Burosumab an emerging therapy in TIO: a local clinical survey and a systematic review with individual patient data analysis

Introduction: Burosumab, a recombinant antibody against fibroblast growth factor 23 (FGF23), is a new therapeutical option for Tumor induced osteomalacia (TIO). To estimate the clinical need and to evaluate the efficacy and safety of burosumab, we conducted a hybrid study composed by a clinical survey and a systematic review. Methods: All patients referring for TIO to the Federico II University were enrolled in our clinical survey. A comprehensive literature search on a Medline, Google Scholar, Google Books, and the Cochrane Library was conducted for the Systematic Review. Data were extracted on 12/31/2025. Results: For the local survey, we collected 10 patients affected by TIO [M: F = 5 (50.0%): 5 (50.0%); mean age at symptom onset 57.6 ± 14.3 years]. Two (20.0%) patients received burosumab, obtaining clinical and biochemical improvement. Two who didn't receive the treatment died. For the systematic review, we collected 42 studies and 49 cases [M: F = 19 (44.2%): 24 (55.8%); mean age at onset 36.8 ± 21.3 years; mean age at diagnosis 44.5 ± 22.9 years]. Burosumab reduced clinical symptoms and ameliorates biochemical investigations by normalizing phosphate serum levels. It is also safe and well tolerated. Conclusion: Burosumab represents a safe and efficient treatment in TIO patients, to be administered in case of tumor identification while waiting for surgery, and in case of surgical inoperability to manage hormonal FGF23 effect.