Endocrine Abstracts

JOINT2911

Background: Chronic hypoparathyroidism (HypoPT) is a rare endocrine disorder characterized by deficient parathyroid hormone (PTH) levels, leading to hypocalcemia and dependency on calcium and active vitamin D., Trans-conPTH 1-34 formulation (Yorvipath), has emerged as a potential therapeutic option for patients with uncontrolled hypoparathyroidism or those previously treated with rhPTH(1-84). This study presents preliminary results from an ongoing prospective cohort-study evaluating the real-world effectiveness of Yorvipath.

Methods: Eligible patients were adults diagnosed with HypoPT who required trans-conPTH due to inadequate control on conventional therapy or as a replacement for prior treatment with rhPTH(1-84). All included patients started Yorvipath at 18 mg and were followed regularly during the titration period.

Results: Thirty-seven patients (aged 21–70years) were included. The majority (29/37) had surgical hypoparathyroidism, including eight cases related to thyroid cancer. Six patients had idiopathic hypoparathyroidism, one developed infiltrative hypoparathyroidism due to sarcoidosis, and another due to iron deposition from transfusion-dependent thalassemia. The mean disease duration was 12±9. 7 years (range 1-44y). Before initiating Yorvipath, 21 patients (56%) had been treated with rhPTH (1-84) at doses ranging from 75 to 100 mg/day. Baseline conventional treatment included an average of 2000 mg/day of calcium-supplements (divided into 3–4 doses), 1. 5 mg/day of active vitamin-D, 1400 IU/day of cholecalciferol, and 746 mg/day of magnesium. Additionally, 15 patients (40%) were on hydrochlorothiazide for hypercalciuria. The mean duration of Yorvipath treatment was 90±59 days (range 11-210). By the last study visit, albumin-corrected calcium levels had significantly increased compared to baseline (9. 0±0. 58mg/dL vs. 8. 15±0. 65mg/dL, respectively, P < 0. 001), while phosphate levels had decreased (4. 0±0. 59mg/dL vs. 4. 64±1. 12mg/dL, respectively, P = 0. 004). Notably, 60% of the cohort (23/37) achieved independence from both calcium and active vitamin D within the first 21 days of treatment (range:7–60 days). Among the remaining patients, eight continued with low-dose calcium supplements (<600 mg/day), and only five required ongoing activated vitamin D. No significant differences were observed between drug-naïve patients and those previously-treated with rhPTH(1-84). The median dose of Yorvipath was 21mg(range 12-30mg). No adverse events were reported during treatment with Yorvipath. Two patients (5%) experienced transient hypercalcemia during the titration period.

Conclusion: Preliminary findings suggest that Yorvipath is effective in reducing or eliminating the need for calcium and activated vitamin-D treatment in patients with HypoPT. Most patients achieved Ca/active VitD independence within the first few weeks of treatment. Further studies with longer follow-up are warranted to confirm the long-term efficacy and safety of Yorvipath in this patient population.