Delivering tAN to Reduce HMB: The LUNA Study

The LUNA study is a prospective, randomized, double-blind, sham-controlled, decentralized clinical trial in participants with heavy menstrual bleeding of no known structural cause. The study includes two age-based cohorts: adolescents aged 14-21 and adults aged 22-45. Participants in both cohorts will be randomized to receive transcutaneous auricular neurostimulation (tAN), which targets the auricular branch of the vagus nerve (ABVN) and the auriculotemporal nerve (ATN), or sham stimulation. Participants will be enrolled into the study over the course of five consecutive menstrual cycles. All study activities will occur remotely and in addition to participants' typical treatment for HMB (as allowed by the eligibility criteria). During the first two consecutive menstrual cycles (M1 - M2, "Baseline Phase"), no tAN treatment will be delivered. Participants will estimate blood loss using the Pictorial Bleeding Assessment Chart (PBAC), and menstrual cramp pain will be assessed with a Numerical Rating Scale (NRS), daily throughout the duration of the menstruation phase of their two baseline menstrual cycles. Menstrual symptoms will be assessed using the Cox Menstrual Symptom Scale (CMSS) and a general quality of life assessment will be conducted on the final day of menstruation using the RAND Short-Form 36 (RAND-36). Menstrual-related quality of life assessments will also be conducted on the final day of each menstruation using the Menstrual Bleeding Questionnaire (MBQ) in the adult cohort, and the adolescent version (aMBQ) in the adolescent cohort. During the following three consecutive menstruations (M3 - M5, "Treatment Phase"), participants will self-administer one 2-hour sham or active tAN session daily, beginning Day 1 of menstruation through the final day of menstruation in each menstrual cycle. Blood loss (via the PBAC) and menstrual cramp pain (via the NRS) will be assessed daily throughout the duration of each menstruation. Quality of life will be assessed with the CMSS, RAND-36, and the MBQ (adults) or aMBQ (adolescents) on the final day of each menstruation. A device usability survey will be completed at the end of M3 and M5. Participants will exit the study after the final day of M5.

NCT Number	NCT07326722
Lead Sponsor	Spark Biomedical, Inc. Collaborators: Lindus Health, Wellcome Leap, Oregon Health and Science University, University of Michigan Health, Yale University
Conditions	Heavy Menstrual Bleeding
Enrollment	80 participants
Start Date	2026-03-06
Primary Completion	2027-08-31 (estimated)
Study Completion	2027-08-31 (estimated)
Updated on ClinicalTrials.gov	2026-06-02