Klaus Hollmig

Magnetic Resonance Imaging in Multiple Myeloma: Diagnostic and Clinical Implications

PURPOSE Magnetic resonance imaging (MRI) permits the detection of diffuse and focal bone marrow infiltration in the absence of osteopenia or focal osteolysis on standard metastatic bone surveys (MBSs). PATIENTS AND METHODS Both baseline MBS and MRI were available in 611 of 668 myeloma patients who were treated uniformly with a tandem autologous transplantation-based protocol and were evaluated to determine their respective merits for disease staging, response assessment, and outcome prediction. RESULTS MRI detected focal lesions (FLs) in 74% and MBS in 56% of imaged anatomic sites; 52% of 267 patients with normal MBS results and 20% of 160 with normal MRI results had FL on MRI and MBS, respectively. MRI- but not MBS-defined FL independently affected survival. Cytogenetic abnormalities (CAs) and more than seven FLs on MRI (MRI-FLs) distinguished three risk groups: 5-year survival was 76% in the absence of both more than seven MRI-FLs and CA (n = 276), 61% in the presence of one MRI-FL (n = 262), and 37% in the presence of both unfavorable parameters (n = 67). MRI-FL correlated with low albumin and elevated levels of C-reactive protein, lactate dehydrogenase, and creatinine, but did not correlate with age, beta-2-microglobulin, and CA. Resolution of MRI-FL, occurring in 60% of cases and not seen with MBS-defined FL, conferred superior survival. CONCLUSION MRI is a more powerful tool for detection of FLs than is MBS. MRI-FL number had independent prognostic implications; additionally, MRI-FL resolution identified a subgroup with superior survival. We therefore recommend that, in addition to MBS, MRI be used routinely for staging, prognosis, and response assessment in myeloma.

Incorporating bortezomib into upfront treatment for multiple myeloma: early results of total therapy 3.

Total therapy 3 incorporated bortezomib into a melphalan‐based tandem transplant regimen for 303 newly diagnosed patients with myeloma. Induction chemotherapy prior to and consolidation chemotherapy after transplants each consisted of two cycles of VTD‐PACE (bortezomib, thalidomide, dexamethasone and 4‐d continuous infusions of cis‐platin, doxorubicin, cyclophosphamide, etoposide); 3‐year maintenance comprised monthly cycles of VTD in the first and TD in the remaining years. The median age was 59 years (age >64 years, 28%). A minimum of 20 × 106 CD34 cells/kg was collected in 87% of patients; 83% completed both transplants, and only 5% suffered a treatment‐related death. At 24 months, 83% had achieved near‐complete remission, which was sustained in 88% at 2 years from its onset. With a median follow‐up of 20 months, 2‐year estimates of event‐free and overall survival were 84% and 86% respectively. The 44 patients who experienced an event more often had a high‐risk gene array profile, cytogenetic abnormalities and indicators of high lactate dehydrogenase, beta‐2‐microglobulin, creatinine and International Staging System stage. Toxicities of grade > 2 included thrombo‐embolic events in 27% and peripheral neuropathy in 12%. Results of this phase‐2 study demonstrated that bortezomib could be safely combined with multi‐agent chemotherapy, effecting near‐complete remission status and 2‐year survival rates in more than 80% of patients.

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.

Complete Remission Sustained 3 Years From Treatment Initiation Is a Powerful Surrogate for Extended Survival in Multiple Myeloma

Complete response (CR) has been considered a necessary although not sufficient early clinical endpoint for extended survival in multiple myeloma.

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.

Dialysis-dependent renal failure in patients with myeloma can be reversed by high-dose myeloablative therapy and autotransplant

Summary:To evaluate the role of high-dose melphalan and autologous transplant (AT) in reversing dialysis-dependent renal failure, 59 patients still on dialysis at the time of AT were analyzed. A total of 37 patients had been on dialysis ⩽6 months. A 5-year event-free and overall survival rate of all patients after AT was 24 and 36%, respectively. Of 54 patients evaluable for renal function improvement, 13 (24%) became dialysis independent at a median of 4 months after AT (range: 1–16). Dialysis duration ⩽6 months prior to first AT and pre-transplant creatinine clearance >10 ml/min were significant for renal function recovery: 12 of 36 (33%) ⩽6 months vs one of 18 patients (6%) >6 months on dialysis recovered renal function; 10 of 26 (38%) with >10 ml/min vs three of 28 (11%) with ⩽10 ml/min of creatinine clearance (both P<0.05). Quality of response after autotransplant was also significant: 12 of 31 (39%) being greater than partial remission after AT vs one of 21 patients (5%) attaining partial remission or less became independent of dialysis (P<0.05). Our data suggest that significant renal failure can be reversible and AT should be considered early in the disease course.

Benefit of complete response in multiple myeloma limited to high-risk subgroup identified by gene expression profiling.

Experimental Design: To determine whether the clinical benefit of complete remission (CR) may depend on prognostic subgroups of patients with multiple myeloma. Patients and Methods: Newly diagnosed patients with myeloma received a tandem autotransplant regimen. Using multivariate regression analyses, we examined the prognostic implications of time-dependent onset of CR on overall survival and event-free survival in the context of standard prognostic factors (SPF) and gene expression profiling–derived data available for 326 patients. Results: CR benefited patients regardless of risk status when only SPFs were examined. With knowledge of gene array data, a survival (and event-free survival) benefit of CR only pertained to the small high-risk subgroup of 13% of patients (hazard ratio, 0.23; P = 0.001), whereas the majority of patients with low-risk disease had similar survival expectations whether or not CR was achieved (hazard ratio, 0.68; P = 0.128). Conclusions: Access to gene expression information permitted the recognition of a small very high-risk subgroup of 13% of patients, in whom prolonged survival critically depended on achieving CR. Absence of such benefit in the remainder should lead to a reassessment of clinical trial designs that rely on this end point as a surrogate for long-term prognosis.

Seven-year median time to progression with thalidomide for smoldering myeloma: partial response identifies subset requiring earlier salvage therapy for symptomatic disease

Smoldering multiple myeloma (SMM) is usually followed expectantly without therapy. We conducted a phase 2 trial in 76 eligible patients with SMM, combining thalidomide (THAL, 200 mg/d) with monthly pamidronate. In the first 2 years, THAL dose reduction was required in 86% and drug was discontinued in 50%. Within 4 years, 63% improved, including 25% qualifying for partial response (PR); by then, 34 patients had progressed and 17 required salvage therapy. Unexpectedly, attaining PR status was associated with a shorter time to salvage therapy for disease progression (P < .001), perhaps reflecting greater drug sensitivity of more aggressive disease. Low beta-2-microglobulin levels less than 2 mg/L were independently associated with superior overall and event-free survival. Four-year survival and event-free survival estimates of 91% and 60%, respectively, together with a median postsalvage therapy survival of more than 5 years justify the conduct of a prospective randomized clinical trial to determine the clinical value of preemptive therapy in SMM. Trial registered at http://www.clinicaltrials.gov under identifier NCT00083382.

Complete response in myeloma extends survival without, but not with history of prior monoclonal gammopathy of undetermined significance or smouldering disease

Complete response (CR) is still considered an important surrogate marker for outcome in multiple myeloma (MM). Long‐term survival after transplantation, however, has been observed in a substantial proportion of patients who never achieved CR. The tandem transplant trial, Total Therapy 2, enrolled 668 patients, who were randomised up‐front to thalidomide (THAL) or no THAL; 56 patients were identified as having had, for at least 6 months prior to initiation of therapy, monoclonal gammopathy of undetermined significance (MGUS, n = 21), smouldering MM (SMM, n = 22) or solitary plasmacytoma of bone (SPC, n = 13). The clinical characteristics and outcomes of patients with such ‘evolved’ MM (E‐MM) and of those with ‘unknown’ prior history (U‐MM) were compared. Fewer patients with MGUS/SMM‐E‐MM had anaemia or renal failure; CR was lower (22% vs. 48%) but 4‐year estimates of event‐free survival (54% vs. 56% with U‐MM) and overall survival (65% vs. 70% with U‐MM) were similar to those with SPC‐E‐MM or U‐MM. In the latter group, achieving CR was associated with prolonged survival. In comparison with U‐MM, E‐MM evolved from MGUS/SMM was associated with lower CR rate without adversely affecting survival. In contrast, CR was an independent favourable feature for survival in U‐MM.

Testing standard and genetic parameters in 220 patients with multiple myeloma with complete data sets: superiority of molecular genetics

Prognostic models for multiple myeloma have been fraught with tremendous heterogeneity in outcome among subgroups. In the context of Total Therapy 2, a tandem transplant trial for newly diagnosed myeloma, comprehensive information was available in 220 patients on standard prognostic factors (SPF), magnetic resonance imaging (MRI)‐defined focal lesions, cytogenetic abnormalities (CA), fluorescence‐in‐situ‐hybridisation (FISH)‐derived amplification of chromosome 1q21 (amp1q21) and deletion of 13q14, as well as gene expression profiling (GEP). Five multivariate analysis‐based survival models were derived, utilising SPF only (model 1), with progressive addition of CA (model 2), MRI (model 3), FISH (model 4) and GEP (model 5). The R2 value, a measure of accounting for clinical outcome variability, increased progressively from 18% in model 1 to 38% in model 5. The hazard ratio for overall survival was highest for GEP (3·07, P < 0·001) followed by amp1q21 (1·71, P = 0·05). According to the presence of none (49%), one (35%) or both of these two risk features (16%), 3‐year survival decreased progressively from 92% to 78% to 43% (P < 0·0001). Thus, the dominance over other prognostic parameters of molecular genetics justifies the generation of quantitative reverse transcription polymerase chain reaction methodology (‘MM genetic kit’) for the optimal risk stratification of patients participating in therapeutic trials.