An international group of XLH medical experts have been meeting annually since 2021 to discuss the current state of treatment and research. They recognize that the understanding of XLH is undergoing fairly rapid changes, and also that their colleagues have useful clinical experience to share where hard data is missing.
Th group recently published an extensive article — more like several articles’ worth of information in one! — based on their 2022 meeting, “XLH Matters: 2022 Insights and Recommendations to Improve the Lives of People with XLH.”
It concludes, in much more scientific language than I use, what patients have been saying for a while: phosphate/calcitriol treatment is only marginally effective. They say: “Conventional therapy, comprising oral phosphate and active vitamin D analogues, insufficiently improves specific clinical manifestations associated with XLH, including growth velocity, lower limb alignment and dental health. Indeed, cohort data show that adults commonly experience unresolved complications of childhood disease due to insufficient action of conventional therapy or absence of treatment during childhood.”
I love how truly patient-focused the article is, demonstrating true understanding of the patient experience (to the extent anyone can understand it without experiencing it for themself), and the importance of looking at the long-term consequences of treatment (or the failure to treat). They go about as far as they can, as emphatically as they can, given the limits of existing data, to say (in essence) that the old treatment regimen is inadequate, and patients should generally be on the newer, more effective treatment for life. They can’t be quite that blunt (yet), but they come pretty close, and I think they’ll get even more blunt in the future, as more data and clinical experience reports become available.
There’s a summary graphic that’s particularly interesting, gathering a lot of information into a single image: https://ojrd.biomedcentral.com/articles/10.1186/s13023-023-02883-3/figures/1 It shows which symptoms manifest in which age range, how they worsen over time, and even indicates which symptoms are commonly overlooked by clinicians without a lot of XLH experience (especially pseudofractures, enthesopathy and spinal stenosis).
I highly recommend downloading the article for your own records and for sharing with your clinician. There’s a good section on clinical goals, both short-term and long-term, that’s worth considering for yourself and perhaps discussing with your clinician if you don’t feel your treatment goals are being met. It might also be a good article to send to your health insurer if they try to deny (or non-renew) your coverage for burosumab or for auxiliary treatments like physical therapy or occupational therapy.
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Please note that the author is a well-read patient, not a doctor, and is not offering medical or legal advice.
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