Weight-Based Dosing with Pharmacy-Led Stewardship Could Reduce Cancer Drug Spending by Millions
BACKGROUND:
The annual cost of cancer care in the U.S. is expected to approach $250 billion by 2030, much of it driven by drug spending. One commonly used class of cancer therapies – known as immune checkpoint inhibitors (ICIs) – are approved for use in about 40 unique cancer indications and accounted for more than $6 billion in Medicare Part B spending in 2020 alone. ICIs were originally FDA approved for weight-based dosing but currently are usually given as “one size fits all” doses (flat doses) based on a subsequent drug company request to add flat dose approval. [Nearly all ICI doses administered within VA are flat doses.] There are both patient safety and economic motivations to reconsider flat dosing. Compared with weight-based dosing, flat doses are higher for most patients, increasing the cost of cancer treatment and, potentially, exposure-related risks. This simulation analysis assessed the extent to which combining personalized weight-based dosing with common stewardship efforts at the pharmacy level that are supported by clinical pharmacy evidence (i.e., dose rounding and vial sharing) would reduce ICI use and, thus, lower spending. Investigators created a natural language processing algorithm to identify ICI administration events and their dates, drugs, and dosages in the VA healthcare system. The algorithm extracted information from facility-specific, semi-structured chemotherapy administration notes in VA’s electronic health record. They also developed an algorithm that converted flat doses to weight-based doses and allowed partially used drug vials to be used within each VA pharmacy. Drug spending was estimated as the sum of – for each ICI – the product of total vials used and acquisition cost using Medicare drug prices. They also conducted an additional analysis using VA drug prices.
FINDINGS:
- VA could save upward of $50 million per year (~14%) on ICI spending by combining weight-based dosing with pharmacy-level operational changes.
- Cost savings depend upon the amount of time that opened drug vials are allowed to be stored and used.
- The natural language processing algorithm identified ICI administration events and related details with 95% or greater accuracy when compared with manual chart review.
IMPLICATIONS:
- Results reinforce that applying stewardship principles to specialty drug spending can generate savings.
- Regulators, payers, and prescribers can use clinical pharmacology data to help ensure that patients receive the right dose of the right drug at the right time, thus enhancing value.
LIMITATIONS:
- Investigators did not account for potential toxicity of excessive dosing; therefore, ICI stewardship could have additional clinical benefits not captured by their analysis.
AUTHOR/FUNDING INFORMATION:
Drs. Bazzell, Moeller, Kerr, Ramnath, Hofer, and Strohbehn are part of the VA Ann Arbor Health Care, and Drs. Kerr, Hofer, and Strohbehn are core investigators with HSR&D’s Center for Clinical Management Research (CCMR) in Ann Arbor, MI. Dr Kelley is Director of VA’s National Oncology Program and part of VA Durham Health Care.
Bryant A, Chopra Z, Edwards D, Whalley A, Bazzell B, Moeller J, Kelley M, Fendrick AM, Kerr E, Ramnath N, Green M, Hofer T, and Strohbehn G. Adopting Weight-Based Dosing with Pharmacy-Level Stewardship Strategies Could Reduce Cancer Drug Spending by Millions. Health Affairs. July 2023;42(7):946-955.
