AB Science has announced that it will not pursue re-examination of its European marketing application for masitinib as a treatment for amyotrophic lateral sclerosis (ALS) after all.

The company initially said it would be asking regulators to take another look at the submission after masitinib was rejected by the Committee for Medicinal Products for Human Use, which said reliability of the data was not robust enough to support a registration, based on an inspection at two of the main clinical study sites.

However, the firm has since concluded that the re-examination procedure “would not be the most appropriate format” to address all the pending concerns raised by the CHMP, largely because new data cannot be submitted as part of the process.

Instead, it intends to discuss with the European Medicines Agency the pathway forward to seek marketing authorisation for the use of masitinib in the treatment of ALS, including the submission of final safety data from study AB10015 and new preclinical data reinforcing the mechanisms of action of the drug.

The company also reiterated its commitment to develop the tyrosine kinase inhibitor for ALS in order to provide a new treatment option to patients.

ALS, which is also referred to as Lou Gehrig's disease, is a rare degenerative disorder that causes muscle wasting and progressive paralysis.

Around 50,000 people in the European Union and in the US currently have the condition, with more than 16,000 new cases diagnosed each year in these regions. The prognosis for patients is very poor, as the disease has a fatal outcome for most within five years of diagnosis.

The condition is inherited in 5 percent to 10 percent of cases, but the cause for the majority of cases is not well understood, and there is currently no cure.