# Successful transition from rhPTH(1-84) to palopegteriparatide in chronic hypoparathyroidism

## TL;DR

A patient successfully transitioned from rhPTH(1-84) to palopegteriparatide for chronic hypoparathyroidism, achieving stable calcium levels and improved well-being.

## Contribution

This is the first documented case of transitioning from rhPTH(1-84) to palopegteriparatide before the former's global withdrawal.

## Key findings

- Transition to palopegteriparatide allowed complete withdrawal of calcium and magnesium supplements.
- The patient maintained stable biochemical values and reported improved well-being.
- No adverse events were observed during the transition.

## Abstract

Hypoparathyroidism management has advanced in recent decades, particularly for patients unresponsive to conventional therapy. Several parathyroid hormone–based agents have been developed to better imitate physiologic hormone replacement. Recombinant human parathyroid hormone (1-84) [rhPTH(1-84), Natpar®] was approved as an adjunct to calcium and vitamin D for chronic hypoparathyroidism but was later withdrawn, with global production ceasing in 2024. Palopegteriparatide (Yorvipath®; TransCon PTH), a long-acting parathyroid hormone (1-34) prodrug recently approved, represents a new-generation replacement therapy. Transitioning patients from rhPTH(1-84) to palopegteriparatide is increasingly relevant but remains scarcely documented, with only a single real-world report available. We describe a patient with chronic postsurgical hypoparathyroidism after total thyroidectomy who continued to experience symptoms despite conventional therapy. rhPTH(1-84) initially improved symptoms and stabilized calcium levels, but additional supplementation became necessary over time. In September 2024, ahead of rhPTH(1-84) withdrawal, therapy was switched to palopegteriparatide, allowing gradual dose titration and complete withdrawal of calcium and magnesium supplements. The patient maintained stable biochemical values and reported improved well-being, with no adverse events. This case supports the effective transition from rhPTH(1-84) to palopegteriparatide, restoring biochemical stability and independence from conventional therapy.