Efficacy and safety of using Etelcalcetide for controlling secondary hyperparathyroidism

Background

In Qatar, secondary hyperparathyroidism (SHPT) is a common problem in haemodialysis (HD) patients, associated with significant clinical consequences for Chronic Kidney Disease (CKD) patients, including osteitis fibrosa cystica and calcific cardiovascular disease, broadly referred to as CKD–mineral bone disorder. Cinacalcet is used in controlling SHPT in HD patients. Unfortunately, 56 % of patients do not tolerate it due to mainly gastrointestinal side effects leading to poor compliance, especially during the COVID-19 pandemic when patients had difficulties in accessing the medicine and having proper follow-up. The project aims to evaluate the safety and effectiveness of Etelcalcetide compared with Cinacalcet in controlling SHPT.

Methods

We included 89 HD patients with SHPT who switched from Cinacalcet to Etelcalcetide with a monthly follow-up of 6 months of laboratory values for Parathyroid hormone (PTH), Calcium, and phosphorus. We measured the percentage changes from baseline in serum intact PTH. The safety and tolerability profiles of Etelcalcetide were assessed.

Results

Patients within the PTH target range of 150 to 500pg/ml improved from 8% in June 2021 (on Cinacalcet) to 54% in June 2023 (on Etelcalcetide) (p=0 .0032) while patients with PTH above 1,000pg/ml decreased from 50% to 4% during the same period (p=0.00001) (Figure 2). Reasons for conversion from Cinacalcet to Etelcalcetide were non-compliance due to gastrointestinal Side effects (with resistant elevation of PTH despite optimal dose in almost 90% of patients) also due to the COVID-19 pandemic and its effect in following medication in the face of the shortage of our nurses and physicians (Figure 1). 3.3% (3 patients) had moderate intolerance symptoms (e.g. nausea, vomiting) and they were referred for parathyroidectomy.

Conclusion

The conversion of Cinacalcet to Etelcalcetide in HD patients with secondary hyperparathyroidism resulted in a significant improvement in PTH level. It was well tolerated by patients with no reported side effects.