MCL1 (Kd = 0.19 nM)

S63845 induces death of cancer cell lines with known reliance on MCL-1, which also causes the mitochondrial outer membrane to permeabilize and display the traditional signs of apoptosis. It is 6 times more affine for human MCL-1 than for mouse MCL-1[1]. S63845 is efficient against haematological cancer-derived cell lines in vitro and in vivo, as well as AML samples, but it is not very effective against healthy human haematopoietic progenitor cells[2].

In vivo, S63845 exhibits strong anti-tumor activity in a number of cancers with a tolerable safety margin. The mice tolerate S63845 well, and no discernible weight loss was seen. Some solid tumor models respond well to S63845 monotherapy, but many others only respond to the combination of S63845 and oncogenic kinase inhibitors[2].

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A mouse model of hematopoietic injury was constructed, and the effects of the inhibitor on the hematopoietic system of mice were evaluated via routine blood tests and flow cytometry. The results showed that S63845 affected the hematopoiesis of various lineages in the early stage of action, causing extramedullary compensatory hematopoiesis in the myeloid and megakaryocytic lineages. The maturation of the erythroid lineage in the intramedullary and extramedullary segments was blocked to varying degrees, and both the intramedullary and extramedullary lymphoid lineages were inhibited. This study provides a complete description of the effects of MCL-1 inhibitor on the intramedullary and extramedullary hematopoietic lineages, which is important for the selection of combinations of antitumor drugs and the prevention of adverse hematopoiesis-related effects.https://pubmed.ncbi.nlm.nih.gov/37111571/

As a running buffer, 10 mM HEPES pH 7.4, 175 mM NaCl, 25 μM EDTA, 1 mM TCEP, 0.01% P20 and 1% DMSO. Using proteins with two His tags, the ligand surface is produced. The substance is applied to the protein surface after being diluted in buffer in steps. With injection times of 120 seconds and dissociation times of 360 seconds, all sample measurements are carried out at a flow rate of 30 μL per minute. Injections of 0.35 M EDTA pH 8.0, 0.1 mg/mL trypsin, 0.5 M imidazole, and 45% DMSO over a 60 second period at a rate of 15 μL per minute are used to repeatedly regenerate the sensor surface.

HeLa cells transduced with Flag–BCL-XL, Flag–BCL-2 or Flag–MCL1 expression constructs are treated for 4 h with increasing concentrations of S63845, before immunopreciptation using anti-FLAG antibody. Immunoblotting is used to look for FLAG-tagged proteins as well as the related BAK and BAX proteins in immunoprecipitates and total inputs.

S63845 is dissolved extemporaneously in 25 mM HCl, 20% 2-hydroxy propyl β -cyclo dextrin 20% and administrated at the 6.25, 12.5, 25 mg/kg for 0, 20, 40, 60, 80 days. [2]

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Intravenously injected (i.v.), 25 mg/kg

Human multiple myeloma (H929 and AMO1) xenografted mice

[1]. The MCL-1 inhibitor S63845: an exciting new addition to the armoury of anti-cancer agents.

[2]. Nature . 2016 Oct 27;538(7626):477-482.

Defects in apoptotic machinery have long been recognised as both a significant contributor to cancer development, and as an important mechanism by which tumour cells develop chemotherapeutic resistance. The resistance of multiple malignancies to apoptosis has been attributed to increases in a number of pro-survival BCL-2 family members (e.g., BCL-2, BCL-XL, MCL-1, BCL-W, BFL-1 and BCL-B), which prevent BAX/BAK-mediated mitochondrial outer membrane permeabilisation. Inhibitors targeting these BCL-2 family members have garnered significant interest with the most promising lead being the BH3 mimetic venetoclax (also known as ABT-199, and marketed as Venclexta™ and Venclyxto™), a selective inhibitor of the BCL-2 protein recently approved for 17p deletion chronic lymphocytic leukemia (CLL). In a phase I trial in relapsed or refractory CLL, venetoclax induced a 79% response rate (1) which has subsequently prompted further trials in other haematological malignancies. Despite this success in CLL, venetoclax used as a monotherapy in other haematological malignancies have shown poor response rates (2), mainly due to the reliance of other BCL-2 family members such as MCL-1 for cell survival in these cancers. Indeed, studies using genetic knockout models and RNA interference have demonstrated MCL-1 to be crucial for disease development and progression in acute myeloid leukaemia (AML) (3), MYC-driven lymphomas (4), and multiple myeloma (5), and a mechanism of venetoclax resistance in these cancers (6). Indirect approaches to target MCL-1 through transcriptional repression (7,8) or post-translational degradation (9) have recently been developed. However, direct targeting strategies with obatoclax, an inhibitor of MCL-1 and also BCL-2 and BCL-XL, induced neuronal toxicity (10,11). More recently, a reported MCL-1-selective inhibitor termed A-1210477 (12) displayed in vitro activity against multiple myeloma cells (13); however, these anti-cancer effects appear likely to result from combination of both targeting MCL-1 and off-target effects (14).[1]

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Avoidance of apoptosis is critical for the development and sustained growth of tumours. The pro-survival protein myeloid cell leukemia 1 (MCL1) is overexpressed in many cancers, but the development of small molecules targeting this protein that are amenable for clinical testing has been challenging. Here we describe S63845, a small molecule that specifically binds with high affinity to the BH3-binding groove of MCL1. Our mechanistic studies demonstrate that S63845 potently kills MCL1-dependent cancer cells, including multiple myeloma, leukaemia and lymphoma cells, by activating the BAX/BAK-dependent mitochondrial apoptotic pathway. In vivo, S63845 shows potent anti-tumour activity with an acceptable safety margin as a single agent in several cancers. Moreover, MCL1 inhibition, either alone or in combination with other anti-cancer drugs, proved effective against several solid cancer-derived cell lines. These results point towards MCL1 as a target for the treatment of a wide range of tumours.[2]

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Conventional chemotherapy for killing cancer cells using cytotoxic drugs suffers from low selectivity, significant toxicity, and a narrow therapeutic index. Hyper-specific targeted drugs achieve precise destruction of tumors by inhibiting molecular pathways that are critical to tumor growth. Myeloid cell leukemia 1 (MCL-1), an important pro-survival protein in the BCL-2 family, is a promising antitumor target. In this study, we chose to investigate the effects of S63845, a small-molecule inhibitor that targets MCL-1, on the normal hematopoietic system.https://pubmed.ncbi.nlm.nih.gov/37111571/

C39H37CLF4N6O6S

829.2593

828.212

C, 56.49; H, 4.50; Cl, 4.27; F, 9.16; N, 10.13; O, 11.58; S, 3.87

1799633-27-4

(S,R)-S63845;(R,R)-S63845

122197581

White to off-white solid powder

5.7

1

16

15

57

1300

1

CC1=C(C=CC(=C1Cl)OCCN2CCN(CC2)C)C3=C(SC4=NC=NC(=C34)O[C@H](CC5=CC=CC=C5OCC6=CC=NN6CC(F)(F)F)C(=O)O)C7=CC=C(O7)F

ZFBHXVOCZBPADE-SSEXGKCCSA-N

InChI=1S/C39H37ClF4N6O6S/c1-23-26(7-8-28(34(23)40)53-18-17-49-15-13-48(2)14-16-49)32-33-36(45-22-46-37(33)57-35(32)29-9-10-31(41)55-29)56-30(38(51)52)19-24-5-3-4-6-27(24)54-20-25-11-12-47-50(25)21-39(42,43)44/h3-12,22,30H,13-21H2,1-2H3,(H,51,52)/t30-/m1/s1

(2R)-2-[5-[3-chloro-2-methyl-4-[2-(4-methylpiperazin-1-yl)ethoxy]phenyl]-6-(5-fluorofuran-2-yl)thieno[2,3-d]pyrimidin-4-yl]oxy-3-[2-[[2-(2,2,2-trifluoroethyl)pyrazol-3-yl]methoxy]phenyl]propanoic acid

S-63845; S 63845; CHEMBL4439276; (2~{r})-2-[5-[3-Chloranyl-2-Methyl-4-[2-(4-Methylpiperazin-1-Yl)ethoxy]phenyl]-6-(5-Fluoranylfuran-2-Yl)thieno[2,3-D]pyrimidin-4-Yl]oxy-3-[2-[[2-[2,2,2-Tris(Fluoranyl)ethyl]pyrazol-3-Yl]methoxy]phenyl]propanoic Acid; (2R)-2-[5-[3-chloro-2-methyl-4-[2-(4-methylpiperazin-1-yl)ethoxy]phenyl]-6-(5-fluorofuran-2-yl)thieno[2,3-d]pyrimidin-4-yl]oxy-3-[2-[[2-(2,2,2-trifluoroethyl)pyrazol-3-yl]methoxy]phenyl]propanoic acid; S63845

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: (1). This product requires protection from light (avoid light exposure) during transportation and storage.  (2). Please store this product in a sealed and protected environment (e.g. under nitrogen), 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)

Solubility in Formulation 1: ≥ 2.08 mg/mL (2.51 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 (2.51 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: 5 mg/mL (6.03 mM) in 50% PEG300 50% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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