Patients starting Natpara have low quality of life: Real-world study
Symptom burden high prior to chronic hypoparathyroidism treatment
People with chronic hypoparathyroidism who were prescribed the parathyroid hormone (PTH) replacement therapy Natpara had low health-related quality of life (HRQoL) and high symptom burden before starting treatment, according to a real-world study.
The study compared patients who switched from conventional treatment to Natpara against those who stayed on the conventional therapy of calcium and active vitamin D supplements. Natpara is a recombinant, or lab-made, form of PTH.
The study, “Health-related quality of life in a cohort of 1070 patients with hypoparathyroidism,” was published in the European Journal of Endocrinology. Several study authors are or were employed at Takeda Pharmaceuticals, which decided to stop manufacturing Natpara at the end of last year.
Hypoparathyroidism characterized by low levels of key hormone
Hypoparathyroidism is characterized by low levels of PTH, a hormone that helps regulate calcium and phosphorus levels in the body. Chronic hypoparathyroidism, which most often develops after surgery in the neck that damages the parathyroid glands, can cause a range of symptoms, including muscle spasms and bone problems.
Studies have shown that people with chronic hypoparathyroidism on conventional therapy have a lower HRQoL compared to the general population.
However, “there is a lack of real-world evidence regarding the characteristics and HRQoL of patients receiving conventional therapy and rhPTH (1-84) [Natpara] and regarding whether the use of rhPTH (1-84) in routine clinical practice reflects the clinical guidance,” the researchers wrote.
To learn more, researchers designed the PARADIGHM registry, which enrolled 1,302 patients across 95 centers in 11 countries up to May 2022. This analysis included 1,070 individuals with a mean age of 52.3 years who were mainly women (80.7%) and white (86%).
The most common cause of chronic hypoparathyroidism was surgery (82.2%), and participants had a mean disease duration of 11.4 years. The most commonly reported symptoms included muscle cramps (40.1%), numbness or tingling sensations (36.8%), and muscle twitching (26.5%).
Hospitalization rate higher for Natpara-treated patients
HRQoL was evaluated using the SF-36v2 score, which covers eight domains including physical functioning and mental health, while disease impact on daily life was evaluated using the Work Productivity and Activity Impairment Specific Health Problem (WPAI:SHP) questionnaire. In addition, symptoms were assessed with the patient-reported Hypoparathyroidism Symptom Diary (HypoPT-SD).
Participants who developed chronic hypoparathyroidism after surgery had lower (worse) scores of physical (45.6 vs. 49.9) and mental health (47.4 vs. 48.3) compared to those with non-surgical chronic hypoparathyroidism. Scores were also worse in all parameters measured by HypoPT-SD. Women showed worse scores than men.
Overall, 102 patients (9.5%) were prescribed Natpara. There were no clinically meaningful differences between these patients and those who continued on conventional therapy regarding clinical and biochemical parameters.
This implies that poor HRQoL may be a relatively independent consideration when physicians initiate [Natpara] in accordance with the recent clinical recommendations on the use of PTH replacement.
However, at baseline, patients who received Natpara more commonly used medications such as opioids (for pain), antidepressants, anxiolytics ( for anxiety), and diuretics (often used to lower blood pressure) than those who continued on conventional therapies. Based on the HypoPT-SD, they also had a higher burden of symptoms and worse physical and mental health scores. Finally, they had greater activity impairment, overall work impairment, and impairment while working using the WPAI:SHP score.
Women, but not men, and patients who had hypoparathyroidism after surgery generally showed the same differences.
“This implies that poor HRQoL may be a relatively independent consideration when physicians initiate [Natpara] in accordance with the recent clinical recommendations on the use of PTH replacement,” the researchers wrote.
Finally, the proportion of patients who required at least one visit to the emergency room in the one-year period before study enrollment was significantly higher in the Natpara group, both due to any cause (57.3% vs. 31.6%) or due to hypoparathyroidism (78.6% vs. 45.6%). The rate of hospitalizations was also higher (39.6% vs. 16.7%) in Natpara-treated participants.
According to the team, these results “may reflect the higher symptom burden in this group.”
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