Sodium Thiosulphate Not Much Help for Calciphylaxis in CKD

— Though used off-label for years, treatment isn't very beneficial

MedpageToday

alternative text

Credit: Niels Olson

Intravenous sodium thiosulphate flopped for treating calciphylaxis in people with chronic kidney disease (CKD), researchers reported.

In a systematic review and meta-analysis, there was no significant difference in skin lesion improvement seen across 12 studies of patients treated with and without IV sodium thiosulphate (risk ratio 1.23, 95% CI 0.85-1.78), found Wen Wen, MD, MMSc, of Beijing Tsinghua Changgung Hospital, and colleagues.

Sodium thiosulphate treatment also didn't help reduce the risk of death in patients with CKD experiencing calciphylaxis in 15 studies looking at this outcome (RR 0.88, 95% CI 0.70-1.10), the group detailed in JAMA Network Open.

In the handful of studies that looked at overall survival using time-to-event data, there also wasn't any significant benefit noted (HR 0.82, 95% CI 0.57-1.18).

Caused by vascular calcification, patients diagnosed with calciphylaxis live about 6 months, according to the National Kidney Foundation.

Though not indicated for the condition, sodium thiosulphate has been used off-label for years for calciphylaxis to help heal wounds and improve pain. There's currently no treatment approved specifically for CKD-related calciphylaxis, which is more common in patients with kidney failure or on dialysis.

The same null findings were seen when the studies were narrowed down to only CKD patients on dialysis experiencing calciphylaxis:

  • Lesion improvement: RR 0.68 (95% CI 0.41-1.14)
  • All-cause death: RR 1.15 (95% CI 0.73-1.80)

What Wen's group did find was a negative correlation between studies that found sodium thiosulphate-related improvement in skin lesions with publication year, implying "a publication bias where successful treatment with STS [sodium thiosulphate] was more likely to be published in the past, while more recently nonresponders have also been published."

For the 12 studies that measured lesion improvement as an outcome of interest -- ranging in publication year from 2006 to 2021 -- only one significantly favored sodium thiosulphate treatment. This was seen in a 2015 study where lesion improvement was a relative 86% higher with sodium thiosulphate. And across the 15 studies that looked at all-cause death in CKD patients with calciphylaxis, only one published in 2016 found a 27% reduced risk for death with sodium thiosulphate treatment.

"In case reports and multi-case reports, the effective rates for STS treatment were 67% and 84.4%, respectively," the researchers pointed out. "Complete and partial wound healing was observed in 80.3% of the patients receiving STS in case reports and case series, and 72.1% of those patients in cohort studies."

"However, the mortality rate remained high," they added. "In the largest cohort study of 172 patients treated with STS for calciphylaxis, the mortality rate was 35% at 1 year and 42% for the entire follow-up."

Because the current data on sodium thiosulphate's effect on calciphylaxis are conflicting at best and null at worst, Wen's group called for a well-designed, randomized control trial. They added that due to the rare and fatal nature of the condition, this has proven to be a tricky feat. One phase III trial, the CALISTA trial, was actually pulled early because of problems enrolling enough patients.

Wen's group did note one study -- the BEAT-CALCI trial -- that's currently underway, comparing sodium thiosulphate, magnesium, and vitamin K treatments for patients with calciphylaxis. This study is expected to be completed at the end of 2026.

They said they hope these future studies can help pinpoint if there are any subgroups of CKD patients suffering from calciphylaxis that might benefit from sodium thiosulphate treatment in light of the dearth of treatment options.

  • author['full_name']

    Kristen Monaco is a staff writer, focusing on endocrinology, psychiatry, and nephrology news. Based out of the New York City office, she’s worked at the company since 2015.

Disclosures

Several study authors disclosed support from the National Institute of Diabetes and Digestive and Kidney Diseases, the National Heart, Lung, and Blood Institute, the American Heart Association, the Wild Family Foundation, and the National Institute of Biomedical Imaging and Bioengineering. Many also reported ties to industry.

Primary Source

JAMA Network Open

Source Reference: Wen W, et al "Intravenous sodium thiosulphate for calciphylaxis of chronic kidney disease" JAMA Netw Open 2023; DOI: 10.1001/jamanetworkopen.2023.10068.