A Double-blind Randomised, Placebo-controlled Clinical Trial to Test Ambroxol Treatment in ALS

Participants in the study will receive varying doses of ambroxol in solution, 3 times per day. Doses will be increased pending a safety review, up to a maximum of 1260mg/day. Blood tests will be conducted weekly to assess tolerance. Compliance will be monitored by returning used bottles. The study will last 32 weeks, including 24 weeks of drug administration and follow-up visits. After the final follow-up, there will be an end of study safety visit occurring 4 weeks later. The total time of participation will be 32 weeks. This includes a screening visit up to 4 weeks prior to Baseline, then a Baseline visit, followed by 24 weeks of follow-up (3x in clinic follow-up visits). These 24 weeks will be the drug administration period, meaning that the total duration of drug administration is 24 weeks. Following this drug administration and follow-up period, there will be an EoS safety-follow up visit that will occur 4 weeks after the final follow-up visit (28 weeks from baseline).

Participants randomised to the control arm will receive a placebo for the duration of the study. The placebo will look and taste like ambroxol, but will have no active ingredient. Participants will not be told which arm they have been randomised to. The placebo will primarily be a glucose solution, however it will also have flavouring (e.g. bitters) and colouring, so as to make it look and taste like ambroxol, to maintain blinding.