## Endpoint to Predict
- Endpoint scope: assay
- Measurement type: IC50
- Label type: continuous
- Binary semantics: pchembl
- Assay description: FGFR Enzymatic Assay (pre-incubated for 4 hours): The inhibitor potency of the exemplified compounds was measured in an enzyme assay that measures peptide phosphorylation using FRET measurements to detect product formation. Inhibitors were serially diluted in DMSO and a volume of 0.5 μL was transferred to the wells of a 384-well plate. For FGFR3, a 10 μL volume of FGFR3 enzyme (Millipore) diluted in assay buffer (50 mM HEPES, 10 mM MgCl2, 1 mM EGTA, 0.01% Tween-20, 5 mM DTT, pH 7.5) was added to the plate and pre-incubated for a time between 5-10 minutes and up to 4 hours. Appropriate controls (enzyme blank and enzyme with no inhibitor) were included on the plate.The assay was initiated by the addition of a 10 μL solution containing biotinylated EQEDEPEGDYFEWLE peptide substrate (SEQ ID NO: 1) and ATP (final concentrations of 500 nM and 140 μM respectively) in assay buffer to the wells. The plate was incubated at 25° C. for 1 hr. The reactions were ended with the addition of 10 μL/well of quench solution (50 mM Tris, 150 mM NaCl, 0.5 mg/mL BSA, pH 7.8; 30 mM EDTA with Perkin Elmer Lance Reagents at 3.75 nM Eu-antibody PY20 and 180 nM APC-Streptavidin). The plate was allowed to equilibrate for 1 hr before scanning the wells on a PheraStar plate reader (BMG Labtech).FGFR1, FGFR2, and FGFR4 are measured under equivalent conditions with the following changes in enzyme and ATP concentrations: FGFR1, 0.02 nM and 210 uM respectively, FGFR2, 0.01 nM and 100 uM, respectively, and FGFR4, 0.04 nM and 600 uM respectively. The enzymes were purchased from Millipore or Invitrogen.GraphPad prism3 was used to analyze the data. The IC50 values were derived by fitting the data to the equation for a sigmoidal dose-response with a variable slope. Y=Bottom+(Top−Bottom)/(1+10^((LogIC50−X)*HillSlope)) where X is the logarithm of concentration and Y is the response. Compounds having an IC50 of 1 μM or less are considered active.
- Assay organism: Homo sapiens
- Target name: Fibroblast growth factor receptor 3
- Target type: SINGLE PROTEIN
- Target organism: Homo sapiens

## Reference Molecule A
- Canonical SMILES: COc1cc(OC)c(F)c(N2Cc3cnc(-c4[nH]ncc4C#N)cc3C3(CC3)C2=O)c1F
- Properties:
- ChEMBL ID: CHEMBL5802865
- Molecular weight: 437.41
- Heavy atoms: 32
- Hydrogen bond donors: 1
- Hydrogen bond acceptors: 6
- TPSA: 104.13
- LogP: 3.22
- Rotatable bonds: 4
- Ring count: 5
- Aromatic rings: 3
- Formal charge: 0
- Fraction Csp3: 0.27
- QED: 0.67

## Known Reference Result on This Endpoint
- Molecule A clean result: median pChEMBL = 6.94
- This result is provided as context for predicting Molecule B on the same endpoint.

## Reference Molecule A Other ChEMBL Evidence
- type IC50; relation =; value 115; units nM; pChEMBL 6.94; comment 745843

## Query Molecule B
- Canonical SMILES: COc1cc(OC)c(F)c(N2Cc3cnc(-c4cn(C)nc4C)cc3N(c3cnc(C)cn3)C2=O)c1F
- Properties:
- ChEMBL ID: CHEMBL5837246
- Molecular weight: 507.5
- Heavy atoms: 37
- Hydrogen bond donors: 0
- Hydrogen bond acceptors: 7
- TPSA: 98.5
- LogP: 4.46
- Rotatable bonds: 5
- Ring count: 5
- Aromatic rings: 4
- Formal charge: 0
- Fraction Csp3: 0.24
- QED: 0.39

## Molecule Similarity
- Weighted Tanimoto: 0.38

Answer: 7.7