The price tag can reach the millions — cumulatively, the cost is estimated to hit $25 billion annually by 2034. Just last year, the FDA approved Hemgenix, the most expensive treatment to date. And in the future, treatments like these are likely to become even more common as more than 500 gene therapies are currently in clinical trials and an estimated one million Americans are forecasted to be treated by gene therapies by 2034. The pharmaceutical company struck a deal with payers that provides an option to pay over five years and allows for an outcome-based contract. The pharmaceutical company offers an outcome-based contract that provides payers with a guarantee to reimburse 80% of the therapy cost if the patient fails to achieve and maintain the agreed outcomes.