This Phase 2, multi-center, open-label extension trial will provide CAP-1002 to participants who were randomized to the Usual Care treatment group of the HOPE-Duchenne study (NCT02485938) and completed 12 months of follow-up.

The trial will assess the safety and efficacy of two intravenous administrations of CAP-1002, each separated by three months.

Participants with documented enrollment in the Usual Care treatment group of the HOPE-Duchenne study and completion of study follow-up through Month 12 were eligible for this study.

Participants will undergo a targeted screening during a 30-day screening period, eligible subjects will then undergo baseline safety and efficacy assessments on Day 1 prior to their first infusion of CAP-1002.

All CAP-1002 infusions will be conducted in an outpatient setting at the investigative site on Day 1 and at Month 3. Participants will be observed in the outpatient setting for at least two hours post-infusion and then discharged the same day if medically cleared by the site Investigator.

Inclusion Criteria:

1. Documented enrollment in the Usual Care Treatment Group of the HOPE-Duchenne trial and completion of trial follow-up through Month 12.
2. Willing and able to provide informed consent to participate in the trial if greater than or equal to (>=) 18 years of age, and assent with parental or guardian informed consent if less than (<) 18 years of age.
3. Adequate venous access for intravenous CAP-1002 infusions and routine blood collections in the judgement of the Investigator.
4. Assessed by the Investigator as willing and able to comply with the requirements of the trial.

Exclusion Criteria:

1. Left ventricular ejection fraction (LVEF) < 35 percent (%) within 6 months of screening.
2. Planned or likely major surgery in the next 6 months after planned first infusion.
3. Risk of near-term respiratory decompensation in the judgment of the investigator, or the need for initiation of non-invasive ventilator support as defined by serum bicarbonate >= 29 millimoles per liter (mmol/L) at screening.
4. History of non DMD-related chronic respiratory disease including, but not limited to, asthma, bronchitis, and tuberculosis.
5. Acute respiratory illness within 30 days prior to screening.
6. Known hypersensitivity to dimethyl sulfoxide (DMSO) or bovine products.
7. Treatment with investigational product <= 6 months prior to first infusion.
8. History, or current use, of drugs or alcohol that could impair ability to comply with participation in the trial.
9. Inability to comply with the investigational plan and follow-up visit schedule for any reason, in the judgment of the investigator.

From Day 1 up to Month 6