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In this paper we extend the use of a relational approach to simulation modelling, a widely used knowledge practice in sustainability science. Among modellers, there is awareness that model results can only be interpreted in view of the assumptions that inform model construction and analysis, but less systematic questioning of those assumptions. Moreover, current methodological discussions tend to focus on integrating social and ecological dynamics or diverse knowledges and data within a model. Yet choices regarding types of modelling, model structure, data handling, interpretation of results and model validation are not purely epistemic. They are entangled with values, contexts of production and use, power relations, and pragmatic considerations. Situated Modelling extends a relational understanding of the world to scientific knowledge production and with that to modelling itself in order to enable a systematic interrogation of these choices and to research social-ecological transformations relationally. To make tangible the situatedness of simulation modelling, we build on existing practices and describe the situatedness of three distinct modelling approaches. We then suggest four guiding principles for Situated Modelling: 1. attending to the apparatus of knowledge production that is socially and materially embedded and produced by e.g. research infrastructures, power relations, and ways of thinking; 2. considering how agency is distributed between model, world, data, modeller in model construction; 3. creating heterogenous collectives which together occupy the formerly individualised subject position; and 4. using agonism as an epistemic virtue to retain and work with significant differentiations of social-ecological dynamics throughout the modelling process.

Understanding complex (social) phenomena benefits from combining different tools, perspectives, expertise, and experiences. Research designs that combine approaches are gaining in popularity. Carrying out research in interdisciplinary teams, however, is a challenging, high-investment activity. Unawareness of and reflecting on conflicting ways of seeing or studying the world may endanger project success. Agent-based modelling has proven instrumental in bringing together different approaches. Yet, this potential enabler remains an unusual combination partner: the additional prevalent lack of transparency about what is combined, and how, obstructs advancement. We therefore invite our readers behind the scenes of our multi-year research collaboration where we combine agent-based modelling with controlled behavioural experiments to advance the understanding of collective resource use in a common pool resource dilemma. The paper contributes by (1) being an example in sharing the processes of combining approaches, and by (2) highlighting the enabling role of ABM in combining research approaches.

The sustainable governance and management of small-scale fisheries (SSF) is challenging, largely due to their dynamic and complex nature. Agent-based modeling (ABM) is a computational modeling approach that can account for the dynamism and complexity in SSF by modeling entities as individual agents with different characteristics and behavior, and simulate how their interactions can give rise to emergent phenomena, such as over-fishing and social inequalities. The structurally realistic design of agent-based models allow stakeholders, experts, and scientists across disciplines and sectors to reconcile different knowledge bases, assumptions, and goals. ABMs can also be designed using any combination of theory, quantitative data, or qualitative data. In this publication we elaborate on the untapped potential of ABM to tackle governance and management challenges in SSF, discuss the limitations of ABM, and review its application in published SSF models. Our review shows that, although few models exist to date, ABM has been used for diverse purposes, including as a research tool for understanding cooperation and over-harvesting, and as a decision-support tool, or participatory tool, in case-specific fisheries. Even though the development of ABMs is often time- and resource intensive, it is the only dynamic modeling approach that can represent entities of different types, their heterogeneity, actions, and interactions, thus doing justice to the complex and dynamic nature of SSF which, if ignored can lead to unintended policy outcomes and less sustainable SSF.

Hematologic responses to hypomethylating agents are often delayed in patients with myelodysplastic syndrome or acute myeloid leukemia. Fetal hemoglobin is a potential novel bio-marker of response: recently, we demonstrated that a high fetal hemoglobin level prior to decitabine treatment was associated with superior outcome. Here we investigated whether early fetal hemoglobin induction during decitabine treatment also had prognostic value, and studied the potential of decitabine to induce erythroid differentiation and fetal hemoglobin expression in vitro. Fetal hemoglobin levels were measured by high-performance liquid chromatography in patients with higher-risk myelodysplastic syndrome (n=16) and acute myeloid leukemia (n=37) before treatment and after each course of decitabine. Levels above 1.0% were considered induced. Patients achieving complete or partial remission as best response had attained a median fetal hemoglobin of 1.9% after two courses of treatment, whereas the median value in patients who did not reach complete or partial remission was 0.8% (P=0.015). Fetal hemoglobin induction after two courses of decitabine treatment was associated with early platelet doubling (P=0.006), and its subsequent decrease with hematologic relapse. In patients with myelodysplastic syndrome, induction of fetal hemoglobin after course 2 of treatment was associated with longer overall survival: median of 22.9 versus 7.3 months in patients with or without induction of fetal hemoglobin, respectively [hazard ratio=0.2 (95% confidence interval: 0.1–0.9); P=0.03]. In vitro decitabine treatment of two bi-potential myeloid leukemia cell lines (K562 and HEL) resulted in induction of an erythroid (not megakaryocytic) differentiation program, and of fetal hemoglobin mRNA and protein, associated with GATA1 gene demethylation and upregulation. In conclusion, fetal hemoglobin may provide a useful dynamic biomarker during hypomethylating agent therapy in patients with myelodysplastic syndrome or acute myeloid leukemia.

Epigenetic changes play an important role in the development of acute myeloid leukemia (AML). Unlike gene mutations, epigenetic changes are potentially reversible, which makes them attractive for therapeutic intervention. Agents that affect epigenetics are the DNA methyltransferase inhibitors, azacitidine and decitabine. Because of their relatively mild side effects, azacitidine and decitabine are particularly feasible for the treatment of older patients and patients with co-morbidities. Both drugs have remarkable activity against AML blasts with unfavorable cytogenetic characteristics. Recent phase 3 trials have shown the superiority of azacitidine and decitabine compared with conventional care for older AML patients (not eligible for intensive treatment). Results of treatment with modifications of the standard azacitidine (seven days 75 mg/m2 SC; every four weeks) and decitabine (five days 20 mg/m2 IV; every four weeks) schedules have been reported. Particularly, the results of the 10-day decitabine schedule are promising, revealing complete remission (CR) rates around 45% (CR + CRi (i.e., CR with incomplete blood count recovery) around 64%) almost comparable with intensive chemotherapy. Application of hypomethylating agents to control AML at the cost of minimal toxicity is a very promising strategy to “bridge” older patients with co-morbidities to the potential curative treatment of allogeneic hematopoietic cell transplantation. In this article, we discuss the role of DNA methyltransferase inhibitors in AML.

This is an editorial to the special section on “Social Identity Modelling”, published in Volume 26, Issues 2 and 3, 2023 of the Journal of Artificial Societies and Social Simulation. It provides information on how the Social Identity Approach (SIA) and the research using its theoretical framework explains collective behaviour, tailored specifically for modellers. The discussion centres around describing and reflecting on the state of the art in modelling SIA. The editorial ends with looking ahead towards formalising SIA as a means to enable more collective behavioural realism in agent-based social simulations. [ABSTRACT FROM AUTHOR]

Flow cytometric analysis is a recommended tool in the diagnosis of myelodysplastic syndromes. Current flow cytometric approaches evaluate the (im)mature myelo-/monocytic lineage with a median sensitivity and specificity of ~71% and ~93%, respectively. We hypothesized that the addition of erythroid lineage analysis could increase the sensitivity of flow cytometry. Hereto, we validated the analysis of erythroid lineage parameters recommended by the International/European LeukemiaNet Working Group for Flow Cytometry in Myelodysplastic Syndromes, and incorporated this evaluation in currently applied flow cytometric models. One hundred and sixty-seven bone marrow aspirates were analyzed; 106 patients with myelodysplastic syndromes, and 61 cytopenic controls. There was a strong correlation between presence of erythroid aberrancies assessed by flow cytometry and the diagnosis of myelodysplastic syndromes when validating the previously described erythroid evaluation. Furthermore, addition of erythroid aberrancies to two different flow cytometric models led to an increased sensitivity in detecting myelodysplastic syndromes: from 74% to 86% for the addition to the diagnostic score designed by Ogata and colleagues, and from 69% to 80% for the addition to the integrated flow cytometric score for myelodysplastic syndromes, designed by our group. In both models the specificity was unaffected. The high sensitivity and specificity of flow cytometry in the detection of myelodysplastic syndromes illustrates the important value of flow cytometry in a standardized diagnostic approach. The trial is registered at www.trialregister.nl as NTR1825; EudraCT n.: 2008-002195-10

This single blind, multicenter randomized controlled trial aimed to evaluate the effectiveness of a supervised high intensity exercise program on physical fitness and fatigue in patients with multiple myeloma or lymphoma recently treated with autologous stem cell transplantation.109 patients were randomly assigned to the 18-week exercise intervention or the usual care control group. The primary outcomes included physical fitness (VO2peak and Wpeak determined using a cardiopulmonary exercise test; grip strength and the 30s chair stand test) and fatigue (Multidimensional Fatigue Inventory) and were assessed prior to randomization and after completion of the intervention or at similar time points for the control group. Multivariable multilevel linear regression analyses were performed to assess intervention effects.Patients in the intervention group attended 86% of the prescribed exercise sessions. Of the patients in the control group, 47% reported ≥10 physiotherapy sessions, which most likely included supervised exercise, suggesting a high rate of contamination. Median improvements in physical fitness ranged between 16 and 25% in the intervention group and between 12 and 19% in the control group. Fatigue decreased in both groups. There were no significant differences between the intervention and control group.We found no significant beneficial effects of the supervised high intensity exercise program on physical fitness and fatigue when compared to usual care. We hypothesized that the lack of significant intervention effects may relate to suboptimal timing of intervention delivery, contamination in the control group and/or suboptimal compliance to the prescribed exercise intervention.Netherlands Trial Register-NTR2341.

Social-ecological systems (SES) are complex adaptive systems. Social-ecological system phenomena, such as regime shifts, transformations, or traps, emerge from interactions among and between human and nonhuman entities within and across scales. Analyses of SES phenomena thus require approaches that can account for (1) the intertwinedness of social and ecological processes and (2) the ways they jointly give rise to emergent social-ecological patterns, structures, and dynamics that feedback on the entities and processes that generated them. We have developed a framework of linked action situations (AS) as a tool to capture those interactions that are hypothesized to have jointly and dynamically generated a social-ecological phenomenon of interest. The framework extends the concept of an action situation to provide a conceptualization of SES that focusses on social-ecological interactions and their links across levels. The aim of our SE-AS (social-ecological action situations) framework is to support a process of developing hypotheses about configurations of ASs that may explain an emergent social-ecological phenomenon. We suggest six social-ecological ASs along with social and ecological action situations that can commonly be found in natural resource or ecosystem management contexts. We test the ability of the framework to structure an analysis of processes of emergence by applying it to different case studies of regime shifts, traps, and sustainable resource use. The framework goes beyond existing frameworks and approaches, such as the SES framework or causal loop diagrams, by establishing a way of analyzing SES that focuses on the interplay of social-ecological interactions with the emergent outcomes they produce. We conclude by discussing the added value of the framework and discussing the different purposes it can serve: from supporting the development of theories of the emergence of social-ecological phenomena, enhancing transparency of SES understandings to serving as a boundary object for interdisciplinary knowledge integration.

Simulating collective decision-making and behaviour is at the heart of many agent-based models (ABMs). However, the representation of social context and its influence on an agent’s behaviour remains challenging. Here, the Social Identity Approach (SIA) from social psychology, offers a promising explanation, as it describes how people behave while being part of a group, how groups interact and how these interactions and ingroup norms can change over time. SIA is valuable for various application domains while also being challenging to formalise. To address this challenge and enable modellers to learn from existing work, we took stock of ABM formalisations of SIA and present a systematic review of SIA in ABMs. Our results show a diversity of application areas and formalisations of (parts of) SIA without any converging practice towards a default formalisation. Models range from simple to (cognitively) rich, with a group of abstract models in the tradition of opinion dynamics employing SIA to specify group-based social influence. We also found some complex cognitive SIA formalisations incorporating contextual behaviour. When considering the function of SIA in the models, representing collectives, modelling group-based social influence and unpacking contextual behaviour all stood out. Our review was also an inventory of the formalisation challenge attached to using a very promising social-psychological theory in ABMs, revealing a tendency for reference to domain-specific theories to remain vague. [ABSTRACT FROM AUTHOR]

Cooperation amongst resource users holds the key to overcoming the social dilemma that characterizes community-based common-pool resource management. But is cooperation alone enough to achieve sustainable resource use? The short answer is no. Developing management strategies in a complex social-ecological environment also requires ecological knowledge and approaches to deal with perceived environmental uncertainty. Recent behavioral experimental research indicates variation in the degree to which a group of users can identify a sustainable exploitation level. In this paper, we identify social-ecological micro-foundations that facilitate cooperative sustainable common-pool resource use. We do so by using an agent-based model (ABM) that is informed by behavioral common-pool resource experiments. In these experiments, groups that cooperate do not necessarily manage the resource sustainably, but also over- or underexploit. By reproducing the patterns of the behavioral experiments in a qualitative way, the ABM represents a social-ecological explanation for the experimental observations. We find that the ecological knowledge of each group member cannot sufficiently explain the relationship between cooperation and sustainable resource use. Instead, the development of a sustainable exploitation level depends on the distribution of ecological knowledge among the group members, their influence on each other's knowledge, and the environmental uncertainty the individuals perceive. The study provides insights about critical social-ecological micro-foundations underpinning collective action and sustainable resource management. These insights may inform policy-making, but also point to future research needs regarding the mechanisms of social learning, the development of shared management strategies and the interplay of social and ecological uncertainty.

In a prospective multicenter phase II study, we evaluated the effect of three courses of vincristine, doxorubicin and dexamethasone followed by high-dose melphalan and autologous stem cell transplantation on an intention-to-treat basis. Sixty-nine newly diagnosed patients with amyloid light chain amyloidosis were included between November 2000 and January 2006: 37 men and 32 women with a median age of 56 years, including 46% of patients with cardiac and 22% of patients with involvement of 3 or 4 organs. Initial results presented in 2008 showed a 4-year overall survival rate of 62% among all the patients, while the 4-year survival rate after transplantation was 78%. Here we report the long-term follow-up data after a median follow up of 115 months of the patients still alive. Median survival of all patients was 96 months from registration and for the transplanted patients ten years from the date of transplantation. Twelve (12%) patients died during induction therapy with vincristine, doxorubicin and dexamethasone, including 8 patients (12%) due to treatment-related mortality. Two patients died within one month following high-dose melphalan. We conclude that vincristine, doxorubicin and dexamethasone should not be applied as induction therapy for intensification in amyloid light chain amyloidosis. However, a 2-step approach consisting of a non-intensive less toxic induction therapy followed by high-dose melphalan and autologous stem cell transplantation may result in extended survival in newly diagnosed patients with amyloid light chain amyloidosis (clinicaltrials.gov identifier: 01207094).

Renal impairment is frequent in patients with multiple myeloma and is correlated with an inferior prognosis. This analysis evaluates the prognostic role of renal impairment in patients with myeloma treated with bortezomib before and after autologous stem cell transplantation within a prospective randomized phase III trial. Eight hundred and twenty-seven newly diagnosed myeloma patients in the HOVON-65/GMMG-HD4 trial were randomized to receive three cycles of vincristine, adriamycin, dexamethasone (VAD) or bortezomib, adriamycin, dexamethasone (PAD) followed by autologous stem cell transplantation and maintenance with thalidomide 50 mg daily (VAD-arm) or bortezomib 1.3 mg/m2 every 2 weeks (PAD-arm). Baseline serum creatinine was less than 2 mg/dL (Durie-Salmon-stage A) in 746 patients and 2 mg/dL or higher (stage B) in 81. In myeloma patients with a baseline creatinine ≥2 mg/dL the renal response rate was 63% in the VAD-arm and 81% in the PAD-arm (P=0.31). The overall myeloma response rate was 64% in the VAD-arm versus 89% in the PAD-arm with 13% complete responses in the VAD-arm versus 36% in the PAD-arm (P=0.01). Overall survival at 3 years for patients with a baseline creatinine ≥2 mg/dL was 34% in the VAD-arm versus 74% in the PAD-arm (P

Thalidomide and bortezomib are extensively used to treat elderly myeloma patients. In these patients, treatment-related side effects are frequent and full drug doses difficult to tolerate. We retrospectively analyzed data from 1435 elderly patients enrolled in 4 European phase III trials including thalidomide and/or bortezomib. After a median follow up of 33 months (95%CI: 10–56 months), 513 of 1435 patients (36%) died; median overall survival was 50 months (95%CI: 46–60 months). The risk of death was increased in patients aged 75 years or over (HR 1.44, 95%CI: 1.20–1.72; P

Myelodysplastic syndromes and acute myeloid leukemia exemplify the complexity of treatment allocation in older patients as options range from best supportive care, non-intensive treatment (e.g. hypomethylating agents) to intensive chemotherapy/hematopoietic cell transplantation. Novel metrics for non-disease variables are urgently needed to help define the best treatment for each older patient. We investigated the feasibility and prognostic value of geriatric/quality of life assessments aside from established disease-specific variables in 195 patients aged 60 years or over with myelodysplastic syndromes/acute myeloid leukemia. These patients were grouped according to treatment intensity and assessed. Assessment consisted of eight instruments evaluating activities of daily living, depression, mental functioning, mobility, comorbidities, Karnofsky Index and quality of life. Patients with a median age of 71 years (range 60-87 years) with myelodysplastic syndromes (n=63) or acute myeloid leukemia (n=132) were treated either with best supportive care (n=47), hypomethylating agents (n=73) or intensive chemotherapy/hematopoietic cell transplantation (n=75). After selection of variables, pathological activities of daily living and quality of life/fatigue remained highly predictive for overall survival in the entire patient group beyond disease-related risk factors adverse cytogenetics and blast count of 20% or over. In 107 patients treated non-intensively activities of daily living of less than 100 (hazard ratio, HR 2.94), Karnofsky Index below 80 (HR 2.34) and quality of life/’fatigue’ of 50 or over (HR 1.77) were significant prognosticators. Summation of adverse features revealed a high risk of death (HR 9.36). In-depth evaluation of older patients prior to individual treatment allocation is feasible and provides additional information to standard assessment. Patients aged 60 years or over with newly diagnosed myelodysplastic syndromes/acute myeloid leukemia and impairments in activities of daily living, Karnofsky Index below 80%, quality of life/’fatigue’ of 50 or over, are likely to have poor outcomes.

Treatment with melphalan-prednisone-thalidomide improves the outcome of patients with multiple myeloma and is now considered a standard of care for patients not eligible for transplantation. However, this treatment is a major source of morbidity. A meta-analysis of data from individual patients (n=1680) in six randomized trials was performed, comparing the effects of melphalan-prednisone-thalidomide versus melphalan-prednisone. The main objective was to estimate the risk of serious adverse events and their impact on outcome. The primary endpoints were the 2-year cumulative incidence of grade 3-4 hematologic and non-hematologic toxicities. At least 75% of the grade 3-4 toxicities occurred during the first 6 months of treatment in both treatment groups. The cumulative incidence of grade 3-4 hematologic toxicities was higher in the melphalan-prednisone-thalidomide group than in the melphalan-prednisone group (28% versus 22%; HR 1.32, 95% CI 1.05-1.66) as was the cumulative incidence of non-hematologic toxicities (39% versus 17%, HR 2.78, 95% CI 2.21-3.50). Grade 3-4 non-hematologic toxicities were significantly increased in patients with poor Performance Status. Occurrence of grade 3-4 non-hematologic toxicities had a negative impact on both progression-free survival (HR 1.24, 95% CI 1.07-1.45) and overall survival, (HR 1.23, 95% CI 1.03-1.47). Besides toxicities, progression-free and overall survival were also negatively affected by advanced International Staging System stage, high creatinine levels and poor Performance Status. Age had a negative impact on survival as well. Although melphalan-prednisone-thalidomide improved outcome, it increased toxicities, especially non-hematologic ones. Serious non-hematologic toxicities, older age, poor Performance Status, and high creatinine levels negatively affected survival.

Background The treatment of acute myeloid leukemia of older, medically non-fit patients still poses a highly unmet clinical need, and only few large, prospective studies have been performed in this setting. Given the established activity of hypomethylating agents such as 5-aza-2'-deoxycytidine (decitabine) in myelodysplastic syndromes and acute myeloid leukemia with 20–30% bone marrow blasts, we investigated whether this drug is also active in patients with more than 30% blasts.Design and Methods To evaluate the efficacy and toxicity of decitabine in patients over 60 years old with untreated acute myeloid leukemia ineligible for induction chemotherapy, 227 patients (median age, 72 years), many with comorbidities, adverse cytogenetics and/or preceding myelodysplastic syndrome were treated with this hypomethylating agent. During the initial decitabine treatment (135 mg/m2 total dose infused intravenously over 72 hours every 6 weeks), a median of two cycles was administered (range, 1–4). All-trans retinoic acid was administered to 100 patients during course 2. Fifty-two patients who completed four cycles of treatment subsequently received a median of five maintenance courses (range, 1–19) with a lower dose of decitabine (20 mg/m2) infused over 1 hour on 3 consecutive days every 4–6 weeks.Results The complete and partial remission rate was 26%, 95% CI (20%, 32%), and an antileukemic effect was noted in 26% of patients. Response rates did not differ between patients with or without adverse cytogenetics; patients with monosomal karyotypes also responded. The median overall survival from the start of decitabine treatment was 5.5 months (range, 0–57.5+) and the 1-year survival rate was 28%, 95%CI (22%,34%). Toxicities were predominantly hematologic.Conclusions Decitabine is well tolerated by older, medically non-fit patients with acute myeloid leukemia; myelosuppression is the major toxicity. The response rate and overall survival were not adversely influenced by poor-risk cytogenetics or myelodysplastic syndrome. Because of these encouraging results, randomized studies evaluating single-agent decitabine versus conventional treatment are warranted. The study is registered with the German Clinical Trials Registry, number DRKS00000069.

Background Allogeneic stem cell transplantation is usually considered the only curative treatment option for patients with advanced or transformed myelodysplastic syndromes in complete remission, but post-remission chemotherapy and autologous stem cell transplantation are potential alternatives, especially in patients over 45 years old.Design and Methods We evaluated, after intensive anti-leukemic remission-induction chemotherapy, the impact of the availability of an HLA-identical sibling donor on an intention-to treat basis. Additionally, all patients without a sibling donor in complete remission after the first consolidation course were randomized to either autologous peripheral blood stem cell transplantation or a second consolidation course consisting of high-dose cytarabine.Results The 4-year survival of the 341 evaluable patients was 28%. After achieving complete remission, the 4-year survival rates of patients under 55 years old with or without a donor were 54% and 41%, respectively, with an adjusted hazard ratio of 0.81 (95% confidence interval [95% CI], 0.49–1.35) for survival and of 0.67 (95% CI, 0.42–1.06) for disease-free survival. In patients with intermediate/high risk cytogenetic abnormalities the hazard ratio in multivariate analysis was 0.58 (99% CI, 0.22–1.50) (P=0.14) for survival and 0.46 (99% CI, 0.22–1.50) for disease-free survival (P=0.03). In contrast, in patients with low risk cytogenetic characteristics the hazard ratio for survival was 1.17 (99% CI, 0.40–3.42) and that for disease-free survival was 1.02 (99% CI, 0.40–2.56). The 4-year survival of the 65 patients randomized to autologous peripheral blood stem cell transplantation or a second consolidation course of high-dose cytarabine was 37% and 27%, respectively. The hazard ratio in multivariate analysis was 1.22 (95% CI, 0.65–2.27) for survival and 1.02 (95% CI, 0.56–1.85) for disease-free survival.Conclusions Patients with a donor and candidates for allogeneic stem cell transplantation in first complete remission may have a better disease-free survival than those without a donor in case of myelodysplastic syndromes with intermediate/high-risk cytogenetics. Autologous peripheral blood stem cell transplantation does not provide longer survival than intensive chemotherapy. (Eudract number: NCT00002926; http://www.cancer.gov/clinicaltrials/EORTC-06961)

Background In order to improve the molecular response rate and prevent resistance to treatment, combination therapy with different dosages of imatinib and cytarabine was studied in newly diagnosed patients with chronic myeloid leukemia in the HOVON-51 study.Design and Methods Having reported feasibility previously, we hereby report the efficacy of escalated imatinib (200 mg, 400 mg, 600 mg or 800 mg) in combination with two cycles of intravenous cytarabine (200 mg/m2 or 1000 mg/m2 days 1 to 7) in 162 patients with chronic myeloid leukemia.Results With a median follow-up of 55 months, the 5-year cumulative incidences of complete cytogenetic response, major molecular response, and complete molecular response were 89%, 71%, and 53%, respectively. A higher Sokal risk score was inversely associated with complete cytogenetic response (hazard ratio of 0.63; 95% confidence interval, 0.50–0.79, P

In the prospective phase 3 HOVON-50/GMMG-HD3 trial, patients randomized to TAD (thalidomide, doxorubicin, dexamethasone) had a significantly higher response rate (at least PR) after induction compared with patients randomized to VAD (vincristine, adriamycin, dexamethasone, 72% vs. 54%, p

Background and Objectives The Dutch-Belgian HOVON group performed a randomized phase 3 trial to compare single non-myeloablative intensive treatment with double, intensive treatment in previously untreated patients with multiple myeloma (MM).Design and Methods Three hundred and three patients with stage II/III MM were randomized after VAD induction chemotherapy to receive two cycles of non-myeloablative intermediate-dose melphalan (70 mg/m2) (single treatment) or the same regimen followed by cyclophosphamide 120 mg/kg iv plus total body irradiation (TBI) 9 Gy and autologous stem cell transplantation (double, intensive treatment). In both treatment arms interferon αIIa was given as maintenance until relapse/progression.Results A significantly higher proportion of patients achieved a complete remission (CR) on protocol treatment with double, intensive therapy (32% vs 13%, p