Patients meeting any of the following exclusion criteria are not to be enrolled in the study:
1. Female patients who are lactating or have a positive serum pregnancy test during the screening period.
2. Failure to have fully recovered (i.e., <= Grade 1 toxicity) from the reversible effects of prior chemotherapy.
3. Progressive disease post-ASCT
4. Failure of haemopoietic recovery post-ASCT
5. Major surgery within 14 days before enrolment.
6. Radiotherapy within 14 days before enrolment. If the involved field is small, 7 days will be considered a sufficient interval between treatment and administration of the ixazomib.
7. Central nervous system involvement with the disease under study (myeloma).
8. Infection requiring systemic antibiotic therapy or other serious infection within 14 days before study enrolment.
9. Evidence of current uncontrolled cardiovascular conditions, including uncontrolled hypertension, uncontrolled cardiac arrhythmias, symptomatic congestive heart failure, unstable angina, or myocardial infarction within the past 6 months.
10. Systemic treatment, within 14 days before the first dose of ixazomib, with strong CYP3A inducers (rifampin, rifapentine, rifabutin, carbamazepine, phenytoin, phenobarbital), or use of Ginkgo biloba or St. John’s wort.
11. Ongoing or active systemic infection, active hepatitis B or C virus infection, or known human immunodeficiency virus (HIV) positive.
12. Any serious medical or psychiatric condition (including uncontrolled infection) that could, in the investigator’s opinion, potentially interfere with the completion of treatment according to this protocol or would be a contraindication to consolidation/maintenance therapy
13. Known allergy to any of the study medications, their analogues, or excipients in the various formulations of any agent.
14. Known GI disease or GI procedure that could interfere with the oral absorption or tolerance of ixazomib including difficulty swallowing.
15. Diagnosed or treated for another malignancy within 2 years before study enrolment or previously diagnosed with another malignancy and have any evidence of residual disease. Patients with non-melanoma skin cancer or carcinoma in situ of any type are not excluded if they have undergone complete resection.
16. Patient has >= Grade 2 peripheral neuropathy, or Grade 1 with pain on clinical examination during the screening period.
17. Participation in other clinical trials, including those with other investigational agents not included in this trial, within 30 days of the start of this trial and throughout the duration of this trial.
18. Contraindication to the use of either thalidomide, ixazomib or dexamethasone