Amondys 45

DMD is a rare, genetic condition that causes muscle weakness and wasting in young people. Your body needs a specific protein called dystrophin to keep muscle cells intact. In people with DMD, this protein is either missing or present at lower levels. Over time, this can cause movement problems (e.g., repeated falls, difficulty walking), heart problems (e.g., irregular heartbeat, heart failure), and stomach problems (e.g., constipation, diarrhea). Amondys 45 (casimersen) helps to raise the levels of dystrophin in certain people, providing relief from symptoms of DMD.

Amondys 45 (casimersen) is used in certain people with DMD that have a mutated exon 45, a specific part of a gene. It skips (cuts out) exon 45 to help the body make a shortened dystrophin protein that somewhat works. About 8% of young people with DMD are affected by this mutation. Typically, a genetic test that looks at changes in DNA can help identify your child's specific mutation. There are also other "exon skipping" medications available to treat different mutations in exons, such as Exondys 51 (eteplirsen) and Vyondys 53 (golodirsen). If you have any questions about whether Amondys 45 (casimersen) is right for your child, follow up with your child's provider for more information.

The FDA's Accelerated Approval Program allows a new medication to be approved faster than usual if it fulfills an unmet need or if it treats serious or life-threatening conditions. These approvals are based on lab measurements that are thought to predict health outcomes before the medication shows clear benefits. For Amondys 45 (casimersen), the medication raised the amount of dystrophin in skeletal muscles, which might predict better muscle control in certain people with DMD. After accelerated approval, the manufacturer is required to complete clinical studies to confirm beneficial health outcomes (in this case, if Amondys 45 (casimersen) improves muscle control and other symptoms in people with DMD). Depending on the results of these studies, the FDA can either give the medication full approval or pull it off the market.

It's not currently clear whether Amondys 45 (casimersen) can improve muscle control in certain people with DMD. As mentioned in the above FAQ, it's only known that the medication raises the amount of dystrophin. More clinical studies are still required to make sure this medication can help with muscle movement. Typically, physical therapy and gentle exercises (e.g., swimming, stretching) are recommended along with Amondys 45 (casimersen) to build muscle strength and prevent joint stiffening. Talk with your provider to see what exercises can benefit your child while receiving this medication.