Ascendis Pharma has reported encouraging five-year data for its long-acting parathyroid hormone replacement therapy, TransCon PTH (palopegteriparatide), for adults with hypoparathyroidism. The results, presented from its Phase 3 paediatric and adult extension studies, indicate sustained efficacy and a consistent safety profile over the extended period, offering a potential new avenue for managing this rare and often debilitating condition.
Hypoparathyroidism is a rare endocrine disorder where the body produces insufficient levels of parathyroid hormone (PTH), leading to abnormally low calcium levels (hypocalcaemia) and high phosphate levels in the blood. This can result in a range of symptoms including muscle cramps, tingling sensations, fatigue, and in severe cases, seizures and heart rhythm abnormalities. It often arises from damage to the parathyroid glands during thyroid surgery, but can also be autoimmune or genetic.
The current standard of care for hypoparathyroidism in the UK primarily involves lifelong treatment with calcium and active vitamin D supplements. While these treatments can manage symptoms, they do not address the underlying hormonal deficiency and can lead to complications such as kidney stones and kidney damage over time due to high calcium excretion. According to NHS data, hypoparathyroidism affects approximately 2 in 10,000 people in the UK, making it a significant challenge for those living with the condition.
TransCon PTH is designed to provide a more physiological replacement for parathyroid hormone, aiming to normalise serum calcium levels and reduce or eliminate the need for high doses of conventional calcium and active vitamin D supplementation. The five-year data highlighted a sustained normalisation of serum calcium levels and a significant reduction in the use of conventional therapy among participants, suggesting a durable benefit for patients.
The long-term safety profile of the drug was also consistent with previous findings, with no new safety concerns identified. This extended data is crucial for regulatory bodies like the Medicines and Healthcare products Regulatory Agency (MHRA) when evaluating new treatments, as it provides a comprehensive understanding of a drug's performance over an extended period in a patient population.
The implications of these findings for UK patients and the NHS could be substantial. A treatment that offers sustained efficacy and a better quality of life for individuals with chronic hypoparathyroidism could reduce the burden of managing the condition and potentially mitigate long-term complications associated with conventional therapies. While the drug is not yet widely available in the UK, these data represent a significant step towards its potential future adoption.