This clinical trial is focused on studying a condition called X-linked hypophosphatemia, a rare genetic disorder that affects the bones and teeth due to low levels of phosphate in the blood. The study will investigate a new treatment called KK8123, which is a novel protein-based medication designed to be administered as a solution for injection under the skin.
The purpose of the study is to assess the safety and tolerability of KK8123 in adult patients with X-linked hypophosphatemia. The study will be conducted in two parts. In the first part, participants will receive increasing doses of KK8123 to determine the safest and most effective dose. In the second part, participants will receive multiple doses to further evaluate the safety and effects of the treatment over time.
Throughout the study, participants will have regular check-ups to monitor their health, including blood tests and other assessments to measure the levels of phosphate in their blood and to check for any side effects. Some participants may receive a placebo, which is a substance with no active medication, to compare the effects of KK8123. The study aims to provide valuable information about the potential benefits and risks of this new treatment for people with X-linked hypophosphatemia.



France
Germany
Spain