On 7 May, Orphazyme, a Denmark-based late-stage biopharmaceutical company pioneering heat shock protein therapies for the treatment of rare diseases, announced that the ORARIALS-01 pivotal trial of arimoclomol in amyotrophic lateral sclerosis (ALS) did not meet its primary and secondary endpoints to show benefit in people living with ALS. These topline data will be presented at the European Network to Cure ALS (ENCALS) meeting held virtually on 12–14 May, with complete data from the study expected to be published by the end of the year. While most drugs in development target both patient segments in ALS, namely familial (or hereditary) ALS (FALS) and sporadic ALS (SALS), arimoclomol specifically targets the FALS segment, which accounts for less than 10% of all cases of the disease.
The ORARIALS-01 pivotal trial was a randomised, placebo-controlled Phase III trial conducted among 245 patients in North America and Europe. Participants in the trial received either arimoclomol (248mg three times daily) or a placebo for up to 76 weeks. The primary endpoint, which was assessed by the combined assessment of function and survival (CAFS), determined the efficacy of chronic treatment with arimoclomol compared to the placebo in participants with the disease. Secondary endpoints included survival, change in ALS Functional Rating Scale-Revised (ALSFRS-R) and slow vital capacity (SVC). According to the topline data, no important safety signals were reported in the trial.
There is a large unmet need for a curative agent for the treatment of ALS. In the current treatment algorithm, patients have to take daily medication for the rest of their lives, meaning that a drug preventing the onset of the disease would be revolutionary. The only treatment options currently available are Rilutek (riluzole) and Radicava (edaravone), neither of which can stop or significantly slow the progression of the disease. At best, these drugs may increase a patient’s life span by up to six months. This need, therefore, is completely unmet by the current therapies.
There are multiple leading development strategies in ALS across the pharmaceutical industry. Exploring novel targets with mechanisms of action that differ from the two marketed drugs (Rilutek and Radicava) is the main strategy noticeable within the pipeline products. Other strategies include the use of biologic molecules to help discover a curative therapy.
Types of molecules being developed include stem cell therapies, monoclonal antibodies, antisense oligonucleotides and gene therapies. The hope behind these molecules is that they target the underlying mechanisms of the disease and slow, or potentially even stop, the progression of the disease. Cost is the key barrier to this strategy, however, with the cost of developing biologics far higher than that of developing small molecules and the chance of the drug showing clinical benefit remaining low.