according to the authors of a new study.
The US Food and Drug Administration (FDA) approved Vyjuvek (Krystal Biotech) in May 2023 for the treatment of wounds in patients ages 6 months and older with dystrophic epidermolysis bullosa (DEB), which includes two types, the most severe form (autosomal recessive, or RDEB) and the autosomal dominant form of DEB (DDEB), which tends to be milder.
Dr. Raymakers
Treatment with Vyjuvek “represents an important advance in the treatment of RDEB,” wrote Adam J.N. Raymakers, PhD, and colleagues at the Program on Regulation, Therapeutics, and Law; the Department of Dermatology; and the Division of Pulmonary and Critical Care Medicine at Brigham & Women’s Hospital in Boston, Massachusetts, in their paper, published in JAMA Dermatology. But the price “will be high, potentially limiting patients’ access to it,” they added. Evidence to support it in DDEB “is less conclusive,” they wrote, noting that the pivotal phase 3 study that led to approval included one patient with DDEB.
“The wider indication granted by the FDA may lead to friction between payers on the one hand and patients and physicians on the other,” they wrote, noting a potential minimum price of $300,000 per patient a year, which was based on Krystal’s regulatory filings.
There is no cure for DEB. Vyjuvek, applied as a gel on an ongoing basis, uses a nonreplicating herpes simplex virus type 1 vector to deliver the COL7A1 gene directly to skin cells, restoring the COL7 protein fibrils that stabilize skin structure.
The authors estimated that in the United States, 894 individuals – largely children – with both forms of the disease would be eligible for Vyjuvek treatment in the first year. Based on the $300,000 price, spending on gene therapy could range from $179 million to $357 million for those 894 patients, they reported in the study.
Over the first 3 years, spending could range as high as $1 billion, the authors estimated. Even if patients with only the most severe disease (RDEB) — an estimated 442 patients — received treatment, spending could be $132 million and up to $400 million or more over the first 3 years, they wrote.
Some media outlets have reported that Vyjuvek could cost as much as $600,000, said Dr. Raymakers, a research fellow. That price “would double all of our estimates,” he told this news organization.
The study assumed that patients with RDEB would only live to age 50, which led to a lifetime cost estimate of $15 million. But that is likely a conservative estimate, he and his coauthors wrote, noting that many patients with RDEB die from squamous cell carcinoma, but that Vyjuvek could, by attenuating skin damage, also potentially prevent skin cancer.
Dr. Raymakers said he and his colleagues began their study when Vyjuvek was approved, and thus they did not have any real-world data on the price or payer responses. Their estimates also did not include differing dosing regimens, which also could change their spending figures.
Krystal Biotech recently reported that in its third quarter of 2023 – representing just 1 month of Vyjuvek availability – it received requests to begin treatment for 284 patients from 136 unique clinicians. Twenty percent of the start requests were for patients with the milder form (DDEB), and a third of all the requests were for patients 10 years of age or younger. The company also said that it had “received positive coverage determinations from all major commercial national health plans” and that it was on track to receive approval from most state Medicaid plans.
In 1 month, Krystal reported net Vyjuvek revenues of $8.6 million.
The authors suggested that one way to evaluate Vyjuvek’s value — especially for those with DDEB — would be through a cost-effectiveness study. While important, a cost-effectiveness study would not get at the impact on a payer, said Dr. Raymakers. “Something can be cost-effective but unaffordable to the system,” he said.
“When there’s one of these very expensive therapies, that’s one thing,” he said. “But when there’s more and more coming to market, you wonder how much can be tolerated,” said Dr. Raymakers.