Patients with spinal injuries have continued to heal long after they’ve received an initial injection of stem cells, according to data released Oct. 2 by the biotech company conducting a clinical trial on the treatment.
One year after six patients with severe spinal injuries were dosed with 10 million stem cells, four in the group have recovered at least two full motor levels of movement on at least one side of their bodies. That degree of improvement, based on the International Standards for Neurological Classification of Spinal Cord Injury scale, is about twice the rate of recovery patients historically see, according to the company, Asterias Biotherapeutics of Fremont, California.
"The rate of recovery at 12 months is more than double the rates of recovery seen at 12 months in both matched historical controls (29%) and published data in a similar patient population (26%)," the company wrote in a press release.
According to Edward Wirth III, chief medical officer at Asterias, all six patients in the second cohort of the study progressed at least one motor level on one side; three patients improved two levels on one side; and one patient advanced three motor levels on one side. In addition, Wirth said, almost all the patients showed improvement on both sides of their bodies, and two of them jumped two motor levels on both sides.
Regaining two motor levels in spinocervical patients is significant. That could make the difference between full paralysis from the neck down, a condition that would require a ventilator to breathe, versus regaining some arm, hand and finger movement, allowing patients to take care of many of life’s daily tasks unassisted.
We reported last year on the striking initial results of this experimental phase 2 clinical trial, called SCiStar. The updated information suggests patients in this second cohort of the study not only received strong early benefit from the large single dose of stem cells, but that they have continued to improve over time.
Dr. Charles Liu, an investigator on the study and director of the USC Neurorestoration Center, has a patient in the second cohort of the trial, 21-year-old Kris Boesen of Fresno, whose substantial progress we first reported in September 2016.
Liu says most spinal-injury patients, once they’ve gone through initial recovery, tend to remain at the same level of movement.
“They can get a little bit better, but there’s definitely a point of plateau," Liu says.
But the new data from the trial shows continued progress. At the six-month mark, for instance, only two of the patients attained two-motor-level-improvement. After 12 months, two more had attained the milestone.
“Usually what you see is a plateau and that’s not what we’re seeing here. They continued to improve,” Liu says. “It was a durable effect. And that’s incredibly exciting.”
The six people in the second cohort obviously represent a small sample size, and some patients do spontaneously recover from spinal injuries. But Liu believes now that the replication of Boesen's progress has occurred in multiple patients, it’s more difficult to write them off as outliers.
There are five cohorts of patients in the study. The first received 2 million stem cells, the second 10 million, and the third is still in the process of receiving 20 million. The patients who received 2 million stem cells showed some benefit from the treatment, but not nearly as much as the 10-million-cell cohort. The fourth and fifth cohorts target a different level of spinal injury, using dosages of 10 million and 20 million cells.
Enrollment is completed for the first four rounds of the trial; the fifth cohort's enrollment has begun and is expected to be completed by the end of this year, Asterias officials said.
The San Francisco Chronicle also wrote about the trial this week, in a front-page article. Reporter Erin Allday spoke with Christopher Block, a 31-year-old patient in the SCiStar trial who had virtually no movement in his arms after he injured his spinal cord in a biking accident.
“About a month after my stem cells, I was able to begin feeding myself,” Block told the Chronicle. He can now raise himself out of his wheelchair and change his shirt, he said.
On Monday, Asterias announced that the FDA had granted its request for designation of its stem cell treatment as a regenerative medicine advanced therapy, or RMAT. One of the conditions of that designation is that preliminary clinical evidence indicates the treatment has "potential to address unmet medical needs" related to a "serious or life-threatening disease or condition." The designation, which was created under the 21st Century Cures Act last year, was designed to accelerate review and approval by the FDA.
SCiStar is partially funded by the California Institute for Regenerative Medicine, or CIRM, the publicly funded stem cell agency created by a state initiative in 2004.