Biopharmaceutical company Cytokinetics has amended the protocol for Blinded Evaluation of Neuromuscular Effects and Functional Improvement with Tirasemtiv in amyotrophic lateral sclerosis (BENEFIT-ALS). BENEFIT-ALS is a phase IIb, multinational, double-blind, randomized, placebo-controlled clinical trial designed to evaluate the safety, tolerability and potential efficacy of tirasemtiv, a fast skeletal muscle troponin activator, in patients with ALS.

The primary analysis of BENEFIT-ALS will compare the mean change from baseline in the ALS Functional Rating Scale in its revised form, or ALSFRS-R (an instrument that measures disease progression and changes in functional status), in patients receiving tirasemtiv versus those receiving placebo.

A programming error in the electronic data capture system controlling study drug assignment caused 58 patients initially randomized and treated with tirasemtiv to receive placebo instead at a certain study visit and for the remainder of the study. No patients randomized to placebo were dispensed incorrect treatment. Cytokinetics and all trial site personnel remain blinded to patients affected by the error. The company has ensured that no further incorrect drug assignments occurred and to correct the programming error in the electronic data capture system controlling drug assignment.

The company amended the protocol to enable increased enrollment to approximately 680 patients and to update the statistical methods section, in both cases with the objective to maintain the originally intended statistical power of the trial. To date, over 500 patients have been enrolled. The company now expects to complete patient enrollment during the second half of 2013, with results to be available in early 2014. These changes to BENEFIT-ALS are expected to increase the direct clinical trial costs by approximately $5 million in 2013 and 2014.