Cytokinetics Announces Start Of Phase 3 Trial Of Tirasemtiv In Patients With ALS

(RTTNews) - Cytokinetics, Inc. (CYTK), muscle biology company, announced the start of VITALITY-ALS (Ventilatory Investigation of Tirasemtiv and Assessment of Longitudinal Indices after Treatment for a Year in ALS), a Phase 3 clinical trial designed to assess the effects of tirasemtiv versus placebo on slow vital capacity (SVC) and other measures of respiratory function in patients with ALS.

Vital capacity measures the amount of air expelled from the lungs after a maximum inhalation and is used to assess the strength of the skeletal muscles responsible for breathing (e.g., the diaphragm).

Vital capacity is often expressed in terms of the percentage of the normal value predicted for the individual patient's sex, age, and height; i.e., percent predicted vital capacity. It has been shown to be an important predictor of disease progression and survival in previous clinical trials in patients with ALS who typically die of respiratory failure. Percent predicted vital capacity declines an average of 2-3 percentage points per month in patients with ALS and is the most frequently monitored measure of respiratory function to measure disease progression.

Vital Capacity is also used to inform critical clinical decisions, such as initiation of non-invasive ventilation, feeding tube placement and palliative care. Tirasemtiv, a fast skeletal muscle troponin activator, demonstrated a statistically significant and potentially clinically meaningful effect on respiratory function (as assessed by SVC) and muscle strength in the Phase 2b clinical trial, BENEFIT-ALS.

VITALITY-ALS is a multi-national, randomized, double-blind, placebo-controlled trial that is designed to enroll 445 patients with possible, probable or definite ALS, diagnosed within 24 months, and with percent predicted SVC at baseline = 70%. Patients may be enrolled whether or not they are on riluzole therapy. The primary endpoint of the trial will assess change from baseline in SVC, to be assessed after 24 weeks of double-blind, placebo-controlled treatment.