Encorafenib had a reported 72 h A375 viability IC80 of 2.6 nM. In a separate BRAF-wild-type, HRAS-mutant keratinocyte assay, 12 days of exposure at the A375 IC80 increased colony area to 121.2 ± 6.3% of DMSO control (SE). Potency and growth effects therefore depend on the model and endpoint. [1]
In NRAS-mutant melanoma cells, combining encorafenib with binimetinib produced model- and concentration-dependent viability effects. Low-concentration antagonism as well as higher-effect synergy was reported, limiting a general claim of combination superiority. [2]
Paired melanoma viability and keratinocyte ERK dose responses
Cell-based study · BRAF-mutant A375 melanoma cells and BRAF-wild-type HaCaT keratinocytes stably expressing HRAS G12V. [1]
Encorafenib inhibited A375 viability over 72 h while inducing ERK phosphorylation in the keratinocyte model after 15 min. The reported paradox index compares endpoints from different cell types and assay durations; it is an in vitro surrogate, not a measured clinical safety margin.
Literature-Reported Treatment Conditions
- Treatment concentration
- Concentration-response series; 2.6 nM and 130 nM are fitted endpoints, not fixed treatment doses.
- Exposure duration
- 72 h for A375 viability; 15 min for keratinocyte ERK response.
- Method
- CellTiter-Glo and quantitative pERK/total ERK Western blotting.
- Vehicle
- DMSO, 0.05% (v/v) final.
- Co-treatment
- None; vemurafenib, dabrafenib and PLX8394 were separate comparator treatments.
- Reported limits
- Figure 1 caption reports n≥3 for all data points; exact n per fitted point and the biological/technical replication partition are not specified there.
Methods and source locations
Compound reported in the paper: Encorafenib (LGX818); Compound label in the paper: Encorafenib
Findings apply to the encorafenib material tested in the cited study. They do not validate Adooq lots or the separately listed R-isomer.
Figure 1a–d, especially 1c; Table 1 Encorafenib row; Results: BRAFi have unique paradoxical ERK activation profiles; Methods: Inhibitors, Cell viability, ERK activation analysis
A375 cell viability after 72 h: CellTiter-Glo; four-parameter logistic fit to normalized viability. — Figure 1a–d, especially 1c; Table 1 Encorafenib row; Results: BRAFi have unique paradoxical ERK activation profiles; Methods: Inhibitors, Cell viability, ERK activation analysis
ERK2 phosphorylation relative to total ERK2, normalized to DMSO, in HaCaT HRAS G12V cells after 15 min: Quantitative Western blot; induction-curve fit excludes concentrations beyond the peak and constrains the top to the measured peak. — Figure 1a–d, especially 1c; Table 1 Encorafenib row; Results: BRAFi have unique paradoxical ERK activation profiles; Methods: Inhibitors, Cell viability, ERK activation analysis
Ratio of keratinocyte ERK-induction EC80 to A375 viability IC80: Reported ratio of the paired assay endpoints; dimensionless. — Figure 1a–d, especially 1c; Table 1 Encorafenib row; Results: BRAFi have unique paradoxical ERK activation profiles; Methods: Inhibitors, Cell viability, ERK activation analysis
Keratinocyte colony growth during prolonged encorafenib exposure
Cell-based study · BRAF-wild-type HaCaT HRAS G12V keratinocytes. [1]
Encorafenib increased total colony area relative to DMSO during 12 days of exposure at its A375 IC80 concentration. This limits any interpretation that potency in mutant melanoma eliminates growth-promoting activity in a RAS-mutant, BRAF-wild-type model.
Literature-Reported Treatment Conditions
- Treatment concentration
- Each compound tested at its A375 IC80; encorafenib IC80 reported as 2.6 nM.
- Exposure duration
- 12 days; medium exchanged every 2–3 days.
- Method
- Colony formation with crystal violet staining and ImageJ area analysis.
- Vehicle
- DMSO, 0.05% (v/v) final; DMSO-only control.
- Co-treatment
- None; other BRAF inhibitors were separate comparator arms.
- Reported limits
- Exact number of independent colony experiments is not given beyond caption n≥3.
Methods and source locations
Compound reported in the paper: Encorafenib (LGX818); Compound label in the paper: Encorafenib
Findings apply to the encorafenib material tested in the cited study. They do not validate Adooq lots or the separately listed R-isomer.
Figure 2b–c; Table 1 Encorafenib colony-growth column and footnote; Methods: Colony formation assay and Inhibitors
Total colony area relative to DMSO after 12 days: Crystal violet colony assay; ImageJ total-area quantification; unpaired two-tailed Student’s t-test. Caption: n≥3 for all data points. — Figure 2b–c; Table 1 Encorafenib colony-growth column and footnote; Methods: Colony formation assay and Inhibitors
NRAS-mutant melanoma viability with encorafenib and binimetinib
Cell-based study · NRAS-mutant SKMel147, PDX129 and PDX62.1 melanoma cells; SKMel147 and patient-derived models have NRAS Q61R reported in Section 2.1/Table 2. [2]
Viability responses to the combination varied by model and concentration. SKMel147 showed a clearer combination effect; PDX129 responded chiefly at higher concentrations, and PDX62.1 showed limited additional benefit. Combination-index analysis indicated antagonism at low concentrations and synergy at higher effect levels. These results do not establish uniform combination superiority.
Literature-Reported Treatment Conditions
- Treatment concentration
- Encorafenib and binimetinib concentration-response series up to 10 µM each; paired at equimolar concentrations.
- Exposure duration
- 72 h.
- Method
- MUH fluorescent viability readout, normalized to untreated controls.
- Vehicle
- Compounds dissolved in DMSO. Exact final DMSO for this viability series is not specified in Section 2.3.
- Co-treatment
- Encorafenib plus binimetinib, with both single-agent series and untreated controls.
- Reported limits
- Section 2.3 says hexaplicate treatment, whereas the Figure 1 caption says quadruplicate per independent experiment. The figure-specific caption is retained; the discrepancy is unresolved. No curve-derived IC50 or precise viability percentage is extracted.
Methods and source locations
Compound reported in the paper: Encorafenib (LGX818); Compound label in the paper: Encorafenib
Findings concern reported encorafenib in the stated NRAS-mutant models; no Adooq lot or isolated R-isomer validation.
Figure 1D–E,G–H,J–K and caption; Sections 2.1–2.3 and 3.1; Section 2.13; Abstract model scope and Table 2 identity
Viable-cell signal normalized to untreated controls at 72 h: MUH viability assay; Figure 1D,G,J concentration-response curves and Figure 1E,H,K combination-index plots. Caption: mean ± SD of three independent experiments, each measured in quadruplicate. Combination indices were calculated with CompuSyn 1.0 (Section 2.13): CI<1 synergy, CI=1 additive, CI>1 antagonism. — Figure 1D–E,G–H,J–K and caption; Sections 2.1–2.3 and 3.1; Section 2.13; Abstract model scope and Table 2 identity
