AZP-3601 Earns FDA’s Orphan Drug Designation

The U.S. Food and Drug Administration (FDA) has granted orphan drug designation to AZP-3601, an investigational therapy for hypoparathyroidism by Amolyt Pharma.

The designation is given to treatment candidates with the potential to be safe and effective in rare diseases, defined in the U.S as those affecting fewer than 200,000 people.

It is meant to expedite AZP-3601’s clinical development by providing regulatory support and financial benefits, as well as a seven-year marketing exclusivity period in the U.S. upon regulatory approval.

“We believe the FDA’s granting of Orphan Drug Designation to AZP-3601 reflects the agency’s recognition that new and more effective treatment options are needed for this serious endocrine disorder,” Thierry Abribat, PhD, the founder and CEO of Amolyt, formerly Alizé Pharma 3, said in a press release.

“We are pleased to have recently dosed the first subject in our Phase 1 clinical trial, and we are committed to executing an efficient development program to diligently bring this promising therapeutic to patients,” he said.

Hypoparathyroidism is characterized by abnormally low levels of the parathyroid hormone (PTH), resulting in vitamin D deficiency, low levels of calcium and high levels of phosphorus in the blood.

Current treatment typically include calcium and vitamin D supplements, as well as PTH replacement therapy. But many patients still experience fluctuations in calcium levels and excessive calcium loss in the urine, which increases the risk of chronic kidney disease.

Originally developed by researchers at Massachusetts General Hospital and Harvard Medical School, AZP-3601 is a PTH analog designed to bind to a specific configuration of the PTH receptor. An analog is a compound with similar structure, but still slight differences in composition compared with another molecule.

This is thought to promote prolonged responses that help sustain normal calcium levels in the blood and urine, thereby preserving bone integrity and preventing chronic kidney disease.

According to Amolyt, AZP-3601’s potential benefits on bone health are particularly important, as many hypoparathyroidism patients are middle-aged women who often are at higher risk of osteoporosis, a condition that causes brittle bones.

Preclinical studies showed that AZP-3601 outperformed PTH at boosting and maintaining calcium levels, without increasing calcium loss in the urine.

Amolyt is currently evaluating the safety, tolerability, pharmacological properties, and preliminary effectiveness of single and multiple increasing doses of AZP-3601 in a Phase 1 clinical trial.

Expected to enroll 130 people — including healthy individuals and hypoparathyroidism patients — the trial dosed its first participant last October. Those with hypoparathyroidism will be treated at several study sites across Europe specializing in this disorder, while healthy participants will receive the therapy at a single site.