Prophylactic treatment with zoledronic acid (ZA) in individuals at high genetic risk for Paget disease of the bone (PDB) can prevent the development or progression of the condition, according to a new study. The authors argued that the positive results from the trial suggest that individuals with a familial history of PDB should undergo genetic screening.
“If it’s positive, you should be able to have a bone scan and take it from there,” senior author Stuart Ralston, MBChB, MD, professor of rheumatology at the University of Edinburgh, Edinburgh, Scotland, said in an interview with Medscape Medical News.
PDB is a chronic skeletal growth disorder that affects an estimated 1-3 million people in the United States and is most prevalent in individuals over 65 years old. Symptoms of the disease may not present until later stages when there is already skeletal damage that cannot be resolved by medications. Earlier intervention in individuals who have not yet shown signs of the condition could potentially halt disease progression, Ralston said.
Genetics plays a substantial role in PDB, especially pathogenic variants of the gene SQSTM1. An estimated 40%-50% of people with a familial history of PDB have these variants, according to the study, which are associated with earlier PDB onset and more severe disease.
However, it was unclear if early interventions in these higher-risk individuals may result in better health outcomes.
In this new study, published on December 20, 2023, in Annals of the Rheumatic Diseases, researchers recruited participants through family members already diagnosed with PDB who received treatment at outpatient clinics. Over 1400 individuals with PDB underwent genetic testing for pathogenic SQSTM1 variants. If they tested positive, their first-degree relatives — primarily children — were offered the same genetic test. In total, 350 relatives tested positive for these pathogenic SQSTM1 variants, and of these individuals, 222 agreed to participate in the trial.
At the beginning of the study, all participants received a radionuclide bone scan to screen for bone lesions. They also underwent testing for the bone resorption marker type I collagen C-terminal telopeptides (CTX) and the bone formation marker procollagen type I amino-terminal propeptide (P1NP).
Participants were then randomized to receive either a single intravenous infusion of 5 mg of ZA or placebo treatment. Researchers followed up with participants annually for a median of 84 months (7 years), and then baseline assessments were repeated.
A total of 90 individuals in the ZA treatment group and 90 individuals in the placebo group completed the trial.
Participants were, on average, 50 years old at the beginning of the study. In the ZA group, nine individuals had lesions detected in bone scans at baseline, compared with just one at the study’s end. In the placebo group, 12 individuals had detectable lesions at baseline, compared with 11 individuals at the study’s end.
While the proportion of individuals with lesions was similar between the two groups, there were about twice as many lesions overall in the placebo group, compared with the ZA group (29 vs 15), which researchers said was by chance. All but two lesions disappeared in the ZA group, compared with 26 lesions remaining in the placebo group (P
“The bone scan reversal of abnormalities was amazing,” said Ralston, where eight of nine patients with lesions in the ZA group “had their bone scan evidence completely wiped out,” he said. “That’s a very powerful result.”
Both CTX and P1NP concentrations fell in the ZA group at 12 months and remained significantly lower than the placebo group throughout the study (P
Overall, the researchers reported that eight individuals in the placebo group and no individuals in the ZA group had a poor outcome, defined as new bone lesions or lesions that were unchanged or progressed (odds ratio, 0.08; P = .003). Two individuals in the placebo group developed lesions during the study, compared with none in the ZA group, but this difference was not statistically significant.
Importantly, there were no differences in adverse events between the two groups.
While only a small number of people in the study had legions — around 9% of participants — the effect of ZA is “dramatic,” Linda Russell, MD, the director of the Osteoporosis and Metabolic Bone Health Center at the Hospital for Special Surgery in New York City, told Medscape Medical News.
While clinicians primarily diagnose PDB with X-rays or an alkaline phosphatase blood test, testing for SQSTM1 is a new way to understand if someone is at higher risk for the disease, she said.
“Now, it seems like [the test] is fairly easily available, so probably it’s something we can begin to incorporate into our armamentarium,” Russell said.
Individuals who test positive for pathogenic variants of SQSTM1 could then get a bone scan, while those who tested negative may not need any additional testing, she added.
Ralston and coauthors noted that the effect size shown in this study is similar to that of studies examining adjuvant bisphosphonate therapy for postmenopausal women with early breast cancer. That practice, they write, is now a part of the standard of care.
“We believe that a similar approach is now justified in people with a family history of PDB who test positive for SQSTM1 mutations,” they wrote.
However, it is not clear if all individuals with pathogenic SQSTM1 should receive ZA treatment or if treatment should be given to only those with bone lesions.
“Future research to gather the views of people with a family history of PDB will help to inform the most appropriate way forward,” the authors wrote.
The UK Medical Research Council and Arthritis Research UK funded the trial. Zoledronic acid and a placebo were supplied by Novartis. Ralston reported funding to his institution from Kyowa Kirin, UCB, the Paget’s Association, and the Royal Osteoporosis Society. Some coauthors reported financial relationships with pharmaceutical companies outside the trial. Russell had no relevant financial relationships.
Source link : https://www.medscape.com/viewarticle/genetic-screening-targeted-treatment-halts-progression-paget-2024a10000wi?src=rss
Publish date : 2024-01-15 10:31:57
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