The primary objective of this study is to determine the rate of molecular remissions (MolR) assessed by ASO-RQ-PCR technique after induction treatment with bortezomib and dexamethasone (Vel/Dex) prior to high-dose therapy with melphalan and autologous stem cell transplantation (HDT-ASCT), and after HDT-ASCT in patients with multiple myeloma.

HDT-ASCT is so far considered the standard of care for younger patients with multiple myeloma (MM). Current evidence indicates that quality of response is an important prognostic factor for long-term survival in MM. There are only very few data on molecular remissions (MolR) determined by the most sensitive technique, allele-specific-oligonucleotide - real-time quantitative - polymerase chain reaction (ASO-RQ-PCR) in MM, and there are no data available on molecular responses after bortezomib-based induction therapy followed by HDT-ASCT. The main aim of this study is to determine molecular response rate after ASCT following bortezomib-based induction treatment compared to a historical control group with conventional VAD induction treatment. A sensitivity of ASO-RQ-PCR technique will be compared to immunofixation and with immunophenotyping by flow cytometry.

Inclusion Criteria:

• Symptomatic multiple myeloma
• Age 18-65 years
• Written informed consent

Exclusion Criteria:

• WHO performance status ≥ 2, unless related to MM
• Severe cardiac dysfunction
• History of hypotension
• Serious medical or psychiatric illness
• Severe hepatic dysfunction
• Severe polyneuropathy ≥ grade 2
• Active, uncontrolled infection
• Previously treated with chemotherapy or extensive radiotherapy for MM
• Known HIV positivity
• Severe renal dysfunction with need of dialyses
• History of active cancer during past 5 years, except non-melanoma skin cancer or stage 0 cervical cancer
• Female patients who are pregnant or nursing
• Male or female patients of reproductive potential who are not practising effective means of contraception