Solriamfetol Reduces Excessive Sleepiness in Patients With Narcolepsy and OSA

The primary end point was the change in ESS score at the end of the randomized-withdrawal phase. Secondary end points were the changes in PGI-C and the Clinical Global Impression of Change (CGI-C) at the end of the randomized-withdrawal phase. The analysis was performed using a modified intention-to-treat population.

The investigators enrolled 643 participants into the study. Mean age was 49, 52% of the population was male, and mean BMI was 31.7. About 35% of participants had narcolepsy, and 65% had OSA. In all, 282 participants were assigned to the randomized-withdrawal phase, and 361 continued solriamfetol.

By the end of the randomized-withdrawal phase, ESS score had risen from 7.8 to 12.6 in the placebo group, compared with an increase from 7.3 to 8.5 in the solriamfetol group. The least-squares mean difference between the arms was –3.7.

About 65% of patients randomized to placebo reported worsening on PGI-C at the end of the randomized-withdrawal phase, compared with 28% of the solriamfetol group. Similarly, approximately 64% of patients randomized to placebo were rated as worse on the CGI-C at the end of the randomized-withdrawal phase, compared with 29% of the solriamfetol group.

At Week 40, Group A had sustained reductions in ESS score, which indicated long-term efficacy of solriamfetol. Group B had similar results during approximately one year of treatment. “There is no hint of tachyphylaxis,” said Dr. Malhotra. Improvements in PGI-C and CGI-C were stable over time.