Three genetically targeted drugs for Duchenne muscular dystrophy (DMD) — eteplirsen, golodirsen, and casimersen — cost the US health care system more than $3 billion between 2016 and 2022, despite a lack of confirmatory efficacy data, a new analysis showed.
“We were certainly surprised to see how much was spent on these drugs during the period when we were still waiting for evidence to confirm whether or not they were effective,” study investigator Benjamin Rome, MD, MPH, with the Program on Regulation, Therapeutics, and Law, Harvard Medical School and Brigham and Women’s Hospital, Boston, told this news organization.
“With these drugs often costing over $1 million a year, these results show how spending can add up even for drugs that treat a rare disease,” Dr. Rome added.
The study was published online March 11, 2024, in JAMA.
No Confirmatory Research
Investigators estimated public and private spending on eteplirsen, golodirsen, and casimersen for DMD during 2016 and 2022 — years in which these drugs were marketed without the required confirmatory studies completed.
Annual net sales, which include rebates and statutory discounts to Medicaid or 340B entities, for the three drugs totaled $3.1 billion during the study period. Estimated Medicaid and Medicare spending accounted for $1.2 billion of that total. Of this total, Medicaid programs spent $1.1 billion (34% of US net sales) and Medicare spent $104 million (3% of US net sales).
Overall sales for the drugs increased from $7 million in 2016 to $879 million in 2022, while Medicaid and Medicare spending rose from $25 million in 2017 to $327 million in 2022.
Most of the spending on these therapies was for eteplirsen ($2.6 billion [82%]), “the efficacy of which has yet to be determined in a confirmatory trial more than 7 years after the drug’s accelerated approval,” the authors noted.
Of the total amount spent on the three drugs, US payers spent an estimated $301 million (10%) on casimersen and $263 million (8%) on golodirsen.
The findings point to the importance of follow up on drugs that are approved with preliminary evidence, Rome said.
“Congress and the US Food and Drug Administration have already made some important changes to the accelerated approval pathway, so hopefully we won’t see cases of multi-year delays in the future,” he said.
“Payers, including public payers like Medicare and Medicaid, need tools to financially encourage companies to complete the follow-up trials, such as paying less for drugs with accelerated approval or engaging in outcomes-based contracts to ensure they don’t pay billions of dollars for drugs that ultimately turn out not to be effective,” Dr. Rome added.
Reached for comment, Adam C. Powell, PhD, president, Payer+Provider Syndicate, noted that when a condition impacts a small population, as is the case with muscular dystrophy, there are fewer people over which to spread the cost of treatment development.
Dr. Powell pointed to a recent report that showed the average cost of developing a new drug exceeds $2 billion. The finding in the current study, that three DMD treatments had combined net sales of $3.1 billion over a 7-year period, “suggests that their developers may not have yet recouped their development costs,” Dr. Powell told this news organization.
“Unless the cost of drug development can be lessened through innovations in artificial intelligence or other means, high spending per patient for drugs addressing uncommon conditions is to be expected,” noted Dr. Powell, who was not part of the study.
“That said, it is concerning when substantial funds are being spent by public payers on treatments that do not work,” he added. “As the authors suggest, one option is to tie reimbursement to efficacy. While patients living with deadly conditions cannot indefinitely wait for treatments to be validated, clawing back payments in the event of inefficacy is always an option.”
The study was funded by Arnold Ventures. Dr. Rome reported receiving grants from the Elevance Health Public Policy Institute, the National Academy for State Health Policy, and several state prescription drug affordability boards outside the submitted work. Powell had no relevant disclosures.
A version of this article appeared on Medscape.com .