Consolidation with Vtd Significantly Improves the Complete Remission (CR) Rate Following Vtd Induction and Single Autologous Stem Cell Transplantation (auto) in Multiple Myeloma (MM).

Several studies have demonstrated the impact of VTd on response rates and PFS either as induction or consolidation regimen. However there are limitations to these studies, especially that no data is available regarding the role of VTd consolidation in the context of bortezomib-triple based VTd induction regimen followed by a single auto. At completion of therapy, the response rate (ORR, PR and better) was 89%, VGPR+CR rate 74%, CR rate 29%, relapse rate and median PFS was 53% and 26 months (median F-up 32 months) in the VTd arm of the phase 3 IFM2007-02 trial conducted for newly diagnosed MM (Moreau et al, Blood 2012). In this study, only a minority of patients had received a consolidation or maintenance. On the other hand, Cavo et al. (Blood 2012) reported 97.5%, 92%, 61%, 39% 3-year progression and 62% estimated 5-year PFS (F-up 43 months) respectively in the VTd arm. VTd was given as induction before and consolidation after double auto in this upfront GIMEMA phase 3 trial (Cavo et al, Lancet 2010).

We aimed to assess the efficacy and safety of VTd as consolidation therapy in the context of VTd as induction regimen followed by a single auto (VTd-auto-VTd regimen).

This study has included a first group of 121 newly diagnosed MM from 2009 to 2011 across 9 IFM centers. Patients were to be eligible for auto upfront, aged less than 65 and treated with VTd-auto-VTd regimen. The second cohort included MM treated with VTd-auto without consolidation from the IFM2007-02 trial (n=76). A third cohort comprised MM that received upfront a triplet Vd-based combination induction (VCd, VRd) -auto without consolidation (n = 40).

In the whole study, the median age was 56 years, the sex ratio was 1,49, 50% had ISS 2 and 3, 22% had adverse FISH [t(4;14); del17p] (similar in the 3 groups).

Overall, the ORR was identical in the 3 cohorts at completion of therapy, 104 (86%), 72 (94%) and 32 (80%) for the cohort 1 to 3, respectively. Nevertheless, the CR rate was significantly greater in patients that received a consolidation (cohort 1), as compared to the cohorts 2 and 3 that did not receive any consolidation, 59 (53%) vs. 26 (34%) and 13 (32.5%), respectively (p=0.0001). Interestingly, the CR rates were identical at the end of the induction in the 3 cohorts, 13%, 15% and 22.5%, respectively.

With a median follow-up of 25 months, the incidence rate of relapse was significantly greater in the cohort 2 and 3 versus 1, further demonstrating the importance of the consolidation, 25 (21%), 42 (55%) and 13 (32.5%) patients (p=0.0001), respectively; and 9 (8%), 6 (8%) and 8 (20%) had died in cohorts 1 to 3 (p=0.07). The median (95%CI) PFS was not reached in cohort 1, and was 32 (28;36) months and 30 (26;33) months in cohort 2 and 3, respectively. Importantly, 54.5%, 32% and 32% of patients were free of relapse at 32 months in the 3 cohorts, respectively. Similar data were obtained for TTP. The median (95%CI) OS was not significantly different in cohorts 1 to 3, although not reached for the first 2 cohorts and 38 (33;43) months for the 3^rdcohort. The 3-year survival was 84%, 91% and 76%, respectively (p=ns). A longer follow up will certainly demonstrate greater survival end points benefit in favor for consolidation.

The safety profile of the cohort that contained a consolidation was superimposable to that of the remaining 2 cohorts without consolidation. The incidence rate of hematological EIs of grade 3 and 4 was 4%, 6% and 8% in the 3 cohorts (p=ns), respectively. The incidence rate of neuropathy grade 1–2 and 3–4 was 5% and 2% in the cohort 1 with consolidation, but only 1% occurred during the consolidation. This data compares favorably to the 3% reported in the cohort 2 (Moreau et al. Blood 2012). We have also observed 9 (9%) thromboembolic events (TE), 8 of venous type and 1 arterial. None of them happened during the consolidation, and again, this incidence rate if superimposable to that reported in the IFM2007-02 vTd cohort.

This study showed an impressive increase in CR rate in relation to the consolidation that translated into a lower relapse rate. This study also demonstrated that the VTd regimen, used both as induction and consolidation, in the context of a single auto upfront in MM, significantly contributed to improve clinical outcomes with an acceptable toxicity profile. VTd-auto-VTd compared very favorably to the other upfront protocols, and may become in the near future a standard of care in newly diagnosed patients with Myeloma.

Leleu:Celgene: Honoraria, Research Funding, Speakers Bureau; Janssen: Honoraria, Research Funding, Speakers Bureau; Novartis: Honoraria, Research Funding; Amgen: Honoraria, Research Funding; Sanofi: Honoraria; Onyx: Honoraria, Speakers Bureau; LeoPharma: Honoraria, Speakers Bureau. Off Label Use: Pomalidomide. Roussel:celgene: Honoraria; janssen: Honoraria. Facon:onyx: Membership on an entity's Board of Directors or advisory committees; celgene: Membership on an entity's Board of Directors or advisory committees; janssen: Membership on an entity's Board of Directors or advisory committees; millenium: Membership on an entity's Board of Directors or advisory committees. Attal:celgene: Membership on an entity's Board of Directors or advisory committees; janssen: Membership on an entity's Board of Directors or advisory committees.