US FDA targets endpoints, preclinical testing and trial design to advance gene therapies
The US Food and Drug Administration (FDA) has released recommendations aimed at supporting the development of gene therapies in three disease categories: haemophilia, retinal disorders, and rare diseases.
The guidances cover the FDA’s current thinking on clinical trial design, preclinical considerations designed to support development, and surrogate endpoints that could be used by sponsors to help accelerate approval.
According to FDA commissioner Scott Gottlieb, the Agency’s “new commitment” to developing disease-specific recommendations reflects growing activity in this field.
The guidance documents are intended “to serve as the building blocks of a modern, comprehensive framework for how we’ll help advance the field of gene therapy, while making sure new products meet the FDA’s gold standard for safety and effectiveness,” said Gottlieb in a statement.
WCG (WIRB-Copernicus Group)’s senior scientific advisor of gene therapy, Daniel Kavanagh, told us the documents clearly reflect a response by the FDA to challenges encountered by sponsors making decisions about new product development.
“A greater understanding of FDA expectations should help sponsors avoid expending time and resources on unproductive drug development efforts,” he said.
“Sponsors, investigators, and regulators who are accustomed to product development for small molecules and less complex biologics need to orient themselves to operational and regulatory considerations that arise with development of many complex gene therapy products,” he added.
A call for cheaper meds
The Agency has approved three gene therapies to date: Novartis’ Kymriah (tisagenlecleucel) in August 2017, Gilead Sciences’ Yescarta (axicabtagene ciloleucel) in October 2017, and Spark Therapeutics’ Luxturna (voretigene neparvovec-rzyl) in December 2017. Kymriah received US approval for a second indication in May this year.
When approved in 2017, the list price of a single treatment of Kymriah, was set at $474,000 (€390,000), and Yescarta, at $373,000.
While according to Kavanagh, there is a “constant push for improvements” across the development process – from molecular target identification, to gene transfer technology and manufacturing, through to preparing sites and investigators to handle product safety – he said more could be done regarding reimbursement for these expensive medicines.
“Broadly speaking, a major issue facing the field in general relates to reimbursement for approval products, some of which involve a high cost for treatment,” Kavanagh told us.
Novartis made a move to combat this issue in 2017, when the Swiss firm partnered with the US Centers for Medicare and Medicaid Services (CMS) on an indication-based pricing scheme. According to the agreement, only acute lymphoblastic leukaemia (ALL) patients who respond to Kymriah by the end of the first month are required to pay for the treatment.
Kavanagh continued: “The more clarity that sponsors have with the respect to the commercial outlook for specialised indications, the more resources can be applied to broad, systematic product development.”