## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: hERG Electrophysiological Assay: Electrophysiological recordings (all performed at RT) from stably transfected CHO hKv11.1 cells were obtained using the Nanion Syncropatch 768PE. Test compounds, vehicle or positive controls were added with 6 compound plates each at a different concentration to allow cumulative dosing onto cells (10 mM, 3.17 mM, 1 mM, 0.32 mM, 0.1 mM, 0.03 mM). 600 Figure US11325906-20220510-P00001of compound is resuspended into 90 μl of reference buffer (in mM, NaCl 80, KCL 4, CaCl 5, MgCl 1, NMDG Cl 60, D-Glucose monohydrate 5, HEPES 10 (pH7.4 HCL, 298 mOsm) for a final compound concentration of 39.6 μM, 13.2 μM, 4.4 μM, 1.46 μM, 0.48 μM, 0.16 μM. For each Nanion Syncropatch 768PE run, the current amplitude in each cell in the presence of extracellular solution (in mM, NaCl 80, KCL 4, CaCl 5, MgCl 1, NMDG Cl 60, D-Glucose monohydrate 5, HEPES 10 (pH7.4 HCL, 298 mOsm) is measured with all liquid additions performed using the Syncropatch liquid handling system. Add 40 μL external solution (in mM, HBPS, CaCl2 2, MgCl2 1 (pH7.4, NaOH) to 384 well multihole medium resistance recording chip and perfuse internal buffer (in mM, KF 130, KCl 20, MgCl2 1, EGTA 10, HEPES 10, Escin 25 (all Sigma-Aldrich; pH 7.2-7.3 using 10 M KOH, 320 mOsm) to the underside of plate. Dispense 20 μL of cells at a density of 1e6 cells/ml maintained at 9° C. into each well of the chip followed by 20 μL of seal enhancer (in mM, NaCl 80, KCl 3, CaCl 10, HEPES 10, MgCl 1 (pH7.4 NaOH). Perform wash step leaving a residual volume of 40 μL. Dispense 40 μL of reference buffer to establish a stable baseline prior to the addition of test compounds, with a removal step of 40 μL after 3 min, repeat this step. Dispense 40 μL of compound concentration 1 (0.16 μM), real time recordings for 3 min exposure prior to removal of 40 μL. This step is repeated for 5 further subsequent compound plates to generate cumulative curve analysis. All data is leak subtracted, 2 pulses to −80 mV 100 ms with 100 ms delay. Outward K+ currents are then evoked by voltage step to +60 mV from a holding potential of −90 mV, Each pulse is delivered at a frequency of 2 Hz with a 15 s pulse interval.
- Assay organism: Homo sapiens
- Target name: Voltage-gated inwardly rectifying potassium channel KCNH2
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: CCc1cc2cnc(CN3CCN(c4ccc(C(=O)NC)nc4Cl)CC3)cc2[nH]c1=O
- Properties:
- ChEMBL ID: CHEMBL4857071
- Molecule type: Unknown
- Molecular weight: 440.94
- Heavy atoms: 31
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 6
- TPSA: 94.22
- LogP: 2.22
- Rotatable bonds: 5
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.36
- QED: 0.59

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 4.66
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 22000; units nM; pChEMBL 4.66; comment 1168583

## Query Molecule B
- Canonical SMILES: CCCc1nc2ccc(CN3CCN(c4ccc(C(=O)NC)nc4Cl)CC3)cc2[nH]c1=O
- Properties:
- ChEMBL ID: CHEMBL5827773
- Molecular weight: 454.96
- Heavy atoms: 32
- Hydrogen bond donors: 2
- Hydrogen bond acceptors: 6
- TPSA: 94.22
- LogP: 2.61
- Rotatable bonds: 6
- Ring count: 4
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.39
- QED: 0.56

## Molecule Similarity
- Weighted Tanimoto: 0.59

Answer: 4.68