Introduction – Methods – Results
Monday afternoon at ASH found me listening to an abstract by Nora Grieb. It was a study from the German Registry for Hematopoietic Stem Cell Transplantation and Cell Therapy. Autologous stem cell transplantation (ASCT) following high-dose chemotherapy is a standard treatment for newly diagnosed multiple myeloma patients. Tandem transplantation, involving two ASCTs, is generally recommended for those who do not achieve at least a very good partial response (VGPR) after the first ASCT, or those with high-risk features. The reason I found this interesting was that I faced a decision of single or tandem transplant in 2007.
The results of the study got very detailed for me but what I understood was important for the patient. Out of 12,763 patients, 6,581 underwent a single ASCT and 4,027 underwent tandem ASCT. Patients who received a second ASCT or an allogeneic transplant after the first six months of the initial ASCT were considered part of the single ASCT group. There was a shift in transplantation practices over time, with tandem ASCT becoming less common: 47.4% before 2008 versus 25.7% in 2017-2021. Moreover, the percentage of patients in complete remission (CR) post-induction therapy increased over time (7.4% between 1998-2007 versus 13% after 2017), as did the percentage achieving CR after the first ASCT (20.5% before 2008 vs. 32.3% after 2017).
When comparing single and tandem ASCTs, no significant difference in OS or EFS was observed for patients who achieved CR after the first transplant. However, patients who did not achieve CR after the first ASCT experienced a significant OS benefit with tandem ASCT. This benefit was also evident in patients who did not reach CR after induction therapy. Interestingly, there was no significant difference in OS or EFS for patients who transitioned from non-CR to CR after the first ASCT.
The study analyzed the impact of the International Staging System (ISS) and renal impairment on outcomes. ISS stage III was significantly associated with worse OS for patients with renal impairment. Notably, patients with ISS stage I and no renal impairment showed a significant benefit in OS from tandem ASCT, while those with ISS stage III and renal impairment fared better with single ASCT.
Conclusion
Don’t ask me to explain much more than my current thoughts but the study shows that patients who did not achieve CR after induction therapy or the first ASCT benefited from a second ASCT. However, patients with ISS stage III and renal impairment had poorer outcomes, and in these cases, single ASCT was associated with better survival. What I liked about the study was these findings suggest a need for tailored approaches based on patient characteristics to optimize treatment strategies for NDMM patients. And I believe that is a good thing for the patient.