A randomised, multi-centre trial to assess the feasibility of conducting a future phase III randomised trial in primary amyloidosis, comparing cyclophosphamide, thalidomide and dexamethasone with stem cell transplantation in patients with low risk of treatment related mortality and cyclophosphamide, thalidomide and dexamethasone with Mel-Dex in patients with high risk of treatment related mortality

INTERVENTION: Patients will enter one of two treatment pathways (high or low intensity) on the basis of their disease and will be randomised within each pathway to one of two chemotherapy regimens on a 1:1 basis. Patients entering the high intensity pathway will be randomised to Stem Cell Transplantation (SCT) or Cyclophosphamide, Thalidomide, Dexamethasone (CTD) and those randomised to the low intensity pathway will be randomised to receive either CTD or Melphalan and Dexamethasone (Mel Dex). CONDITION: AL amyloidosis ; Nutritional, Metabolic, Endocrine ; Metabolic disorders PRIMARY OUTCOME: 1. Clonal response; 2. Toxicity and safety (including treatment‐related mortality); 3. Recruitment rate and feasibility SECONDARY OUTCOME: 1. Acceptability of randomisations in each pathway ; 2. Quality of life questionnaire validity ; 3. Amyloidotic organ function INCLUSION CRITERIA: 1. Aged 18 years or greater 2. Newly diagnosed as having systemic AL amyloidosis who have: 2.1. Diagnostic Congo red histology confirming amyloid deposits 2.2. Immunohistochemical exclusion of Systemic (AA) and Transthyretin (TTR) amyloidosis 2.3. Exclusion of genetic mutations associated with hereditary amyloidosis whenever doubt about the diagnosis exists, according to Network Advisory Committee (NAC) current practice 2.4. Underlying plasma cell dyscrasia that can be identified and monitored by Freelite serum free light chain assay as follows: absolute serum free light chain concentration more than or equal to 100 mg/l associated with an abnormal kappa/lambda ratio 2.5. Amyloid‐related organ dysfunction or organ syndrome 3. Capable of providing written, informed consent 4. Estimated life expectancy of at least six months 5. Prepared to use contraception in accordance with (and consent to) the Pharmion Risk Management Programme 6. Wo