Bortezomib Plus Melphalan and Prednisone (VMP) Followed By Lenalidomide and Dexamethasone (Rd) in Newly Diagnosed Elderly Myeloma Patients Overcome the Poor Prognosis of High-Risk Cytogenetic Abnormalities (CA) Detected By Fluorescence in Situ Hibridization (FISH)

Background: Novel insights into the biology of myeloma cells have led to the identification of relevant prognosis factors. CA has become one of the most important prognostic factors, and the presence of t(4;14), t(14;16) or del(17p) are associated with poor prognosis. Although there are some reports indicating that 1q gains may be considered as a poor-risk feature, the information is not uniform. Furthermore, there are important controversies about whether or not novel agents-based combinations are able to overcome the poor prognosis of CA. Bortezomib-based combinations have shown to improve the outcome of patients with high-risk CA but they do not completely overcome their adverse prognosis. Here we report a preplanned analysis, in a series of elderly newly diagnosed myeloma patients included in the Spanish GEM2010 trial and receiving VMP and Rd, in a sequential or alternating approach, in order to evaluate the influence of CA by FISH on the response rate and outcome.

Patients and methods: 242 pts were randomized to receive a sequential scheme consisting on 9 cycles of VMP followed by 9 cycles of Rd or the same regimens in an alternating approach (one cycle of VMP alternating with one Rd, up to 18 cycles. VMP included the iv administration of weekly bortezomib (except in the first cycle that was given twice weekly) at 1.3 mg/m² in combination with oral melphalan 9 mg/m² and prednisone 60 mg/m² once daily on days 1-4. Rd treatment consisted on lenalidomide 25 mg daily on days 1-21 plus dexamethasone 40 mg weekly. FISH analysis for t(4;14), t(14;16), del(17p) and 1q gains was performed at diagnosis according to standard procedures using purified plasma cells.

Results: In 174 out of the 233 patients evaluable for efficacy and safety, FISH analysis at diagnosis were available and two groups were identified: high-risk group (n= 32 patients with t(4;14) and/or t(14;16) and/or del(17p)) and standard-risk group (n=142 patients without high-risk CA). There weren't differences in the rates of CA according to the treatment arm. Response Rates (RR) were no different in the high-risk vs standard-risk groups, both in the sequential (74% vs 79% RR and 42% vs 39% CR) and alternating arms (69% vs 86% RR and 39% vs 38% CR). After a median follow-up of 37 months, high-risk patients showed shorter PFS as compared to standard risk in the alternating arm (24 versus 36 months, p=0.01, HR 2.2, 95% IC 1.1-4.2) and this also translated into a significantly shorter 4-years OS (27% vs 72%, p=0.006, HR 3.3, 95% IC 1.4-7.7). However, in the sequential arm, high-risk and standard-risk patients showed similar PFS (32 months vs 30 months) and 4-years OS (64% vs 60%). This effect was observed only in the sequential arm applied to either t(4;14) or del(17p).

As far as 1q gains is concerned, 151 patients had 1q information and 76 of them had 1q gains (50.3%), defined as the presence of more than 3 copies in at least 10% of plasma cells. The rate of 1q gains was well balanced in both sequential and alternating arms. The ORR was similar in patients with or without 1q gains (83% vs 80%) as well as the CR rate (45% vs 31%), and no differences were observed between sequential and alternating arms. Patients with or without 1q gains had a similar PFS (33 months vs 30 months) and 4-years OS (58% vs 65%) in the whole series and no differences were observed in the sequential and alternating arms. This effect has been observed in patients with 1q gains as isolated CA and the outcome was slightly but not significantly worse when 1q gains were present plus either t(4;14) and/or del17p.

Conclusions: The total therapy approach including VMP and Rd administered in a sequential approach is able to overcome the poor prognosis of the presence of high-risk CA in elderly patients with newly diagnosed MM. The presence of 1q gains has no impact in the PFS and OS of elderly patients treated with VMP and Rd.