Duchenne muscular dystrophy (DMD) is treated with a combination of corticosteroids, targeted genetic therapies, heart and lung medications, daily physical therapy, and nutritional support. There is no cure, but treatment has shifted dramatically in the past decade. Boys diagnosed today have access to gene therapies, a new non-steroidal drug, and cardiac medications that together are extending both mobility and lifespan well beyond what was possible a generation ago.
Corticosteroids: The Foundation of Treatment
Corticosteroids remain the first-line treatment for DMD and are typically started around age 4 to 6, though some studies report average starting ages closer to 9. The two options are prednisone and deflazacort. Prednisone is usually prescribed at 0.75 mg per kilogram of body weight daily, which is the dose with the strongest evidence behind it. Deflazacort, dosed slightly higher at 0.9 to 1 mg/kg daily, may delay loss of walking ability by roughly 1.4 to 2.5 years compared to no treatment.
Both drugs slow muscle breakdown, preserve strength, and delay the onset of heart problems. In clinical studies, boys on either corticosteroid were less likely to develop cardiomyopathy by age 18. The tradeoff is a well-known list of side effects: weight gain, mood changes, weakened bones, and metabolic issues like high blood sugar. A lower dose of prednisone (0.3 mg/kg daily) is sometimes used when side effects are severe, though it’s less effective at preserving muscle function.
Givinostat: A Non-Steroidal Option
In 2024, the FDA approved Duvyzat (givinostat) for boys with DMD aged 6 and older, making it the first non-steroidal drug approved for the condition. It works by blocking enzymes involved in inflammation and muscle loss. In an 18-month trial, boys taking givinostat took an average of 1.25 seconds longer to climb four stairs from their baseline, compared to 3.03 seconds longer in the placebo group. That may sound modest, but in a disease where every month of preserved function matters, slowing the decline by roughly half is significant. Boys on givinostat also scored better on a standardized assessment of motor abilities like standing from a chair, walking, and running.
Exon Skipping Therapies
DMD is caused by mutations in the gene that produces dystrophin, a protein muscles need to stay intact. Exon skipping drugs work by telling the body’s protein-building machinery to skip over the damaged section of the gene, producing a shorter but partially functional version of dystrophin. These therapies only work for patients whose specific mutation is in the right location, so genetic testing determines eligibility.
Four exon skipping drugs currently have accelerated FDA approval:
- Eteplirsen (Exondys 51), approved in 2016, targets exon 51 skipping
- Golodirsen (Vyondys 53), approved in 2019, targets exon 53 skipping
- Viltolarsen (Viltepso), approved in 2020, also targets exon 53 skipping
- Casimersen (Amondys 45), approved in 2021, targets exon 45 skipping
All four are given as weekly intravenous infusions. Together, these drugs cover mutations affecting roughly 30% of boys with DMD. The remaining patients with different mutation types are not currently eligible for exon skipping but may benefit from gene therapy or other approaches.
Gene Therapy
Elevidys (delandistrogene moxeparvovec) is a one-time gene therapy approved for boys aged 4 and older with DMD who are still able to walk. It uses a harmless virus to deliver a miniaturized version of the dystrophin gene, called micro-dystrophin, into muscle cells. Because the full dystrophin gene is too large to fit inside the delivery virus, this shortened version produces a smaller but functional protein.
Elevidys is not recommended for patients with pre-existing liver problems, active infections, or those who have been vaccinated within the past four weeks. Because it’s delivered as a single infusion, it represents a fundamentally different approach from the ongoing weekly or daily treatments that make up the rest of DMD care. Additional gene therapies, including RGX-202 from REGENXBIO and SGT-003 from Solid Biosciences, are currently in Phase 3 clinical trials using similar micro-dystrophin strategies.
Heart Protection
Heart muscle deteriorates in DMD just like skeletal muscle does, and cardiomyopathy is one of the leading causes of death. Advanced imaging can detect early signs of heart damage in children as young as 6, well before standard echocardiograms show any problems. Current guidelines recommend starting a heart-protective medication by age 10, typically an ACE inhibitor. In practice, the median age of starting these medications is about 10.3 years. ACE inhibitors are prescribed first in roughly 87% of cases, with other blood pressure medications used less often.
Echocardiograms are used for regular screening, looking for a drop in the heart’s pumping efficiency below 50%. Corticosteroids themselves appear to help delay heart involvement, which is another reason they remain central to treatment even as newer therapies emerge.
Respiratory Support
As the muscles used for breathing weaken, lung function gradually declines. Pulmonary function testing tracks this over time using a measure called forced vital capacity (FVC), which reflects how much air the lungs can push out. When FVC drops below 50% of the predicted value for someone’s age and size, assisted cough devices are typically introduced. These devices help clear mucus and reduce the risk of lung infections, which become increasingly dangerous as cough strength fades.
Nighttime ventilation, usually through a mask, is added when breathing becomes shallow during sleep. Some patients eventually need daytime ventilation as well. The timing of each intervention is guided by sleep studies and regular pulmonary function tests, and respiratory care teams work closely with families to introduce support gradually.
Daily Stretching and Physical Therapy
A daily stretching routine is the most effective way to prevent the joint tightness (contractures) that develops as muscles shorten and weaken. Stretches target the calves, hamstrings, hip flexors, wrists, and forearms. Each stretch should be held for 60 seconds and repeated, with gentle pressure increased as the muscle relaxes. Stretching should never be painful.
Some of the key stretches can be done independently. For the calves, standing at a wall with one foot behind the other and leaning forward with the back knee straight provides a good Achilles stretch. Hamstring stretches can be done lying down at the corner of two walls, with one heel placed up on the wall and slowly sliding closer until a stretch is felt. For boys who are still walking, these stretches help maintain the ankle and knee range of motion needed for stable gait. After walking ability is lost, stretching continues to prevent pain and preserve enough flexibility for comfortable positioning in a wheelchair.
Occupational therapists also fit ankle-foot orthotics and wrist splints to hold joints in functional positions, particularly at night when muscles tend to tighten.
Bone Health
Corticosteroids weaken bones significantly, and boys with DMD already face bone loss from reduced weight-bearing activity. A bone density scan (DXA) of the spine should be done before starting steroids, then repeated every 1 to 2 years. A lateral spine X-ray checks for compression fractures in the vertebrae, which can happen without obvious injury.
Vitamin D levels are checked every 1 to 2 years, with a target of at least 30 ng/mL. Boys whose levels fall below that threshold receive vitamin D supplements at doses tailored to how low their levels are, ranging from 1,000 to 4,000 IU daily. Calcium supplementation is also standard. If a vertebral fracture is found, bisphosphonate therapy is recommended to strengthen bone. For boys who can’t sit upright reliably for 30 minutes after taking an oral bisphosphonate (a requirement to prevent throat irritation), intravenous forms are a better option.
Nutrition and Weight Management
Weight gain is one of the most visible and frustrating side effects of long-term steroid use, and excess weight places additional strain on weakening muscles. Obesity prevention in DMD centers on building a structured home food environment: regular mealtimes, mostly home-prepared whole foods, limited sugary drinks, and eating at the table without screens. A dietitian with training in weight management can help families create a structured daily eating plan, sometimes incorporating food logs for self-monitoring.
As the disease progresses and swallowing becomes more difficult, the nutritional focus shifts. Softer foods, thickened liquids, and eventually feeding tubes may be needed to maintain adequate calorie and nutrient intake. Metabolic complications from both steroids and reduced mobility, including high blood sugar, elevated blood pressure, and abnormal cholesterol, are monitored through regular dietary assessments and blood work.