心不全治療を目指した新規低分子化合物

心室ミオシン調節軽鎖の選択的アップレギュレーター
特にHFrEF患者に効果的Dr. Osamu Tsukamoto
Department of Medical Biochemistry Osaka University
Department of Biochemistry, Hyogo Medical University
Tech Manage Corp.
Keiji FUJITO

Concept

cMLCK活性化因子：カルシウム非依存性メカニズムを介してサルコメアタンパク質を直接活性化することにより心臓収縮を増強する

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Background-1

効果的で信頼性の高い強心薬が強く求められています Heart Failure•

1,200,000 人（日本）, 6,500,000人米国,

患者数には更に増加の見込み.

•約40% が駆出率の減少による心不全 (HFrEF)

 Inotrope Treatment for HFrEF Stage C/D
Modulation of calcium transients: PDEIII inhibitor, catecholamine, beta-adrenergic stimulator Problems of Traditional Inotropes (Calcinotrope)
長期使用により死亡リスクが高まることが問題 心筋ミオシン活性化剤: Omecamtive mecarbil (OM),•

選択的心臓ミオシン ATPase 活性化剤, PIII development•

transientsに影響を与えることなく心臓の収縮性を改善します•

心筋虚calcium血患者には注意が必要（相対拡張期が短縮するため）

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BackgroundcMLCK 活性化剤 は 有望な治療薬候補

Functional analysis of MYLK3 frame-shift mutation

Knock-in mice of the MYLK3 frame-shift mutation
Reduction of MLC2v
Reduced cMLCK
phosphorylation
expression

Development of heart failure(LV pressure-volume loop)
Mylk3+/+

Phospho-MLC2v

cMLCK activities in failing hearts from DCM patients

Mylk3+/fs

Mylk3+/fs+ AAV

Non-phosphor MLC2v

Replenishment of cMLCK by AAV restores MLC2v phosphorylation and cardiac function.

iPSC-cardiomyocytes from DCM patient with the MYLK3 frame-shift mutation
Reduced cMLCKReduction of MLC2v
Reduced contractility
expression
phosphorylation

Gene correction by CRISPR/Cas9 restores MLC2v phosphorylation and cardiac function.

cMLCK activities were suppressed also in the hearts from DCM patientsnot caused by MYLK3 mutations.

Normal heart

HYPOTHESIS

Failing heart

Reduction of MLC2v phosphorylation by depressedcMLCK activity was a common pathway for
reduced cardiac contractility observed in advanced HFrEF.
4Result - 1

LEUO-1154：新規アロステリックcMLCK活性化因子

The chemical structure ofLEUO-1154, a cMLCK activator

MLC2v dose-dependence of human cMLCKactivities in the presence of LEUO-1154.

N = 3 for each point

The dose-response effects of LEUO-1154 on theactivities of human cMLCK, skMLCK, and smMLCK

N = 3 for each point

Km(MLC2v) values of human cMLCK were 1.57 ± 0.58 or 2.81 ± 0.53 μM, and maximum luminescence values were 44,400 ± 4,400 or 92,800 ± 5,500
relative light unit (RLU) that corresponded to a Vmax of 3.31 ± 0.19 or 7.10± 0.27 mol/min/mol kinase in the presence of DMSO or LEUO-1154 (10 µM),
respectively.
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Result - 2

LEUO-1154：患者iPS由来心筋細胞の機能を回復

MLC2v phosphorylation (phos-tag SDS-PAGE)

Cardiomyocyte contraction and relaxation (SI8000)

Profiles of calcium transients (FDSS)
CTAs, amplitude ofcalcium transients atsystole;

Force measurements using self-organized tissue rings (MicroTester G2)

PWD50, pulse widthduration measured
at 50% CTAs

N = 5 for each point

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Result - 3

LEUO-1154：サルコメアの再構成を促進

The effect of LEU1154 on the sarcomere structure
DMSO

LEU-1154 (10 µM)

Not published7SummarycMLCK 活性化剤：••••

心臓サルコメアを直接活性化することによる筋萎縮効果
機能不全の心臓における心臓サルコメアの回復効果あり
カルシトロープに伴う副作用を伴わない心不全患者の血行動態の改善
Omecamtive Mecambirとは異なるメカニズム

Publication

Circulation. 2023 May 2. doi:10.1161/CIRCULATIONAHA.122.062885

PatentFiled, not published
8Expectation●•••

Future works

Further optimization of LEUO-1154.
Exploring molecules with other backbone structures.
Identification of cMLCK inhibitors for treatment of HCM with hypercontraction.

Suggestions● We are looking for companies who are interested in developing small molecule
LEUO-1154 or its derivatives.
● Collaboration for identifying novel small molecules with our high throughput
screening system is also welcome.
● We have other seed compounds, which need further evaluation.
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