Clinical characteristics and outcomes of IgD myeloma: experience across UK national trials.

Immunoglobulin D (IgD) myeloma is a subtype often considered to have adverse features and inferior survival, but there is a paucity of data from large clinical studies. We compare the clinical characteristics and outcomes of patients with IgD myeloma from UK phase 3 myeloma trials analyzed in 2 groups: old (1980-2002) and recent (2002-2016) clinical trials, based on the time of adoption of novel myeloma therapies. Patients with IgD myeloma comprised 44 of 2789 (1.6%) and 70 of 5773 (1.2%) of the old and recent trials, respectively. Overall, IgD myeloma was associated with male predominance, low-level paraproteinemia (<10g/L), and λ light chain preference. The frequency of ultra-high-risk cytogenetics was similar in IgD myeloma compared with other subtypes (4.3% vs 5.3%, P > .99). Despite the old trial series being a younger group (median age: 59 vs 63 years, P = .015), there was a higher frequency of bone lesions, advanced stage at diagnosis, worse performance status, and severe renal impairment compared with the recent trials. Furthermore, the early mortality rate was significantly higher for the old trial series (20% vs 4%, P = .01). The overall response rate following induction therapy was significantly higher in the recent trials (89% vs 43%, P < .0001), and this was consistent with improved median overall survival (48 months; 95% confidence interval [CI] 35-67 months vs 22 months; 95% CI, 16-29 months). Survival outcomes for IgD myeloma have significantly improved and are now comparable to other myeloma types because of earlier diagnosis, novel therapies, and improved supportive care. This trial was registered at clinicaltrials.gov as # NCT01554852.

Thrombosis in patients with myeloma treated in the Myeloma IX and Myeloma XI phase 3 randomized controlled trials.

Newly diagnosed multiple myeloma (NDMM) patients treated with immunomodulatory drugs are at high risk of venous thromboembolism (VTE), but data are lacking from large prospective cohorts. We present thrombosis outcome data from Myeloma IX (n = 1936) and Myeloma XI (n = 4358) phase 3 randomized controlled trials for NDMM that treated transplant-eligible and transplant-ineligible patients before and after publication of thrombosis prevention guidelines. In Myeloma IX, transplant-eligible patients randomly assigned to cyclophosphamide, vincristine, doxorubicin, and dexamethasone (CVAD) induction had higher risk of VTE compared with patients treated with cyclophosphamide, thalidomide, and dexamethasone (CTD) (22.5% [n = 121 of 538] vs 16.1% [n = 89 of 554]; adjusted hazard ratio [aHR],1.46; 95% confidence interval [95% CI], 1.11-1.93). For transplant-ineligible patients, those randomly assigned to attenuated CTD (CTDa) induction had a higher risk of VTE compared with those treated with melphalan and prednisolone (MP) (16.0% [n = 68 of 425] vs 4.1% [n = 17 of 419]; aHR, 4.25; 95% CI, 2.50-7.20). In Myeloma XI, there was no difference in risk of VTE (12.2% [n = 124 of 1014] vs 13.2% [n = 133 of 1008]; aHR, 0.92; 95% CI, 0.72-1.18) or arterial thrombosis (1.2% [n = 12 of 1014] vs 1.5% [n = 15 of 1008]; aHR, 0.80; 95% CI, 0.37-1.70) between transplant-eligible pathways for patients treated with cyclophosphamide, lenalidomide, and dexamethasone (CRD) or CTD. For transplant-ineligible patients, there was no difference in VTEs between attenuated CRD (CRDa) and CTDa (10.4% [n = 95 of 916] vs 10.7% [n = 97 of 910]; aHR, 0.97; 95% CI, 0.73-1.29). However, arterial risk was higher with CRDa than with CTDa (3.1% [n = 28 of 916] vs 1.6% [n = 15 of 910]; aHR, 1.91; 95% CI, 1.02-3.57). Thrombotic events occurred almost entirely within 6 months of treatment initiation. Thrombosis was not associated with inferior progression-free survival (PFS) or overall survival (OS), apart from inferior OS for patients with arterial events (aHR, 1.53; 95% CI, 1.12-2.08) in Myeloma XI. The Myeloma XI trial protocol incorporated International Myeloma Working Group (IMWG) thrombosis prevention recommendations and compared with Myeloma IX, more patients received thromboprophylaxis (80.5% vs 22.3%) with lower rates of VTE for identical regimens (CTD, 13.2% vs 16.1%; CTDa, 10.7% vs 16.0%). However, thrombosis remained frequent in spite of IMWG-guided thromboprophylaxis, suggesting that new approaches are needed.

A clinical prediction model for outcome and therapy delivery in transplant-ineligible patients with myeloma (UK Myeloma Research Alliance Risk Profile): a development and validation study.

BACKGROUND: Tolerability of treatments for multiple myeloma can depend on the characteristics of the patient being treated. We aimed to develop and validate a risk profile, using routinely collected data, that could predict overall survival in patients with multiple myeloma who were ineligible for stem-cell transplantation. METHODS: We used patient data from two randomised controlled trials done in patients with newly diagnosed multiple myeloma who were ineligible for stem-cell transplantation (the NCRI Myeloma XI study [NCRI-XI, n=1852] and the MRC Myeloma IX study [MRC-IX, n=520]), to develop the UK Myeloma Research Alliance Risk Profile (MRP) for overall survival. We used multivariable Cox regression with a least absolute shrinkage and selection operator penalty term. Multiple imputation by chained equations was used to account for missing data in the development and internal validation of the model. The MRP was internally validated in NCRI-XI and externally validated in MRC-IX. The D-statistic was estimated in the developed model and used to internally and externally validate the model according to prespecified criteria. FINDINGS: The MRP included WHO performance status, International Staging System, age, and C-reactive protein concentration as prognostic variables. The MRP was prognostic of overall survival and was successfully internally validated in NCRI-XI and externally validated in MRC-IX (D-statistic NCRI-XI: 0·840 [95% CI 0·718-0·963] and MRC-IX: 0·654 [0·497-0·811]). The MRP groups defining low-risk, medium-risk, and high-risk patients were associated with progression-free survival and early mortality. A decrease in the percentage of protocol dose delivered and quality of life at baseline were associated with increased risk. The MRP groups remained prognostic in patients exposed to different therapeutic combinations and in patients with genetic high-risk disease defined according to both the UK and International Myeloma Working Group definitions. INTERPRETATION: We have developed and externally validated a risk profile for overall survival containing widely available clinical parameters. This risk profile could aid decision making in patients with multiple myeloma ineligible for stem-cell transplantation, but further external validation is required. FUNDING: Medical Research Council, Novartis, Schering Health Care, Chugai, Pharmion, Celgene, Ortho Biotech, Cancer Research UK, Celgene, Merck Sharp & Dohme, and Amgen.

Quality of life during and following sequential treatment of previously untreated patients with multiple myeloma: findings of the Medical Research Council Myeloma IX randomised study.

In the Medical Research Council (MRC) Myeloma IX trial (ISRCTN684564111) patients were randomised to sodium clodronate or zoledronic acid and induction treatment: cyclophosphamide, vincristine, doxorubicin and dexamethasone (CVAD) or cyclophosphamide, thalidomide and dexamethasone (CTD) followed by autologous stem cell transplant (ASCT) in the intensive pathway; attenuated CTD or melphalan and prednisolone (MP) in the non-intensive pathway. Subsequent randomisation allocated patients to either thalidomide or observation. The European Organisation for Research and Treatment of Cancer (EORTC) quality of life (QoL) questionnaires, QLQ-C30 and QLQ-MY24, were administered at baseline, 3, 6 and 12 months and annually thereafter, enabling the effect of sequential treatment on patient-reported health-related QoL (HR-QoL) to be investigated. The protocol specified four subscales of interest: Pain, Fatigue, Global Health Status/Quality of Life and Physical Functioning at 3, 6 and 12 months that were compared using linear models. The intensive pathway showed significant differences in favour of CTD for Fatigue at 3 months and Physical Functioning at 12 months. The non-intensive pathway and maintenance phase reported significant differences at 3 months; Pain (improved with attenuated CTD) and Global Health status/Quality of Life (improved with observation). The improved outcomes in MRC Myeloma IX were accompanied by some beneficial and few detrimental effects on HR-QoL.

Serum free light chain levels and renal function at diagnosis in patients with multiple myeloma.

BACKGROUND: Renal impairment (RI) is common in multiple myeloma (MM) and is associated with poor survival. This study reports the associations between renal function and disease characteristics including serum free light chain (FLC) level at diagnosis in patients with MM. METHODS: Using data from the Medical Research Council Myeloma IX trial, a multicentre, randomized, open-label, phase III and factorial-design trial, we assessed the relationships between renal function, demographic, and disease characteristics, including serum FLC levels, in 1595 newly diagnosed MM patients. Multivariable linear regression was utilised to identify factors that were associated with renal function at diagnosis. A receiver operating characteristic curve (ROC) was used to identify the optimal threshold for serum FLC level at diagnosis to predict severe RI. RESULTS: 52.8% of patients had an estimated glomerular filtration rate (eGFR) ≥60 ml/min/1.73 m2 (no RI), 37.3% an eGFR 30-59 ml/min/1.73 m2 (mild to moderate RI), and 9.8% an eGFR < 30 ml/min/1.73 m2 (severe RI). In a multivariable analysis, factors independently and negatively associated with eGFR at diagnosis were: higher serum FLC level, female gender, and older age. Elevated serum FLC level at diagnosis, irrespective of the paraprotein type, was strongly associated with severe RI. Receiver operating characteristic curve analysis showed a serum FLC level of > 800 mg/L as the optimal cut-off associated with severe RI (area under curve 0.86, 95% confidence interval 0.77-0.84). CONCLUSION: There was a strong relationship between higher serum FLC levels at diagnosis and the severity of RI that was irrespective of the paraprotein type. We report an increased risk of severe RI in patients presenting with serum FLC levels above 800 mg/L at diagnosis.

Characterisation of immunoparesis in newly diagnosed myeloma and its impact on progression-free and overall survival in both old and recent myeloma trials.

We measured immunosuppression at myeloma diagnosis and assessed the impact on survival in 5826 UK myeloma trial patients. Polyclonal immunoglobulin levels were below normal in 85% of patients and above normal in only 0.4% of cases for IgA, 0.2% for IgM and no cases for IgG. Immunoparesis had a greater impact in recent trials: median overall survival (OS) was up to 3 years longer for patients without immunoparesis compared to the old trials, less than 1 year longer. Median progression-free survival (PFS) was 39%, 36% and 57% longer for patients with normal IgG, IgA and IgM levels, respectively. The depth of IgM suppression, but not the depth of IgG or IgA suppression, was prognostic for survival: the most severely suppressed IgM tertile of patients OS was 0.9 years shorter than those in the top tertile, and 2.6 years shorter than OS of those with normal IgM levels (p = .007). The degree of suppression of polyclonal IgM levels below normal was associated with worse PFS (p = .0002). Infection does not appear to be the main mechanism through which immunoparesis affects survival. We hypothesise that IgM immunoparesis impacts through a combination of being associated with more aggressive disease and reduced immune surveillance against relapse.

Response comparison of multiple myeloma and monoclonal gammopathy of undetermined significance to the same anti-myeloma therapy: a retrospective cohort study.

BACKGROUND: Multiple myeloma is consistently preceded by monoclonal gammopathy of undetermined significance (MGUS), which is usually only treated by a form of anti-multiple myeloma therapy if it is causing substantial disease through deposition of secreted M proteins. However, studies comparing how MGUS and multiple myeloma plasma cell clones respond to these therapies are scarce. Biclonal gammopathy multiple myeloma is characterised by the coexistence of an active multiple myeloma clone and a benign MGUS clone, and thus provides a unique model to assess the responses of separate clones to the same anti-multiple myeloma therapy, in the same patient, at the same time. We aimed to identify how MGUS and multiple myeloma plasma cell clones responded to anti-multiple myeloma therapy in patients newly diagnosed with biclonal gammopathy multiple myeloma. METHODS: In this retrospective cohort study, we identified patients with biclonal gammopathy multiple myeloma by central laboratory analysis of 6399 newly diagnosed patients with multiple myeloma enrolled in three UK clinical trials (Myeloma IX, Myeloma XI, and TEAMM) between July 7, 2004, and June 2, 2015. In addition to the inclusion criteria of these trials, our study necessitated at trial entry the presence of two distinct M proteins in immunofixation electrophoresis. The primary endpoint was difference in response achieved with anti-multiple myeloma therapy on MGUS (which we defined as M2) and multiple myeloma (M1) clones-overall, within patients, and between therapy types-with international therapy response criteria assessed with χ2 analyses. We analysed by intention to treat. FINDINGS: 44 patients with biclonal gammopathy multiple myeloma with IgG or IgA MGUS clones were subsequently identified from the three trials and then longitudinally monitored. 41 (93%) of M1 clones had a response to therapy (either complete response, very good partial response, partial response, or minor response) compared with only 28 (64%) of M2 clones (p=0·0010). For the 20 patients who received intensive therapy, there was no difference between the proportion of responding clones in M1 (19 [95%]) and M2 (15 [75%], p=0·13). However, for the 17 patients who received non-intensive therapy, 16 (94%) of M1 clones had a response compared with ten [59%] of M2 clones (p=0·031). When examining clones within the same patient, 30 (68%) of 44 individual patients had different levels of responses within the M1 and M2 clones. One patient exhibited M2 progression to myeloma and subsequently died. INTERPRETATION: These results show that, in patients with biclonal gammopathy multiple myeloma, anti-multiple myeloma therapies exert a greater depth of response against multiple myeloma plasma cell clones than MGUS plasma cell clones. Although some MGUS clones exhibited a complete response, many did not respond, which suggests that the underlying features that render multiple myeloma plasma cells susceptible to therapy are present in only some MGUS plasma cell clones. To determine MGUS clone susceptibly to therapy, future studies might seek to identify, with biclonal gammopathy multiple myeloma as an investigative model, the genetic and epigenetic alterations that affect whether MGUS plasma cell clones are responsive to anti-multiple myeloma therapy. FUNDING: National Institute of Health Research, Medical Research Council, and Cancer Research UK.

Active multiple myeloma suppresses and typically eliminates coexisting MGUS.

BACKGROUND: Myeloma is consistently preceded by premalignant monoclonal gammopathy of undetermined significance (MGUS). In >5% of MGUS patients there is a second MGUS clone (biclonal gammopathy of undetermined significance; BGUS), yet, at myeloma diagnosis, presentation of biclonal gammopathy myeloma (BGMy) is considered less frequent, implying that myeloma eradicates coexisting MGUS. METHODS: In the largest study of its kind, we assessed BGMy frequency amongst 6399 newly diagnosed myeloma patients enrolled in recent UK clinical trials. RESULTS: Compared to expected prevalence (i.e., >5% of MGUS have BGUS), only 58 of 6399 (0.91%) newly diagnosed myeloma patients had BGMy, indicating myeloma typically eliminates coexistent MGUS. In these 58 BGMy cases, the MGUS plasma cell clone was greatly suppressed in size compared to typical levels observed in conventional MGUS; contrarily, the MGUS clone did not inhibit the myeloma plasma cell clone in BGMy. CONCLUSION: Myeloma eliminates the majority of competing MGUS, and when it does not, the MGUS clone is substantially reduced in size.

Diagnosis and monitoring for light chain only and oligosecretory myeloma using serum free light chain tests.

This study aims to guide the integration of serum free light chain (sFLC) tests into clinical practice, including a new rapid test (Seralite® ). Blood and urine analysis from 5573 newly diagnosed myeloma patients identified 576 light chain only (LCO) and 60 non-secretory (NS) cases. Serum was tested by Freelite® and Seralite® at diagnosis, maximum response and relapse. 20% of LCO patients had urine FLC levels below that recommended for measuring response but >97% of these had adequate sFLC levels (oligosecretory). The recommended Freelite® sFLC ≥100 mg/l for measuring response was confirmed and the equivalent Seralite® FLC difference (dFLC) >20 mg/l identified. By both methods, ≥38% of NS patients had measurable disease (oligosecretory). Higher sFLC levels were observed on Freelite® at all time points. However, good clinical concordance was observed at diagnosis and in response to therapy. Achieving at least a very good partial response according to either sFLC method was associated with better patient survival. Relapse was identified using a Freelite® sFLC increase >200 mg/l and found 100% concordance with a corresponding Seralite® dFLC increase >30 mg/l. Both Freelite® and Seralite® sensitively diagnose and monitor LCO/oligosecretory myeloma. Rapid testing by Seralite® could fast-track FLC screening and monitoring. Response by sFLC assessment was prognostic for survival and demonstrates the clinical value of routine sFLC testing.

Association of Minimal Residual Disease With Superior Survival Outcomes in Patients With Multiple Myeloma: A Meta-analysis.

IMPORTANCE: Numerous studies have evaluated the prognostic value of minimal residual disease (MRD) in patients with multiple myeloma (MM). Most studies were small and varied in terms of patient population, treatment, and MRD assessment methods. OBJECTIVE: To evaluate the utility of MRD detection in patients with newly diagnosed MM. DATA SOURCES: A Medline search was conducted for articles published in English between January 1990 and January 2016. STUDY SELECTION: Eligible studies reported MRD status and progression-free survival (PFS) or overall survival (OS) in 20 or more patients following treatment. Among 405 articles identified, 21 met the initial eligibility criteria and were included in the analysis. DATA EXTRACTION AND SYNTHESIS: Information on patient characteristics, treatment, MRD assessment, and outcomes were extracted using a standard form. MAIN OUTCOMES AND MEASURES: The impact of MRD status on PFS and OS was assessed by pooling data from relevant trials. Data were adjusted to allow for different proportions of patients with MRD in different studies, and analyzed using the Peto method. Forest plots were created based on Cox model analysis. Other prespecified research questions were addressed qualitatively. RESULTS: Fourteen studies (n = 1273) provided data on the impact of MRD on PFS, and 12 studies (n = 1100) on OS. Results were reported specifically in patients who had achieved conventional complete response (CR) in 5 studies for PFS (n = 574) and 6 studies for OS (n = 616). An MRD-negative status was associated with significantly better PFS overall (hazard ratio [HR], 0.41; 95% CI, 0.36-0.48; P < .001) and in studies specifically looking at CR patients (HR, 0.44; 95% CI, 0.34-0.56; P < .001). Overall survival was also favorable in MRD-negative patients overall (HR, 0.57; 95% CI, 0.46-0.71; P < .001) and in CR patients (HR, 0.47; 95% CI, 0.33-0.67; P < .001). Tests of heterogeneity found no significant differences among the studies for PFS and OS. CONCLUSIONS AND RELEVANCE: Minimal residual disease-negative status after treatment for newly diagnosed MM is associated with long-term survival. These findings provide quantitative evidence to support the integration of MRD assessment as an end point in clinical trials of MM.

Minimal residual disease in myeloma by flow cytometry: independent prediction of survival benefit per log reduction.

The detection of minimal residual disease (MRD) in myeloma using a 0.01% threshold (10(-4)) after treatment is an independent predictor of progression-free survival (PFS), but not always of overall survival (OS). However, MRD level is a continuous variable, and the predictive value of the depth of tumor depletion was evaluated in 397 patients treated intensively in the Medical Research Council Myeloma IX study. There was a significant improvement in OS for each log depletion in MRD level (median OS was 1 year for ≥10%, 4 years for 1% to <10%, 5.9 years for 0.1% to <1%, 6.8 years for 0.01% to <0.1%, and more than 7.5 years for <0.01% MRD). MRD level as a continuous variable determined by flow cytometry independently predicts both PFS and OS, with approximately 1 year median OS benefit per log depletion. The trial was registered at www.isrctn.com as #68454111.

Serum free immunoglobulin light chain evaluation as a marker of impact from intraclonal heterogeneity on myeloma outcome.

Intraclonal heterogeneity was recently described in multiple myeloma (MM), but its full impact on disease progression and relapse has not been entirely explored. The immunoglobulin type produced by myeloma cells provides an excellent marker to follow changes in clonal substructure over time. We have prospectively evaluated serial paraprotein and serum free light chain (FLC) measurements and found that 258 of 520 and 54 of 520 patients who presented with a whole paraprotein relapsed with paraprotein only (PO) and "FLC escape," respectively. The median overall survival of PO patients was longer, when compared with patients whose relapse manifested as an increase in FLC both alone and with a whole paraprotein, as a result of a significantly shorter survival from relapse of the latter groups. These observations fit a model in which 1 clone is able to produce a complete antibody, whereas the other secretes only FLC; the type of relapse represents the outgrowth of different clones, some of which are more resistant to therapy. To our knowledge, this is the largest series describing patients who have relapsed with FLC escape and highlights the importance of monitoring FLC when there is a suspicion of clinical relapse. This study was registered at www.isrctn.org as ISRCTN68454111.

Osteonecrosis of the jaw and renal safety in patients with newly diagnosed multiple myeloma: Medical Research Council Myeloma IX Study results.

Bisphosphonates are recommended in patients with osteolytic lesions secondary to multiple myeloma. We report on the safety of bisphosphonate therapy with long-term follow-up in the Medical Research Council Myeloma IX study. Patients with newly diagnosed multiple myeloma were randomised to zoledronic acid (ZOL; 4 mg intravenously every 21-28 d) or clodronate (CLO; 1600 mg/d orally) plus chemotherapy. Among 1960 patients (5.9-year median follow-up), both bisphosphonates were well tolerated. Acute renal failure events were similar between groups (ZOL 5.2% vs. CLO 5.8% at 2 years; incidence plateaued thereafter). The overall incidence of confirmed osteonecrosis of the jaw (ONJ) was low, but higher with ZOL (ZOL 3.7% vs. CLO 0.5%; P < 0.0001). ONJ events were generally low grade and most occurred between 8 and 30 months (median time to ONJ, 23.7 months). Among 10 patients with ONJ recovery data, four patients in the ZOL group completely recovered, two patients improved, and three patients experienced no improvement; one CLO patient experienced no improvement. Dental surgery or trauma preceded ONJ in six ZOL patients. The incidence of renal adverse events was similar for ZOL and CLO. ONJ incidence remained low and was lower with CLO compared to ZOL. We have seen no further ONJ cases to date.

Long-term follow-up of MRC Myeloma IX trial: Survival outcomes with bisphosphonate and thalidomide treatment.

PURPOSE: Medical Research Council (MRC) Myeloma IX was a phase III trial evaluating bisphosphonate and thalidomide-based therapy for newly diagnosed multiple myeloma. Results were reported previously after a median follow-up of 3.7 years (current controlled trials number: ISRCTN68454111). Survival outcomes were reanalyzed after an extended follow-up (median, 5.9 years). EXPERIMENTAL DESIGN: At first randomization, patients (N = 1,970) were assigned to bisphosphonate (clodronic acid or zoledronic acid) and induction therapies [cyclophosphamide-vincristine-doxorubicin-dexamethasone (CVAD) or cyclophosphamide-thalidomide-dexamethasone (CTD) followed by high-dose therapy plus autologous stem cell transplantation for younger/fitter patients (intensive pathway), and melphalan-prednisone (MP) or attenuated CTD (CTDa) for older/less fit patients (nonintensive pathway)]. At second randomization, patients were assigned to thalidomide maintenance therapy or no maintenance. Interphase FISH (iFISH) was used to analyze cytogenics. RESULTS: Zoledronic acid significantly improved progression-free survival (PFS; HR, 0.89; P = 0.02) and overall survival (OS; HR, 0.86; P = 0.01) compared with clodronic acid. In the intensive pathway, CTD showed noninferior PFS and OS compared with CVAD, with a trend toward improved OS in patients with favorable cytogenics (P = 0.068). In the nonintensive pathway, CTDa significantly improved PFS (HR, 0.81; P = 0.007) compared with MP and there was an emergent survival benefit after 18 to 24 months. Thalidomide maintenance improved PFS (HR, 1.44; P < 0.0001) but not OS (HR, 0.96; P = 0.70), and was associated with shorter OS in patients with adverse cytogenics (P = 0.01). CONCLUSIONS: Long-term follow-up is essential to identify clinically meaningful treatment effects in myeloma subgroups based on cytogenetics.

The impact of response on bone-directed therapy in patients with multiple myeloma.

Significant benefits for zoledronic acid (ZOL) over clodronate acid (CLO) were seen in the Medical Research Council Myeloma IX randomized trial. ZOL significantly reduced skeletal-related events (SREs), and improved progression-free survival and overall survival (OS), making it the bisphosphonate of choice for newly diagnosed myeloma patients. In this analysis of Myeloma IX data, we have investigated the impact of response on bone disease in 1111 transplant-eligible patients. At posttransplant day 100, complete response (CR) was seen in 48% of patients, very good partial response (VGPR) in 20%, and partial response (PR) in 23%. For patients in VGPR or less, ZOL was superior to CLO in reducing SREs (P = .048), whereas for patients in CR, both agents were equivalent (P = .83). For OS, ZOL was associated with a significant benefit in patients in PR (P = .0091). No difference in OS was seen with patients in CR (P = .91) or VGPR (P = .74). These findings indicate that response category posttransplant may influence the impact of bisphosphonate therapy.

Minimal residual disease assessed by multiparameter flow cytometry in multiple myeloma: impact on outcome in the Medical Research Council Myeloma IX Study.

PURPOSE: To investigate the prognostic value of minimal residual disease (MRD) assessment in patients with multiple myeloma treated in the MRC (Medical Research Council) Myeloma IX trial. PATIENTS AND METHODS: Multiparameter flow cytometry (MFC) was used to assess MRD after induction therapy (n = 378) and at day 100 after autologous stem-cell transplantation (ASCT; n = 397) in intensive-pathway patients and at the end of induction therapy in non-intensive-pathway patients (n = 245). RESULTS: In intensive-pathway patients, absence of MRD at day 100 after ASCT was highly predictive of a favorable outcome (PFS, P < .001; OS, P = .0183). This outcome advantage was demonstrable in patients with favorable and adverse cytogenetics (PFS, P = .014 and P < .001, respectively) and in patients achieving immunofixation-negative complete response (CR; PFS, P = .0068). The effect of maintenance thalidomide was assessed, with the shortest PFS demonstrable in those MRD-positive patients who did not receive maintenance and longest in those who were MRD negative and did receive thalidomide (P < .001). Further analysis demonstrated that 28% of MRD-positive patients who received maintenance thalidomide became MRD negative. MRD assessment after induction therapy in the non-intensive-pathway patients did not seem to be predictive of outcome (PFS, P = .1). CONCLUSION: MRD assessment by MFC was predictive of overall outcome in patients with myeloma undergoing ASCT. This predictive value was seen in patients achieving conventional CR as well as patients with favorable and adverse cytogenetics. The effects of maintenance strategies can also be evaluated, and our data suggest that maintenance thalidomide can eradicate MRD in some patients.

Effects of induction and maintenance plus long-term bisphosphonates on bone disease in patients with multiple myeloma: the Medical Research Council Myeloma IX Trial.

The Medical Research Council Myeloma IX Trial (ISRCTNG8454111) examined traditional and thalidomide-based induction and maintenance regimens and IV zoledronic acid (ZOL) and oral clodronate (CLO) in 1960 patients with newly diagnosed multiple myeloma. Overall survival (OS) and skeletal-related event (SRE) data have been reported for the overall trial population. The present analysis investigated optimal therapy regimens for different patient populations in Myeloma IX. Patients were assigned to intensive or nonintensive treatment pathways and randomized to induction cyclophosphamide, vincristine, doxorubicin, and dexamethasone (CVAD) versus cyclophosphamide, thalidomide, and dexamethasone (CTD; intensive) or melphalan and prednisolone versus attenuated oral CTD (CTDa; nonintensive). Patients were also randomized to ZOL or CLO. In the nonintensive pathway, CTDa produced better responses and lower SRE rates than melphalan and prednisolone. ZOL improved OS compared with CLO independently of sex, stage, or myeloma subtype, most profoundly in patients with baseline bone disease or other SREs. In patients treated for ≥ 2 years, ZOL improved OS compared with CLO from randomization (median not reached for either; P = .02) and also from first on-study disease progression (median, 34 months for ZOL vs 27 months for CLO; P = .03). Thalidomide-containing regimens had better efficacy than traditional regimens, and ZOL demonstrated greater benefits than CLO.