Olanzapine for the Treatment of Appetite Loss in Amyotrophic Lateral Sclerosis (ALS)

Inclusion Criteria: * Patients between the ages of 18 and 80 years old * Clinical diagnosis of definitive, probable, and possible ALS (revised El Escorial Criteria) or diagnosis of the clinical ALS-variants of Progressive Muscle Atrophy (PMA) * Sporadic and familial ALS * Beginning of symptoms of paralysis at least 6 months prior * Treatment with a steady dose of RIL 100 mg/day for at least 1 month * A score of ≤ 28 in the symptom-oriented Council on Nutrition appetite questionnaire (CNAQ) by which appetite is evaluated * Patient consent Exclusion Criteria: * Patients with known hypersensitivity to OLN, RIL, or one of the active ingredients * Percutaneous Endoscopic Gastronomy (PEG) * Clinically significant eating disorder * Deliberate weight loss * Underlying consumptive disease with undesired weight loss * Overweight with BMI ≥ 25 kg/m2 * Clinically significant hypotonia and history of recurrent syncopes (\> 1 syncope) * Clinically severe concomitant illnesses, including psychiatric illnesses * Pregnant or nursing women * Severe neutropenia (\< 750/mm3) * Open angle glaucoma * Diabetes mellitus * Prostatic hyperplasia * Extrapyramidal movement disorders including from late dyskinesia * Dementia and incompetence to grant informed consent * Clinically significant EKG changes * EKG proof of a QT time corrected according to Fridericia (QTcF) \> 500 ms * Treatment with substances that are metabolized by the Cytochrom-P450-System CYP1A2 (e. g. Carbamazepine, Fluvoxamin, and Ciprofloxacin) * Treatment with Mirtazapine within the past 3 months * Treatment with steroids or appetite-stimulating substances including anabolics within the past 3 months * Treatment with Valproat within the past 3 months * Treatment with hepatotoxic medicines * Treatment with tetrahydrocannabinol within the past 3 months * Treatment with another atypical or typical neuroleptic within the past 3 months * Treatment with any other study medication \< 1 month before the beginning of the study * Destructive use of psychotropic substances within the past 3 months * Destructive use of alcohol * Laboratory parameters outside the normal range that are associated with a clinically significant cardiovascular, pulmonologic, hematologic, hepatological, metabolic, or renal disease or that interfere with interpretation of the clinical study or that require medications that are not permitted in the study protocol * Elevation of the serum transaminase levels (ALT/AST) to more than 3-times of the upper normal value * Elevation of the bilirubin and gamma glutamyl transferase levels (GGT) to beyond the maximum normal value * History of a cardiopulmonary reanimation und prevention of sudden cardiac death * History of clinically significant EKG changes * History of thrombotic events including deep leg vein thrombosis and pulmonary artery embolism * History of a paralytic ileus * History of epilepsy or an episodic seizure