There was found to be a significant association between the achievement of a complete response (CR) and improvements in the long term outcomes for both progression free survival (PFS) and overall survival (OS) in patients with Multiple Myeloma (MM), concludes a retrospective analysis in Blood. The findings, say the Italian researchers, support the use of novel agents to achieve maximal response in elderly patients, including those aged over 75 years.

In patients with MM not eligible for autologous transplantation, complete response (CR) was found to be rare until the advent of new treatment strategies combining standard oral melphalan-prednisone with novel agents such as thalidomide or bortezomib. While trials have reported improvements in PFS with combinations of novel agents, results have been mixed regarding how this translates into improvements in OS.

In the current study, Antonio Palumbo and colleagues from the University of Torino (Italy) retrospectively analysed 1,175 newly diagnosed MM patients who were not eligible for high-dose therapy or autologous stem cell transplants due being older than 65 years. The patients had been enrolled in three multicentre trials where they were treated with melphalan-prednisone (MP) alone (n=332), melphalan-prednisone-thalidomide (MPT), (n=332), melphalan-prednisone-bortezomib (MPB), (n=257) or melphalan-prednisone-bortezomib-thalidomide (MPBT), (n=254). The investigators compared PFS and OS according to the response achieved by patients – complete response (CR), very good partial response (VGPR) and partial response (PR).

Results show that at a median follow-up of 29 months (range 1-81 months) three year progression free survival for the entire study population was 29% and that overall survival was 65%. CR was reported in 195 (17%), VGPR in 212 (19%), PR in 397 (35%), while the remaining patients achieved less than PR.

The three year PFS was 67% in patients who achieved CR, 27% in patients with VGPR (HR0.16, 95% CI 0.10-0.24, P<0.001) and 27% in patients with PR only (HR0.07, 95%CI 0.04-0.13, P<0.001). Similarly, the three-year overall survival was 91% in patients who obtained CR, 70% in patients with VGPR (HR 0.15, 95%CI 0.08-0.28, P<0.001), and 67% in those with PR only (HR 0.08, 0.04-0.16, P<0.001).

The three year PFS was 26% in patients older than 75 years and 29% in those 75 years or younger, while the three year OS was 54% and 65% respectively.

"The achievement of CR was an independent predictor of long-term outcome regardless of age, and International Staging System stage," write the authors, adding that their findings support the use of novel agents to achieve a maximal response even in elderly patients.

Article: F Gay, A Larocca, P Wijermans et al. Complete response correlates with long-term progression-free and overall survivals in elderly myeloma treated with novel agents: an analysis of 1175 patients. Blood. Doi:10.1182/blood-2010-09-307645