Hypoparathyroidism (HP) is a rare endocrine disorder characterized by insufficient levels of parathyroid hormone (PTH) resulting in low calcium and elevated phosphate levels in the blood.
HP affects over 200,000 patients worldwide, the majority of whom develop the condition following damage or accidental removal of the parathyroid glands during thyroid surgery.
In the short term, symptoms include weakness, severe muscle cramps (tetany), abnormal sensations such as tingling, burning and numbness (paresthesia), memory loss, impaired judgment and headache. Patients often experience decreased quality of life. Over the long term, this complex disorder can increase risk of major complications, such as extraskeletal calcium depositions occurring within the brain, lens of the eye, and kidneys, which can lead to impaired renal function.
Until recently, HP remained among the few hormonal insufficiency conditions not treated by replacement of the missing hormone. Standard of care with active vitamin D analogs and calcium supplementation do not fully control the disease and may contribute to risk of renal disease. This is due to progressive calcification of the kidney and kidney stones due to increased calciuria (urinary calcium). As a result, patients with HP have an estimated 4-fold to 8-fold greater risk of renal disease compared to healthy controls.
TransCon PTH is an investigational long-acting prodrug of PTH in development as a potential replacement therapy for HP. By providing PTH at physiologic levels for 24 hours a day, seven days a week, TransCon PTH is designed to normalize blood and urinary calcium levels, serum phosphate levels and bone turnover.
TransCon PTH has completed a phase 1 clinical trial in healthy adults that evaluated safety and pharmacodynamics and supported its intended target profile as a hormone replacement therapy for HP. We are currently conducting PaTH Forward, a global, phase 2, randomized, double-blind, placebo-controlled, parallel group trial that is evaluating the safety and efficacy of three fixed doses of TransCon PTH in adult subjects with HP. The goal of PaTH Forward is to evaluate the ability of TransCon PTH to control serum and urinary calcium and to identify a titration regimen that permits the complete withdrawal of the current standard of care (i.e., active vitamin D and calcium supplements).
TransCon PTH received Orphan Drug Designation (ODD) for the treatment of HP from the FDA in 2018.
Hypoparathyroidism is defined as a decrease or lack of parathyroid hormone, leading to low levels of calcium in the blood and an increase in serum phosphorus. Calcium and/or vitamin D supplementation can help relieve symptoms, but these treatments can have undesirable side effects including an increased risk of kidney stones and chronic kidney disease.
Hypoparathyroidism: Significant Global Prevalence
Hypoparathyroidism treatment represents a significant unmet patient need with an estimated prevalence of over 200,000 people living with the condition worldwide.
Source: Company data and analysis of published literature on file