Annualized Rates of Change from A Phase 2, Randomized, Double-Blind, Placebo-Controlled, 48-Week Study of Losmapimod in Subjects with FSHD: ReDUX4

Topic:

Clinical Trials

Poster Number: 58

Author(s):

Rabi Tawil, MD, University of Rochester, Sabrina Sacconi, MD, Nice University, Jordi Diaz Manera, MD, Hospital de la Santa Cruz, Barcelona Spain, David Reyes Levia, Hospital de la Santa Cruz, Barcelona Spain, Doris Leung, MD, Kennedy Krieger Institute, Kathryn Wagner, MD, PhD,Kennedy Krieger Institute, Angela Genge, MD, FRCP(C), Montreal Neurological Institute and Hospital, Juan Vilchez, MD, Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe,Valencia, Spain, Nuria Gomez, MD, PhD,Neuromuscular and Ataxias Research Group, Instituto de Investigación Sanitaria La Fe,Valencia, Spain, Miriam Freimer, MD, Ohio State University Medical Center, Samantha LoRusso, MD,Ohio State University Medical Center, Hanns Lochmuller, MD, Childrens Hospital of Eastern Ontario Research Institute, Joost Kools, MD, Radboud University Medical Centre (Radboudumc), Nijmegen, NL, Baziel van Engelen, MD, PhD, Radboud University Medical Centre (Radboudumc), Nijmegen, NL, Namita Goyol, MD, University of California, Irvine, Perry Sheih, MD, University of California, Los Angeles, David Geffen School of Medicine, S H Subramony, MD, University of Florida College of Medicine, Jeffrey Statland, MD, University of Kansas School of Medicine, Lawrence Hayward, MD, PhD, University of Massachusetts Medical School, Johanna Hamel, MD, University of Rochester Medical Center, Summer Gibson, MD, University of Utah, Leo Wang, MD, University of Washington, Nicholas Johnson, MD, Virginia Commonwealth University, Alan Pestronak, MD, Washington University, Michelle L Mellion, MD, Fulcrum Therapeutics, Inc., Christopher Morabito, MD, Fulcrum Therapeutics, Inc., Jennifer Shoskes, PharmD, Fulcrum Therapeutics, Inc., John Jiang, PhD, Fulcrum Therapeutics, Inc., Anthony Accorsi, PhD, Fulcrum Therapeutics, Inc., L. Alejandro Rojas, PhD, Fulcrum Therapeutics, Inc.

Objective: Evaluate annualized clinical outcome changes in subjects with facioscapulohumeral muscular dystrophy (FSHD) treated with losmapimod compared with placebo.

Background:
FSHD is a relentless, variably progressive disease leading to accumulation of disability over decades. Fulcrum is developing losmapimod, a small molecule p38 ?/? MAPK inhibitor, to treat FSHD. An annualized analysis provides data on the slope of disease progression and the potential for treatment with losmapimod to change that slope over time.

Methods:
Subjects aged 18-65 years with FSHD1, CSS 2-4, and MRI-eligible muscles for biopsy were randomized 1:1; losmapimod (15 mg BID): placebo. Assessments included for analysis: MRI assessments of muscle health, reachable workspace (RWS), dynamometry and TUG. Annualized rate of change (%/yr) was calculated using a linear mixed-effects model to estimate slope and percent change per year. Annualized analysis of RWS (measured in Reachable Surface Area, RSA) was prespecified; all other analyses are post-hoc.

Results:
Eighty subjects (N=40/group), mean age 45.7 (±12.5) years, Ricci score 3.2 were enrolled.
Annualized rate of change (%/yr) in total RSA for losmapimod vs. placebo dominant arm: -0.44 vs. -8.42; p=0.07; non-dominant arm: 4.88 vs. -4.02; p=0.01. This slowing or improvement is supported by structural measures via MRI and functional outcomes (dynamometry and TUG). MRI annualized rates of change for losmapimod vs. placebo were 0.31 vs 3.82 for MFI, 4.42 vs 5.96 for MFF, and -7.15 vs -4.50 for LMV. Maximum dynamometry in the shoulder abductors showed variability in annualized rate of change for losmapimod vs. placebo (L -1.98 vs 13.62; R -14.39 vs -8.49) and in hand grip (L -8.30 vs -13.44; R -13.95 vs -15.27). In TUG, the annualized rate of change was -0.93 vs 2.23% in the losmapimod vs placebo group.

Conclusions: Annualized rates of change in clinical outcomes support disease slowing or improvement in losmapimod treated subjects compared to placebo.