The Institute for Clinical and Economic Review concluded that the few existing therapies for Duchenne muscular dystrophy require steep discounts to be cost-effective and more clinical data to demonstrate their benefit.
A genetic disorder characterized by progressive muscle degeneration and weakness, Duchenne muscular dystrophy, or DMD, mainly affects boys.
The U.S. pricing watchdog known as ICER wrote in its final evidence report, published Aug. 15, that PTC Therapeutics Inc.'s corticosteroid treatment Emflaza would need to be discounted by at least 73% from its current list price to meet "commonly accepted thresholds for cost-effectiveness."
Emflaza, also known as deflazacort, has an annual list price of $117,400 and a net price of $81,400. That equates to $344,000 per quality-adjusted life year, or QALY, gained, above ICER's determined cost-effective range of $50,000 to $150,000 per QALY gained.
"An inexpensive drug that was available overseas for years and could be easily brought into the U.S. became unaffordably expensive with [U.S. Food and Drug Administration] approval when the U.S. manufacturer massively increased its price," ICER Chief Medical Officer David Rind said in an Aug. 15 statement.
ICER said Emflaza should instead have an annual price of $19,900 to $31,700.
While the majority of the New England Comparative Effectiveness Public Advisory Council, at a July 25 meeting discussing ICER's key questions, said Emflaza could significantly reduce caregiver or family burden of disease, the panel's majority determined that Emflaza provides low long-term value for money.
The panel majority voted similarly on Sarepta Therapeutics Inc.'s gene therapy Exondys 51, which costs slightly more than $1 million annually, or $1.1 million per QALY gained.
In addition, ICER reiterated that insufficient evidence exists to support Exondys 51's effects in DMD, with the panel emphasizing "significant uncertainty" regarding the treatment's long-term benefits.
"[T]he wholly inadequate evidence base from the manufacturer has created such doubt that payers, faced with the outrageously high price charged by the manufacturer, have created extremely narrow coverage policies," Rind said.
Exondys 51, or eteplirsen, was FDA-approved in 2016. It is an "exon-skipping" gene therapy, meaning it causes a certain section of the disease-driving gene to be skipped, thus allowing the gene to code for a functional protein. Exondys 51 skips exon 51, which affects about 13% of DMD patients.
"Three years after approval, the manufacturer has provided no high-quality evidence of benefit, many patients and families are surely losing out, and only the manufacturer truly benefits from this deplorable situation," Rind continued. "Families and patients with DMD deserve better."
Exondys 51 has not been approved in other countries.
According to ICER, drugs granted accelerated approval such as in the case of Exondys 51 should be priced more closely to the marginal cost of production until clinical benefits are proven.
Sarepta has another DMD drug candidate under FDA priority review, called golodirsen, with an expected decision in August. Golodirsen, also a gene therapy, skips exon 53, which affects about 9% of the DMD patient population.
ICER and the New England panel also noted that Sarepta has yet to prove golodirsen's clinical benefit.