Safety, Tolerability, Pharmacokinetics (PK), and Activity of ATYR1940 in Participants With Muscular Dystrophy - Study Extension

An Open-Label Extension Study to Evaluate the Long-Term Safety, Tolerability, Biological Activity, and Systemic Exposure of ATYR1940 in Adult Patients With Fascioscapulohumeral Muscular Dystrophy (FSHD)

The purpose of this study is to assess the safety and tolerability profile of ATYR1940 in the treatment of adult participants with molecularly defined genetic muscular dystrophies.

The purpose of this study is to assess the safety and tolerability profile of ATYR1940 in the treatment of adult participants with molecularly defined genetic muscular dystrophies, and to additionally explore the pharmacokinetics and biologic activity of ATYR1940 in adult participants with molecularly defined genetic muscular dystrophies. Participants who successfully complete the parent study (NCT02239224) are eligible for enrollment into this long-term extension study.

Inclusion Criteria:

• Participant has an established, genetically-confirmed, diagnosis of facioscapulohumeral dystrophy with clinical findings meeting existing criteria.
• Participant is a male or female aged 18 to 65 years, inclusive.
• Participants who previously participated in study ATYR1940-C-002 and who meet the entry criteria above for the current study will be eligible for enrollment.

Exclusion Criteria:

• Participant is currently receiving treatment with an immunomodulatory agent or has a history of such treatment, including targeted biological therapies (for example, etanercept, omalizumab) within the 3 months before Baseline; corticosteroids within 4 weeks before Baseline; or non-steroidal anti-inflammatory agents (NSAIDs) within 2 weeks before Baseline.
• Participant has a severe retinopathy.
• Participant has a history of obstructive or restrictive lung disease (including interstitial lung disease, pulmonary fibrosis, or asthma), or evidence for interstitial lung disease on Screening chest radiograph.
• Participant has evidence of clinically significant cardiovascular, pulmonary, hepatic, renal, hematological, metabolic, dermatological, or gastrointestinal disease, or has a condition that requires immediate surgical intervention, other treatment or may not allow safe participation.
• Participant has used any investigational product or device (other than a mobility assistance device) within 30 days before Baseline.
• If female and of childbearing potential (premenopausal and not surgically sterile), participant has a positive pregnancy test at Screening or is unwilling to use contraception from the time of Screening through the 1-month Follow-up visit. Acceptable methods of birth control include abstinence, barrier methods, hormones, or intra-uterine device.
• If male, participant is unwilling to use a condom plus spermicide during sexual intercourse from the time of Screening through the 1-month Follow-up visit.