Answer:
This is because of reasons of-
safety,
cost-effectiveness and
difficulty in accessibility of needed protein
Step-by-step explanation:
In order to reduce cost of production for maximal profit, bio.companies usually design their production of therapeutic proteins in possible cost -effective way.This is to ensure maximal yields from production sales. Therefore maximum cost effectiveness is achieved through GMO rather through isolation from blood products or other sources which are expensive and capital intensive to get
In addition safety concerns during production is of ultimost importance to theses companies.Therefore when using of protein from different sources high safety measures are needed to be put in place to achieve best results. whereas GMO comes with little risks.
These companies experiences difficulty in collecting required amount of low abundant protein needed for the synthesis of therapeutic proteins, thus they will rather prefer the design of GMO for abundant supply.