Novel approach for oligospermia (NAPO) - Protocol for a randomized controlled trial

BACKGROUND: Infertility affects millions of couples globally, with up to 40-50 % of cases linked to impaired semen quality. Insemination or in vitro fertilization are used frequently, regardless of the cause of infertility due to the lack of specific medical interventions for male infertility. Denosumab, an antibody blocking RANKL signaling, may enhance semen quality in infertile men. This randomized controlled trial evaluates if denosumab improves spermatogenesis in men with severely impaired semen quality identified by serum AMH levels as a predictive marker.

METHODS: NAPO is a single-center, sponsor-investigator-initiated, placebo-controlled, double-blinded randomized trial. Subjects will be randomized in a 2:1 fashion to receive either denosumab 60 mg subcutaneously or a placebo. The study will be carried out at the Division of Translational Endocrinology, Copenhagen University Hospital, Herlev, Denmark. The primary outcome of the study is defined as the difference in sperm concentration (millions/mL) at one spermatogenesis (80 days) after inclusion.

DISCUSSION: An important step in addressing infertility is establishing a viable treatment option for male infertility. With this study, we describe the protocol for a planned RCT aimed at evaluating whether treatment with denosumab can improve sperm concentration in men with severely impaired semen quality. The results of this study will provide evidence crucial for future treatment in a patient group where treatment options are minimal at best.

TRIAL REGISTRATION: Clinical Trials: NCT06300229. Registered on March 12, 2024. Clinical Trials Information System (CTIS): 2023-508325-27-00. Approved on December 19, 2023.