The present invention relates to an agent for the prevention/therapy of a disease caused by keratinocyte growth, which comprises, as an active ingredient, a compound represented by General Formula (1):

wherein A represents a group selected from groups of the following formulas:

X represents CH or N;
Y represents CH 2 or C=O;
Z represents CH or N;
R 1 represents an alkoxy group;
R 2 and R 3 each independently represent an alkyl group;
R 4 represents an alkyl group, and a group of the following formula:

R 5 each independently represent an alkoxy group or an alkylthio group;
m represents an integer from 1 to 3;
n represents an integer of 1 or 2; and
o represents an integer of 1 or 2,
or a salt thereof, or a solvate of the compound or the salt.