ClinicalTrials.gov record NCT03582800

Subcutaneous Injection of Sodium Thiosulfate for Ectopic Calcifications or Ossifications. A Pilot Study

Record copied from ClinicalTrials.gov: Oct 10, 2026AI summaries generated: Sep 17, 2026

Subcutaneous Injection of Sodium Thiosulfate for Ectopic Calcifications or Ossifications. A Pilot Study

StatusRecruitingThe study is currently enrolling participants. Only the study team can say whether a particular person can join.
Study typeInterventionalA study in which researchers assign participants to one or more interventions, such as a drug, procedure, device, behavioural programme or other approach, to measure their effects.
PhasePhase 2A study that tests whether a treatment has the intended effect and continues to check safety, usually in a larger group than phase 1.
AgeSee eligibility The registry's age field and its own written criteria give different ages for this study. Check the full criteria below and ask the study team.
SexAll
LocationFrance
AI summaryWhat this study is about, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

This phase 2, open-label study evaluates local subcutaneous sodium thiosulfate (STS) for people who have ectopic calcifications or ossifications linked to systemic sclerosis, dermatomyositis, or iPPSD2. Participants have a 6-month run-in (observation) period, then up to 6 months of STS given as repeated local injections for dermatomyositis or systemic sclerosis, or as subcutaneous infusion by portable pump for iPPSD2. The study uses CT scans to measure lesion size and density and collects pain, quality-of-life, and safety data.

What it is studying. The study tests whether locally administering STS changes the volume or density of treated ectopic calcifications or ossifications. It also collects information on safety, pain, and quality of life while treatment is given.

What the researchers hope to learn. To gather data on the safety and activity of intralesional or subcutaneous STS in reducing or altering the density of ectopic calcifications and ossifications in the three listed conditions, and to measure effects on pain and quality of life to inform future research.

What this study is about

The study's own summary, as published on ClinicalTrials.gov. Underlined terms have a short explanation.

Ectopic soft tissue calcifications or ossifications can complicate the course of numerous diseases; most of them are rare or very rare. Even if the clinical, radiological and pathological presentation of ectopic calcifications and ossifications are different, the same hypotheses are discussed considering their hypothetical pathophysiology. Indeed, high calcium phosphate product, local cellular lesions and abnormal transdifferentiation of mesenchymal cells are regularly evoked when pathophysiology of such calcifications or ossifications are discussed. Apart from several case reports that have not been confirmed so far, no medical treatments are available, leading to significant pain and impairment of quality of life for patients. Therefore, only surgical treatment can be proposed when the volume or the consequences of these calcifications/ossifications become too important. Sodium thiosulfate (STS) is currently used as a cyanide poisoning antagonist and a chemoprotectant against adverse effects of several chemotherapies such as Cisplatin. Numerous case reports and several studies have revealed the potential interest of STS in the treatment of uremic induced vascular or soft tissues calcifications. Recently, our group has developed an expertise in the use of STS for the treatment of ectopic soft tissue calcifications or ossifications. Considering these promising preliminary data, and their limits, we developed a strategy to treat soft tissue calcifications or ossifications based on a local administration of STS. The first results of this therapeutic strategy are highly promising and the local or systemic safety is satisfactory so far. These preliminary data also reported by others deserve to be confirmed in a prospective study. We propose in this project to conduct a prospective open controlled phase II trial in order to assess the efficacy and the safety of intralesional administration of STS for the treatment of calcifications secondary to dermatomyositis or systemic sclerosis and ectopic ossifications secondary to pseudo-hypoparathyroidism 1a type (PHP1A/iPPSD2) (inactivating parathyroid hormone / parathyroid-hormone-related peptid (PTH/PTHrP) signalling disorder).

Interventions being studied

Being studied in this trial does not mean the treatment or procedure is approved or available for this condition.

Drug
  • STS

Eligibility

The criteria exactly as listed on ClinicalTrials.gov. Only the study team can say whether they apply to you.

Inclusion criteria

  • Patient presenting with:
  • ectopic ossification secondary to iPPSD2 or
  • ectopic calcification secondary to dermatomyositis or
  • ectopic calcification secondary to systemic sclerosis
  • Patient aged 2 years or over
  • Indication of STS infusion validated by a multidisciplinary committee, based on the significant morbidity and/or functional impact of the targeted calcification/ossification
  • Patient with no planned surgery of the calcifications/ossifications for the twelve coming months
  • Women of childbearing potential on highly effective contraception (such as hormonal contraception, intrauterine device, intrauterine hormone-releasing system, bilateral tubal occlusion, vasectomised partner or sexual abstinence)
  • Men with women of childbearing potential partners should use condoms during the whole treatment period and until 91 days after the last injection.
  • Informed consent signed by the patient / parents
  • Patient affiliated to the social security system

Exclusion criteria

  • Allergy to STS or one of the excipients used
  • Contraindication to local injection of STS
  • Anticoagulant therapy
  • Pregnant, parturient or breastfeeding woman
  • Patient deprived of freedom by a court judgment or an administrative decision
  • Patient undergoing psychiatric care under coercion
  • Legally protected adult patients (guardianship / curatorship)
  • Patient unable to give consent
  • Patient placed under judicial protection

Study description and what participation involves

The registry record has no detailed description beyond the summary above.

AI summaryWhat participation may involve, in plain languageShow ▾Hide ▴

AI-written from the registry record, not the study's own wording. May contain errors or omissions. Check the registry text on this page and the original record ↗ before acting on it.

There is a 6‑month run-in period with usual care (months 0–6), then a 6‑month STS treatment period (months 6–12). People with iPPSD2 receive subcutaneous STS infusion via a portable pump; people with dermatomyositis or systemic sclerosis receive local STS injections every two weeks, up to 11 injections in total. Study visits include clinical evaluations, photographs, CT scans at inclusion, month 6 and month 12, pain and quality-of-life questionnaires, and monitoring/collection of adverse events (clinical and biological). Participants will sign informed consent and must follow the study's contraception and condom-use requirements.

How the study is structured. Phase 2 interventional (treatment) study, single-group and open-label. There is a 6-month run-in observational period followed by 6 months of local STS treatment; no randomization or masking. Outcomes are assessed with CT scans, pain and quality-of-life questionnaires, and adverse event monitoring.

Questions you could ask

These questions are suggestions for a conversation with the study team or your own clinician, not advice.

  • The registry lists this study under Systemic Sclerosis; Dermatomyositis; iPPSD2. Does it apply to my diagnosis?
  • The listed sites are in France. Is any of them reachable for me, and does the study help with travel?
  • Which of the eligibility criteria would need to be checked with tests before I could join?

More on polymyositis

This trial is also listed on this site under dermatomyositis.

Clinical trials55 trials listed for polymyositisEvery trial the registry lists for polymyositis, with recruitment status, phase and sites, updated from ClinicalTrials.gov.See all trials →Research updatesWhat changed in polymyositis researchLatest monthly update: September 2026. Includes: CD4 count risk. New research summarized each month in plain language, with links to every source paper.Read the latest update →

Important dates

Study start
Jan 6, 2020
Primary completion
Jun 6, 2029 (estimated)
Study completion
Jun 6, 2029 (estimated)
Target enrollment
40 participants (estimated)
Last updated on registry
Sep 15, 2026
Data verified
Oct 10, 2026

Sponsor and research team

The lead sponsor funds and oversees the trial. A pharmaceutical or biotech company sponsor typically means the study is testing that company's drug or device; a hospital, university, or government agency usually indicates investigator-initiated or publicly funded research.

Lead sponsor
University Hospital, Limoges

Central study contact

If you're interested in participating, the central contact can answer general questions about the study — including eligibility requirements and how to find a recruiting site near you. Actual eligibility is determined by the site's medical team.

Participating sites (11)

Terms used on this page · explanations by MedicalUpdates.ai

Women of childbearing potential
Studies often ask participants who could become pregnant, or could father a child, to use contraception during the study and for a period afterwards, because the effect of the treatment on a pregnancy is unknown.
Informed consent
The process of explaining a study, including its risks and what participation involves, so that a person can decide freely whether to take part. Consent is usually documented in writing, and a participant can choose to leave the study later.
Contraindication
A reason a particular test or treatment should not be used for a person, for example a metal implant that rules out an MRI scan.
Inclusion Criteria
The conditions a person must meet to be considered for the study, for example a confirmed diagnosis, an age range or a test result.
Exclusion Criteria
The conditions that rule a person out even if they meet the inclusion criteria, for example other illnesses, certain medicines or pregnancy.

The study record on this page is reproduced from ClinicalTrials.gov, a database of the U.S. National Library of Medicine, where it was submitted by the study sponsor. MedicalUpdates.ai does not own this content, is not affiliated with or endorsed by ClinicalTrials.gov, NIH, or the U.S. Government, and does not verify the record. Plain-language notes, the glossary and the questions above are added by this site; text in the boxes marked "AI summary" was written by an AI model and may contain errors. Registry records change over time. Check the original record for the current version and discuss eligibility or participation with a qualified healthcare professional.

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