Pharmaceutical compositions for treating bone lesions in multiple
myeloma or pharmaceutical compositions for treating multiple myeloma which contain
as an active ingredient a compound having both of an effect of suppressing bone
resorption accompanying multiple myeloma and an effect of inhibiting multiple myeloma,
more particularly, 1-hydroxy-2-(imidazo[1,2-a]pyridin-3-yl)ethane-1,1-bisphosphonic
acid or its salt.