About AMONDYS 45

Amondys 45 Packaging

Weekly infusions of AMONDYS 45 (casimersen) have been shown to help the body make a shorter form of the dystrophin protein.^a

^aBoys treated with AMONDYS 45 showed varying levels of increased dystrophin production after 48 weeks. In an ongoing clinical study, 27 boys (median age 9 years) receiving AMONDYS 45 had an average dystrophin level of 1.74% of normal, compared to 0.76% in 16 boys who received a placebo infusion.

Meet Colin, age 11. Amenable to exon 45 skipping

Understanding AMONDYS 45.

AMONDYS 45 is a treatment for Duchenne muscular dystrophy (DMD). It uses a technology called exon skipping to help the body make a shorter form of the dystrophin protein.^a AMONDYS 45 is given in a once-weekly infusion.

AMONDYS 45 is used to treat patients with Duchenne muscular dystrophy (DMD) who have a confirmed mutation in the dystrophin gene that can be treated by skipping exon 45.

This indication is approved under accelerated approval based on an increase in dystrophin production in skeletal muscle observed in patients treated with AMONDYS 45. Continued approval for this indication may be contingent upon verification of a clinical benefit in confirmatory trials.

^aBoys treated with AMONDYS 45 showed varying levels of increased dystrophin production after 48 weeks. In an ongoing clinical study, 27 boys (median age 9 years) receiving AMONDYS 45 had an average dystrophin level of 1.74% of normal, compared to 0.76% in 16 boys who received a placebo infusion.

Results from an ongoing AMONDYS 45 clinical study.

Researchers are conducting a clinical study of AMONDYS 45 to review different aspects of the medicine, including whether it triggers skipping of exon 45 on the dystrophin gene. They also analyzed the amount of dystrophin produced, along with its safety profile. AMONDYS 45 was studied in boys who had a confirmed mutation in the dystrophin gene that could be treated by skipping exon 45. Learn what this means.

Beck's Inspiration: Navigating Duchenne with AMONDYS 45

Join Beck and his family as they navigate living with Duchenne muscular dystrophy. Discover Beck's diverse interests, his contributions to the Duchenne community, and the motivation behind his continued treatment with AMONDYS 45.

Designed to skip exon 45.

Patients who received AMONDYS 45 (27 patients) showed a significant increase in exon skipping, based on muscle biopsies taken at the start of the clinical study and after 48 weeks.

This significant increase in exon skipping was not seen in the 16 patients who received a placebo.

Patients treated with AMONDYS 45 demonstrated a significant increase in exon skipping

Dystrophin levels increased over baseline in clinical trial participants.

An ongoing clinical study of 27 boys with Duchenne muscular dystrophy compared the level of dystrophin in their bodies before the first infusion (baseline) of AMONDYS 45 with the level of dystrophin after 48 weeks of treatment with AMONDYS 45. The results were compared to 16 boys with Duchenne who received placebo for 48 weeks. Interim results showed weekly infusions of AMONDYS 45 helped the body make a shorter form of the dystrophin protein. The amount of dystrophin produced varied in the study.

Average dystrophin protein level in muscle tissue in patients amenable to exon 45 skipping, as measured by Sarepta western blot

AMONDYS 45 vs. placebo, % normal dystriphin (mean) chart

Dystrophin levels measured by western blot can be strongly affected by differences in how the sample is processed and analyzed, the reference material used, and the quantification method.

Comparing dystrophin results from other methods of measurement requires standard reference material and additional studies.

What do the results tell us?

Average dystrophin level at baseline was 0.93% of normal

After 48 weeks, the average dystrophin level in boys treated with AMONDYS 45 was 1.74% of normal

AMONDYS 45 demonstrated a significantly greater increase in dystrophin levels – 0.81% of normal from baseline to week 48 compared to those who received placebo (0.22% of normal [average difference of 0.59%; P=0.004])

Icon representing risks and side effects

What about risks? Researchers assessed the risks and tolerability of AMONDYS 45. As with any medication, you should discuss the risks and side effects associated with AMONDYS 45 with your doctor.

Review Risks and Side Effects

What is AMONDYS 45 (casimersen)?

AMONDYS 45 is used to treat patients with Duchenne muscular dystrophy (DMD) who have a confirmed mutation of the dystrophin gene that can be treated by skipping exon 45.

This indication is approved under accelerated approval based on an increase in dystrophin production in skeletal muscle observed in patients treated with AMONDYS 45. Continued approval for this indication may be contingent upon verification of a clinical benefit in confirmatory trials.

IMPORTANT SAFETY INFORMATION

Contraindications: Do not receive AMONDYS 45 if you are allergic to casimersen or any of the ingredients in AMONDYS 45. Serious allergic reactions to casimersen have included anaphylaxis, which may include difficulty breathing, tightness in the chest, and angioedema which may include swelling of the mouth, face, lips, or tongue.

Hypersensitivity Reactions: Serious allergic reactions, including angioedema and anaphylaxis, have occurred in patients who were treated with AMONDYS 45. Patients should seek immediate medical care should they experience signs and symptoms of allergic reactions. Your doctor will institute appropriate medical treatment which may include slowing, interrupting, or discontinuing the AMONDYS 45 infusion. Your doctor will monitor you until the condition resolves.

Kidney Toxicity and Monitoring: Damage to the kidneys was seen in animals who received casimersen. Although damage to the kidneys was not seen in clinical studies with AMONDYS 45, potentially fatal kidney damage has occurred with other drugs that work in a similar way. Your doctor may recommend urine and blood testing before starting treatment followed by urine testing every month and a blood test every 3 months to monitor your kidneys.

Adverse Reactions: Side effects occurring in at least 20% of patients treated with AMONDYS 45 and at least 5% more frequently than in patients who received an inactive intravenous (IV) infusion were (AMONDYS 45, placebo): upper respiratory tract infection (65%, 55%), cough (33%, 26%), fever (33%, 23%), headache (32%, 19%), joint pain (21%, 10%), and pain in mouth and throat (21%, 7%).

Other side effects that occurred in at least 10% of patients treated with AMONDYS 45 and at least 5% more frequently than patients who received an inactive IV infusion were: ear pain, nausea, ear infection, pain after injury, and dizziness and light-headedness.

What do I do if I have side effects?

Ask your healthcare provider for advice about any side effects that concern you.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch or call 1-800-FDA-1088. You may also report side effects to Sarepta Therapeutics at 1-888-SAREPTA (1-888-727-3782).

The information provided here does not include all that is known about AMONDYS 45. To learn more, talk with your healthcare provider.

Before receiving this infusion, please see the full Prescribing Information for AMONDYS 45 (casimersen).