TNFSF11 Inhibition and Fertility: a Prospective Study

Summary

The receptor activator of NF-kB ligand (RANKL) system is considered important for bone homeostasis and comprises three important factors. RANKL exist in three isoforms but the predominant function is mediated by the transmembrane ligand that binds to a specific receptor (receptor activator of NF-KB (RANK)) on a neighbour cell that subsequently activates NFKB and regulates cell cycle OPG is an endogenous secreted protein that binds RANKL and inhibits its signalling. Thus, the RANK/RANKL system is vital for activation of the bone resorbing cells (osteoclasts). In bone the bone synthesizing cells (osteoblasts) express RANKL that signals to RANK on the immature osteoclasts. This induces proliferation and activation of the cells they start to proliferate and resorp bone. OPG is produced by somatic cells in the bone and this production is regulated by sex hormones, TGF-B and various other substances. Today a human made recombinant antibody against RANKL, Denosumab is used to treat osteoporosis as it inhibits RANKL signalling and thus causes less bone resorption in humans. RANKL, RANK and OPG are expressed in the testis and this pathway appears to be a novel regulator of germ cell proliferation. Decreased semen quality is a major factor of male infertility. Semen quality is a measure of the ability of the sperm to accomplish fertilization. Evaluation of male fertility potential is today basically conducted through semen analysis. There is no treatment for men with no sperm in the ejaculate and there exist no drug that can increase sperm counts.Therefore, drugs that can lower RANKL expression/activity for instance an antibody against RANKL such as Denosumab may be used for this new indication: A new treatment option of infertile men with impaired semen quality.

Timeline

Start

2015-05

Primary completion

2017-02

Completion

2019-01

Publications

• Background Anastasilakis AD, Toulis KA, Goulis DG, Polyzos SA, Delaroudis S, Giomisi A, Terpos E. Efficacy and safety of denosumab in postmenopausal women with osteopenia or osteoporosis: a systematic review and a meta-analysis. Horm Metab Res. 2009 Oct;41(10):721-9. doi: 10.1055/s-0029-1224109. Epub 2009 Jun 17.
• Background Anastasilakis, A. D., et al.
• Background Anastasilakis AD, Toulis KA, Polyzos SA, Terpos E. RANKL inhibition for the management of patients with benign metabolic bone disorders. Expert Opin Investig Drugs. 2009 Aug;18(8):1085-102. doi: 10.1517/13543780903048929.
• Background Blomberg, Jensen M.
• Background one, H. G., et al.
• Background Boonen, S., et al.
• Background Cummings SR, San Martin J, McClung MR, Siris ES, Eastell R, Reid IR, Delmas P, Zoog HB, Austin M, Wang A, Kutilek S, Adami S, Zanchetta J, Libanati C, Siddhanti S, Christiansen C; FREEDOM Trial. Denosumab for prevention of fractures in postmenopausal women with osteoporosis. N Engl J Med. 2009 Aug 20;361(8):756-65. doi: 10.1056/NEJMoa0809493. Epub 2009 Aug 11.
• Background Jorgensen, A., et al.
• Background Kwiecinski GG, Petrie GI, DeLuca HF. Vitamin D is necessary for reproductive functions of the male rat. J Nutr. 1989 May;119(5):741-4. doi: 10.1093/jn/119.5.741.
• Background Papapoulos, S., et al.
• Background Polyzos, S. A., et al.
• Background Schwarz, P., et al.
• Background Skakkebaek NE, Rajpert-De Meyts E, Main KM. Testicular dysgenesis syndrome: an increasingly common developmental disorder with environmental aspects. Hum Reprod. 2001 May;16(5):972-8. doi: 10.1093/humrep/16.5.972.
• Background Toulis KA, Anastasilakis AD. Increased risk of serious infections in women with osteopenia or osteoporosis treated with denosumab. Osteoporos Int. 2010 Nov;21(11):1963-4. doi: 10.1007/s00198-009-1145-1. Epub 2009 Dec 15. No abstract available.
• Background Uhland AM, Kwiecinski GG, DeLuca HF. Normalization of serum calcium restores fertility in vitamin D-deficient male rats. J Nutr. 1992 Jun;122(6):1338-44. doi: 10.1093/jn/122.6.1338.

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Indications