Assessment of Clobetasol Propionate's Impact on Bone Mineral Density in Patients with Bullous Pemphigoid: A 6-Month Topical Corticosteroid Study

The primary objective of the DERMOS study is to assess the variation in **bone mineral density** (BMD) in patients with **bullous pemphigoid** following a prolonged treatment period of six months with topical corticosteroids, specifically Clobetasol Propionate (Dermoval®). This evaluation is clinically relevant as it aims to understand the potential impact of long-term corticosteroid use on bone health, which is crucial for managing the risk of osteoporosis and fractures in this patient population.

Secondary objectives include:

• Studying the correlation between total exposure to topical corticosteroids per patient and the variation in BMD.
• Investigating variations in phosphocalcic biological parameters, such as corrected serum calcium, serum phosphorus, and 25 OH vitamin D, associated with prolonged use of topical corticosteroids.
• Examining the variations in cortisolemia at 8 A.M. linked to extended corticosteroid use.
• Evaluating the association between exposure to topical corticosteroids and the occurrence of fractures, both axial and peripheral.

The clinical trial involves participants diagnosed with **bullous pemphigoid**, a chronic autoimmune skin condition. The study population includes both male and female subjects aged 18 years and older. Participants are required to have a newly diagnosed condition and must be treated according to the national diagnosis and care protocol for autoimmune bullous diseases. The trial does not specify the total number of participants, as this information was not provided by the sponsor. The selection process includes obtaining informed consent from the patients or their legal representatives. The study population may include individuals with significant lumbar osteoarthritis or those with a history of lumbar vertebroplasty, as bone mineral density measurements will be adjusted accordingly. The trial does not specify any particular lifestyle considerations such as diet or physical activity. The inclusion of a vulnerable population is noted, indicating that special considerations may be in place for these participants.

The clinical trial is designed to assess the **variation in bone mineral density** (BMD) in patients diagnosed with **bullous pemphigoid** following a six-month treatment with topical corticosteroids, specifically Clobetasol Propionate cream. This study is structured as a randomized, double-blind, controlled trial, ensuring that neither the participants nor the researchers know who is receiving the treatment or placebo, thus minimizing bias. The trial is expected to span from December 2020 to June 2026, with participant involvement lasting approximately six months.

Participants will undergo a series of study visits, beginning with an inclusion visit where eligibility is confirmed based on criteria such as age (≥18 years) and a new diagnosis of bullous pemphigoid. During this visit, informed consent will be obtained. The primary endpoint is the variation in BMD at the lumbar spine between the initial measurement at month zero (M0) and the end of treatment at month six (M6). Secondary endpoints include correlations between corticosteroid exposure and BMD reduction, as well as variations in BMD at the hip and lumbar spine at M3 and M6, and changes in specific plasma concentrations.

Follow-up visits will occur at M3 and M6 to monitor BMD and other biological parameters. The end-of-study visit at M6 will conclude the participant's involvement, with data collection on BMD and any adverse events. Participants may be terminated early from the study if they experience significant adverse effects or if they withdraw consent. The trial's rigorous design and comprehensive visit schedule aim to provide valuable insights into the effects of prolonged corticosteroid use on bone health in this patient population.

The clinical trial involves the use of **CLOBETASOL PROPIONATE**, a potent topical corticosteroid, as the experimental medication. This medication is formulated as a cream and is intended for **cutaneous use**. The active substance, clobetasol propionate, is of chemical origin. The maximum daily dose is 30 grams, with a total maximum dose of 2460 grams over the treatment period. The treatment duration is set for a maximum of 12 weeks. Participants are required to apply the cream as per the prescribed dosage schedule to ensure compliance and efficacy. Monitoring of participant compliance will be conducted throughout the study to ensure adherence to the treatment regimen.

In this study, no non-experimental treatments such as standard-of-care therapy, placebo, or comparator treatments are specified. The focus is solely on the administration of clobetasol propionate to assess its impact on bone mineral density in patients with bullous pemphigoid. The trial aims to evaluate the variation in bone mineral density following prolonged treatment with this topical corticosteroid. Participants' adherence to the dosing schedule will be closely monitored to ensure the integrity of the study results.

The efficacy of the clinical trial will be assessed by evaluating the variation in **bone mineral density (BMD)** in patients with bullous pemphigoid following a six-month treatment with topical corticosteroids. The primary endpoint is the change in BMD, expressed in g/cm², at the lumbar spine from the initial measurement at month 0 (M0) to the end of the treatment period at month 6 (M6). Secondary endpoints include the correlation between total exposure to topical corticosteroids and reduction in BMD, variation in BMD at the lumbar spine between M0 and M3, and at the hip between M0, M3, and M6. Additionally, changes in plasma concentrations of corrected serum calcium, phosphorus, 25 OH vitamin D, and cortisolemia at 8 a.m. will be measured at M0, M3, and M6. The frequency of fractures, both axial and peripheral, according to corticosteroid exposure at M6, will also be recorded. Correlations between these biological parameters and BMD at M0, M3, and M6 will be analyzed. Measurements will be conducted using validated laboratory tests and imaging techniques at specified timepoints throughout the study duration.