Cancer drug repurposed as first oral achondroplasia treatment in phase III trial

A cancer drug that failed to save oncology patients is about to transform the lives of children with achondroplasia, the most common genetic form of dwarfism. An Australian-led clinical trial published last month in The New England Journal of Medicine shows that infigratinib, a compound originally designed to block fibroblast growth factor receptors in tumor cells, can do something medicine has never managed before: deliver oral treatment that actually increases growth velocity in children born with this bone-development disorder.

The trial enrolled 74 children between ages 3 and 17 with achondroplasia. Over 52 weeks of treatment with infigratinib, these children grew at an accelerated rate of 1.58 centimeters per year—a substantial gain when measured against what their bodies would otherwise do. The comparison is stark: a control group of 39 untreated children saw their growth velocity decline by 0.16 centimeters per year during the same period. The treated group also showed improvement in height Z-score, a statistical measure of how far a child's height deviates from the average for their age, improving by 0.32 standard deviations relative to placebo.

Achondroplasia arises from a mutation in the fibroblast growth factor receptor 3 gene, which disrupts the normal signaling that allows bones to lengthen. The condition affects roughly one in 25,000 births worldwide. People with achondroplasia typically reach adult heights between 4 feet and 4 feet 10 inches, and the shortened stature can bring complications: spinal stenosis, sleep apnea, ear infections, and the accumulated weight of social stigma. Until now, there has been no pharmaceutical intervention. Growth hormone therapy, the standard treatment for other forms of growth deficiency, does not work for achondroplasia because the underlying problem is not hormone deficiency but a faulty growth signal itself.

Infigratinib works by inhibiting the overactive receptor, essentially dampening the signal that tells bones to stop growing. The drug was originally developed by pharmaceutical researchers hunting for cancer treatments—fibroblast growth factor receptors are implicated in certain malignancies. It failed those trials. But failure in one disease space does not mean failure everywhere. Researchers recognized that the same mechanism that might slow tumor growth could counteract the bone-growth suppression in achondroplasia. The pivot from oncology to rare genetic disease represents a growing pattern in pharmaceutical development, where compounds abandoned in high-profile cancer programs find second lives treating conditions with smaller patient populations but profound unmet medical need.

Professor Ravi Savarirayan, who led the Australian arm of the research, has noted that this kind of drug repurposing is becoming more common as researchers map the molecular basis of rare diseases. The phase III results position infigratinib for regulatory approval, with market arrival expected within the next year. If approved, it will be the first oral medication available to families facing achondroplasia—a shift from the current landscape where management is largely supportive, focused on monitoring and managing complications rather than addressing the root cause.

The implications extend beyond the immediate patient population. A successful market entry for infigratinib could establish a template for how failed oncology compounds might be systematically screened against rare genetic disorders. It signals to pharmaceutical companies that a drug's first failure need not be its final chapter, and it offers hope to families living with conditions that have long seemed untreatable at the molecular level. For the children in this trial and those who will follow, it means the possibility of growing taller, of reducing the medical complications that come with severe short stature, and of accessing treatment through a pill rather than injection or surgery.