Abstract
Immune checkpoint inhibitors, a class of drugs used in approximately forty unique cancer indications, are a sizable component of the economic burden of cancer care in the US. Instead of personalized weight-based dosing, immune checkpoint inhibitors are most commonly administered at "one-size-fits-all" flat doses that are higher than necessary for the vast majority of patients. We hypothesized that personalized weight-based dosing along with common stewardship efforts at the pharmacy level, such as dose rounding and vial sharing, would lead to reductions in immune checkpoint inhibitor use and lower spending. Using data from the Veterans Health Administration (VHA) and Medicare drug prices, we estimated reductions in immune checkpoint inhibitor use and spending that would be associated with pharmacy-level stewardship strategies, in a case-control simulation study of individual patient-level immune checkpoint inhibitor administration events. We identified baseline annual VHA spending for these drugs of approximately $537 million. Combining weight-based dosing, dose rounding, and pharmacy-level vial sharing would generate expected annual VHA health system savings of $74 million (13.7 percent). We conclude that adoption of pharmacologically justified immune checkpoint inhibitor stewardship measures would generate sizable reductions in spending for these drugs. Combining these operational innovations with value-based drug price negotiation enabled by recent policy changes may improve the long-term financial viability of cancer care in the US.