RecruitingPhase 2

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

France40 participantsStarted 2020-01-06

Plain-language summary

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).

Who can participate

Age range

6 Months

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

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

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Change of the percentage of volume of the treated calcifications / ossifications

Timeframe: between Month 6 and Month 12

Trial details

NCT IDNCT03582800

SponsorUniversity Hospital, Limoges

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2027-06-06

Contact for this trial

Vincent GUIGONIS, MD

555056358 vincent.guigonis@unilim.fr

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