NSI-566 is an experimental stem cell-based therapy being developed by Neuralstem as a potential treatment for amyotrophic lateral sclerosis (ALS).

NSI-566 is also being investigated as a potential treatment for chronic spinal cord injury (cSCI) and for restoring motor deficits after an ischemic stroke.

The treatment was granted orphan drug designation for ALS by the U.S. Food and Drug Administration (FDA) in August 2018.

How NSI-566 works

NSI-566 is a human spinal cord-derived neural stem cell line (HSSC), which originates from the spinal cord of an eight-week-old aborted fetus.

When injected into the spinal cord, these fetal stem cells differentiate into the kind of neurons that are usually found in the adult human body. They surround and support the impaired motor neurons in ALS by integrating into the neural network and forming connections (synapses) with the patient’s neurons. They also secrete neurotrophic factors or proteins that promote the growth and survival of motor neurons.

Through these mechanisms, NSI-566 is thought to decrease motor neuron loss in ALS patients and improve motor function.

NSI-566 in clinical trials

A study that analyzed long-term follow-up results from Phase 1 (NCT01348451) and Phase 2 (NCT01730716) clinical trials of NSI-566 transplants was published in March 2018 in Annals of Clinical and Translational Neurology.

The Phase 1 study assessed the safety of HSSC injection into the spine of ALS patients and the Phase 2 study assessed the safety of escalating doses of the treatment. Both studies confirmed the safety of HSSC transplants.

In the follow-up analysis of these two studies, clinical outcome and survival of ALS patients for up to three years were compared with data from previous ALS clinical trials.

The previous data were obtained from the PRO-ACT database and the ceftriaxone (Rocephin) trial. The PRO-ACT database contains results from 23 Phase 2 and 3 ALS clinical trials. The ceftriaxone trial assessed the safety and efficacy of ceftriaxone (an antibiotic) in the treatment of ALS.

Measurements that were included in the analysis were ALSFRS-R, an ALS functional rating scale that is based on a questionnaire, and ALS/SURV, a composite statistical analysis that combines survival and functional outcomes.

Data from 21 Phase 1/2 clinical trial participants were compared to data from 1,108 people from the PRO-ACT database and data from 20 Phase 1/2 clinical trial participants were compared to data from 177 people from the ceftriaxone trial.

The results showed that after 24 months, the ALSFRS-R and ALS/SURV scores were significantly higher in people who received an NSI-566 transplantation than in both comparison groups. Survival did not differ significantly between groups.

Neurostem is hoping to use the results from this study to design a Phase 3 clinical trial to further testNSI-566 for the treatment of ALS.


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