This is Day 1 so the price and how well it works today is almost certainly the worst it will ever be. Insurance will likely cover the cost. It's a very bad, painful, and outright deadly genetic mutation and $2.2 million is practically nothing compared to doubling someone's lifespan or giving them an extra 10 years.
More info I found relevant regarding cost for typical treatment and out of pocket estimated costs: https://www.hematology.org/newsroom/press-releases/2022/the-...