Treatment of Myeloma in Patients <= 65 Years Old With Response >= 50% After HSC Autotransplant by Allogenic Transplant Genoidentical or Phenoidentical After Reduced Intensity Conditioning

Donor mobilization :

Donor will be mobilized with G-CSF (Granocyte) sub-cutaneous 10 µg/kg/day during 5 to 6 days.

Hematopoïetic Stem Cell Harvest:

By 1, 2, or 3 aphaeresis, a number of 4 x 106 cellules CD34+ /kg is required. If the CD34+ >= 2 and <= 4x106/kg: the center must decide on the strategy Decision. In case of insufficient graft : a Bone Marrow Harvest is recommended Conditioning : Fludarabine - Busulfan - ATG

* D-5 : Fludarabine (30 mg/m²) * D-4 : Fludarabine (30 mg/m²)+ Busilvex (0,8 mg/kg every 6 h) * D-3 : Fludarabine (30 mg/m²)+ Busilvex (0,8 mg/kg every 6 h) * D-2 : Fludarabine (30 mg/m²) + ATG (Genzyme) (2.5 mg/Kg) * D-1 : Fludarabine (30 mg/m²) + ATG (Genzyme) (2.5 mg/Kg) GVHD Prophylaxis: CsA alone at 3 mg/ kg + Methotrexate D1, D3 and D6 only in case of minor ABO incompatibility and with an anti A/B antibodies titer> 1/32.

Transplant : HSC at D0

• 3 months after Transplantation :

Disease Evaluation :

* If CR : Supervision. Then if progression: 4 cycles of Bortezomib. * If no CR : Bortezomib (4 cycles)

• Evaluation after Bortezomib cycles * If CR : Supervision. Then, if progression and no GvHD : DLI If no RC and no GVHD : DLI