Deflazacort (Daflacort) Indication
Deflazacort is indicated for the treatment of Duchenne muscular dystrophy (DMD) in patients 5 years of age and older. 1
Primary Indication: Duchenne Muscular Dystrophy
Deflazacort is FDA-approved specifically for DMD patients aged ≥5 years. This corticosteroid is the only medication class currently available that slows the decline in muscle strength and function in DMD 2.
Key Treatment Goals in DMD
When used in ambulatory children with DMD, deflazacort aims to:
- Preserve ambulation and prolong walking ability
- Reduce risk of scoliosis development
- Stabilize pulmonary function and delay respiratory decline
- Slow cardiac dysfunction progression
- Minimize later respiratory, cardiac, and orthopedic complications 2
When to Initiate Treatment
Initiation is highly recommended when patients reach a functional plateau or show decline, typically around age 6 years (±2 years) 2. The specific timing depends on:
- Age ≥6 years with plateau or declining function: Glucocorticoid initiation highly recommended
- Age <6 years with improving function: Glucocorticoid initiation not recommended (this is typical development)
- Non-ambulatory patients: May be initiated to retard scoliosis progression, stabilize pulmonary function, and possibly delay heart failure 2
Standard Dosing
The recommended dose is 0.9 mg/kg/day given once daily 2, 1. This dose has demonstrated similar efficacy to prednisone 0.75 mg/kg/day but with a slightly different side-effect profile, particularly less weight gain 2.
Deflazacort may be preferred as first-line when pre-existing weight and/or behavioral issues are present 2, as it carries lower risk of weight gain compared to prednisone 3, 4.
Evidence Quality
The FDA approval is supported by Class I evidence from a phase III randomized controlled trial demonstrating that deflazacort 0.9 mg/kg/day significantly improved muscle strength compared to placebo at 12 weeks, with continued benefits and less weight gain than prednisone over 52 weeks 3. Meta-analysis of recent trials shows deflazacort-treated patients experienced significantly lower functional decline over 48 weeks compared to prednisone/prednisolone 4.
Important Caveats
- Complete immunization schedule before initiating, particularly varicella vaccination 2
- Close monitoring for side-effects is essential, especially within the initial 6 months 2
- Daily dosing is preferred over alternate-day or intermittent regimens for optimal efficacy 2
- Continue treatment even after loss of ambulation to maintain upper limb strength and delay cardiopulmonary complications 2
Off-Label Uses (Not FDA-Approved Primary Indications)
While deflazacort has been studied in other conditions including rheumatoid arthritis, juvenile chronic arthritis, sarcoidosis, nephrotic syndrome, and post-transplant immunosuppression 5, 6, 7, 8, these are not FDA-approved indications and the drug should be reserved for DMD in clinical practice given its specific approval and the availability of alternative corticosteroids for other conditions.