The "real" costs of making ordinary drugs are small in terms of manufacturing. It is very inexpensive to synthesize the chemicals that make up most drugs. You're paying for the R&D of the drug as well as all the ones that failed along the way. In the days when software used to be sold in cardboard boxes and came on CD's, nobody was making the argument that someone like Microsoft should charge a few dollars since CD's and cardboard are cheap.
All that said, in this specific case, the therapy is enormously complex, time consuming, and expensive. It's not a simple chemical compound that can be manufactured in bulk. Furthermore, it has to be tailor-made in a lab under highly controlled conditions for each individual receiving the treatment. As a result, it is likely to be extremely costly when it finally makes it out of the experimental phase.
"It is very inexpensive to synthesize the chemicals that make up most drugs"
Can I ask a stupid q? How exactly inexpensive is it? Thinking in line of 3d printing, how possible could it be to get the chemicals needed, and the machines needed to mix them appropriately, to make a known drug? Ie, how possible would be to "download a pill"? The recipe, and you make it yourself at home?
All that said, in this specific case, the therapy is enormously complex, time consuming, and expensive. It's not a simple chemical compound that can be manufactured in bulk. Furthermore, it has to be tailor-made in a lab under highly controlled conditions for each individual receiving the treatment. As a result, it is likely to be extremely costly when it finally makes it out of the experimental phase.