For Stem Cell Therapy, No Prescriptions Yet
Date: November 30, 2009
Every week, Nicholas Maragakis hears from patients who have read about advertised stem cell treatments offered abroad for neurological conditions. They want to know whether the therapy might work for them. One company attests that its stem cell therapy can help patients with ALS. Another offers fetal stem cell therapy for Down syndrome, spinal cord injury, epilepsy and brain damage. Still others claim to have stem cell treatments for stroke, Parkinson disease, Alzheimer disease and more.
But Maragakis and many other Johns Hopkins neurologists say the claims come far in advance of solid data to support them. “I tell patients,” says the neuromuscular disease specialist, “that stem cell transplantation on a large scale is not ready for prime time.”
Almost all the ads in question are based on patient testimonials, not published results, he explains. And the formal studies that have been conducted have involved too few patients to demonstrate safety or efficacy. Plus, he says, “A lot of these strategies lack a sound scientific explanation for how or why they should be working.” One purported treatment, for example, involves injecting stem cells intravenously, but its proponents fail to explain how the cells would reach the nervous system.
However, says Maragakis, research progress is being made. In his own studies, he has focused on stem cell therapy for various motor neuron conditions. He and his colleagues recently demonstrated that stem cell treatments improved breathing function and prolonged survival in an animal model of ALS. Other teams have found similar results in other models. And recently, the FDA approved the first phase I trial of stem cell therapy for ALS. At this point, Maragakis notes, the studies are principally intended to evaluate the safety of the procedure.
Hopkins scientists are also studying various ways of exploiting stem cells for brain cancer therapy. One approach involves targeting tumors’ own stem cells. In the past few years, scientists have discovered that various types of cancers produce stem-cell-like precursor cells. These cells appear to have the ability to replenish the tumor’s own cells and are possibly the factor responsible for metastasis. Many research groups are now searching for drugs that will target and kill such tumor stem cells. At Hopkins, neurologist John Laterra and his colleagues are preparing to launch several clinical trials aimed at targeting the stem cells in gliomas.
Using another approach, Hopkins neurosurgeon Alfredo Quinones-Hinojosa is developing methods for genetically programming stem cells derived from fat to home in on glioma cells and deliver drugs or genes that destroy them.
“Stem cell research—my work and other scientists’—is promising and exciting,” says Quinones-Hinojosa. “It brings hope and offers new experimental paradigms.” But, he adds, that’s not to say that the therapy is anywhere near ready for clinical use.
“It will be another five to 10 years before we understand whether this concept will be feasible or not. The field is like a movie that just began, and we’re [just] rolling the opening credits. We don’t even know what the plot is yet. We’re very much in the earliest stages.” He stresses the need for continuing research on stem cell therapy, in the hope that it might one day improve the prognosis for patients with brain cancers.
For more information: www.hopkinsmedicine.org/neuro