Express Scripts has criticized the $475,000 price tag on Novartis AG's latest breakthrough cancer therapy. The cost of the leukemia treatment—tisagenlecleucel (Kymriah) is "dramatically higher" than other such complex treatments, and the health care system is not ready to pay for it, Steve Miller, chief medical officer at Express Scripts, said Thursday. Gene therapies are targeted at a small number of patients and typically used just once, meaning that drug companies have limited chances to recoup their investment. "Therein lies the challenge," Miller said. "We need a new payment model." Tisagenlecleucel is the first drug approved from the CAR-Ts class of treatment that have been heralded as a promising approach to treating and potentially curing cancers as well as genetic conditions such as blindness. Paying for CAR-Ts and similar therapies, some of which cost as much as $1.4 million, will require new collaborative approaches among payers, drugmakers and policymakers, according to Miller. Novartis has said it will attempt to address the pricing hurdle with a new type of agreement: for patients whose care is covered by U.S. government programs, the company will get paid only if patients show signs that the treatment is working within a month of getting it.