CytRx initiates ALS drug extension trial

In January 2005, CytRx announced the filing of a clinical protocol with the FDA to allow amyotrophic lateral sclerosis (ALS or Lou Gehrig’s disease) patients who have completed the company’s phase IIa clinical trial to receive treatment with orally-administered arimoclomol at the highest of the three phase IIa dose levels for up to an additional six months.

The open-label extension trial is designed to provide additional safety and tolerability data in combination with the current phase IIa trial.

The company also announced that it is on track to complete enrollment this quarter in its 80-patient, multi-center, double-blind, placebo-controlled phase IIa clinical trial with arimoclomol for the treatment of ALS. To date, of the 80 patients who have been screened for participation, 59 have started the treatment regimen.

The primary endpoints for this trial are safety and tolerability. Secondary endpoints include a preliminary evaluation of efficacy using two widely accepted surrogate markers, the revised ALS functional rating scale (ALSFRS-R), which is used to determine patient’s capacity and independence in 13 functional activities, and vital capacity (VC), an assessment of lung capacity.

CytRx expects to report final data from its phase IIa trial in the third quarter of 2006, followed by initiation of a potentially pivotal phase IIb clinical trial, subject to FDA review and acceptance.

The phase IIb trial will be powered to detect more subtle efficacy responses than the current trial. Although this second trial is still in the planning stages, it is expected to include approximately 300 ALS patients recruited from 25 clinical sites. The company believes that successfully demonstrating safety and efficacy in this latter phase II clinical trial could be sufficient to support product registration with the FDA.