Sarah Waheed

Thalidomide arm of Total Therapy 2 improves complete remission duration and survival in myeloma patients with metaphase cytogenetic abnormalities.

Total Therapy 2 examined the clinical benefit of adding thalidomide up-front to a tandem transplant regimen for newly diagnosed patients with multiple myeloma. When initially reported with a median follow-up of 42 months, complete response rate and event-free survival were superior among the 323 patients randomized to thalidomide, whereas overall survival was indistinguishable from that of the 345 patients treated on the control arm. With further follow-up currently at a median of 72 months, survival plots segregated 5 years after initiation of therapy in favor of thalidomide (P = .09), reaching statistical significance for the one third of patients exhibiting cytogenetic abnormalities (CAs; P = .02), a well-recognized adverse prognostic feature. The duration of complete remission was also superior in the cohort presenting with CAs such that, at 7 years from onset of complete remission, 45% remained relapse-free as opposed to 20% on the control arm (P = .05). These observations were confirmed when examined by multivariate analysis demonstrating that thalidomide reduced the hazard of death by 41% among patients with CA-positive disease (P = .008). Because two thirds of patients without CAs have remained alive at 7 years, the presently emerging separation in favor of thalidomide may eventually reach statistical significance as well.

Superior results of Total Therapy 3 (2003-33) in gene expression profiling–defined low-risk multiple myeloma confirmed in subsequent trial 2006-66 with VRD maintenance

The Total Therapy 3 trial 2003-33 enrolled 303 newly diagnosed multiple myeloma patients and was noted to provide superior clinical outcomes compared with predecessor trial Total Therapy 2, especially in gene expression profiling (GEP)-defined low-risk disease. We report here on the results of successor trial 2006-66 with 177 patients, using bortezomib, lenalidomide, and dexamethasone maintenance for 3 years versus bortezomib, thalidomide, and dexamethasone in year 1 and thalidomide/dexamethasone in years 2 and 3 in the 2003-33 protocol. Overall survival (OS) and event-free survival (EFS) plots were super-imposable for the 2 trials, as were onset of complete response and complete response duration (CRD), regardless of GEP risk. GEP-defined high-risk designation, pertinent to 17% of patients, imparted inferior OS, EFS, and CRD in both protocols and, on multivariate analysis, was the sole adverse feature affecting OS, EFS, and CRD. Mathematical modeling of CRD in low-risk myeloma predicted a 55% cure fraction (P < .001). Despite more rapid onset and higher rate of CR than in other molecular subgroups, CRD was inferior in CCND1 without CD20 myeloma, resembling outcomes in MAF/MAFB and proliferation entities. The robustness of the GEP risk model should be exploited in clinical trials aimed at improving the notoriously poor outcome in high-risk disease.

High-risk myeloma is associated with global elevation of miRNAs and overexpression of EIF2C2/AGO2

MicroRNAs (miRNAs) are noncoding RNAs that regulate global gene expression. miRNAs often act synergistically to repress target genes, and their dysregulation can contribute to the initiation and progression of a variety of cancers. The clinical relationship between global expression of miRNA and mRNA in cancer has not been studied in detail. We used whole-genome microarray analyses of CD138-enriched plasma cells from 52 newly diagnosed cases of multiple myeloma to correlate miRNA expression profiles with a validated mRNA-based risk stratification score, proliferation index, and predefined gene sets. In stark contrast to mRNAs, we discovered that all tested miRNAs were significantly up-regulated in high-risk disease as defined by a validated 70-gene risk score (P < 0.01) and proliferation index (P < 0.05). Increased expression of EIF2C2/AGO2, a master regulator of the maturation and function of miRNAs and a component of the 70-gene mRNA risk model, is driven by DNA copy number gains in MM. Silencing of AGO2 dramatically decreased viability in MM cell lines. Genome-wide elevated expression of miRNAs in high-risk MM may be secondary to deregulation of AGO2 and the enzyme complexes that regulate miRNA maturation and function.

Complete remission in multiple myeloma examined as time-dependent variable in terms of both onset and duration in Total Therapy protocols

Landmark analyses are used to investigate the importance for survival of achieving complete response (CR), an important initial goal of myeloma therapy. With median times to CR in Total Therapy (TT) trials of approximately 1 year, this approach excludes a sizeable fraction of patients dying before such a landmark. To permit inclusion of all trial participants, we investigated the prognostic implications of both onset and duration of CR as time-dependent variables. Superseding the adverse effects of cytogenetic abnormalities and other standard prognostic parameters, both failure to achieve CR (non-CR) and, especially, loss of CR (los-CR) were independently associated with inferior survival in TT1, TT2, and TT3 protocols. In the context of gene array-defined risk, available in TT2 and TT3 subsets, both los-CR and non-CR terms were retained in the survival model as dominant adverse variables, stressing the prognostic importance of sustaining CR status, especially in high-risk disease.

Clinical, genomic and imaging predictors of myeloma progression from asymptomatic monoclonal gammopathies (SWOG S0120)

All cases of clinical myeloma (CMM) are preceded by an asymptomatic monoclonal gammopathy (AMG), classified as either monoclonal gammopathy of undetermined significance (MGUS) or asymptomatic multiple myeloma (AMM). We analyzed data from AMG patients (n = 331) enrolled in a prospective, observational clinical trial (S0120). Baseline data from clinical variables, gene expression profiles (GEP) of purified tumor cells, and findings of magnetic resonance imaging (MRI) were correlated with the risk of progression to CMM requiring therapy. GEP of purified tumor cells revealed that all molecular subtypes of CMM are also represented in the AMG phase. An increased risk score (>-0.26) (based on a 70-gene signature, GEP70) was an independent predictor of the risk of progression to CMM. Combination of elevated serum free light chain, M-spike, and GEP70 risk score identified a subset with high risk (67% at 2 years) of progression to CMM requiring therapy. Importantly, absence of these factors in AMM patients predicted low risk similar to MGUS. Detection of multiple (>1) focal lesions by MRI also conferred an increased risk of progression. These data demonstrate that signatures associated with high-risk CMM impact disease risk and support inclusion of genomic analysis in the clinical management of AMGs.

Improvement in long-term outcomes with successive Total Therapy trials for multiple myeloma: are patients now being cured?

The concept of applying all active therapeutic agents in Total Therapy (TT) clinical trials for newly diagnosed multiple myeloma was pursued with the intent of developing curative treatment. The results of TT1 (n=231), TT2 (n=668) without or with thalidomide and TT3 with added bortezomib (n=303) have been reported. An update with median follow-up times of 17.1, 8.7 and 5.5 years, respectively, is provided. Conditional overall survival (OS) analysis from a 4-year landmark was applied to account for earlier protocol failure owing to disease aggressiveness and toxicities. Cumulative relative survival was computed in the context of age- and gender-matched US population, and interval-specific relative survival ratios were estimated to determine times to normal survival expectation. Based on Cox model-adjusted statistics, OS, progression-free survival and complete-response duration all improved with the transitions from TT1 to TT2 to TT3; improvement was also evident from time-to-progression estimates, 4-year conditional survival data and cumulative relative survival. Interval-specific relative survival normalized progressively sooner, reaching near-normal levels with TT3 in patients who attained complete response. Thus, a strategy using all myeloma-effective agents up-front seems effective at preventing, in progressively larger patient cohorts over time, the outgrowth of resistant tumor cells that account for ongoing relapses.

Total Therapy 3 for multiple myeloma: prognostic implications of cumulative dosing and premature discontinuation of VTD maintenance components, bortezomib, thalidomide, and dexamethasone, relevant to all phases of therapy

The impact of cumulative dosing and premature drug discontinuation (PMDD) of bortezomib (V), thalidomide (T), and dexamethasone (D) on overall survival (OS), event-free survival (EFS), time to next therapy, and post-relapse survival in Total Therapy 3 were examined, using time-dependent methodology, relevant to induction, peritransplantation, consolidation, and maintenance phases. Univariately, OS and EFS were longer in case higher doses were used of all agents during induction, consolidation (except T), and maintenance (except V and T). The favorable OS and EFS impact of D induction dosing provided the rationale for examining the expression of glucocorticoid receptor NR3C1, top-tertile levels of which significantly prolonged OS and EFS and rendered outcomes independent of D and T dosing, whereas T and D, but not V, dosing was critical to outcome improvement in the bottom-tertile NR3C1 setting. PMDD of V was an independent highly adverse feature for OS (hazard ratio = 6.44; P < .001), whereas PMDD of both T and D independently imparted shorter time to next therapy. The absence of adverse effects on postrelapse survival of dosing of any VTD components and indeed a benefit from V supports the use up-front of all active agents in a dose-dense and dose-intense fashion, as practiced in Total Therapy 3, toward maximizing myeloma survival.

Prognostic implications of serial 18-fluoro-deoxyglucose emission tomography in multiple myeloma treated with total therapy 3

Prognostic implications of 3 imaging tools, metastatic bone survey, magnetic resonance imaging, and positron emission tomography (PET), were evaluated in 2 consecutive Total Therapy 3 trials for newly diagnosed myeloma. Data including PET at baseline and on day 7 of induction as well as standard prognostic factors were available in 302 patients of whom 277 also had gene expression profiling (GEP)-derived risk information. According to multivariate analysis, more than 3 focal lesions on day 7 imparted inferior overall survival and progression-free survival, overall and in the subset with GEP-risk data. GEP high-risk designation retained independent significance for all 3 end points examined. Thus, the presence of > 3 focal lesions on day 7 PET follow-up may be exploited toward early therapy change, especially for the 15% of patients with GEP-defined high-risk disease with a median overall survival expectation of 2 years. This trial was registered at www.clinicaltrials.gov as #NCT00081939 and # NCT00572169.

TP53 deletion is not an adverse feature in multiple myeloma treated with total therapy 3

Contrary to Total Therapy (TT) 2 for multiple myeloma patients, FGFR3− translocation bore no adverse effects on outcome in TT3 with added bortezomib. Del TP53, another poor‐risk feature in TT2 and present in 10% of 441 patients treated, was examined for its prognostic consequences in TT3. Not affecting rate or duration of complete response, TP53 haplo‐insufficiency also did not compromise, in the 83% with genomically defined low‐risk myeloma, survival or event‐free survival. FGFR3+ and FGFR3− molecular subgroups fared worse in the presence of del TP53 when applying TT2 but not TT3. Thus, the prognostic implications of del TP53 were protocol‐, genome‐defined risk‐ and molecular subgroup‐dependent.

Second malignancies in total therapy 2 and 3 for newly diagnosed multiple myeloma: influence of thalidomide and lenalidomide during maintenance

Thalidomide and lenalidomide constitute an important part of effective myeloma therapy. Recent data from the Intergroup Francophone du Myélome, Cancer and Leukemia Group B, and Gruppo Italiano Malattie Ematologiche dell Adulto MM-015 trials suggest that lenalidomide maintenance therapy is associated with a higher incidence of second primary malignancies (SPMs), including both hematologic and solid malignancies. In the present study, we analyzed data from the Total Therapy 2 (TT2) trial, along with the 2 Total Therapy 3 (TT3) trials. TT2 patients were assigned randomly to either a control group (no thalidomide) or to the experimental group (thalidomide during induction, between transplantations, and during consolidation and maintenance). The 2 TT3 trials used thalidomide and bortezomib during induction, before and in consolidation after tandem melphalan-based transplantation; TT3A applied VTD (bortezomib, thalidomide, dexamethasone) in the first year of maintenance and TD for 2 more years, whereas TT3B used VRD (bortezomib, lenalidomide, dexamethasone) maintenance for 3 years. The cumulative incidence of SPMs did not differ significantly among the TT trial components when measured from enrollment (P = .78) or from initiation of maintenance (P = .82). However, a pairwise comparison of the TT2 arms suggested a lower incidence of hematologic SPMs in the thalidomide maintenance arm (hazard ratio = 0.38; P = .09). These trials are registered at www.clinicaltrials.gov as NCT00573391 (TT2), NCT00081939 (TT3A), and NCT00572169 (TT3B).