Shire presented new data on its approved therapy Natpara for the treatment of patients with chronic hypoparathyroidism at ENDO 2018, the Endocrine Society’s 100th Annual Meeting and Exposition held March 17-20 in Chicago.
Natpara is a recombinant human parathyroid hormone (rhPTH) that’s designed to replace the natural hormone, called PTH, which is present at low levels in patients with hypoparathyroidism.
Chronic hypoparathyroidism is associated with an imbalance in body minerals, which can have dangerous consequences.
Natpara was approved in 2015 for adult chronic hypoparathyroidism patients as an add-on to the conventional therapy of calcium and activated vitamin D.
In the study, “Symptom burden and HRQoL reported among patients with chronic hypoparathyroidism: impact of treatment with rhPTH (1-84) and with standard therapy,” presented at ENDO 2018, Shire researchers used a web-based survey to analyze symptom burden and health-related quality of life in patients treated with Natpara compared to those on standard therapy.
Patients treated with Natpara experienced an average of 9.1 symptoms compared to an average of 20.2 symptoms experienced by patients on standard therapy.
Also, a greater proportion of patients on standard therapy experienced disease-associated interference in their daily lives and a greater impact on work responsibilities compared to those taking Natpara.
Data from the ongoing open-label Phase 3 RACE clinical trial (NCT01297309) was also presented. The trial enrolled patients with a history of hypoparathyroidism who received Natpara for up to 80 months, injected daily in their thighs.
The study, “Comparison of 3-Year Estimated Glomerular Filtration Rates Between Recombinant Human Parathyroid Hormone (1-84) (rhPTH[1-84])-Treated Patients With Chronic Hypoparathyroidism and a Historical Control Cohort,” investigated renal complications in 119 patients from the RACE trial using the estimated glomerular filtration rates (eGFR) — a measure of kidney function — between patients treated with Natpara and a nontreated control group.
Nontreated patients experienced a greater decline in mean eGFR compared to those receiving Natpara. According to researchers, while these data seem promising, additional research is still necessary.
The study titled “Five-year efficacy and safety of rhPTH(1-84) for the treatment of adults with chronic hypoparathyroidism: analysis from the open-label RACE study,” revealed five-year results on the long-term safety and tolerability of Natpara obtained from the RACE trial.
At month 60, 70% of patients were able to reduce their oral calcium dose by 53.4% and calcitriol (vitamin D) by 75.7%. Treatment-emergent adverse events (TEAEs) were present in 98% of patients, with the most common being hypocalcemia, muscle spasms, paresthesia, sinusitis, and nausea. Serious TEAEs were seen in 26.5% of patients.
“The new data we are presenting at ENDO demonstrates a step forward in our understanding of chronic hypoparathyroidism, providing us with new insights into the burden of illness and how it may impact patients living with this rare disease,” Howard Mayer, MD, senior vice president and chief medical officer of Shire, said in a press release.
“These clinical and real-world studies reflect our commitment to advancing our knowledge of rare diseases and improving patient care,” he added.
Dolores M. Shoback MD, lead author of the RACE study, explained that hypoparathyroidism is a “rare disorder of mineral homeostasis due to deficiency of parathyroid hormone.
“Recombinant human parathyroid hormone is a relatively new treatment in the management of the disease in its chronic form, and therefore it is important to further improve our understanding of the safety and efficacy profile, especially in longer-term management of the condition,” she added.