ASH 2018 Abstract 253 and 254

Dr. Marc-A. Baertsch from the Department of Hematology, Oncology and Rheumatology, University Hospital Heidelberg, Heidelberg, Germany discusses abstract 253 and 254:
Salvage Autologous Transplant and Lenalidomide Maintenance Versus Continuous Lenalidomide/Dexamethasone for Relapsed Multiple Myeloma: Results of the Randomized GMMG Phase III Multicenter Trial Relapse (View Abstract)

Subgroup Analyses of the Randomized GMMG Phase III Multicenter Trial Relapse Suggest Survival Benefit of Salvage Autologous Transplant Primarily in Low Risk Multiple Myeloma (View Abstract)


Introduction Salvage high dose chemotherapy (HDCT) followed by autologous stem cell transplantation (ASCT) is used in fit patients with relapsed multiple myeloma (RMM) in clinical practice. However, the role of this approach in the era of continuous novel agent based treatment has not been defined in randomized trials. The ReLApsE trial compared lenalidomide/dexamethasone (Rd) re-induction, salvage HDCT/ASCT and lenalidomide (R) maintenance with standard continuous Rd in a randomized controlled multicenter trial.

Methods Between 2010 and 2016, 282 patients were randomized of whom 277 constituted the intention-to-treat (ITT) population (arm B/A n=139/138). Arm B received 3 cycles of Rd (lenalidomide 25 mg, day 1-21; dexamethasone 40 mg, day 1, 8, 15, 22; 4 week cycles) re-induction, HDCT (melphalan 200 mg/m2), ASCT and R maintenance (10 mg daily) until progression (PD). Arm A was treated with Rd until PD. In both arms stem cells were harvested after the 3rd Rd cycle if no back-up transplant was available. Key inclusion criteria were 1-3 prior therapy lines, age ≤ 75 years, time to PD ≥ 12 months in case of front-line HDCT/ASCT and WHO PS ≤ 2. The primary endpoint was progression free survival (PFS). Secondary endpoints included overall survival (OS), response rates and toxicity. ISRCTN16345835, Eudra CT-No: 2009-013856-61.

Results Arm B and A were balanced regarding age (median 61.3 vs. 62.2 years), ISS (I/II/III in 62.6/24.4/13% vs. 59.7/31/9.3%) and WHO PS (0/1/2 in 69.1/30.9/0% vs. 76.1/23.2/0.7%). Almost all patients had only 1 prior therapy line (arm B: 94.2% vs. arm A: 93.5%) and had received front-line HDCT/ASCT (92.8% vs. 94.2%). More patients in arm B had high risk cytogenetic aberrations (HR-CA; 42.9% vs. 31.6%) based on a higher frequency of t(4;14) (20.2% vs. 10.1%).

The overall response rate (≥ partial response; ORR) for arm B and A was 77.9% and 74.6% (p=0.57) with 49.3% and 47.1% (p=0.81) achieving ≥ very good partial response as best response. Within a median follow up of 36.3 months, 183 PFS events and 76 deaths occurred. Median PFS in the ITT population was 20.7 months in arm B and 18.8 months in arm A without a statistically significant difference (HR 0.87; 95% CI 0.65-1.16; p=0.34). Median OS was not reached (NR) in arm B vs. 62.7 months in arm A (HR 0.81; 95% CI 0.52-1.28; p=0.37).

In arm B, 41 patients (29.5%) did not receive the planned HDCT/ASCT. Thus, exploratory landmark (LM) analyses from HDCT and the contemporaneous Rd cycle 5 in arm A were performed (median interval from randomization to HDCT/Rd cycle 5: 117/122 days; n=103[B]/114[A]). They showed a trend towards superior PFS (23.3 vs. 20.1 months; HR 0.74; p=0.09) and significantly superior OS (NR vs. 57 months; HR 0.56; p=0.046) in arm B vs. A. Multivariate analyses revealed significant associations of treatment in arm B with superior LM PFS (HR 0.6; p=0.01) and LM OS (HR 0.39; p=0.006). Other factors in the LM multivariate models showing significant associations with survival were HR-CA (PFS, OS), number of prior therapy lines (PFS), and age (PFS). The ORR in arm B after HDCT/ASCT was significantly higher than in arm A after Rd cycle 5 (82.3% vs. 69.6%; p=0.04).

Grade ≥3 adverse events were reported in 83% (arm B) and 74.5% (arm A; p=0.11). Grade ≥3 leukopenia/neutropenia was reported in 61.5 vs. 24.8% (p<0.001), grade ≥3 thrombopenia in 45.2 vs. 11% (p<0.001) and grade ≥3 mucositis in 10.4% vs. 2.1% (p=0.005). No significant difference in grade ≥3 infections/infestations (33.3 vs. 27.6%; p=0.3) was observed. Eleven patients died on protocol treatment (B: 4 vs. A: 7). No deaths occurred in the HDCT/ASCT phase.

Conclusions This is the first RCT comparing salvage HDCT/ASCT with continuous novel agent based treatment. No significant PFS or OS difference was observed in the overall trial population. However, HR-CA were more frequent in the HDCT/ASCT arm and ~30% of patients did not receive the planned HDCT/ASCT. Landmark analyses from the time of HDCT indicate superior PFS and OS in patients actually undergoing salvage HDCT/ASCT. Salvage HDCT/ASCT was safe with an expected increase in hematological as wells as gastrointestinal toxicity but without treatment-related mortality in patients up to the age of 75 years in this multicenter trial. However, the number of patients not undergoing salvage HDCT/ASCT and the approval of more active Rd-based triplet regimens after the initiation of this trial prevents definite conclusions on the role of salvage HDCT/ASCT.

Introduction The ReLApsE trial compared lenalidomide (LEN)/dexamethasone (DEX; Rd) re-induction, salvage high dose chemotherapy (HDCT), autologous stem cell transplantation (ASCT) and LEN maintenance with continuous Rd in relapsed multiple myeloma. Landmark (LM) analyses from salvage HDCT were performed due to the fact that ~30% of patients in the HDCT arm did not receive salvage HDCT/ASCT. These analyses showed a survival benefit in patients actually undergoing salvage HDCT/ASCT. Median PFS and OS from LM were 23.3 vs. 20.1 months (HR 0.74; p=0.09) and not reached vs. 57 months (HR 0.56; p=0.046) favoring the salvage HDCT/ASCT arm. Multivariate LM analyses showed significant associations of the salvage HDCT/ASCT arm with superior PFS (HR 0.6; p=0.01) and OS (HR 0.39; p=0.006). The present analysis aims to dissect treatment efficacy in relevant subgroups and provide clues for treatment stratification.

Methods The ReLApsE trial (ISRCTN16345835) compared 3 Rd (LEN 25 mg, d1-21; DEX 40 mg, d1,8,15,22; 4 week cycles) re-induction cycles, HDCT (melphalan 200 mg/m2), ASCT and LEN maintenance (10 mg/d) until PD (arm B, n=139) with Rd until PD (arm A, n=138). Key inclusion criteria were 1-3 prior therapy lines, age ≤ 75, time to PD in case of front-line HDCT/ASCT (TTP1) ≥ 12 months and WHO PS ≤ 2. Exploratory subgroup analyses were performed in the ITT population for PFS/OS using an LM at HDCT (B; n=103) and the contemporaneous Rd cycle 5 (A; n=114). The median interval from randomization to LM was 117/122 days in arm B/A. Heterogeneity of treatment effect was assessed by cox regression with interaction term between treatment and subgroup factor.

Results No significant differences in the PFS/OS benefit between arms were observed in subgroups according to baseline ISS (I/II/III; interaction p[i-p]=0.5/0.66), age (</≥65 yrs; i-p=0.13/0.89), renal function (MDRD </≥ 60 ml/min; i-p=0.68/0.34), response to re-induction (</≥ PR; i-p=0.92/0.48), prior therapy lines (1/>1; i-p=0.37/0.22), single vs. tandem front-line HDCT/ASCT (i-p=0.34/0.56), and TTP1 (12-24 vs. 24-48 vs. >48 months; i-p=0.91/0.21).

The subgroups according to front-line HDCT/ASCT (yes/no) differed significantly with regard to PFS/OS benefit in arm B (i-p=0.006/0.001). A significant benefit was observed in patients with front-line HDCT/ASCT treated in arm B regarding PFS (HR 0.68, p=0.03; n=107[A]/98[B]) and OS (HR 0.43, p=0.009). Patients without front-line HDCT/ASCT constituted a very small subgroup with imbalances in baseline parameters adversely affecting arm B and had expectably inferior survival in arm B (PFS: HR 4.35, p=0.08; OS: HR 19.83, p=0.0078; n=7[A]/5[B]).

The subgroup with baseline LDH </> upper limit of normal (ULN) differed significantly in PFS benefit in arm B (i-p=0.03) but not in OS benefit (i-p=0.46). Patients with LDH<ULN had significantly better PFS (HR 0.61, p=0.01; n=98[A]/85[B]) in arm B whereas no significant difference between trial arms was observed in patients with LDH>ULN (PFS: HR 1.54, p=0.31; n=16[A]/18[B]).

The subgroups according to baseline cytogenetic risk and R-ISS showed a trend towards a differential benefit in arm B regarding OS (i-p=0.05 and 0.09) but not PFS (i-p=0.5 and 0.88). Patients with low risk cytogenetics (i.e. absence of t(4;14), del17p, +1q>3 copies and t(14;16)) had significantly superior OS in arm B (HR 0.21; p=0.01; n=57[A]/35[B]), whereas patients with high risk cytogenetics had no significant difference in OS according to trial arm (HR 0.82, p=0.67; n=25[A]/28[B]). Patients with R-ISS I had significantly superior OS in arm B (HR 0.08; p=0.02; n=33[A]/25[B]), whereas no significant difference in OS according to trial arm was seen in patients with R-ISS II (HR 0.72, p=0.42; n=52[A]/43[B]) and R-ISS III (HR 0.65, p=0.6; n=3[A]/5[B]).

Conclusions The ReLApsE trial is the first RCT of salvage HDCT/ASCT vs. continuous novel agent treatment. In the absence of a significant survival benefit for the primary endpoint, LM analyses indicated a significant PFS/OS benefit in patients actually undergoing HDCT/ASCT. No heterogeneity of treatment effect was observed according to ISS, age, renal function, response to re-induction, prior therapy lines, single vs. tandem front-line HDCT/ASCT, and TTP1. Subgroup effects regarding PFS and/or OS benefit from HDCT/ASCT were seen favoring patients with front-line HDCT/ASCT and patients with low risk according to LDH, cytogenetics and R-ISS.

Education Conference Coverage ASH 2018 Conference Coverage ASH 2018 Abstract 253