Abstract

Background: Len maintenance after autoHCT has improved progression-free (PFS) and overall survival (OS). However, the role of additional interventions after autoHCT such as tandem autoHCT or triple therapy consolidation remains to be determined.

Methods: This is a phase III clinical trial (NCT#01109004) of transplant-eligible patients (pts) with symptomatic MM <71 years of age within 12 months of initiating therapy and without prior progression who were randomly assigned 1:1:1 to receive melphalan 200mg/m2 autoHCT and 4 cycles of RVD consolidation (lenalidomide 15mg daily days 1-14, dexamethasone 40mg day 1,8 and 15, and bortezomib 1.3mg/m2 days 1,4,8 and 11 every 21 days) (ACM), versus tandem melphalan 200mg/m2 autoHCT (TAM) or versus a single autoHCT (AM). Randomization was stratified by disease risk (cytogenetic abnormalities - del13q by karyotype, del17q, t(4;14), t(14;16), t(14;20) and hypodyploid; or high beta-2 microglobulin) and center. All arms included Len maintenance (at maximum tolerated dose of 5 to 15 mg orally daily until progression) with dose modifications for toxicities. All patients were reviewed centrally for eligibility, response and progression. The primary objective was to compare 38-month PFS of the three arms. The events for PFS included progression, non-protocol anti-myeloma therapy, or death. Comparisons between treatment groups were based on pairwise log-rank tests stratified on disease risk, with significance levels adjusted for the 3 pairwise comparisons and for interim analyses. In calculating the cumulative incidence of progression, the events were progression or non-protocol anti-myeloma therapy, and death was a competing risk.

Results: From June 2010 to November 2013, 758 pts (ACM, N=254; TAM, N=247; AM, N=257) aged 20-70 years (median 57y) were enrolled. Of those enrolled, 24% were classified as high risk. Non-compliance rates following the first autoHCT were 12%, 32% and 5% for ACM, TAM and AM, respectively. Median available follow up from randomization was 38 months. Follow-up is continuing through January 2017. 38-month estimated probabilities for PFS were 57% (95% CI: 50-63%), 56% (95% CI: 49-63%) and 52% (95% CI: 45-59%) for ACM, TAM and AM, respectively (ACM vs TAM p=0.75, ACM vs AM p=0.21, TAM vs AM p=0.37). Corresponding probabilities of OS were 86% (95% CI: 80-90%), 82% (95%CI: 76-87%) and 83% (95% CI: 78-88%). Median OS has not been reached. Cumulative incidences of disease progression at 38 months were 42% (95% CI: 36-48%), 42% (95% CI: 35-48%) and 47% (95% CI: 40-54%) for the ACM, TAM and AM arms, respectively. There were 39 cases of second primary malignancy (SPM) reported in 36 participants and the cumulative incidences for first SPM were 6.0% (95% CI: 3.4-9.6%), 5.9% (95% CI: 3.3-9.6%) and 4.0% (95% CI: 1.9-7.2%) for the ACM, TAM, and AM, respectively.

Conclusions: The primary results of the largest randomized US transplant trial in MM demonstrated comparable PFS and OS. The addition of RVD consolidation or a second auto-HCT was not superior to a single auto HCT followed by Len maintenance in the upfront treatment of MM. A long term follow-up trial to track outcomes in these patients is ongoing.

Disclosures

Stadtmauer:Amgen: Consultancy; Takeda: Consultancy; Celgene: Consultancy; Novartis: Consultancy; Janssen: Consultancy. Pasquini:Atara: Other: travel reimbursement for a meeting; Baxalta: Honoraria, Membership on an entity's Board of Directors or advisory committees. Efebera:Millennium/Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Honoraria. Ganguly:Onyx: Speakers Bureau; Seattle Genetics: Speakers Bureau; Amgen: Membership on an entity's Board of Directors or advisory committees. Giralt:Celgene: Consultancy; Millenium/Takeda: Consultancy. Hari:Celgene: Consultancy; Millennium/Takeda: Consultancy. McCarthy:Celgene: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Karyopharm: Consultancy, Honoraria; Millennium/Takeda: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Sanofi: Consultancy, Honoraria; The Binding Site: Consultancy, Honoraria. Qazilbash:Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees. Shah:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millennium/Takeda: Membership on an entity's Board of Directors or advisory committees. Vesole:Takeda: Speakers Bureau; Celgene: Speakers Bureau. Vij:Millennium/Takeda: Consultancy; Celgene: Consultancy. Vogl:Celgene: Consultancy; Millennium/Takeda: Consultancy, Research Funding. Somlo:PUMA: Consultancy; Abbvie: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium/Takeda: Speakers Bureau; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees. Krishnan:Celgene: Consultancy, Speakers Bureau; Millennium/Takeda: Consultancy, Speakers Bureau; Onyx: Consultancy, Speakers Bureau; Janssen: Consultancy, Speakers Bureau.

Author notes

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Asterisk with author names denotes non-ASH members.