Belinostat (PXD101)

Preparation Method

Reaction was carried out in a total volume of 150 μl of buffer [60 mm Tris (pH 7.4) containing 30% glycerol] containing 2 μl of cell extract and, where used, 2 μl of Belinostat. The reaction was started by the addition of 2 μl of [3H] labeled substrate (acetylated histone H4 peptide corresponding to the 20 NH2-terminal residues). Samples were incubated at 37°C for 45 min, and the reaction stopped by the addition of HCl and acetic acid (0.72 and 0.12 m final concentrations, respectively).

Reaction Conditions

2 μl of Belinostat, incubated at 37°C for 45 min

Applications

Belinostat inhibited histone deacetylase activity in cell lysates with an IC50 in the range 9–100 nM 

Cell lines

The human ovarian cell line A2780, cisplatin (A2780/cp70) and doxorubicin (2780AD) resistant derivatives

Preparation Method

Cells were plated in 5 ml of medium at a density of 8 × 104 cells/25 cm2 flask and allowed to attach and grow for 48 h. Cells were exposed to Belinostat (five concentrations from 0.016 to 10 μm) for 24 h.

Reaction Conditions

0.016 to 10 μm, for 24 h

Applications

Belinostat inhibited the growth of a number of human tumor cell lines with IC50s determined by a clonogenic assay in the range 0.2–3.4 μm 

Animal models

female CD-1 athymic nude mice

Preparation Method

Once tumors became established (∼100 mm3 in size), animals were randomized (10 animals/group) and drug treatments were initiated. Belinostat was given by i.p. injection once daily for 15 consecutive days. Belinostat was prepared as a 50 mg/mL stock in Belinostat vehicle (pH ∼9.4) and for administration was diluted in Belinostat vehicle to 10 mg/mL (for 100 mg/kg dose)

Dosage form

i.p , 20, 40, 100 mg/kg, for 15 d.

Applications

Belinostat monotherapy induced dose-proportional antitumor effects. When administered at 100 mg/kg, Belinostat inhibited tumor size by 47% at day 15 relative to vehicle-treated control animals.

References:

[1]. Plumb J A, Finn P W, Williams R J, et al. Pharmacodynamic response and inhibition of growth of human tumor xenografts by the novel histone deacetylase inhibitor PXD101[J]. Molecular cancer therapeutics, 2003, 2(8): 721-728.

[2]. Qian X, LaRochelle W J, Ara G, et al. Activity of PXD101, a histone deacetylase inhibitor, in preclinical ovarian cancer studies[J]. Molecular cancer therapeutics, 2006, 5(8): 2086-2095.