Neural stem cell transplant improves outcomes for chronic ischemic stroke at 12 months

Key takeaways:

• At 12 months, patients demonstrated improved neurological function and better gait speed.
• All adverse events, which initially worsened from baseline, spontaneously resolved.

Transplantation of neural stem cells improved neurologic and motor function for adults with chronic ischemic stroke at 12 months, according to a study presented at the International Stroke Conference.

“There are approximately 7 million chronic stroke survivors in the United States living with severe disability and little hope for recovery,” Gary K. Steinberg, MD, PhD, founder and co-director of the Stanford Stroke Center, told Healio.

As no other treatment aside from vagus nerve stimulation exists to restore function in patients with chronic stroke, Steinberg and colleagues sought to investigate the safety and efficacy of intracerebral transplantation of NR1, human embryonic-derived neural stem cells.

Their first-in-human clinical trial, which spanned 12 months, included 18 adults who were 6 to 60 months post-ischemic subcortical middle cerebral arterial stroke and recorded a Modified Rankin Scale score of 3 or 4. All participants were transplanted with 2.5 million, 5 million, 10 million or 20 million of NR1, with the primary outcome being total adverse events at 12 months as well as change in total Fugl-Meyer motor score (FMMS, 0-100) in both upper and lower extremities compared with baseline at 12 months. Secondary outcomes included performance on a gait speed test, Barthel Index (BI), NIH Stroke Scale score (NIHSS), Fluid-attenuated inversion recovery (FLAIR) MRI, resting state fMRI and Fludeoxyglucose F 18 positron emission tomography (18F FDG PET).

Participants recorded mean increases of 12.1 points for total FMMS, 7.4 points for upper extremity FMMS, 4.7 points for lower extremity FMMS, along with mean changes of 7.7 points for BI, mean NIHSS improvement of 1.77, as well as substantial improvement in gait speed at 12 months.

Data further showed that 14 of 18 participants had a new transient FLAIR signal in premotor cortex that resolved at the 2-month mark, indicative of sustained neurologic recovery, the researchers wrote.

Steinberg and colleagues also reported improved functional sensorimotor connectivity via resting state fMRI as well as increased activity in the ipsilesional motor cortex and contralesional cerebellum confirmed via 18F FDG PET.

Adverse events such as headache, expressive aphasia and asymptomatic chronic subdural hygroma, which worsened from baseline, eventually spontaneously resolved, according to the researchers.

“Our study demonstrated that intracerebral transplantation of NR1 neural stem cells in 18 patients markedly improved neurologic function at 12 months,” Steinberg told Healio. “If confirmed in larger randomized studies, this therapy has the potential to revolutionize chronic stroke care.”