In a significant breakthrough, Ultragenyx and Mereo’s genetic bone disease treatment has shown an impressive 67% decrease in bone fractures. Six months after the release of biomarker data that raised hopes for Ultragenyx’s brittle bone disease therapy, recent fracture statistics are further validating the excitement.
This biotech company, specializing in rare diseases, in partnership with Mereo BioPharma, disclosed that Setrusumab has reduced bone fractures by 67% in a group of 24 patients with osteogenesis imperfecta, each tracked for at least six months. During the phase 2 segment of the phase 2/3 clinical trial, the annualized fracture rate of 0.72 dropped to zero over an average nine-month treatment period. Ultragenyx’s stock soared by more than 11%, rising from $33.57 to $37.35 as of noon ET.
Among the 24 patients, 20 experienced no “radiographically confirmed fractures,” while four patients reported seven such fractures in five separate incidents. This genetic condition renders bones extremely fragile, making them prone to breaking without an apparent cause. Dr. Gary Gottesman, a professor of Pediatrics and Medicine at Washington University School of Medicine, noted that none of his patients had experienced fractures to date in a press release on Saturday.
These recent findings follow previous interim results published in June, demonstrating that Setrusumab led to a 9.4% improvement in bone density three months into treatment, surpassing the 8.97% improvement observed in a phase 1/2 study. The two companies now possess six-month follow-up data indicating ongoing progress.
Among the eleven patients given a 20mg dose, there was a 13% increase in lumbar spine bone mineral density, while eight individuals receiving 40mg reported a 16% improvement. So far, no serious adverse events related to the treatment have been reported, with the most common side effects being infusion-related events and headaches.
Ultragenyx seems to be on a promising trajectory after acquiring the rights to the drug for non-European markets almost three years ago, investing an initial $50 million and offering an additional $254 million in potential payments. Enrollment for the phase 3 portion of the trial is ongoing, with the two companies aiming to recruit 195 patients across 50 clinical sites.
