Long-term outcomes of previously untreated myeloma patients: responses to induction chemotherapy and high-dose melphalan incorporated within a risk stratification model can help to direct the use of novel treatments

Induction chemotherapy followed by high-dose melphalan (HDM) is the standard treatment for fitter patients with myeloma. The place of bortezomib and the thalidomide analogues within this treatment paradigm is yet to be established. We sought to identify patients who may benefit from the introduction of novel agents during their initial management. An intention-to-treat analysis was performed on 383 patients with newly diagnosed myeloma eligible for HDM to determine whether the extent of response to induction therapy and HDM correlated with long-term survival. Early response [complete response (CR) and partial response (PR)] to induction therapy was predictive of overall survival (OS) [median OS, 7.47 years for responders (CR and PR) versus 4.89 years for non-responders; P = 0.035]. The attainment of CR at 3 months post-HDM correlated with a prolonged progression-free survival (PFS) (median PFS, 7.4 years in CR group versus 5.3 years in non-CR group; P = 0.023). This data suggests that, at every stage of treatment, the aim should be to achieve CR. Patients with suboptimal responses could be offered alternative therapy. We propose a multiparametric risk-adapted model that includes response to induction chemotherapy and HDM, for identifying patients who may benefit from novel approaches to treatment.