Reldesemtiv is an investigational, small molecule fast skeletal muscle troponin activator, or FSTA. Reldesemtiv slows the rate of calcium release from the regulatory troponin complex of fast skeletal muscle fibers. Contraction of skeletal muscles is driven by the sarcomere, the fundamental unit of muscle contraction, which contains myosin, a protein which converts chemical energy into mechanical force through its interaction with another protein, actin. This interaction is regulated by other proteins including troponin and tropomyosin, and is dependent on changes in calcium. By slowing the rate of calcium release, reldesemtiv sensitizes the sarcomere to calcium, leading to an increase in muscle contractility

Reldesemtiv was the subject of COURAGE-ALS (Clinical Outcomes Using Reldesemtiv on ALSFRS-R in a Global Evaluation in ALS), a Phase 3, multi-center, double-blind, randomized, placebo-controlled trial in patients with ALS. In March 2023, COURAGE-ALS was discontinued due to futility at the second planned interim analysis.

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Omecamtiv Mecarbil

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Aficamten is an investigational cardiac myosin inhibitor for the potential treatment of patients with hypertrophic cardiomyopathy (HCM disease).

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CK-136 is an investigational cardiac troponin activator for the potential treatment of patients with heart failure with reduced ejection fraction (HFrEF).

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  1. Murphy SP, Ibrahim NE, Januzzi JL. Heart failure with reduced ejection fraction: a review. JAMA. 2020;324(5):488-504.
  2. American Heart Association. Types of heart failure. Available at: Accessed 12/16/2022.
  3. Heidenreich PA, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines. Circulation. 2022;145:e895-e1032.