Endocrine Abstracts

Changes in estimated glomerular filtration rate (eGFR) over 5 years were evaluated in adult patients with chronic hypoparathyroidism. A cohort of patients treated with recombinant human parathyroid hormone (1–84), rhPTH(1–84), was derived from NCT01297309 (RACE) and NCT01199614 (HEXT) clinical trials. A historical control patient cohort with hypoparathyroidism who did not receive rhPTH(1–84) or rhPTH(1–34) were from the large national US Explorys electronic medical record database (Jan 2007-Aug 2019) using criteria similar to trial enrolment criteria. Index date was the day after treatment initiation for the rhPTH(1–84) cohort and the day after first calcitriol prescription for the control. The analysis included patients with eGFR ≥60 ml/min/1.73 m² during the 6 months before index date, ≥2 eGFR measurements ≥3 months apart during the 5 years on/after the index date, and ≥1 eGFR measurement at 5±0.5 years. For patients from RACE, baseline and study visit data after rhPTH(1–84) initiation were collected from antecedent trials. Changes in eGFR were assessed in linear mixed and multivariable models (adjusted for age/sex/race, baseline eGFR, history of hypercalciuria/hypertension/type 2 diabetes [T2D]/acute hypoparathyroidism manifestations/cardiovascular condition). There were 72 patients in the rhPTH(1–84) cohort and 174 in the control cohort. Before the index date, patients in the rhPTH(1–84) cohort, compared with the control, were younger (mean±S.D., 47.5±11.0 vs 53.9±15.5 years; P <0.01), and a lower proportion had acute manifestations of hypoparathyroidism (22.2% vs 69.0%; P <0.001) and T2D (2.8% vs 17.8%; P <0.001). Over 5 years, the difference in rate of eGFR change between the 2 cohorts was 1.45 ml/min/1.73 m² per year and 1.33 ml/min/1.73 m² per year, in unadjusted and adjusted linear mixed models, respectively (both P <0.001). Over 5 years, eGFR was relatively stable in the rhPTH(1–84) cohort, but declined in the control at a rate of -1.58 ml/min/1.73 m² per year (unadjusted model, P <0.001), and -1.57 ml/min/1.73 m² per year (adjusted model, P <0.001). By year 5, patients in the rhPTH(1–84) and control cohort were predicted to have eGFR changes from baseline of +1.51 ml/min/1.73 m² and -10.48 ml/min/1.73 m², respectively. Data interpretation is limited by differing patient management (ie, predefined trial protocols and clinical practice for the control). In patients with chronic hypoparathyroidism, the annual rate of eGFR decline over 5 years was significantly lower in patients treated with rhPTH(1–84) compared with controls not treated with rhPTH(1–84). These results support a prior analysis of data from the same trials and a regional US health record database.¹

Reference

¹Chen et al. JCEM 2020;105(10):e3557–e3565.

Encore abstract from ENDO 2021.