FROM THE JOURNAL OF CLINICAL ENDOCRINOLOGY & METABOLISM
A new industry-funded analysis suggests that recombinant human parathyroid hormone, an extraordinarily expensive treatment for hypoparathyroidism, produces slight improvement in some health-related quality of life (HRQoL) domains.
While researchers didn’t find any statistically significant between-group differences vs. a placebo, the lead study lead author said the positive findings about within-group differences reflect her experiences with some patients. “They’re telling me they feel much better, and they don’t have emergency room visits,” endocrinologist Tamara J. Vokes, MD, of the University of Chicago, said in an interview.
And, she said, as reflected in the findings, she’s seen that those with the lowest HRQoL levels at baseline especially show signs of improvement.
The treatment, known as rhPTH(1-84) or Natpara, was approved by the Food and Drug Administration as a treatment for hypoparathyroidism in 2015. The FDA stated that the drug “is only for people who do not respond well to treatment with calcium and active forms of vitamin D alone, because it may increase the possible risk of bone cancer, known as osteosarcoma.”
Pharmacies list the drug as costing $9,500-$9,900 per month with a coupon or discount. According to the new study, research has shown that quality of life is often impaired in patients who have tried the traditional hypoparathyroidism treatments of calcium supplements and vitamin D. Dr. Vokes and her colleagues aimed to expand upon previous studies of HRQoL that did not reach conclusions or failed to include controls.
They examined findings of a previous multinational, randomized, placebo-controlled study of 122 adults with hypoparathyroidism. Average age was 48 years, and roughly 80% of the patients were women.
After their serum calcium levels were adjusted through medication, the patients were randomly assigned to placebo (n = 39) or rhPTH(1-84) (n = 83, starting dose of 50 mg/d that could be raised to 100 mg/d).
The study, which appears in the Journal of Clinical Endocrinology and Metabolism , analyzes the changes in HRQoL from baseline to 24 weeks per the 36-Item Short-Form Health Survey (SF-36).
The researchers found no significant between-group differences. However, those who took the drug did see statistically significant improvements in 4 of 10 domains: physical component summary score (P = .004), body pain (P = .05), general health (P = .05), and vitality (P less than .001). The changes were small, with the vitality score improving the most, from a mean SF-36 score of 49.5 to 53.
“I think the effect is real,” Dr. Vokes said, and may be prompted by the consistent levels of serum calcium that patients encounter when they take Natpara.
In some cases, she said, she’s seen QoL improve in patients whom she normally wouldn’t consider candidates for the medication. “I would have not have recommended PTH for them, but they insisted on taking it, and they report feeling better.”
This may be a placebo effect, she said. Even so, “if someone doesn’t feel well, it’s worth it at least to try to use PTH and see whether they improve.”
She added that lack of well-being is a preexisting condition for some hypoparathyroidism patients. “I’ve seen quite a number of them who have what we call premorbid personality disorder. They didn’t feel well and weren’t happy, and when you get hypoparathyroidism, you’re more unwell and unhappy.”
With medication, however, “you’re a bit less unhappy but you’re still miserable,” she said.
Carol Greenlee, MD, an endocrinologist in Grand Junction, Colo., said in an interview that she saw a patient in a clinical study who had experienced a marked improvement in QoL. However, she said, “it will be the cost of the PTH that is the burden.”
She advised that “the biggest [return on investment] should be to start to use PTH therapy with the patients who currently have the most burden on standard therapy as far as fluctuations in calcium levels on current treatment, challenges with the complexity of remembering/missing doses of medications, and coexisting issues that make the current treatment more problematic (limitations in self-management, seizure disorder, frequent GI upset/vomiting, etc.).”
For her part, Dr. Vokes cautioned that it’s important to take special care with patients taking Natpara. “You can’t just give this injection and say, ‘Goodbye, you will be better.’ It requires following certain protocol, frequent monitoring of the blood levels. Be sure the patient has access to the lab, and insurance that covers the test.”
Dr. Greenlee reported no relevant disclosures. The study was funded by Shire Human Genetic Therapies, and the initial clinical trial was funded by NPS Pharmaceuticals, a wholly owned indirect subsidiary. Dr. Vokes reported consulting for Shire and serving as an investigator for the initial clinical trial. Other study authors reported serving as clinical investigators and/or consulting for Shire, and three authors are employees of Shire.
SOURCE: Vokes, TJ et al. J Clin Endocrinol Metab. 2018 Feb 1;103(2):722-31
