Management strategies in facioscapulohumeral muscular dystrophy

Combined Lumbar-Sacral Plexus Block in Facioscapulohumeral Muscular Dystrophy for Hip Fracture Surgery: A Case Report

Facioscapulohumeral muscular dystrophy (FSHD) is a muscular dystrophy that can affect individuals of all age groups. Its prevalence is reported to be 0.4-1 in 10,000 people. Because of the low occurrence of FSHD, anaesthetic management is primarily based on expert opinions, case reviews, or brief series. Here, we present the case of a 72-year-old woman with FSHD who underwent hip fracture (HF) surgery. To prevent respiratory compromise due to FSHD, we opted for lumbar-sacral plexus block. To the best of our knowledge, there is no information in the literature regarding the use of combined lumbar-sacral plexus block in patients with FSHD undergoing HF surgery.

Erector Spinae Plane Block for Scapulothoracic Arthrodesis for Facioscapulohumeral Dystrophy Patients: A Case Series

Facioscapulohumeral dystrophy (FSHD) typically affects the periscapular muscles, resulting in scapular winging. Scapulothoracic arthrodesis (STA) stabilizes the scapula to provide better movement for these patients. Analgesia regimen for FSHD patients who received a single-shot erector spinae plane block (ESPB) and a catheter at the area were retrospectively analyzed in this study. Patients were asked to rate their pain postoperatively and only 5 of 10 patients needed rescue analgesic. No complications occurred. Our experience suggests that continuous ESPB may be helpful for providing analgesia in FSHD patients undergoing STA.

Randomized phase 2 study of ACE-083, a muscle-promoting agent, in facioscapulohumeral muscular dystrophy

Introduction/Aims

Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive muscular dystrophy without approved therapies. In this study we evaluated whether locally acting ACE‐083 could safely increase muscle volume and improve functional outcomes in adults with FSHD.

Methods

Participants were at least 18 years old and had FSHD1/FSHD2. Part 1 was open label, ascending dose, assessing safety and tolerability (primary objective). Part 2 was randomized, double‐blind for 6 months, evaluating ACE‐083240 mg/muscle vs placebo injected bilaterally every 3 weeks in the biceps brachii (BB) or tibialis anterior (TA) muscles, followed by 6 months of open label. Magnetic resonance imaging measures included total muscle volume (TMV; primary objective), fat fraction (FF), and contractile muscle volume (CMV). Functional measures included 6‐minute walk test, 10‐meter walk/run, and 4‐stair climb (TA group), and performance of upper limb midlevel/elbow score (BB group). Strength, patient‐reported outcomes (PROs), and safety were also evaluated.

Results

Parts 1 and 2 enrolled 37 and 58 participants, respectively. Among 55 participants evaluable in Part 2, the least‐squares mean (90% confidence interval, analysis of covariance) treatment difference for TMV was 16.4% (9.8%‐23.0%) in the BB group (P < .0001) and 9.5% (3.2%‐15.9%) in the TA group (P = .01). CMV increased significantly in the BB and TA groups and FF decreased in the TA group. There were no consistent improvements in functional or PRO measures in either group. The most common adverse events were mild or moderate injection‐site reactions.

Discussion

Significant increases in TMV with ACE‐083 vs placebo did not result in consistent functional or PRO improvements with up to 12 months of treatment.

DUX4 Transcript Knockdown with Antisense 2'-O-Methoxyethyl Gapmers for the Treatment of Facioscapulohumeral Muscular Dystrophy

Facioscapulohumeral muscular dystrophy (FSHD) is an autosomal dominant disorder characterized by a progressive, asymmetric weakening of muscles, starting with those in the upper body. It is caused by aberrant expression of the double homeobox protein 4 gene (DUX4) in skeletal muscle. FSHD is currently incurable. We propose to develop a therapy for FSHD using antisense 2'-O-methoxyethyl (2'-MOE) gapmers, to knock down DUX4 mRNA expression. Using immortalized patient-derived muscle cells and local intramuscular injections in the FLExDUX4 FSHD mouse model, we showed that our designed 2'-MOE gapmers significantly reduced DUX4 transcript levels in vitro and in vivo, respectively. Furthermore, in vitro, we observed significantly reduced expression of DUX4-activated downstream targets, restoration of FSHD signature genes by RNA sequencing, significant improvements in myotube morphology, and minimal off-target activity. This work facilitates the development of a promising candidate therapy for FSHD and lays down the foundation for in vivo systemic treatment studies.

DNA aptamers against the DUX4 protein reveal novel therapeutic implications for FSHD

Aberrant expression of the transcription factor double homeobox protein 4 (DUX4) can lead to a number of diseases including facio‐scapulo‐humeral muscular dystrophy (FSHD), acute lymphoblastic leukemia, and sarcomas. Inhibition of DUX4 may represent a therapeutic strategy for these diseases. By applying Systematic Evolution of Ligands by EXponential Enrichment (SELEX), we identified aptamers against DUX4 with specific secondary structural elements conveying high affinity to DUX4 as assessed by fluorescence resonance energy transfer and fluorescence polarization techniques. Sequences analysis of these aptamers revealed the presence of two consensus DUX4 motifs in a reverse complementary fashion forming hairpins interspersed with bulge loops at distinct positions that enlarged the binding surface with the DUX4 protein, as determined by crystal structure analysis. We demonstrate that insertion of specific structural elements into transcription factor binding oligonucleotides can enhance specificity and affinity.