Thalidomide-dexamethasone versus Interferon-alpha-dexamethasone as maintenance treatment after ThaDD induction for multiple myeloma: a prospective, multicentre, randomised study

Maintenance therapy was explored in multiple myeloma (MM) patients after conventional thalidomide, dexamethasone and pegylated liposomal doxorubicin (ThaDD). Patients with newly or relapsed MM obtaining at least minor response after 6 ThaDD courses, were randomised to receive α-interferon (IFN) 3 MU 3 times a week or thalidomide 100 mg daily until relapse. Both groups also received pulsed dexamethasone 20 mg 4 d a month. Fifty-one patients were randomized in the IFN-dexamethasone (ID) arm and 52 in the thalidomide-dexamethasone (TD) arm. The characteristics of two groups were similar. A significantly better 2-years progression-free survival (PFS; 63% vs. 32%; P  = 0·024) and overall survival (84% vs. 68%; P  = 0·030) was observed in the thalidomide arm. In high-risk patients and in those achieving less than very good partial response after induction, TD fared better in term of PFS. Main side effects were peripheral neuropathy and constipation in TD group, fatigue, anorexia and haematological toxicity in ID arm. There was a 21% probability of discontinuation at 3 years in the thalidomide arm and 44% in the IFN arm ( P  = 0·014). Low-dose thalidomide plus pulsed low-dose dexamethasone after conventional thalidomide combination-based therapy was also feasible in the long term, enabling significantly better residual disease control if compared with a standard maintenance therapy.