per week for 3 weeks)
Experimental Results: Tumor enhanced growth inhibition in U2932, RIVA, SU-DHL-4 and NU-DHL-1 models in addition to OCI-LY10 model.

[1]. Voruciclib, a clinical stage oral CDK9 inhibitor, represses MCL-1 and sensitizes high-risk Diffuse Large B-cell Lymphoma to BCL2 inhibition. Sci Rep. 2017 Dec 21;7(1):18007.

Voruciclib is under investigation in clinical trial NCT03547115 (A Phase 1 Study of Voruciclib in Subjects With B-Cell Malignancies or AML).
Voruciclib is a cyclin-dependent kinase (CDK) inhibitor with potential antineoplastic activity. Upon administration, voruciclib selectively inhibits cyclin-dependent kinase 4 (CDK4) and 6 (CDK6). This inhibits retinoblastoma (Rb) protein phosphorylation early in the G1 phase, which prevents CDK-mediated G1-S phase transition and leads to cell cycle arrest. This suppresses DNA replication and decreases tumor cell proliferation. CDK4 and 6 are serine/threonine kinases that are upregulated in many tumor cell types and play a key role in the regulation of cell cycle progression.

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Aberrant regulation of BCL-2 family members enables evasion of apoptosis and tumor resistance to chemotherapy. BCL-2 and functionally redundant counterpart, MCL-1, are frequently over-expressed in high-risk diffuse large B-cell lymphoma (DLBCL). While clinical inhibition of BCL-2 has been achieved with the BH3 mimetic venetoclax, anti-tumor efficacy is limited by compensatory induction of MCL-1. Voruciclib, an orally bioavailable clinical stage CDK-selective inhibitor, potently blocks CDK9, the transcriptional regulator of MCL-1. Here, we demonstrate that voruciclib represses MCL-1 protein expression in preclinical models of DLBCL. When combined with venetoclax in vivo, voruciclib leads to model-dependent tumor cell apoptosis and tumor growth inhibition. Strongest responses were observed in two models representing high-risk activated B-cell (ABC) DLBCL, while no response was observed in a third ABC model, and intermediate responses were observed in two models of germinal center B-cell like (GCB) DLBCL. Given the range of responses, we show that CIVO, a multiplexed tumor micro-dosing technology, represents a viable functional precision medicine approach for differentiating responders from non-responders to BCL-2/MCL-1 targeted therapy. These findings suggest that the combination of voruciclib and venetoclax holds promise as a novel, exclusively oral combination therapy for a subset of high-risk DLBCL patients.[1]

C₂₂H₂₀CL₂F₃NO₅

506.30

505.067

1000023-05-1

Voruciclib;1000023-04-0;(2S,3R)-Voruciclib hydrochloride;rel-(2S,3R)-Voruciclib;1253731-24-6; 1000023-04-0; 2505206-37-9 (malonate)

67409218

Typically exists as Light yellow to yellow solid at room temperature

5.063

4

9

3

33

750

2

ClC1C=C(C(F)(F)F)C=CC=1C1=CC(C2=C(C=C(C(=C2O1)[C@@H]1CCN(C)[C@H]1CO)O)O)=O.Cl

QCWRANLELLMJSH-OJMBIDBESA-N

InChI=1S/C22H19ClF3NO5.ClH/c1-27-5-4-12(14(27)9-28)19-15(29)7-16(30)20-17(31)8-18(32-21(19)20)11-3-2-10(6-13(11)23)22(24,25)26;/h2-3,6-8,12,14,28-30H,4-5,9H2,1H3;1H/t12-,14+;/m1./s1

2-[2-chloro-4-(trifluoromethyl)phenyl]-5,7-dihydroxy-8-[(2R,3S)-2-(hydroxymethyl)-1-methylpyrrolidin-3-yl]chromen-4-one;hydrochloride

Voruciclib hydrochloride; 1000023-05-1; Voruciclib (hydrochloride); UNII-8BEP29W01U; 8BEP29W01U; 2-[2-chloro-4-(trifluoromethyl)phenyl]-5,7-dihydroxy-8-[(2R,3S)-2-(hydroxymethyl)-1-methylpyrrolidin-3-yl]chromen-4-one;hydrochloride; 4H-1-Benzopyran-4-one, 2-(2-chloro-4-(trifluoromethyl)phenyl)-5,7-dihydroxy-8-((2R,3S)-2-(hydroxymethyl)-1-methyl-3-pyrrolidinyl)-, hydrochloride (1:1); 4H-1-Benzopyran-4-one, 2-[2-chloro-4-(trifluoromethyl)phenyl]-5,7-dihydroxy-8-[(2R,3S)-2-(hydroxymethyl)-1-methyl-3-pyrrolidinyl]-, hydrochloride (1:1);

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

DMSO : ≥ 250 mg/mL (~493.78 mM)

Solubility in Formulation 1: ≥ 2.08 mg/mL (4.11 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 20.8 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: ≥ 2.08 mg/mL (4.11 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 20.8 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: ≥ 2.08 mg/mL (4.11 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 20.8 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.)