## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: Determination of the Effects of the Compounds of the Present Invention on FGFR Kinase Activity: The following assay was used to determine the inhibition rate of the preferred compounds of the present invention to the kinase activity of the recombinant human FGFR protein in vitro conditions. This assay used Cisbio's HTRF®KinEASE-TK tyrosine kinase kit (Cat. No. 62TK0PEB), through determining the degree of phosphorylation of the biotinylated polypeptide substrate, the determination was carried out by time-resolved fluorescence energy resonance transfer method (TF-FRET). Human FGFR protein was purchased from Carna bioscience (Japan, Cat. No. FGFR1#08-133, FGFR2#08-134, FGFR3#08-135, FGFR4#08-136).For detailed assay, please refer to the kit instructions, the experimental procedure was summarized as follows: the compound of the present invention was first dissolved in DMSO, the solution was subjected to gradient dilution with the buffer solution provided in the kit so that the range of the final concentration of the compound to be tested in the reaction system was 10 μM to 0.1 nM, the final concentration of DMSO was 0.1%. The concentration of the tested adenosine triphosphate (ATP) was the pre-determined Km value corresponding to the ATP of each FGFR subtype. The compound was first incubated with a certain amount of FGFR protein at room temperature for 5 to 30 minutes, followed by the addition of ATP and the biotinylated polypeptide substrate to the reaction solution to initiate the phosphorylation reaction, and the mixture was incubated at room temperature for 50 minutes. Subsequently, an antiphosphorylated tyrosine antibody coupled with a compound containing europium-based element and streptavidin coupled with a modified allophycocyanin XL665 were added to the reaction and the mixture was incubated continuously for 1 hour at room temperature. After incubation, the fluorescence intensity of each well at emission wavelengths of 620 nM and 665 nM were read at the excitation wavelength of 304 nm in the TF-FRET mode of the microplate reader.
- Assay organism: Homo sapiens
- Target name: Fibroblast growth factor receptor 4
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: Nc1c(C(=O)c2cc3ccc(Br)cc3[nH]2)cnn1-c1ccc2[nH]c(C3CC3)nc2c1
- Properties:
- ChEMBL ID: CHEMBL5944846
- Molecular weight: 461.32
- Heavy atoms: 30
- Hydrogen bond donors: 3
- Hydrogen bond acceptors: 4
- TPSA: 105.38
- LogP: 4.68
- Rotatable bonds: 4
- Ring count: 6
- Aromatic rings: 5
- Formal charge: 0
- Fraction Csp3: 0.14
- QED: 0.34

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 5.76
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 1738; units nM; pChEMBL 5.76; comment 706336

## Query Molecule B
- Canonical SMILES: Nc1c(C(=O)c2cc3ccccc3[nH]2)cnn1-c1ccc2[nH]c(C3CC3)nc2c1
- Properties:
- ChEMBL ID: CHEMBL5784523
- Molecular weight: 382.43
- Heavy atoms: 29
- Hydrogen bond donors: 3
- Hydrogen bond acceptors: 4
- TPSA: 105.38
- LogP: 3.92
- Rotatable bonds: 4
- Ring count: 6
- Aromatic rings: 5
- Formal charge: 0
- Fraction Csp3: 0.14
- QED: 0.41

## Molecule Similarity
- Weighted Tanimoto: 0.81

Answer: 6