J.L. Harousseau,1 M. Attal,2 P. Moreau,1 T. Facon,3 H. Avet-Loiseau1
1Hôpital Hôtel Dieu, Nantes; 2Hôpital Purpan, Toulouse; 3CHU, Lille, France
by Lynne Lederman, PhD
Dr. Harousseau reviewed data from three situations to support his argument that CR should be a major treatment objective. One situation includes trials of high dose therapy followed by double autologous stem cell transplant (ASCT) in which all patients are randomized, where CR and very good partial response (VGPR) are associated with longer event free survival (EFS) and overall survival (OS). The second situation is represented by trials of conventional chemotherapy with and without novel agents, e.g., MP vs. MP-T, in which increased CR rates translate to greater OS. Third, in relapsed/refractory myeloma, Dr. Harousseau stated that the objective should still be to induce CR, because in this setting, CR is also associated with longer OS based on trial data from trials of lenalidomide or bortezomib plus dexamethasone vs. dexamethasone alone. Dr. Harousseau concluded that CR/VGPR is associated with longer progression free survival (PFS) and OS in all of these clinical situations, although he agreed with Dr. Alexanian that some patients who are not in CR do live longer.
Dr. Harousseau brought up several questions that remain to be answered. These include: which definition of CR is clinically relevant, e.g., EBMT vs. IMWG, the best measure of CR, e.g., molecular, flow cytometry, MRI, or immunofixation (IF), and if VGPR should be included in analysis, as it is in studies in which CR rates are low; is maintenance after CR useful (Dr. Harousseau believes it is not); and is it better to have CR before or after SCT. Dr. Boccadoro asked if the quality of CR after treatment with dexamethasone was the same as CR after ASCT. Dr. Harousseau felt that molecular remission was better than IF negative CR, but because molecular techniques are not available everywhere, a new definition of CR might be based on free light chain. Dr. Alexanian asked if the magnitude of CR was as important as patient quality of life.