." ▁For ▁the ▁same ▁de cade ▁the ▁comp ound ▁annual ▁growth ▁rate ▁( CA GR ) ▁of ▁the ▁or phan ▁dru gs ▁was ▁an ▁" im press ive ▁ 2 5 . 8 %, ▁compared ▁to ▁only ▁ 2 0 . 1 % ▁for ▁a ▁matched ▁control ▁group ▁of ▁non - orph an ▁dru gs ." ▁By ▁ 2 0 1 2 , ▁the ▁market ▁for ▁or phan ▁dru gs ▁was ▁worth ▁US D $ 6 3 7 ▁million , ▁compared ▁with ▁US D $ 6 3 8 ▁million ▁for ▁a ▁control ▁group ▁of ▁non - orph an ▁dru gs . ▁ ▁By ▁ 2 0 1 2 , ▁ ▁According ▁to ▁a ▁ 2 0 1 4 ▁report , ▁the ▁or phan ▁drug ▁market ▁has ▁become ▁increasing ly ▁luc r ative ▁for ▁a ▁number ▁of ▁reasons . ▁The ▁cost ▁of ▁clin ical ▁tri als ▁for ▁or phan ▁dru gs ▁is ▁substantial ly ▁lower ▁than ▁for ▁other ▁dise ases ▁because ▁trial ▁sizes ▁are ▁naturally ▁much ▁smaller ▁than ▁for ▁more ▁dise ases ▁with ▁larger ▁numbers ▁of ▁patients . ▁Small ▁clin ical ▁tri als ▁and ▁minimal ▁competition ▁place ▁or phan ▁agents ▁at ▁an ▁advantage ▁in ▁regul atory ▁review . ▁ ▁Tax ▁in cent ives ▁reduce ▁the ▁cost ▁of ▁development . ▁On ▁average ▁the ▁cost ▁per ▁patient ▁for ▁or phan ▁dru gs ▁is ▁" six ▁times ▁that ▁of ▁non - orph an ▁dru gs , ▁a ▁clear ▁indic ation ▁of ▁their ▁pr icing ▁power ." ▁The ▁cost ▁of ▁per - person ▁out l ays ▁are ▁large