A 29-year-old British man is the first person to be treated in a gene therapy clinical trial for X-linked retinitis pigmentosa (XLRP). Robert MacLaren, MD, the lead investigator for the trial taking place at the Oxford Eye Hospital in the United Kingdom, says the patient is doing well and has gone home. The trial is being run by Nightstar, a biopharmaceutical company in the U.K. developing therapies for inherited retinal diseases. As many as 24 patients will be enrolled in the 12-month trial.
Company Builds on FFB’s Initial Investment to Garner $265 Million in Therapy Development Funding
In the early 1990s, scientists began discovering the genetic defects causing blinding, inherited retinal diseases and saw a unique opportunity to overcome them. They envisioned gene therapy — delivering healthy genes to the retina to replace the bad ones — as an elegant approach to saving and restoring vision. Furthermore, a single injection of gene therapy would likely halt or reverse the disease process and work effectively for several years, perhaps the patients’ lifetimes.
The Foundation Fighting Blindness, the world’s leading private, nonprofit retinal research organization, funded most of these genetic discoveries for retinal diseases and immediately recognized the enormous opportunity for gene therapy to beat blindness.
Sometimes, fighting blindness means helping people save the vision they have, or at least slowing disease progression enough so they can maintain useful vision for all of their lives.
That’s the idea behind a promising, emerging drug for retinitis pigmentosa (RP) known as N-acetylcysteine-amide (NACA). The Foundation Fighting Blindness Clinical Research Institute (FFB-CRI) has announced an investment of up to $7.5 million to advance the potential therapy into and through a Phase II clinical trial. In several animal models, including previous FFB-funded lab studies of rodent models at Johns Hopkins University, NACA slowed retinal degeneration.
No, people with inherited retinal diseases don’t have to adopt new names or personas, or go into witness protection programs, to save their vision. But by changing the identity of cells in the retina — namely rods — researchers may someday be able to slow or halt vision loss for those with retinitis pigmentosa (RP) and other related conditions.
While the innovative therapeutic approach is not ready to be tested in humans, a research team led by Tom Reh, PhD, University of Washington, and Sheng Ding, PhD, University of California, San Francisco, accomplished the feat in mice with RP. The investigators treated rods in the mice with a compound known as photoregulin1 (PR1) that blocked a gene involved in rod development called Nr2e3. That, in turn, reduced the expression (activity) of other rod-associated genes, making the rods less rod-like and more like cones. Doing so stopped retinal degeneration, preserving both rods and cones. Rods and cones are important, because they’re the cells that make vision possible. Results of the PR1 study were published online in the journal Investigative Ophthalmology & Visual Science.
When scientists embark on developing a treatment for an inherited retinal disease, one of their first tasks is to identify or create a model of the condition. Disease models can be cells in a Petri dish, a genetically engineered mouse or rat, or larger animal such as a pig. Each type of model has its pros and cons, including cost and similarity of disease characteristics to those in humans.
The investigators then use the model to study how vision is lost — that is, they figure out which types of retinal cells degenerate, what is causing the degeneration, and how quickly the cells stop working. After they gain an understanding of the disease, researchers evaluate potential therapeutic approaches using the model as a testing platform.
The goal: Move a therapy into a human study.
Considering all that Richard Weleber, M.D., has accomplished over four decades —
including leadership and oversight of clinical trials for emerging retinal-disease therapies and innovations in retina imaging and functional evaluation at the world-renowned Casey Eye Institute, Oregon Health & Science University — it comes as no surprise that he’s been given FFB’s Llura Liggett Gund Award for career achievement. Dr. Weleber became the 10th recipient of the Foundation’s highest honor, named after FFB co-founder Lulie Gund, during the opening lunch of the VISIONS 2016 conference.
Inherited retinal conditions such as Stargardt disease and retinitis pigmentosa (RP) run in families. The diseases in some families span several generations with dozens of affected members. In other cases, a disease may only affect one or more siblings within a single generation. Researchers have understood the nature of these different inheritance patterns fairly well for several decades.