They say it was because of FDA approval. As it was GM, in order to prove it is safe they wanted a study done on healthy people who are completely isolated from

They say it was because of FDA approval. As it was GM, in order to prove it is safe they wanted a study done on healthy people who are completely isolated from the human race so that they can't spread it. As nobody lives in a place where they are completely isolated from the human race it wasn't a very realistic. Then the patent ran out so it wasn't worth it for any drug company to proceed with approval because everyone else would just wait until they've paid the fee and then sell it too.