In addition to the Phase 3 clinical trials of KRN23 that we mentioned previously (starting in October, not yet recruiting), there's another, smaller study that will begin in November (also not yet recruiting). You can read about it here: https://clinicaltrials.gov/ct2/show/NCT02537431?term=XLH&rank=2
This study is for XLHers who have NOT been on the standard treatment regimen at any time during the past two years. This study will consist of approximately ten patients, and will involve bone biopsies rather than blood and urine samples. The intent is to study the effects on the bone directly, rather than indirectly (using blood tests as a proxy for what is happening to the bones).
If you're interested in participating, be sure to read the information at the link above, and watch for an announcement (here, on the listserv and at the official Facebook page) that recruiting has begun.
The XLH Network, Inc. does not endorse or critique specific clinical trials, and does not counsel individual patients either for or against participation in any specific clinical trial. Prospective volunteers should always carefully review the clinical trial's informed consent documentation, and discuss the pros and cons of their participation with trusted advisers, including their health care providers and family members.