VISEN's Phase 3 PaTHway China Trial of Palopegteriparatide meets key endpoints in adult hypoparathyroidism treatment

VISEN Pharmaceuticals, a biopharmaceutical company specializing in endocrine disorders, has announced the promising results from the 26-week Phase 3 PaTHway China trial of palopegteriparatide (TransCon PTH) in adults suffering from chronic hypoparathyroidism. This randomized, double-blind, placebo-controlled study involved 81 patients who were divided in a 3:1 ratio to receive either palopegteriparatide or a placebo. The trial aimed to assess the effectiveness and safety of palopegteriparatide as a potential treatment option for this patient group.

The primary endpoint of the trial was the achievement of serum calcium levels within the normal range (8.3–10.6 mg/dL or 2.07-2.64 mmol/L) and independence from conventional therapy, which includes no active vitamin D intake and a maximum of 600 mg/day of oral calcium, without increasing the study drug dosage four weeks before the Week 26 visit. Remarkably, 77.6% of the patients treated with palopegteriparatide (45 out of 58) met this primary endpoint compared to none in the placebo group (0 out of 22), reinforcing the significant efficacy of this treatment (p < 0.0001).

Professor XIA Weibo, the primary investigator and Director of the Department of Endocrinology at Peking Union Medical College Hospital, emphasized the importance of these findings. He highlighted that hypoparathyroidism remains an endocrine deficiency where hormone replacement is not yet the standard care. The trial’s results suggest that PTH replacement therapy effectively stabilizes calcium levels in the blood, thereby reducing symptoms without exacerbating hypercalciuria. This approach lowers urinary calcium to normal levels, potentially minimizing long-term complications such as soft-tissue calcifications and decreased kidney function. Therefore, PTH replacement could significantly enhance the overall health and quality of life for hypoparathyroidism patients.

Additional findings from the trial include that 89.7% of the patients treated with palopegteriparatide achieved independence from conventional therapy by Week 26. Furthermore, there was a significant improvement in patient-reported physical symptoms specific to hypoparathyroidism as measured by the Hypoparathyroidism Patient Experience Scales (HPES) Symptom-Physical domain scores (p = 0.022).

The safety profile of palopegteriparatide was also favorable, with the treatment being generally well tolerated and no patients discontinuing due to adverse effects related to the study drug. No serious treatment-emergent adverse events (TEAEs) were reported in either the treatment or placebo groups. Additionally, the mean 24-hour urinary calcium levels for patients treated with palopegteriparatide decreased significantly from baseline, whereas levels in the placebo group remained relatively unchanged.

Subsequent to the initial 26-week blinded trial period, 76 patients elected to continue in the open-label extension phase of the study to receive palopegteriparatide for up to three years.

Pony LU, CEO and Executive Director of VISEN Pharmaceuticals, expressed optimism about the future of this treatment. He emphasized the urgency of providing new therapeutic options to Chinese patients with hypoparathyroidism to improve their quality of life. VISEN Pharmaceuticals plans to submit a New Drug Application (NDA) to the National Medical Products Administration (NMPA) as soon as the preparatory work is finalized.

Palopegteriparatide, an investigational prodrug of PTH (1-34), is designed for once-daily administration to maintain physiological PTH levels over a 24-hour period. VISEN Pharmaceuticals has exclusive rights to develop, manufacture, and commercialize the drug in Greater China, granted by Ascendis Pharma. The drug has already received marketing authorization in Europe for treating chronic hypoparathyroidism in adults and is under review by the U.S. FDA.

This promising development underscores VISEN Pharmaceuticals' commitment to introducing advanced treatment solutions for endocrine disorders in China, aiming to enhance patient care and outcomes.