Gene shot tested for rare nerve disease

This was an early Phase 1/2a study for adults with genetically confirmed CMT1A. All 12 participants received Engensis injections into weakened leg muscles and were followed for about 270 days.

Because there was no placebo group, this study was not designed to give a final answer. Its job was more humble than that. Think of it like dipping a toe into the water before crossing the river: first you ask, “Does this seem safe?” and only later do you ask, “How far can this really take us?”

On safety, the official results were reassuring for such an early trial. A few adverse events were reported, including injection-site itching, peripheral edema, pneumonia, and uterine leiomyoma, each in one participant. The sponsor described the treatment as well tolerated, and the safety goals of the study were met.

That matters, because in early-stage research, safety is the first gate. Before a treatment can try to help people more, it has to show it can enter the room without breaking the furniture.

The most encouraging signal came from the CMT Neuropathy Score version 2 (CMTNS-v2). On average, the score improved from 15.58 at baseline to 13.42 at day 270, which means symptoms looked less severe over time.

Other measures also moved in a hopeful direction. The Functional Disability Score improved on average, and the Overall Neuropathy Limitation Score for the legs also showed a modest improvement. The 10-meter walk test, however, changed very little, so walking speed did not clearly improve in this small study.

In other words, the picture was not perfect, but it was not empty either. It was more like hearing a few clear notes from a piano in another room — not yet a full song, but enough to know someone may be playing.

The official results also included MRI muscle measurements and nerve testing, and those findings were more mixed. Still, the overall pattern gave the sponsor enough reason to describe the trial as promising.

So what should families and patients take from this?

The fairest answer is: hope, with caution.

This study was small. It was early. And without a placebo group, it cannot prove that Engensis works. But it did show a signal that may be worth following. In rare diseases like CMT1A, that matters. Sometimes progress does not arrive like a thunderclap. Sometimes it starts as a knock at the door.