ProLynx Awarded NIH Grant to Develop Long-acting PTH Therapy

ProLynx has been awarded a small business innovation research grant from the National Institutes of Health (NIH) to develop its long-acting parathyroid hormone (PTH) therapy — known as PTH(1-34) — for people with hypoparathyroidism.

Hypoparathyroidism is an uncommon condition characterized by low levels of PTH, most commonly resulting from damage to the parathyroid glands, which produce the hormone. PTH is important for regulating calcium, and low PTH levels often result in low levels of calcium in the blood, or hypocalcemia.

One commonly used therapy is Natpara, by Takeda, which is a synthetic form of PTH intended to mimic the effects of the natural hormone. It is given as a subcutaneous (under-the-skin) injection in combination with calcium and vitamin D supplements. Natpara, or PTH(1-84), is approved in the U.S. to treat chronic hypoparathyroidism in people for whom supplements alone are inadequate.

A drawback of Natpara is the therapy’s relatively short half-life — it tends to be present at fairly high levels immediately after administration, then levels rapidly decrease, which can cause hypocalcemia. As such, patients still need a PTH therapy that delivers the hormone at a more stable rate, so that blood levels of PTH can be constant, ProLynx said in a press release.

The aim of the funded project is for ProLynx to advance such a treatment. ProLynx is developing PTH(1-34) with the use of its hydrogel microsphere technology. In simplest terms, the technology involves coupling PTH to a tiny droplet made of specially engineered molecules. The coupling is designed such that the therapy is slowly released into the bloodstream at a programmable, constant, and tunable rate.

ProLynx intends to deliver PTH(1-34) once per week, also via under-the-skin injection. According to the company, such a regimen would closely mimic continuous infusion, and offer a safer and more effective alternative to Natpara, which is given once daily.

“Treatment of hypoparathyroidism with PTH(1-34) has been shown to be more effective and less toxic when a continuous infusion-like profile is applied rather than bolus injections,” Bora Han, senior vice president of translational science at ProLynx, said in the release.

“Using our platform technology, a similar profile can be achieved for PTH(1-34) in a once-weekly dosing regimen,” Han said. “In addition, the added benefit of the simplified dosing regimen will improve patients comfort and compliance.”

Notably, an oral formulation of the therapy is being developed by Entera Bio. Positive results have been reported in Phase 2 trials for its hPTH(1-34) therapy.