Treatment of facioscapulohumeral muscular dystrophy with losmapimod

JP2024526998A5Pending Publication Date: 2026-04-28FULCRUM THERAPEUTICS INC
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Patent Information

Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
FULCRUM THERAPEUTICS INC
Filing Date
2022-07-27
Publication Date
2026-04-28

AI Technical Summary

Technical Problem

There are currently no approved treatments that can stop or reverse the effects of facioscapulohumeral muscular dystrophy (FSHD), with non-steroidal anti-inflammatory drugs only providing limited relief for comfort and mobility.

Method used

Administering 15 mg of rosmapimod, a p38α/β MAPK inhibitor, twice daily for at least 40 weeks to treat FSHD, as measured by improvements in muscle health using whole body musculoskeletal magnetic resonance imaging (WB-MSK-MRI).

Benefits of technology

Rosmapimod significantly reduces muscle fat accumulation and improves muscle health, slowing the progression of FSHD by preserving muscle function and structure, as evidenced by MRI and clinical outcome assessments.

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Abstract

Provided herein, in part, is a method of treating facioscapulohumeral muscular dystrophy in a patient in need thereof, comprising administering to the patient losmapimod.
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Description

[Technical field]

[0001] cross reference

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 203,628, filed July 27, 2021, U.S. Provisional Patent Application No. 63 / 320,510, filed March 16, 2022, U.S. Provisional Patent Application No. 63 / 328,975, filed April 8, 2022, and U.S. Provisional Patent Application No. 63 / 344,844, filed May 23, 2022, the contents of each of which are incorporated by reference into this specification. [Background technology]

[0002] background

[0002] Muscular dystrophies (MD) are a group of more than 30 different genetic disorders characterized by progressive weakness and degeneration of the skeletal muscles that control movement. Some forms of MD have an onset in infancy or childhood, whereas other forms may not manifest until middle age. The various MD disorders differ in the distribution and degree of muscle weakness (some forms of MD also affect the heart muscle), age of onset, rate of progression, and inheritance pattern.

[0003]

[0003] Facioscapulohumeral muscular dystrophy (FSHD) is the third most common form of muscular dystrophy. FSHD is caused by genetic mutations that result in epigenetic derepression of the DUX4 gene, making the disease unique among muscular dystrophies. Summary of the Invention [Problem to be solved by the invention]

[0004]

[0004] Currently, there is no approved treatment that can halt or reverse the effects of FSHD, but nonsteroidal anti-inflammatory drugs are often prescribed to improve comfort and mobility. New methods of treating FSHD are needed. [Means for solving the problem]

[0005] overview

[0005] The present disclosure provides, in part, a method of treating facioscapulohumeral muscular dystrophy (FSHD) in a patient in need thereof.

[0006]

[0006] In one embodiment, provided herein is a method for treating facioscapulohumeral muscular dystrophy (FSHD) in a patient in need thereof, comprising administering to the patient 15 mg of losmapimod twice daily for at least 40 weeks, after which the patient experiences improved muscle health as measured by whole-body musculoskeletal magnetic resonance imaging (WB-MSK-MRI).

[0007]

[0007] In another embodiment, provided herein is a method for reducing fat accumulation in muscles at high risk of progression to facioscapulohumeral muscular dystrophy (FSHD) in a patient in need thereof, comprising administering 15 mg of losmapimod twice daily for at least 40 weeks. [Brief description of the drawings]

[0008] BRIEF DESCRIPTION OF THE DRAWINGS [Figure 1]

[0008] A schematic diagram of the clinical study of Example 1 is shown. [Diagram 2]

[0009] The muscle types included in the regional correlation composite study of clinical outcome measures are shown. [Figure 3A]

[0010] FIG. 1 shows exemplary pharmacokinetic and target engagement results of the study of Example 1. Plasma concentrations of losmapimod are shown. Red dots represent mean concentrations in ng / mL and error bars represent standard error (SE). [Figure 3B]

[0010] Figure 1 shows exemplary pharmacokinetic and target engagement results from the study of Example 1. Target engagement in blood is shown as determined by the ratio of phosphorylated HSP27 to total HSP27 relative to placebo levels at each time point. Orange boxes represent the mean and error bars (SE). [Figure 4]

[0011] Selected secondary and exploratory efficacy endpoints of the study of Example 1 are shown. [Figure 5A]

[0012] 1 shows exemplary DUX4-driven gene expression distribution and heterogeneity results from the study of Example 1, as shown by scatter plots depicting individual measurements of DUX4-driven gene expression in muscle needle biopsies. Pooled baseline and post-baseline values ​​(weeks 16 and 36) are shown. [Figure 5B]

[0012] Figure 1 shows exemplary DUX4-driven gene expression distribution and heterogeneity results from the study of Example 1, as shown by scatter plots showing each measurement of DUX4-driven gene expression in muscle needle biopsies. Cohorts separated by week 16 or week 36 visits are shown. At week 16, n=21 for placebo and n=24 for losmapimod. At week 36, n=17 for placebo and n=15 for losmapimod. Lines represent the mean per group. [Figure 6]

[0013] Selected secondary and exploratory efficacy endpoints of the study of Example 1 are shown. [Figure 7]

[0014] 1 shows an exemplary Patient Global Impression of Change breakdown from the study in Example 1. Response breakdown is the percentage by time point on the PGIC assessment. The number of participants at each time point is listed at the top. [Figure 8]

[0015] 1 shows exemplary reachable workspace results from the study of Example 1. [Figure 9]

[0016] Figure 1 shows an exemplary annualized percent change in achievable workspace. To estimate the annualized percent change, a linear mixed-effects model was used to calculate the annualized percent change (y-axis). As indicated in the legend, the orange line represents losmapimod and the blue line represents placebo. The lighter lines represent standard errors for losmapimod and placebo. [Figure 10]

[0017] 1 shows exemplary muscle strength measurement results from the study of Example 1. [Figure 11]

[0018] 1 shows other exemplary endpoints of the study of Example 1, including FSHD-TUG, MFM, and FSHD-HI. [Figure 12A]

[0019] Distribution of muscle echogenicity z scores (<2, 2-4, 4-6, and >6) in FSHD patients receiving losmapimod at baseline versus week 60. [Figure 12B]

[0019] Figure 1 shows the change from baseline to week 60 in echogenicity of multiple muscles and muscle groups in FSHD patients receiving 15 mg losmapimod twice daily. [Figure 13A]

[0020] FIG. 1 shows the correlation between echogenicity z-score versus reachable workspace of the upper extremities in FSHD patients at baseline. [Figure 13B]

[0020] Figure 1 shows the correlation of upper extremity echogenicity z-score versus attainable workspace at week 60 in FSHD patients receiving losmapimod 15 mg twice daily. [Figure 14A]

[0021] Correlation between echo intensity of the tibialis anterior muscle and handheld muscle strength data of ankle dorsiflexion in patients with FSHD at baseline is shown. [Figure 14B]

[0021] Correlation of tibialis anterior echo intensity with handheld ankle dorsiflexion strength data at week 60 in FSHD patients receiving 15 mg losmapimod twice daily. [Figure 15A]

[0022] 1 shows the correlation between echo intensity versus time up and go (TUG) in the lower extremities of FSHD patients at baseline. [Figure 15B]

[0022] Figure 1 shows the correlation of lower extremity echo intensity vs. TUG at week 60 in FSHD patients receiving losmapimod 15 mg twice daily. [Figure 16]

[0023] FIG. 1 shows a schematic diagram of a wearable sensor study of Example 4 in FSHD patients receiving 15 mg losmapimod twice daily. [Figure 17]

[0024] 1 shows feasibility and compliance results of FSHD patients in the wearable sensor study of Example 4. [Figure 18]

[0025] 1 shows the analysis, processing, and reliability results of FSHD patients in the wearable sensor study of Example 4. [Figure 19]

[0026] 1 shows correlation data between clinical variables of FSHD patients and wearable sensor variables in the wearable sensor study of Example 4. [Figure 20]

[0027] 13 shows the results of location of disability between in-clinic and wearable variables in the wearable sensor study of Example 4. [Figure 21]

[0028] FIG. 20 shows physical function as measured by walking speed in FSHD patients categorized by groups over a one-year period of losmapimod treatment in the wearable sensor study of Example 4. [Figure 22]

[0029] 1 shows the updated annualized percent change in weighted total RSA in FSHD patients receiving 15 mg losmapimod twice daily in the study of Example 1. [Diagram 23]

[0030] 1 shows the annualized percent change in RSA by domain, with and without weights, and total RSA in patients receiving 15 mg losmapimod twice daily in the study of Example 1. [Figure 24]

[0031] 1 shows the annualized percent change in MFI, the annualized percent change in MFF, and the annualized percent change in LMV for patients receiving 15 mg losmapimod twice daily in the study of Example 1. [Diagram 25]

[0032] 1 shows the annualized percent change in mean time to complete TUG in patients receiving 15 mg losmapimod twice daily in the study of Example 1. [Figure 26]

[0033] 1 shows the change in hand grip and shoulder maximal voluntary isometric contraction test (MVICT) in patients receiving 15 mg losmapimod twice daily in the study of Example 1. [Figure 27]

[0034] 1 shows results from an exploratory annualized reachable workspace (RWS) analysis in the open-label study (OLS) of Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Detailed Description

[0035] Throughout this disclosure, various patents, patent applications, and publications are referenced. The disclosures of these patents, patent applications, and publications are incorporated by reference in their entirety into this disclosure to more fully describe the prior art known to those skilled in the art as of the date of this disclosure. In the event of a conflict between the patents, patent applications, and publications and this disclosure, the present disclosure shall control.

[0010] definition

[0036] "Individual", "patient" or "subject" are used interchangeably herein and include any animal, including mammals such as mice, rats, other rodents, rabbits, dogs, cats, pigs, cows, sheep, horses or primates and humans. The compounds described herein can be administered to mammals, such as humans, but can also be administered to other mammals, such as animals in need of veterinary treatment, for example, farm animals (e.g., dogs, cats, etc.), livestock (e.g., cows, sheep, pigs, horses, etc.) and laboratory animals (e.g., rats, mice, guinea pigs, etc.). The mammal treated by the methods described herein is desirably a mammal in which treatment of a disorder described herein is desired, such as a human.

[0011]

[0037] As used herein, the term "pharmaceutically acceptable salt" refers to a salt that is suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, etc., within the scope of sound medical judgment, and commensurate with a reasonable benefit / risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, SM Berge et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 1977, 66, 1-19, which is incorporated herein by reference. Pharmaceutically acceptable salts of the compounds of the present disclosure include those derived from suitable inorganic and organic acids and inorganic and organic bases. Examples of pharmaceutically acceptable non-toxic acid addition salts are salts of amino groups formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid, and perchloric acid, or organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid, or by other methods used in the art, such as ion exchange. Other pharma- ceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecyl sulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy-ethanesulfate, and the like. Examples of salts that may be used include sulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate, and the like.

[0012]

[0038] Salts derived from appropriate bases include alkali metal, alkaline earth metal, ammonium and N + (C 1~4 Alkyl)4 Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, etc. Further pharma-ceutically acceptable salts include non-toxic ammonium, quaternary ammonium and amine cations formed, where appropriate, with counterions such as halides, hydroxides, carboxylates, sulfates, phosphates, nitrates, lower alkylsulfonates and arylsulfonates.

[0013]

[0039] Unless otherwise stated, a structure depicted herein is also meant to include all enantiomers, diastereomers, and geometric (or conformational) isomers of that structure, such as the R and S configurations of each asymmetric center, Z and E double bond isomers, and Z and E conformational isomers. Thus, single stereochemical isomers as well as mixtures of enantiomers, diastereomers, and geometric (or conformational) isomers of the present compounds are included within the scope of the disclosure. Unless otherwise stated, all tautomers of the compounds of the disclosure are included within the scope of the disclosure.

[0014]

[0040] A "therapeutically effective amount" includes an amount of the subject compound that can elicit the biological or medical response in a tissue, system, animal or human that is being sought by a researcher, veterinarian, physician or other clinician. The compounds described herein, such as the p38α / β MAPK inhibitors described herein, are administered in a therapeutically effective amount to treat a condition, such as a condition described herein. Alternatively, a therapeutically effective amount of a compound is the amount required to achieve the desired therapeutic and / or prophylactic effect, such as an amount that results in the prevention or reduction of symptoms associated with the condition.

[0015]

[0041] As used herein, "Wk" refers to weeks.

[0016]

[0042] The compounds described herein, such as the p38α / β MAPK inhibitors described herein, can be formulated into pharmaceutical compositions using pharma- ceutically acceptable carriers and administered by various routes. In some embodiments, such compositions are for oral (PO) administration. In some embodiments, such compositions are for parenteral (by injection) administration. In some embodiments, such compositions are for transdermal (TD) administration. In some embodiments, such compositions are for intravenous (IV) administration. In some embodiments, such compositions are for intramuscular (IM) administration. Such pharmaceutical compositions and methods for their preparation are well known in the art. See, for example, REMINGTON: THE SCIENCE AND PRACTICE OF PHARMACY (A. Gennaro, et al., eds., 19th ed., Mack Publishing Co., 1995).

[0017] Methods of Use and Treatment

[0043] In another embodiment, the disclosure also provides a method of treating facioscapulohumeral muscular dystrophy (FSHD) in a patient in need thereof, comprising administering to the patient a therapeutic agent described herein, such as a p38α / β MAPK inhibitor. In certain embodiments, the p38α / β MAPK inhibitor has the formula (I): [ka] or a pharma- ceutically acceptable salt thereof.

[0018]

[0044] In another embodiment, provided herein is a method of treating facioscapulohumeral muscular dystrophy (FSHD) in a patient in need thereof, comprising administering to the patient 15 mg of losmapimod twice daily for at least 40 weeks, wherein after at least 40 weeks, the patient experiences improved muscle health as measured by whole body musculoskeletal magnetic resonance imaging (WB-MSK-MRI).

[0019]

[0045] In another embodiment, provided herein is a method of reducing fat accumulation in muscles at high risk of progressing to facioscapulohumeral muscular dystrophy (FSHD) in a patient in need thereof, comprising administering 15 mg of losmapimod twice daily for at least 40 weeks.

[0020]

[0046] In some embodiments, after at least 40 weeks, the muscle has reduced fat deposition as measured by whole body musculoskeletal magnetic resonance imaging (WB-MSK-MRI). In some embodiments, the method includes imaging the muscle using whole body musculoskeletal magnetic resonance imaging (WB-MSK-MRI) to determine a correlation between the measure of muscle health and the patient's clinical outcome assessment. In some embodiments, the measure of muscle health is selected from the group consisting of muscle fat fraction (MFF), muscle fat infiltration (MFI) and lean muscle mass (LMV). In some embodiments, the clinical outcome assessment is selected from the group consisting of assessments made from reachable workspace (RWS), relative surface area (RSA) and timed up and go (TUG) testing. In some embodiments, the muscle is characterized by a muscle fat infiltration (MFI) of less than about 0.10 and a muscle fat fraction (MFF) of less than about 0.50 prior to administering losmapimod to the patient. In some embodiments, the muscle is characterized by a muscle fat infiltration (MFI) of about 0.10 or greater and a muscle fat fraction (MFF) of less than about 0.50 prior to administering losmapimod to the patient. In some embodiments, the muscle is characterized by a muscle fat fraction (MFF) of about 0.50 or greater prior to administering losmapimod to the patient. In some embodiments, the method comprises administering to the patient 15 mg of losmapimod twice daily for at least 48 weeks. In some embodiments, the FSHD is FSHD1. In some embodiments, the muscle is selected from the group consisting of upper limb muscles and lower limb muscles. In some embodiments, the muscle is selected from the group consisting of shoulder abductors and ankle dorsiflexors. In some embodiments, the shoulder abductors are selected from the group consisting of bilateral shoulder abductors, dominant shoulder abductors, and non-dominant shoulder abductors.

[0021]

[0047] In other embodiments, the treatment of a patient with the methods described herein is assessed by patient assessments including, but not limited to, quantification of reachable workspace of total relative surface area (Q1-Q5) (e.g., with a 500 g wrist weight on the dominant arm), Quality of Life in Neuropathy Upper Extremity Scale (Neuro-QoL UE), Patient Global Impression of Change (PGIC), and muscle ultrasound. In some embodiments, the treatment of a patient with the methods described herein is assessed by Functional Assessment of Chronic Illness Therapy (FACIT). In some embodiments, the method comprises administering 15 mg of losmapimod twice daily to a patient in need thereof.

[0022]

[0048] In some embodiments, the treatment of a patient in the methods described herein is evaluated by a patient-reported outcome (PRO). In some embodiments, the PRO is a PRO of physical function. Exemplary physical functions measured by the PRO described herein include, but are not limited to, mobility, upper limb dexterity, daily activities, facial function (e.g., smiling, verbal communication), central / axial function, pain, fatigue, upper limb range of motion, upper limb weakness, midsection weakness, lower limb weakness, facial weakness, and foot drop.

[0023] compound

[0049] In one embodiment, the methods of the disclosure comprise administration of a therapeutically effective amount of a compound of formula (I), also referred to herein as "losmapimod." Losmapimod is an inhibitor of p38α / β MAPK and has the chemical name 6-(5-cyclopropylcarbamoyl-3-fluoro-2-methyl-phenyl)-N-(2,2-dimethylpropyl-)-nicotinamide and the structure: [ka] has.

[0024]

[0050] Suitable methods for preparing losmapimod are disclosed, for example, in US Pat. No. 7,125,898. EXAMPLES

[0025] Working Example

[0051] The examples set forth below are provided to illustrate the compounds, pharmaceutical compositions and methods provided herein and should not be construed in any way as limiting the scope thereof.

[0026] Example 1. A 48-Week, Randomized, Double-Blind, Placebo-Controlled Study of the Efficacy and Safety of Losmapimod in the Treatment of Facioscapulohumeral Muscular Dystrophy

[0052] This is a 48-week Phase 2b, randomized, double-blind, placebo-controlled, international, parallel-group study (RCT) of the efficacy and safety of losmapimod in subjects with FSHD with open-label extension (OLE) designed and conducted to evaluate the efficacy of losmapimod in the treatment of FSHD.

[0027]

[0053] The trial is being conducted in two parts: the RCT treatment period and the OLE period (all subjects are treated with losmapimod). The RCT period evaluated the efficacy and safety of losmapimod in subjects with FSHD for up to 48 weeks. The OLE period is ongoing.

[0028]

[0054] Eighty subjects were randomized 1:1 to receive losmapimod or placebo 15 mg tablets orally BID. The RCT period was planned to last 24 weeks. Due to the COVID-19 pandemic, it was amended to 48 weeks. The OLE period is ongoing until marketing is approved or the sponsor stops the study (Figure 1). Seventy-seven subjects completed the RCT period. Sixteen subjects entered the OLE after completing the Wk24 visit (before the COVID19 amendment). Sixty subjects entered the OLE after the Wk48 visit. One subject declined the OLE after completing the RCT. Common inclusion criteria were age 18–65 years, confirmed diagnosis of FSHD1, Ricci score 2–4 at screening, and STIR+ muscles safely accessible for needle biopsy by MRI as determined by a central reader.

[0029]

[0055] The primary endpoint was change in DUX4 expression assessed by a composite measure of selected DUX4-regulated gene transcripts in skeletal muscle.Secondary endpoints included safety and tolerability (AE), pre-specified WB-MSK-MRI composite scores of muscle fatty infiltration (MFI), muscle fat fraction (MFF) and lean muscle mass (LMV) in muscles at high risk of progression (classified as B muscles), and PK (plasma and muscle) / target engagement (blood). Exploratory endpoints included assessment of change in two PROs (Patient Global Impression of Change [PGIC] questionnaire and FSHD-Health Index [FSHD-HI]) and FSHD-related COAs including Reachable Workspace (RWS), a 3D motion sensor-based outcome measure that measures global function of each individual upper limb, including the shoulder and proximal arm; Timed Up and Go (TUG), which measures the time it takes a subject to stand from a sitting position, walk 3 m, and return to a chair; FSHD-TUG; muscle strength (shoulder abduction, elbow flexion / extension, ankle dorsiflexion, and hand grasp) measured by handheld manual dynamometry, and Motor Function Scale Domain 1 (MFM).

[0030]

[0056] All randomized subjects were included in the efficacy analyses, and subjects were analyzed according to their randomized treatment (full analysis set). Efficacy endpoints with only one post-baseline follow-up, such as the primary endpoint, were analyzed using an analysis of covariance (ANCOVA) approach. Efficacy endpoints with two or more post-baseline follow-ups, such as secondary and exploratory efficacy endpoints, were analyzed using a mixed-effects model for repeated measures (MMRM). Hierarchical hypothesis testing began with the primary endpoint, then LMV, then FSHD-TUG. Other secondary and exploratory analyses were prespecified without hierarchical prioritization.

[0031] method Ricci Score

[0057] The Ricci score is a well-established measure of a patient's disability. Scores range from 0 to 10, with 0 indicating no muscle weakness and 10 indicating wheelchair dependency.

[0032] statistical methods

[0058] Assuming an effect size of 0.70, a sample size of 68 subjects (34 subjects per group) was deemed necessary to provide 80% power at a two-sided test with a significance level of 0.05 to detect a difference between losmapimod and placebo in the change from baseline in DUX4 activity in affected skeletal muscle after 16 or 36 weeks (depending on when the muscle biopsy was performed) during the placebo-controlled treatment period. Assuming that approximately 10% of subjects were unevaluable, approximately 76 subjects would have been required to be randomly assigned in a 1:1 ratio to losmapimod and placebo (38 subjects per group).

[0033]

[0059] Subjects were randomly assigned using a 1:1 allocation ratio to receive losmapimod (active drug) or placebo at the baseline visit (Day 1). Randomization was stratified to ensure that treatment assignment was balanced across FSHD repeat number categories (i.e., 1-3 repeats vs. 4-9 repeats). Study medication was administered according to the randomization schedule using an interactive response technology (IRT) system.

[0034]

[0060] All efficacy analyses were performed using the full analysis set (FAS) according to randomized treatment group. The primary endpoint, change from baseline in DUX4 activity (DUX4 score 1), was analyzed using an analysis of covariance approach with treatment group and FSHD repeat number category (1-3 repeats vs. 4-9 repeats) as fixed effects and baseline DUX4 score 1 as covariate. No multiplicity adjustment was performed because the primary endpoint was not met.

[0035]

[0061] Continuous secondary and exploratory efficacy outcomes with ≥2 post-baseline follow-ups were analyzed using mixed-effects models for repeated measures (MMRM) with change from baseline as the dependent variable, treatment group, visit, treatment group-visit interaction, and FSHD repeat number category as fixed effects, and baseline value as a covariate. Correlations between repeated measures in each subject were modeled using an unstructured covariance matrix. Denominator degrees of freedom were estimated using the Kenward-Roger approximation.

[0036]

[0062] RWS RSA scores were also analyzed using linear mixed-effects models with treatment group as a fixed effect and intercept, time, and treatment group by time interaction as random effects, adjusting for FSHD repeat number category and region (US, Canada, and EU).

[0037]

[0063] The placebo-controlled treatment period was conducted in a double-blind manner: the investigators, study staff, subjects, sponsors, and monitors remained blinded to treatment until the end of the study.

[0038]

[0064] Study hierarchies for the primary and key secondary analyses were ordered as follows: change from baseline in pooled DUX4 activity (DUX4 score 1) at weeks 16 or 36, change from baseline in longitudinal whole-body LMV composite score at week 48, and change from baseline in mean time to complete FSHD TUG at week 48. These were each tested at a 5% significance level. Other secondary and exploratory endpoints were analyzed as prespecified (unless otherwise noted) without hierarchical prioritization.

[0039]

[0065] All safety analyses were performed using the safety analysis set based on the as-treated treatment group. Safety analyses included TEAEs, clinical laboratory tests, vital signs, and ECG summaries.

[0040] Muscle needle biopsy

[0066] Muscle needle biopsies were performed at D1 and Wk16 using a Bergstrom or fine needle, or at Wk36 if muscle biopsy could not be performed at Wk16. The choice of muscle to biopsy was determined by the investigator, informed by MRI taken during screening. Only STIR+ muscles with 10% ≤ MFF ≤ 40% were eligible for biopsy. Previous studies have demonstrated a high probability of detecting DUX4 activity in STIR+ muscles. Bilateral vastus lateralis, vastus medialis, gastrocnemius lateralis, gastrocnemius medialis, and tibialis anterior were assessed for eligibility by MRI using a central reader. Muscle needle biopsies at Wk16 or Wk36 were performed in the same approximate location as the pretreatment (D1) muscle biopsy. MRI fiducials were placed at baseline to identify the location of the needle biopsy. The location of the muscle biopsy was defined by the coordinates relative to the closest fiducial. A grid was used to record the placement of fiducials so that the location (and therefore the area to be biopsied) could be identified at the time points of Wk16 or Wk36. Approximately 15-40 mg of tissue was collected for each biopsy, frozen in liquid nitrogen within 60 seconds after excision, and stored at -80°C until analysis (SciSafe Inc. Billerica, MA, USA).

[0041] Analysis of DUX4-regulated transcripts by RT-qPCR in muscle biopsies

[0067] Muscle tissue taken at each muscle needle biopsy (D1 and Wk16 or Wk36) was analyzed for DUX4 activity using a molecular panel of DUX4-regulated gene transcripts (CCNA1, KHDC1L, MBD3L2, PRAMEF6, SLC34A2 and ZSCAN4, with TBP, HMBS, CDKN1B as reference genes). Raw cycle threshold (Ct) values ​​from quantitative polymerase chain reaction (qPCR) were determined for DUX4-regulated genes using a validated assay (Fluidigm). Raw Ct values ​​per gene per sample (usually in duplicate) were normalized to the reference gene values ​​by a blinded scientist. Reference genes were confirmed to have a coefficient of variation of less than 30% for all gene pairs. Sample-analyte mean Ct values ​​(arithmetic mean by analyte and by sample) represent the relative abundance level of that analyte in the assayed samples. The arithmetic mean of the sample-analyte averages (geometric mean of the signal) of each reference gene value is the sample reference value used by all target analytes of that sample. The inverted delta Ct value of each sample / analyte is the difference between 30 and the difference between the target analyte Ct and reference Ct values. The first difference is used because 30 is usually the maximum cycle and allows for inversion of the delta Ct value. The average of the inverted delta Ct values ​​by subject and time point across all six transcripts is the DUX4-driven gene expression (primary endpoint).

[0042] WB-MSK MRI

[0068] Images were acquired in five different sections: after repositioning the patient so that the extremities were in the center of the MRI scanner, the rotator cuff was imaged using a cervical coil, the trunk and legs using a frontal coil and integrated table coil, and the upper extremities using a surface and table coil.

[0043]

[0069] T1-weighted Dixon images were acquired for 18 muscles on both sides, for a total of 36 muscles, and water and fat images were reconstructed using a scanner-internal phase-sensitive reconstruction (Siemens: Dixon-Vibe; Philips: mDixon). Three different measures were calculated for each muscle: Muscle fat fraction (MFF) is the total fat fraction within the fascia. Muscle fat infiltration (MFI) represents diffuse fatty infiltration within muscle tissue and is defined as the fat fraction of muscle voxels that contain less than 50% fat. Thus, MFI measures the MFF of non-endstage muscle tissue. Lean muscle mass (LMV) represents the total amount of functional muscle tissue and is measured by removing all fat within the muscle mass. Each muscle was classified based on these measures as appearing normal (category A, MFI<0.10; MFF<0.50), intermediate (category B, MFI≥0.10; MFF<0.50) and late (category C, MFF≥0.50) and was supported by prior literature.

[0044]

[0070] Two composite scores were used to assess correlation with treatment efficacy and relevant clinical outcome measures. The treatment efficacy composite score included only muscles that appeared normal or were identified as at high risk of progression at baseline (category A or B muscles) with good signal quality and measurable at both observation time points. The correlation local composite score consisted of all muscles involved in the specific functional assessment of interest, regardless of their categorization (Figure 2). This score was obtained in a blinded manner by scientists at the MRI service provider (AMRA Medical Inc.), who had no access to treatment assessment information. Measurements of muscles with high quality issues (i.e. muscles with missing values) were imputed. Late stage muscles were not included in the analysis, as they had a high fat fraction that made accurate quantification difficult and were likely already non-functional.

[0045]

[0071] Mixed-effects models for repeated measures (MMRM) were used to evaluate the association between each composite MRI score (MFF) and the mean mean for each treatment group, with number of replicates, treatment group, visit, and treatment-visit interaction as fixed effects and baseline values ​​of parameters as covariates. total , L.M.V.total and MFI total Within-group LS mean change from baseline, associated SE and two-sided 95% CI, treatment difference in LS mean change from baseline at weeks 12 and 48, and associated two-sided 95% CI and two-sided p-values ​​were derived from MMRM.

[0046] Pharmacokinetics and Target Engagement

[0072] Blood samples for PK evaluation (plasma losmapimod concentrations) were collected on D1, Wk4, Wk16, and Wk36 at the following time points: immediately before dosing and 4 hours (± 30 minutes) after administration of the study dose (approximate C max PK samples were also collected, when possible, post-dose during Wk12, Wk24 and Wk48 visits, preferably at least 1 hour post-dose.

[0047]

[0073] Plasma and muscle losmapimod concentrations were measured by two validated bioanalytical high-performance liquid chromatography methods by PPD, USA (PPD 2019).

[0048]

[0074] Blood samples for target engagement were collected at the same pre- and post-dose time points as PK samples on D1 and Wk16 or Wk36.

[0049]

[0075] Total heat shock protein 27 (HSP27 total Blood samples for measurement of HSP27 (pHSP27) and phosphorylated heat shock protein 27 (pHSP27) were collected in EDTA-containing tubes. 2 mL of whole blood was stimulated ex vivo with sorbitol for 30 min at room temperature to induce phosphorylation of HSP27 as a measure of p38a / b MAPK activity. Sorbitol stimulation activates the p38a / b MAPK pathway in blood, allowing more robust detection of inhibition of the p38a / b MAPK pathway by losmapimod. Samples were subsequently thawed on ice and lysates were frozen at -80°C. pHSP27 and HSP27 totalwere measured by validated enzyme-linked immunosorbent assays (Cambridge Biomedical Inc., Boston, MA, USA and Immunologix, Tampa, FL, USA). total The inter- and intra-assay precision of both assays met the pre-approved criteria of CV <25% performed in five replicates, and the LLOQ of pHSP27 was set at 20.7 ng / mL, the ULOQ at 470.1 ng / mL, and the HSP27 total The LLOQ was set at 105.2 ng / mL and the ULOQ at 2168.1 ng / mL.

[0050] Clinical Outcome Assessment (COA)

[0076] All clinical outcome assessments were performed by highly trained physiotherapists.

[0051] Reachable workspace

[0077] The RWS was administered at all visits except week 16. It uses a single 3D sensor-based system (Microsoft Kinect) that can unobtrusively detect a subject's RWS and reflects an individual's overall upper extremity (UE) function, including the shoulder and proximal arm. The RWS has high reliability, reproducibility, face validity, feasibility, and sensitivity to change, making it a promising clinical outcome assessment (COA) for FSHD and other neuromuscular disorders.

[0052]

[0078] During the evaluation, patients underwent a standardized UE operating protocol while seated in front of a Microsoft Kinect sensor and viewing a TV monitor. Evaluations were performed twice per visit, with and without a 500 g weight. The sponsor provided and trained on the same standardized software and hardware for all sites. A central leader was responsible for training, quality control, data analysis, and standardization of the RWS across all study sites.

[0053] Time Up and Go

[0079] TUG assessments were performed at all visits except Wk16. The TUG test is a simple test used to assess a subject's mobility and requires both static and dynamic balance. The TUG is a validated instrument that measures the time it takes a person to stand up from a chair, walk 3 meters, turn, walk back to the chair, and sit down. Subjects used their usual footwear and their usual walking aid (no walkers allowed). Patients were also timed in a modified test (FSHD TUG) that started in a supine position, then rose to their feet, completed the TUG, and lay down again.

[0054] Muscle strength measurement

[0080] Quantitative isometric dynamometric strength assessments were performed at all visits except week 16. Bilateral shoulder, elbow flexor and extensor, and ankle dorsiflexor strength were measured using a MicroFET2 handheld dynamometer. Bilateral grip strength was measured using a Jamar Plus Digital Hand dynamometer. Standard physical therapy techniques were used.

[0055] Motor Function Scale Domain 1

[0081] MFM Domain 1 assessment was performed at all visits except Wk4 and Wk16. The MFM scale assesses the severity of movement disorders. Domain 1 of the MFM provides an assessment of impairment in standing and moving.

[0056] FSHD-HI

[0082] The FSHD Health Index questionnaire was administered at all visits except Wk16. It is an FSHD-specific patient-reported disease burden measure of activities of daily living, quality of life, and prevalence and severity of symptoms. It consists of a 116-item questionnaire developed from qualitative patient interviews followed by a national cross-sectional validation study. The scale consists of 14 subscales measuring patients' perceptions of gait and mobility, hand function, shoulder and arm function, emotional health, back / chest / abdominal strength, fatigue, pain, feeding function, ability to be active, ability to communicate, satisfaction in social situations, competence in social situations, body image, and cognition. Scoring was performed centrally by the developer.

[0057] PGIC

[0083] The Patient Global Impression of Change (PGIC) questionnaire was administered at all post-baseline visits. Subjects were asked to rate their overall condition from the start of the study on a scale of 1 (much improved) to 7 (much worse). The PGIC scale has been validated in several other indications and is recommended by the FDA for use as a meaningful measure of within-patient change.

[0058] result

[0084] Plasma concentrations of losmapimod ranged from 25.2 to 34.4 ng / ml before administration and 66.4 to 91.8 ng / ml 4 hours after administration (approximate C max ), consistent with previous studies. Muscle concentrations were also within the expected range for clinical efficacy, at 61.0 ± 7.7 ng / g in Wk16 and 91.1 ± 10.7 ng / g in Wk36. Phosphorylated heat shock protein 27 (pHSP27) / total heat shock protein 27 (HSP27 total ) level is C max The results showed a 48.0-70.2% reduction in β-blockers compared to placebo, confirming target engagement (Figures 3A and 3B).

[0059]

[0085] Furthermore, the PK profile of losmapimod demonstrated good adherence to the study regimen, with pill counts suggesting treatment compliance was greater than 80%.

[0060]

[0086] No changes in DUX4 activity were observed in either the placebo or losmapimod groups (comparing baseline to pooled data of all samples from Wk16 or Wk36) and there was no difference between the groups (losmapimod 0.83, placebo 0.40, difference 0.43, 95% CI -1.04, 1.89; p=0.56; log2 scale). Prespecified subgroup analysis by DUX4-driven gene expression showed no differences between losmapimod and placebo (Figure 4). Significant variability in DUX4 activity was observed in both groups (pre- and post-dose) (Figures 5A and 5B).

[0061]

[0087] The prespecified composite efficacy measure of MFI showed significantly less fatty infiltration (p=0.01) in the losmapimod group compared to the placebo group in muscles at high risk of progression (classified as B muscles). Reduction in fatty replacement in MFF was not significant, and there was no difference in LMV. Post-hoc analysis of muscles that appeared normal at baseline (classified as A muscles) showed that the losmapimod group had little to no fat accumulation in MFI or MFF compared to the placebo group (Figure 6).

[0062]

[0088] Regional MRI composite scores of muscles involved in specific functional assessments of interest demonstrated moderate and strong cross-sectional correlations with MFI, MFF, and LMV and with TUG, FSHD-TUG, and RWS at individual time points throughout the study, with one exception: dominant-side total reachable surface area (RSA) when weights were used in the placebo group. Table 1 shows Spearman correlation analyses between regional and composite metrics and clinical outcome assessments at week 48. In Table 1, "LOS" refers to losmapimod and "PBO" refers to placebo.

[0063] [Table 1]

[0064]

[0089] At Wk48, the losmapimod group reported significant improvement compared to the placebo group (difference 0.58 on a Likert scale of 1 to 7; p=0.02) (Figure 6). 27.5% of losmapimod patients and 6.4% of placebo patients reported improvement (Likert scale 1 to 3). No losmapimod-treated patients reported being "very much worse" (Likert scale 6 to 7), whereas 12.9% of placebo subjects did. Placebo subjects reported increasing worsening during the RCT, indicating that the PGIC captured disease progression (Figure 7).

[0065]

[0090] Losmapimod produced a significant improvement in RSA measured on a scale of 0 to 1.25 (dominant arm: 0.019 vs placebo -0.048; difference 0.067, 95% CI 0.017, 0.118; p=0.01; non-dominant arm: 0.021 vs -0.024, difference 0.045, 95% CI 0.0007, 0.09; p<0.05) (Figure 6). Placebo subjects lost 2.6-3.6% total RSA in the unweighted and 1.9-3.8% in the weighted RWS, capturing disease progression (Figure 8). The annual percent change in total RSA also showed improvement when assessed using weights (dominant side, annual percent change: 0.28 vs. 8.45; p=0.07; non-dominant side, 4.88 vs. -4.02; p=0.01) (Figure 9). As shown in Figure 22, the updated annual percent change in total RSA also demonstrates that losmapimod slows disease progression or improves function in weighted total RSA (Q1-Q5).

[0066]

[0091] Figure 23 shows that losmapimod slows disease progression or improves function across all domains, most notably in the above-shoulder domain (Q1 and Q3). Additionally, the annualized percent change in MFI, MFF, and LMV are shown in Figure 24. The annualized percent change in mean time to complete TUG is shown in Figure 25. The annualized percent change in hand grip and shoulder maximal voluntary isometric contraction test (MVICT) are shown in Figure 26.

[0067]

[0092] The open-label study also assessed reachable workspace (RWS) with and without weights. Figure 27 provides exploratory annualized percent change in RWS from baseline for patients who participated in the study. The data show that annualized RWS increased in all quadrants in the open-label study, with the greatest increases (7-17%) in Q1 and Q3.

[0068]

[0093] Maximal voluntary isometric contraction (MVICT) assessment was performed using a handheld dynamometer. Post-hoc analysis showed that shoulder abductor and ankle dorsiflexor strength in the losmapimod group was less deteriorated (dominant shoulder -3.79%, ns) or improved (non-dominant shoulder 17.85%, difference 34.89; p<0.01; right ankle 12.72%, difference 38.39; p<0.05; left ankle 27.17%, difference 37.37; p=0.11) (Figure 6). Subjects in the placebo group lost strength in shoulder abductor (dominant, -13.1%, non-dominant -17.0%) and ankle dorsiflexor (right ankle -25.7%, left ankle 10.20%) at Wk48 (Figure 10). The average scores of the three repeated trials were consistent with the MVICT and showed improvement or preservation of the bilateral shoulder abductors and ankle dorsiflexors. No differences were observed in either the average or MVICT for other muscle groups, including the bilateral hand grips, elbow flexors, or extensors (Figure 10).

[0069]

[0094] Losmapimod subjects demonstrated a non-significant but clinically meaningful slowing of progression of TUG time (0.16 vs. 0.74 sec; difference 0.58 sec) (Figure 6). FSHD-TUG, MFM total score and FSHD-HI showed no differences (Figures 6 and 11).

[0070]

[0095] In this study, losmapimod demonstrated clinical benefit in multiple clinical outcome measures (COA) and WB-MSK-MRI scales consistent with the hypothesis that losmapimod may slow the progression of FSHD.Losmapimod continued to demonstrate favorable safety and tolerability consistent with that observed in over 3,500 subjects treated to date.

[0071]

[0096] WB-MSK-MRI provided important information on disease severity, as it captured disease heterogeneity and correlated with clinical endpoints for FSHD. MRI composite scores demonstrated sensitivity to disease progression by correlating with FSHD-related COAs in cross-sectional analyses. MFI has been shown to be a sensitive proximal biomarker for loss of muscle function in sarcopenia, and this study implies the same for FSHD. The reduced progression of MFI and MFF in A and B muscles after 48 weeks suggests that losmapimod affected fat accumulation in muscles that have not yet reached the end-stage previously reported with little functional capacity remaining.

[0072]

[0097] Treatment with losmapimod resulted in slowing of progression or improvement of FSHD-related clinical assessments, as suggested by preservation of muscle structure measured by MRI. Improvement in shoulder function was assessed by the RWS, a COA that has high reliability, reproducibility, face validity, feasibility, and sensitivity to change and is highly correlated with activities of daily living. This finding is supported by preservation or improvement of shoulder abduction strength in muscle strength measurements. Furthermore, improvements in ankle dorsiflexion strength support a trend toward shorter TUG times. The slowing of progression or improvement of these COAs, predicted by annualized percent change over time, is evidence that losmapimod favorably alters disease progression in FSHD.

[0073]

[0098] These improvements were perceived by the subjects (the clinically meaningful difference in PGIC between the losmapimod and placebo groups was 0.58). Nearly 20% of treated subjects reported a perceived improvement in PGIC, while many placebo subjects reported a perceived decline.

[0074]

[0099] Despite downstream evidence indicating benefit of DUX4 reduction, prespecified population and subgroup analyses did not show differences in DUX4-driven gene expression between or within groups at Wk16 or Wk36. A similar 30-70% reduction in DUX4-driven gene expression was hypothesized based on target engagement observed in preclinical studies. At the population level, DUX4-driven gene expression demonstrated high variance with a greater than 1,000-fold spread between subjects at baseline. Multiple factors contributed to this large variability, including the stochastic nature of DUX4-driven gene expression, the very transient duration and relative paucity of DUX4 expression in myonuclei (hypothesized to be approximately 1 / 1000-1 / 3000), the heterogeneity of the composition of FSHD muscle, and the relative imprecision of the biopsy procedure.

[0075] Example 2. A 48-Week Phase 3, Randomized, Double-Blind, Placebo-Controlled Study of the Efficacy and Safety of Losmapimod in FSHD [000100] The objective of this study is to evaluate the efficacy and safety of losmapimod for the treatment of FSHD. Approximately 230 patients, 210 with genetically confirmed FSHD1 and 20 with FSHD2, will be randomized 1:1 to receive losmapimod or placebo orally twice daily for 48 weeks. Efficacy assessments will include quantification of reachable workspace of total relative surface area (Q1-Q5) using a 500g wrist weight on the dominant arm, assessment of the Quality of Life in Neuropathy Upper Extremity scale (Neuro-QoL UE), Patient Global Impression of Change (PGIC), and muscle-fat infiltration (MFI) on whole body musculoskeletal MRI (WB-MSK MRI). Exploratory assessments included muscle fat fraction, muscle strength assessed by handheld dynamometry and patient-reported outcomes (PROs) including the Patient Global Impression of Severity (PGIS), novel FSHD PRO, Numeric Pain Rating Scale (NPRS), 5-point EQ-5D (EQ-5D-5L) and healthcare utilization questionnaire.

[0076] Example 3. Muscle ultrasound in an open-label study of losmapimod in subjects with FSHD1 [000101] Fourteen subjects aged 18-65 years with genetically confirmed FSHD1, clinical severity scores of 2-4 (range 0-5), and MRI-eligible skeletal muscle for needle biopsy were administered 15 mg losmapimod twice daily for 52 weeks in an open-label study with safety as the primary objective. Evaluations included safety, MRI, muscle ultrasound (US), clinical outcomes, and PROs. US was performed in seven muscles bilaterally using a standardized protocol. US echo intensity was expressed as z-score relative to matched healthy controls, and abnormality was defined as >2.

[0077] [000102] The mean (SD) change from baseline in echogenicity for all muscles was -0.17 (0.9), -0.32 (0.9) for upper limb muscles, and -0.13 (1.0) for lower limb muscles, indicating a trend towards improvement. The distribution of muscle z-scores at baseline versus last visit (<2, 2-4, 4-6, and >6) remained the same or declined, consistent with stability. The distribution is shown in more detail in Figure 12A. Furthermore, most muscles showed stability or improvement over the 52 weeks of treatment (Figure 12B). Natural history studies have previously demonstrated that echogenicity increases or worsens over the course of a year. Echo intensity correlated strongly with muscle fatty infiltration (MFI) in the biceps (r=0.84, p<0.01), tibialis anterior (r=0.76, p<0.01), and medial gastrocnemius (r=0.50, p<0.01). A ceiling effect in echogenicity was observed above approximately 10% MFI in the biceps and above approximately 20% in the tibialis anterior and quadriceps. Furthermore, in the medial gastrocnemius, a more heavily fatty-substituted muscle with an MFI above 25%, echo intensity appears to be falsely normalized due to homogeneity of tissue (fat).

[0078] [000103] Correlation with clinical outcome measures (COA) was also evaluated. In one example, reachable workspace data at baseline and week 60 is provided in Figure 13A (baseline) and Figure 13B (week 60) showing a non-significant correlation trend between total weighted RSA and upper limb echogenicity (biceps and deltoid). In another example, handheld muscle strength measurement data of ankle dorsiflexion at baseline and week 60 is provided in Figure 14A (baseline) and Figure 14B (week 60) showing a strong correlation of tibialis anterior echogenicity to maximum ankle dorsiflexion. In another example, timed up and go (TUG) data at baseline and week 60 is provided in Figure 15A (baseline) and Figure 15B (week 60) showing that mean lower limb echogenicity showed a strong correlation to classical TUG at week 60. The baseline correlation was limited by outliers in TUG.

[0079] Example 4. Feasibility of measuring functional performance in FSHD patients using wearable sensors to quantify physical activity [000104] This study evaluated the feasibility of using a wearable sensor device to monitor daily activities and assess functional outcomes in an open-label study (OLS) of losmapimod in facioscapulohumeral muscular dystrophy (FSHD). Fourteen FSHD1 patients received 15 mg losmapimod twice daily during a 52-week open-label treatment period.

[0080] [000105] Feasibility was measured by reliability of data over time and amount of background noise. A secondary objective was patient compliance with use of the wearable device.

[0081] [000106] Mobility of the upper and lower limbs was assessed with "Actimyo" from Sysnav. Actimyo quantifies movement in patients with neuromuscular disorders such as Duchenne muscular dystrophy (DMD), spinal muscular atrophy (SMA), and Parkinson's disease, and records activity based on magnetic-inertial navigation. Raw data from the sensors is loaded into the internal memory of the docking station / charging unit and transmitted daily to a remote storage platform via an internet connection. Participants are provided with two watch-like sensors to measure movement: on the ankle for lower limb movements like walking, and on the wrist for upper limb movements like mobility. Two types of movement were assessed: free-living movements, recorded by wearing the two devices daily (12-16 hours); and forced movements, which are a set of movements assessed twice a day (twice a day). A schematic of the patient's use of the devices is shown in Figure 16.

[0082] result: [000107] Feasibility and Compliance: Participant compliance with wearing the device was 99%. The total number of days all 14 participants were monitored was 2,941 days or 36,758 hours (average 2,626 hours per participant). Patient outcomes by time period are shown in Figure 17.

[0083] [000108] Analysis, processing and reliability results are shown in Figure 18. Moderate to strong correlations between clinic and wearable variables at baseline are also shown in Figure 19.

[0084] [000109] FSHD participants differ in the site of disability. When divided into four groups, the in-clinic and wearable variables are adjusted for site of severity. The results are shown in Figure 20.

[0085] [000110] Furthermore, physical function as measured by walking speed tended to increase over the one-year treatment period in the "mild" or "upper limb" groups compared to the "lower limb" or "both" groups, which is further shown in Figure 21.

[0086] Equivalent [000111] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments specifically described herein which equivalents are intended to be encompassed by the following claims.

Claims

1. A pharmaceutical composition comprising rosmapimod for use in a method of treating facioscapulohumeral muscular dystrophy (FSHD) in patients requiring such treatment, The method comprises administering 15 mg of rosmapimod to the patient twice daily for at least 40 weeks. A pharmaceutical composition wherein, at least 40 weeks later, the patient exhibits improved muscle health as measured by whole-body musculoskeletal magnetic resonance imaging (WB-MSK-MRI).

2. A pharmaceutical composition comprising rosmapimod for use in a method for reducing fat accumulation in muscles at high risk of progression in patients with facioscapulohumeral muscular dystrophy (FSHD), wherein A pharmaceutical composition comprising the above method, which involves administering 15 mg of rosmapimod twice daily for at least 40 weeks.

3. The pharmaceutical composition according to claim 1 or 2, wherein, at least 40 weeks later, the muscle has reduced fat accumulation as measured by whole-body musculoskeletal magnetic resonance imaging (WB-MSK-MRI).

4. The pharmaceutical composition according to claim 2, comprising imaging the muscles using whole-body musculoskeletal magnetic resonance imaging (WB-MSK-MRI) to determine the correlation between a measure of muscle health and the evaluation of the patient's clinical outcomes.

5. The pharmaceutical composition according to claim 4, wherein the measure of muscle health is selected from the group consisting of muscle fat percentage (MFF), muscle fat infiltration (MFI), and lean muscle mass (LMV).

6. The pharmaceutical composition according to claim 4, wherein the clinical outcome assessment is selected from the group consisting of assessments made from reachable workspace (RWS), relative surface area (RSA), and time-up-and-go (TUG) tests.

7. The pharmaceutical composition according to claim 2, wherein the muscle is characterized by a muscle fat infiltration (MFI) of less than 0.10 and a muscle fat percentage (MFF) of less than 0.50 prior to administration of rosmapimod to the patient.

8. The pharmaceutical composition according to claim 2, wherein the muscle is characterized by a muscle fat infiltration (MFI) of about 0.10 or more and a muscle fat percentage (MFF) of less than about 0.50 before administering rosmapimod to the patient.

9. The pharmaceutical composition according to claim 1 or 2, comprising administering 15 mg of rosmapimod to the patient twice daily for at least 48 weeks.

10. The pharmaceutical composition according to claim 1 or 2, wherein the FSHD is FSHD1.

11. The pharmaceutical composition according to claim 1 or 2, wherein the muscle is selected from the group consisting of muscles of the upper limbs and muscles of the lower limbs.

12. The pharmaceutical composition according to claim 1 or 2, wherein the muscle is selected from the group consisting of shoulder abductor muscles and ankle dorsiflexor muscles.

13. The pharmaceutical composition according to claim 12, wherein the shoulder abductor muscle is selected from the group consisting of the bilateral shoulder abductor muscles, the dominant shoulder abductor muscle, and the non-dominant shoulder abductor muscle.