NOTE: I am a paid consultant to Nyxoah, reviewing preoperative drug-induced sleep endoscopy videos. I have no access to any data regarding treatment outcomes.

The just-concluded 2024 Miami International Surgical Sleep Society meeting included presentation of long-awaited trials from Nyxoah’s DREAM study and a number of other important presentations for the field of sleep surgery. This post shares what I feel were the most intriguing presentations from surgeons participating in the Nyxoah and LivaNova trials of neurostimulation technologies to treat obstructive sleep apnea.

Nyxoah’s DREAM study of the Genio system enrolled 115 study participants with moderate to severe obstructive sleep apnea and a body mass index <32 kg/m2 who were not able to tolerate CPAP. Of these, 2 were not implanted and 3 moved away from test sites soon after device activation (2 months following surgery), with the move at least somewhat related to the life disruption of the COVID-19 pandemic. Of the remaining 110, only 88 completed followup to 12 months. Some had adverse events requiring device removal, others withdrew their consent, and others were lost to follow up.

The results showed that, overall, there was a reduction in the average apnea-hypopnea index from 28 to 9.5 events/hour, an impressive result that also includes a response rate of 66% (assuming all of the 22 study participants without 12 month sleep study results were non-respodners) to 82% (the proportion among those who did have a sleep study 12 months after device implantation surgery). There were other meaningful objective and subjective improvements as well.

Whenever we see results that are this impressive, we want to look more deeply. Because sleep apnea tends to be worse when people sleep on their back, one of the ways we look at results more carefully is to examine whether the apnea-hypopnea index specifically in the supine or non-supine body position changes. It turns out that other hypoglossal nerve stimulation technologies (Inspire and LivaNova) often do not have a substantial decrease in the supine apnea-hypopnea index. An important finding of the DREAM study was that there was a 70% reduction in the supine apnea-hypopnea index (49 to 23 events/hour) and the non-supine apnea-hypopnea index (13 to 5 events/hour); these indicate that the reductions in the overall figures were real and not related to differences in body position.

Investigators from LivaNova’s OSPREY trial of the aura6000 system shared the news reported in March that the FDA allowed them to stop the OSPREY trial because preliminary results showed a high likelihood of positive results in the trial. While the OSPREY trial results are not yet available, we all will be looking forward to them.