Dabrafenib

Biological Activity

Dabrafenib (GSK2118436A) is a potent ATP-competitive inhibitor of B-Raf, B-Raf V600E and c-Raf with IC50 of 3.2 nM, 0.8 nM and 5.0 nM, respectively. Dabrafenib is selective for Raf kinase, with 400 fold selectivity towards B-Raf over 91% of the other kinases tested. Dabrafenib (orally administrated) inhibits the growth of B-RafV600E mutant melanoma (A375P) and colon cancer (Colo205) human tumor xenografts, growing subcutaneously in immuno-compromised mice. GSK2118436 treatment results in no detectable negative impact on existing systemic immunity or the de novo generation of tumor-specific T cells. Dabrafenib (GSK2118436A) is currently in phase III clinical trial in patients with melanoma.

Product Citations

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  Int J Mol Sci. 2021 Nov 4;22(21):11951.

  BRAF and MEK Inhibitors Affect Dendritic-Cell Maturation and T-Cell Stimulation
  Dabrafenib purchased from AbMole

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  Int J Mol Sci. 2018 Jan 18;19(1) pii: E289.

  BRAF and MEK Inhibitors Influence the Function of Reprogrammed T Cells: Consequences for Adoptive T-Cell Therapy
  Dabrafenib purchased from AbMole

• 

  Cell Rep. 2016 Jun 28;16(1):263-77.

  BRAF(V600E) Kinase Domain Duplication Identified in Therapy-Refractory Melanoma Patient-Derived Xenografts.
  Dabrafenib purchased from AbMole

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  Journal of Cell Science. 2016 Jun 1;129(11):2261-72.

  PAX5 interacts with RIP2 to promote NF-κB activation and drug-resistance in B-lymphoproliferative disorders.
  Dabrafenib purchased from AbMole

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  EMBO Mol Med. 2015 Jun 23;1104-18.

  Intra- and inter-tumor heterogeneity in a vemurafenib-resistant melanoma patient and derived xenografts.
  Dabrafenib purchased from AbMole

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  Cell Rep. 2014 Nov 20;1375-86.

  Parallel in vivo and in vitro melanoma RNAi dropout screens reveal synthetic lethality between hypoxia and DNA damage response inhibition.
  Dabrafenib purchased from AbMole

Customer Product Validations & Biological Datas

	Source	Int J Mol Sci (2018). Figure 5. GSK2118436A (AbMole BioScience, Houston, TX, USA)
	Method	vitro experiments
	Cell Lines	CAR-T cells
	Concentrations	1 μM
	Incubation Time	16 h
	Results	CAR-T cells in the conditions without inhibitor, with DMSO solvent control, with Vem alone, Tram alone, Dabra alone, and the combination Dabra + Tram

	Source	Int J Mol Sci (2018). Figure 4. GSK2118436A (AbMole BioScience, Houston, TX, USA)
	Method	vitro experiments
	Cell Lines	CAR-T cells
	Concentrations	1 μM
	Incubation Time	16 h
	Results	The presence of Vem alone, Tram alone,Cobi alone, Vem + Cobi, and Dabra + Tram, but not of Dabra alone seemed to reduce these quantities to approximately 50%.

	Source	Int J Mol Sci (2018). Figure 3. GSK2118436A (AbMole BioScience, Houston, TX, USA)
	Method	vitro experiments
	Cell Lines	CAR-T cells
	Concentrations	1 μM
	Incubation Time	16 h
	Results	"The condition with Vem + Cobi was similarly inhibited as Vem alone, while the Dabra + Tram condition was significantly less inhibited"

	Source	Int J Mol Sci (2018). Figure 2. GSK2118436A (AbMole BioScience, Houston, TX, USA)
	Method	vitro experiments
	Cell Lines	CAR-T cells
	Concentrations	1 μM
	Incubation Time	16 h
	Results	Dabra alone had a significantly weaker effect on CD25-upregulation than Vem alone, and the combination Dabra + Tram resulted in the mildest effects on CD25 upregulation

	Source	Journal of Cell Science (2016) . Figure 3. Dabrafenib (M1988, Abmole, Houston, TX)
	Method	Cell apoptosis assay and western blot
	Cell Lines	IM9 and RPMI8226 cells expressing PAX5
	Concentrations	10 μM
	Incubation Time	30 h
	Results	Similarly, the selective RIP2 inhibitor SB 203580, but not the RIP1 inhibitor Necrostatin-1 (Degterev et al., 2013) nor the RIP3 inhibitor Dabrafenib (Li et al., 2014), was able to significantly increase Bortezomib-induced apoptosis in IM9 andPAX5-expressing RPMI8226 cells (Fig. 3D). Furthermore, only SB 203580 decreased Bortezomib-induced activation of RIP2 and NF-κB in IM9 cells (Fig. 3F).

	Source	Cell Report (2016). Figure 7.dabrafenib (GSK2118436, Abmole)
	Method	Tumour volume and Immunoblotting
	Cell Lines
	Concentrations	30 mg/kg
	Incubation Time	25~30 days
	Results	BRAFV600E/DK is Responsible for Resistance to BRAFi.Both PDXs were treated either with the BRAF inhibitor dabrafenib, to which they were completely resistant (Figures 7G and 7H). Indeed, AKT signaling was much more active in the M048R2.X2 PDX (Figure 7I), explaining its only partial sensitivity to LY3009120.

	Source	Cell Report (2016). Figure 3.dabrafenib (GSK2118436, Abmole)
	Method	Immunoblotting and qPCR
	Cell Lines
	Concentrations	30 mg/kg
	Incubation Time	25~30 days
	Results	These results demonstrate concordance between drug responses in patients and their corresponding PDXs, and they illustrate that the therapy response can be either stable or dynamic.

	Source	Cell Report (2014) . Figure 7.Dabrafenib (Abmole)
	Method	In Vivo Experiments
	Cell Lines	M026R.X1 tumors
	Concentrations	30mg/kg
	Incubation Time	33 days
	Results	Synthetic lethality by hypoxia induction and Chek1/2 inhibition in vivo was observed for the PDX derived from a melanoma patient who had acquired resistance to BRAF inhibition.

	Source	EMBO Molecular Medicine (2015) . Figure 4.Dabrafenib (GSK2118436, Abmole)
	Method	Mice--Derived Xenografts
	Cell Lines	A375 cells infected with pQXCIPGFP, MEK1WT, and MEK1T55delinsRT
	Concentrations	30 mg/kg daily by oral gavage
	Incubation Time	12 days
	Results	Altogether, these data confirm that MEK1T55delinsRT confers resistance to BRAF inhibition in vivo and induces local invasion.

	Source	EMBO Molecular Medicine (2015) . Figure 4.Dabrafenib (GSK2118436, Abmole)
	Method	CellTiter-Blue Cell Viability Assay (G8081, Promega)
	Cell Lines	A375-GFP, 888Mel-MEK1T55delinsRT,SK-MEL-28
	Concentrations	0, 0.25, 0.5, 1, 2.5, 5 µ M
	Incubation Time	5 days
	Results	MEK1T55delinsRT-expressing cells were also more resistant to low levels of the ERK inhibitor SCH772984 than control populations (Fig 4F and G).

Protocol (for reference only)

Cell Experiment
Cell lines	A375-GFP, 888Mel-MEK1T55delinsRT,SK-MEL-28
Preparation method	Dose–response curves were performed as follows: 3,000–6,000 cells were plated per well in a 96-well plate. For each condition, triplicates were plated. The next day, drug was added to the wells. At day 5 of the assay, medium-containing drug was removed and survival was measured by CellTiter-Blue Cell Viability Assay (G8081, Promega).
Concentrations	0, 0.25, 0.5, 1, 2.5, 5 µ M
Incubation time	5 Days

Animal Experiment
Animal models	A375 cells infected with pQXCIPGFP, MEK1WT, and MEK1T55delinsRT Mice--Derived Xenografts
Formulation	Dabrafenib powder was first dissolved in DMSO and consequently, before injection, dissolved in 0.5% hydroxypropylmethylcellulose (Sigma-Aldrich), 0.2% Tween-80 in pH 8.0 distilled H2O.
Dosages	30 mg/kg daily (6 days per week)
Administration	oral gavage

Chemical Information

Molecular Weight	519.56
Formula	C23H20F3N5O2S2
CAS Number	1195765-45-7
Solubility (25°C)	DMSO 30 mg/mL
Storage	Powder          -20°C   3 years ;  4°C   2 years In solvent       -80°C   6 months ;  -20°C   1 month

Conversion of different model animals based on BSA (PMID: 27057123)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of Compound A used for a mouse (20 mg/kg) to a dose based on the BSA for a rat, multiply 20 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for Compound A of 10 mg/kg.

References

[1] Greger JG, et al. Mol Cancer Ther. Combinations of BRAF, MEK, and PI3K/mTOR inhibitors overcome acquired resistance to the BRAF inhibitor GSK2118436 dabrafenib, mediated by NRAS or MEK mutations.

[2] Hong DS, et al. Clin Cancer Res. BRAF(V600) inhibitor GSK2118436 targeted inhibition of mutant BRAF in cancer patients does not impair overall immune competency.