Safety and Efficacy of Autologous Stem Cell Transplantation in Dialysis-Dependent Myeloma Patients - the Diadem Study from the Chronic Malignancies Working Party of the EBMT
Authors: Waszczuk-Gajda Anna , Wang Junfeng , de Wreede Liesbeth C. , Sirait Tiarlan , Ozkurt Zubeyde Nur , Snowden John A , Dreger Peter , Illés Árpád , Arat Mutlu , Bulabois Claude-Eric , Baurmann Herrad , Sever Matjaz , Basak Grzegorz W , Nikolousis Manos , Potter Victoria , Schroyens Wilfried , Gyan Emmanuel , Van Gorkom Gwendolyn , de la Serna Javier , Guffroy Blandine , Hayden Patrick J , Beksac Meral , Schönland Stefan O. , Yakoub-Agha Ibrahim 
Published: November 2019

Introduction
Multiple myeloma (MM) patients with renal impairment (RI), especially dialysis-dependent (DD) RI, have poorer outcomes than MM patients with normal renal function. Autologous stem cell transplantation (ASCT) is a treatment option, but there is concern at a perceived higher risk of complications which may be limiting consideration of the use of ASCT in this population. The evidence is inconsistent among studies and interpretation is complicated by heterogeneous datasets, some dating to before the availability of novel agents. Finally, the reversibility of RI following ASCT is an important prognostic factor for both survival and quality of life.
Aim
To evaluate the safety and efficacy of ASCT in MM patients with DD RI transplanted in EBMT centres between 1997 and 2017.
Methods
Baseline characteristics at diagnosis, patient treatment regimens and clinical outcomes were collected using standardised report forms. OS was defined as the period between the date of ASCT and the date of death or the date of last observation. PFS was defined as the period between the date of ASCT and date of progression/relapse or death of any causes or the date of the last observation. Cox proportional hazard regression analysis was applied to assess risk factors for progression and death. Survival curves were plotted by the Kaplan-Meier method and compared using log-rank test. P&lt;0.05 was judged as statistically significant.
Results
A total of 109,959 adult MM patients are registered in the EBMT database as having undergone ASCT between 1997 and 2017. We further analysed 118 DD MM patients who had a first ASCT during this period. The median (range) age was 57 (27-71) years. Seventy (59%) patients were males. Forty nine patients (49/94 patients, 52%) had Karnofsky score ≥90. One hundred and ten patients were treated with hemodialysis and eight with peritoneal dialysis. A total of 68 (58%) patients had Light Chain MM, 43 kappa and 25 Lambda. In first-line induction therapy, 47/76 (62%) patients received bortezomib-based regimens. Forty-four (37%) patients achieved at least VGPR pre-ASCT. The median time from diagnosis to ASCT was 0.7 years (0.3-4.9). Melphalan doses were as follows: 140 mg/m2 (n=55, 67%), 70-100 mg/m2 (n=15, 18%), and &gt;140 mg/m2 (n=12, 15%). The times to Neutrophil (&gt;0.5) and Platelet (&gt;20) engraftment were 12 (10-37) and 14 (4-128) days, respectively. The 30-day and 100-day transplant-related mortality (TRM) rates were 0.0% and 0.9%, respectively.
ASCT was associated with a significant deepening of response (at least VGPR pre- vs post-ASCT: 36/93 (39%) vs 48/93 (52%), p &lt; 0.001). The median PFS was 37 months (95% CI: 24-43) and 5-year PFS was 31% (95% CI: 20-41). The median OS was 102 months (95% CI: 67-129). Five-year OS post-ASCT was 62% (52-72) and 10-year OS 36% (17-55). Thirty-one (26%) DD MM patients achieved dialysis independence.
There were no differences in PFS or OS when comparing the 1997-2007 and 2008-2017 cohorts: 5-year PFS - 28% (6-49) vs 31% (19-43) (p=0.7) and 5-year OS - 61% (38-84) vs 63% (51-74) (p=0.9), respectively.
On univariate analysis of factors affecting PFS, achievement of an Overall Response Rate (ORR) (CR+VGPR+PR vs. Other) pre-ASCT was associated with a lower risk (HR 0.467, p=0.032) and older age (&gt;55 years) with a higher risk (HR 1.786, p=0.035) of post-ASCT progression. Age higher than 55 (HR 2.033, 95%CI: 0.992 - 4.166, p=0.053) increased and achievement of at least VGPR pre-transplant (HR 0.494, 95%CI: 0.224 - 1.091, p=0.081, on the verge of statistical significance) decreased the risk of death.
Conclusion
To the best of our knowledge, the DIADEM study is the largest analysis of ASCT in DD MM pts to date. This cohort of 118 unselected patients had an OS comparable to patients without RI. This may reflect patient selection based on younger age, Karnofsky scores and pre-ASCT response. The low TRM and excellent outcomes support consideration of the use of ASCT in pts with DD RI. Notably, more than a quarter of patients became dialysis independent, an outcome likely to confer an improved Quality-of-Life.. These results can also inform the debate around the role of renal transplantation in younger DD MM patients who do not achieve dialysis independence.

Disclosures
Snowden: IDMC: Honoraria; Kiadis: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria; Mallinckrodt: Honoraria; Jazz: Honoraria; Gilead: Honoraria. Dreger:MSD: Membership on an entity's Board of Directors or advisory committees, Other: Sponsoring of Symposia; AbbVie, AstraZeneca, Gilead, Janssen, Novartis, Riemser, Roche: Consultancy; AbbVie, Gilead, Novartis, Riemser, Roche: Speakers Bureau; Neovii, Riemser: Research Funding. Illés:Takeda, Seattle: Research Funding; Janssen, Celgene, Novartis, Takeda, Roche, Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees. Basak:Teva: Honoraria; Celgene: Honoraria. Gyan:Pfizer: Honoraria. Hayden:Alnylam: Honoraria; Amgen: Honoraria. Beksac:Amgen: Consultancy; Celgene: Consultancy; Janssen&Janssen: Consultancy; Takeda: Consultancy. Schönland:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Medac: Other: Travel Grant; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees, Research Funding.