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

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).

Conditions

• Systemic Sclerosis
• Dermatomyositis
• iPPSD2

Interventions

DRUG

STS

M0-M6 (run-in phase): medical care and follow-up as usual M6-M12 (STS phase): * Patients with iPPSD2 will be treated with subcutaneous infusion using a portable pump. * Patients with dermatomyositis or systemic sclerosis will be treated with repeated injections every two weeks. Patients will receive a maximal total number of 11 STS injections. M12: final visit (V5): clinical evaluation, photograph and CT scan of the treated lesion, pain and quality of life evaluation.

Sponsors & Collaborators

• University Hospital, Limoges

  lead OTHER

Principal Investigators

• Vincent GUIGONIS, MD · University Hospital, Limoges

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

6 Months

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2020-01-06

Primary Completion

2027-06-06

Completion

2027-06-06

Countries

• France

Study Locations