In developing an ALS treatment, two strategies must be distinguished. Causal therapy of ALS will be possible after the disease mechanisms have been researched. Elucidation of the causes of ALS will take several decades from today’s perspective. At the same time, the average costs of developing a new drug amount to 500 to 800 million Euro. Expenditure on this financial scale is unrealistic at present. As an alternative research approach, empirical drug studies are a possibility. The basic concept consists of testing medications that are already licensed for other neurological diseases, e.g. multiple sclerosis or Alzheimer disease. It is known that these medications penetrate effectively into the human central nervous system and have adequate tolerability. The disadvantage of the empirical concept of therapy research is the low a priori likelihood that the drug will be effective.

	Pilot study	Efficacy study
Aim	Discovery of major treatment effects Tolerability	Recording of minor treatment effects
Placebo treatment	yes / no	yes
Duration	6 months	12–18 months
Patient number	10–50	400–500
Number of ALS centres	1–2	10–15
Cost   (without medications)	~ 100.000 Euro	~ 1 Million Euro

The treatment of ALS patients with new medications requires clinical studies even when they are already licensed in other diseases. Drug safety is the priority. Pilot studies with few patients provide information on tolerability. These are followed by an efficacy study, which is conducted by means of visits at one to three month intervals. The following data are recorded at the OPD visits:

• Determination of ALS disease symptoms by neurological examination
• Determination of the severity of the ALS and quality of life by means of a structured interview with patients and relatives
• Measurement of respiratory, cardiac and circulatory parameters (lung function tests, ECG etc.)

All of the data recorded are stored and processed electronically. To ensure the greatest patient safety, the study is analysed by a higher coordinating centre for clinical studies (CCCS). The results of every therapy study are published in an international journal regardless of the outcome of the study series and thus made accessible to the public.