Anakinra, Known Anti-inflammatory, in Phase 2/3 Trial for Sanfilippo

An ongoing clinical trial is investigating an approved anti-inflammatory compound anakinra, sold under the brand name Kineret, as a potential treatment for Sanfilippo syndrome.

The Phase 2/3 pilot trial (NCT04018755) opened in May in the U.S. and has enrolled 20 children, ages 4 and older, all of whom will be treated in this open-label study. It is sponsored by The Lundquist Institute, in collaboration with the Cure Sanfilippo Foundation and Sobi (the company that markets Kineret).

“The fastest way to improve the lives of children affected by Sanfilippo and their families is through meaningful, hand-in-hand collaboration among scientists, industry, and parents,” Cara O’Neill, MD, chief science officer at the Cure Sanfilippo Foundation and the mother of a 10-year-old with this disease, said in a press release.

“By bringing the scientific and caregiver communities together in the evolution of this trial, we are developing innovative patient-focused, caregiver-informed endpoints that will improve the chance of understanding the true impact and potential benefit of this and any future experimental therapy,” O’Neill said, with a goal of “streamlining our path to an FDA-approved treatment for Sanfilippo syndrome.”

One of the characteristics of Sanfilippo syndrome is inflammation in the brain. Previous research in a mouse model of Sanfilippo suggested that this inflammation is driven, in large part, by the pro-inflammatory signaling molecule interleukin-1 (IL-1), which signals by interacting with a protein receptor (called the IL-1 receptor, or IL-1R).

In the mouse model, blocking IL-1R using an IL-1R antagonist normalized such behavioral problems as memory loss and hyperactivity.

Kineret is approved by the U.S. Food and Drug Administration (FDA) to treat rheumatoid arthritis and certain other inflammatory conditions. Its main compound, anakinra, works as an IL-1 antagonist — that is, by blocking IL-1R.

“This unique partnership allows us the freedom to study some non-traditional outcomes that are very important to this group of patients and their families, but have not been the focus of prior clinical trials,” said Lynda Polgreen, MD, with The Lundquist Institute, who, like O’Neill, helped to design this trial.

There are notable benefits to using a medication that is already approved for other conditions, if it is shown to be effective. Since it has already been used and studied in people, its safety profile is better known than a fully investigative treatment. Pre-existing therapies may also be available at lower cost than new ones.

Patients enrolled in this pilot trial are being observed for an initial eight weeks. They then move to treatment, with 100 mg of anakinra given by subcutaneous (under-the-skin) injection once a day for 36 weeks. Patients then undergo another observational period to determine any effects of withdrawal from the treatment.

Its main goal is to assess how the treatment affects a variety of domains, including behavior, communication, sleep, seizure frequency, and motor abilities.

“Our hope is that this study will show that anakinra, the same IL-1RA product we used to treat Sanfilippo mice, will similarly improve behavioral problems in children with Sanfilippo,” said Brian Bigger, PhD, a University of Manchester professor who co-authored the mouse study.