The primary efficacy endpoint was the improvement in International Prostate Symptom Score (IPSS) at 12 months in the Optilume BPH arm compared to the improvement in IPSS at 3 months in the Sham arm with a super-superiority margin on 25%.
The IPSS contains the well-validated, highly reliable and responsive American Urological Association symptom score (AUASS) assessment to identify the severity of BPH symptoms. The first seven questions in the IPSS address frequency, nocturia, weak urinary stream, hesitancy, intermittence, incomplete emptying, and urgency, and scored on a 6-point scale (0 to 5). The IPSS can be interpreted as follows: 0-7 mildly symptomatic, 8-19 moderately symptomatic, and 20-35 severely symptomatic.
The IPSS also includes an eighth question that is designed to assess the degree of "bother" associated with the subject's urinary symptoms. Answers range from "delighted" to "terrible" (0-6). This question is not included in the calculation of the main IPSS score.