Alofanib (RPT835)

Biological Activity

Alofanib (RPT835) is a novel selective allosteric inhibitor of FGFR2 and has a dramatic inhibitory effect with IC50 <10 nM on FGF2-induced phoshphorylation of FRS2a in KATO III cells. Alofanib induces mainly apoptosis with cleavage of caspase 3, PARP and Bcl-2 in SKOV3 cell line. Cytotoxic effect of compound on ovarian cancer cells is low. Alofanib inhibits phosphorylation of FRS2α with the IC50 values of 7 and 9 nmol/l in cancer cells expressing different FGFR2 isoforms. In a panel of four cell lines representing several tumour types (triple-negative breast cancer,melanoma, and ovarian cancer), alofanib inhibits FGF-mediated proliferation with 50% growth inhibition (GI50) values of 16-370 nmol/l. Alofanib dose dependently inhibits the proliferation and migration of human and mouse endothelial cells (GI50: 11-58 nmol/l) compared with brivanib and bevacizumab. 

In vivo, Intravenous alofanib significantly in dose-dependent manner potentiated the efficiency of the combination of paclitaxel and carboplatin. Alofanib suppresses angiogenesis in ovarian cancer mouse model. In a FGFR-driven human tumour xenograft model, oral administration of alofanib is well tolerated and results in potent antitumour activity.

Protocol

Cell Experiment
Cell lines	SKOV3, HS478T, Mel Kor cells
Preparation method	Inhibited growth of SKOV3 and HS578T cells with GI50s of 0.37 and 0.21 μM. Did not potently inhibit growth of Mel Kor cells that do not contain FGFR2 (GI50>10 μM).
Concentrations	0.2, 0.4, 0.8 μM
Incubation time	6 hours after dosing, FGF2 is added at a concentration of 25 ng/ml

Animal Experiment
Animal models	C57Bl/6 × DBA/2 F1 mice of 22-30 g
Formulation	vehicle (water)
Dosages	10 mg/kg/d
Administration	Intraperitoneally, 0, 3 and 6 d

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

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.

Chemical Information

References

[1] Alexandra Tyulyandina, et al. Invest New Drugs. Alofanib, an allosteric FGFR2 inhibitor, has potent effects on ovarian cancer growth in preclinical studies

[2] Ilya Tsimafeyeu, et al. Eur J Cancer. Targeting FGFR2 with alofanib (RPT835) shows potent activity in tumour models

[3] D A Khochenkov, et al. Bull Exp Biol Med. Antiangiogenic Activity of Alofanib, an Allosteric Inhibitor of Fibroblast Growth Factor Receptor 2