Tumor Induced Osteomalacia

Tumor Induced Osteomalacia is an ultrare condition where a tumor excretes excessive amounts of FGF23, which in turn causes phosphate wasting. It's essentially a tumor-caused (instead of genetically caused) version of hypophosphatemia.

For many patients with TIO, removal of the tumor stops the phosphate-wasting. Unfortunately, however, the tumors are difficult to find and may be located in places where surgery cannot completely remove the tumor. In those cases, the patient may need non-surgical treatment to normalize the phosphorus levels.

There's at least one Phase 2 clinical trial under way to see if the new treatment for XLH (KRN23/burosumab) will also treat patients with TIO, and results will likely be available later in 2017. The study is no longer recruiting, but you can read about it here: https://clinicaltrials.gov/ct2/show/NCT02304367?term=tio&rank=1

A separate, completed study investigated whether an existing treatment, Octeotride, might be used for TIO, but the researchers concluded that it was not effective. You can read about it here: http://onlinelibrary.wiley.com/doi/10.1002/jbmr.3162/full?utm_source=ASBMR%20Feb2017%20e-News%20List&utm_campaign=84cbceefb5-EMAIL_CAMPAIGN_2017_05_04&utm_medium=email&utm_term=0_c35b5c9b70-84cbceefb5-182507117