Some data from the clinical trials of KRN23/burosumab were shared with clinicians and researchers during the recent conference of the American Society for Bone and Mineral Research. Dr. Karl Insogna presented about the treatment of adults, and Dr. Michael Whyte presented for pediatric issues.
The data were summarized in an article by MedPage Today, which you can read here: https://www.medpagetoday.com/meetingcoverage/asbmr/67919
Of particular interest is the lack of significant adverse effects reported in the adult study, as reported by MedPage Today:
"The safety profile of burosumab was similar to what was seen for placebo, with no serious drug-related adverse events and no events leading to study discontinuation.
"We conclude that burosumab represents an exciting new therapy for XLH," Insogna said."
And for the pediatric study, as reported by MedPage Today, the improvement in the rickets score (lower is better), even though at least some of the patients had previously been treated with the current therapy (phos and calcitriol): "the most substantial improvements [in rickets scores] being seen for children who had more severe rickets (RSS of 1.5 or higher at baseline). In that subgroup, RSS decreased from a baseline score of 2.46 to 1.01 .... "
Also, side effects in the pediatric study were considered either insignificant or unrelated to the new treatment: "Renal function remained normal and there was no evidence of ectopic mineralization of the myocardium. The most common adverse events were transient injection site reactions, and only one child had a serious adverse event, which was considered unrelated to the therapy. "The favorable benefit-risk profile of burosumab holds promise for long-term outcomes for these children," Whyte concluded."