Ready to use Parkinson’s stem cell therapy put on FDA fast track

An off-the-shelf, or ready to use, stem cell therapy that’s designed to replace the nerve cells lost in Parkinson’s disease and restore neurological function has been put on a developmental fast track by the U.S. Food and Drug Administration (FDA).

The FDA awarded fast track status — a designation that could mean a faster pathway through regulatory review if clinical data are positive — to XS411, being developed by China-based Xellsmart. Clinical trials have already been cleared in both China and the U.S. to test the injection therapy.

According to the developer, a Phase 1/2 study (NCT07166757) in China has shown benefits with the therapy’s use in people with early-onset Parkinson’s.

In a company press release, Xellsmart called the new U.S. designation a “key milestone for [the] global clinical development” of XS411. Such status offers more frequent communication with the FDA and access to rolling review, which means parts of the data can be submitted as they become available rather than waiting until the full package is ready before filing for approval.

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XS411 was cleared by the FDA last year for a Phase 1 clinical trial. The treatment’s now being tested for early-onset Parkinson’s at a single location in Shanghai. The study, which enrolled an estimated 90 people, is evaluating the safety and effectiveness of injecting XS411 directly into the putamen, a key brain region impacted by the disease.

Xellsmart stated that XS411 has already reached Phase 2, after encouraging Phase 1 data showed it was well tolerated and helped patients have more time with their medications working effectively. Participants also experienced less severe motor symptoms and a better quality of life, while brain imaging suggested the transplanted stem cells survived and produced dopamine.

Stem cell therapy aims to replace lost nerve cells

The symptoms of Parkinson’s occur due to the gradual damage of nerve cells that produce dopamine, a chemical messenger that helps control movement. As dopamine-producing nerve cells are lost, patients can experience tremors, stiffness, and balance problems, among other issues.

XS411 contains induced pluripotent stem cells, or iPSCs. These are adult cells from a donor that have been reprogrammed to behave like stem cells, allowing them to develop into different types of cells. In this case, they are turned into dopamine-producing nerve cells, also known as dopaminergic neurons.

Injected directly into the brain, stem cells in XS411 are expected to mature into functioning dopamine-producing nerve cells, replacing the ones lost in Parkinson’s. If successful, this could improve movement and possibly slow the progression of the disease rather than only treating symptoms. XS411 is manufactured in advance, stored, and made available for patients when needed; hence, the off-the-shelf terminology.