Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Ron Schaafsma is active.

Publication


Featured researches published by Ron Schaafsma.


Blood | 2010

A randomized phase 3 study on the effect of thalidomide combined with adriamycin, dexamethasone, and high-dose melphalan, followed by thalidomide maintenance in patients with multiple myeloma

Henk M. Lokhorst; B. van der Holt; Sonja Zweegman; Edo Vellenga; Sandra Croockewit; M. H. J. Van Oers; P.A. von dem Borne; P. Wijermans; Ron Schaafsma; O. de Weerdt; S. Wittebol; Michel Delforge; Henriette W Berenschot; G. Bos; Kon-Siong G. Jie; Harm Sinnige; M. van Marwijk-Kooy; Peter Joosten; Monique C. Minnema; R. van Ammerlaan; Pieter Sonneveld

The phase 3 trial HOVON-50 was designed to evaluate the effect of thalidomide during induction treatment and as maintenance in patients with multiple myeloma who were transplant candidates. A total of 556 patients was randomly assigned to arm A: 3 cycles of vincristine, adriamycin, and dexamethasone, or to arm B: thalidomide 200 mg orally, days 1 to 28 plus adriamycin and dexamethasone. After induction therapy and stem cell mobilization, patients were to receive high-dose melphalan, 200 mg/m(2), followed by maintenance with alpha-interferon (arm A) or thalidomide 50 mg daily (arm B). Thalidomide significantly improved overall response rate as well as quality of the response before and after high dose melphalan. Best overall response rate on protocol was 88% and 79% (P = .005), at least very good partial remission 66% and 54% (P = .005), and complete remission 31% and 23% (P = .04), respectively, in favor of the thalidomide arm. Thalidomide also significantly improved event-free survival from median 22 months to 34 months (P < .001), and prolonged progression free from median 25 months to 34 months (P < .001). Median survival was longer in the thalidomide arm, 73 versus 60 months; however, this difference was not significant (P = .77). Patients randomized to thalidomide had strongly reduced survival after relapse. This trial was registered on www.controlled-trials.com as ISRCTN06413384.


Blood | 2011

Complete response correlates with long-term progression-free and overall survival in elderly myeloma treated with novel agents: analysis of 1175 patients.

Alessandra Larocca; Pierre W. Wijermans; Federica Cavallo; Davide Rossi; Ron Schaafsma; Mariella Genuardi; Alessandra Romano; Anna Marina Liberati; Agostina Siniscalchi; Maria Teresa Petrucci; Chiara Nozzoli; Francesca Patriarca; Massimo Offidani; Roberto Ria; Paola Omedè; Benedetto Bruno; Roberto Passera; Pellegrino Musto; Mario Boccadoro; Pieter Sonneveld; Antonio Palumbo

Complete response (CR) was an uncommon event in elderly myeloma patients until novel agents were combined with standard oral melphalan-prednisone. This analysis assesses the impact of treatment response on progression-free survival (PFS) and overall survival (OS). We retrospectively analyzed 1175 newly diagnosed myeloma patients, enrolled in 3 multicenter trials, treated with melphalan-prednisone alone (n = 332), melphalan-prednisone-thalidomide (n = 332), melphalan-prednisone-bortezomib (n = 257), or melphalan-prednisone-bortezomib-thalidomide (n = 254). After a median follow-up of 29 months, the 3-year PFS and OS were 67% and 27% (hazard ratio = 0.16; P < .001), and 91% and 70% (hazard ratio = 0.15; P < .001) in patients who obtained CR and in those who achieved very good partial response, respectively. Similar results were observed in patients older than 75 years. Multivariate analysis confirmed that the achievement of CR was an independent predictor of longer PFS and OS, regardless of age, International Staging System stage, and treatment. These findings highlight a significant association between the achievement of CR and long-term outcome, and support the use of novel agents to achieve maximal response in elderly patients, including those more than 75 years. This trial was registered at www.clinicaltrials.gov as #NCT00232934, #ISRCTN 90692740, and #NCT01063179.


Haematologica | 2008

Thalidomide in induction treatment increases the very good partial response rate before and after high-dose therapy in previously untreated multiple myeloma

H M Lokhorst; Ingo G. H. Schmidt-Wolf; Pieter Sonneveld; B. van der Holt; Harry Martin; Rmy Barge; Uta Bertsch; Jana Schlenzka; G. Bos; Sandra Croockewit; Sonja Zweegman; Iris Breitkreutz; Peter Joosten; C Scheid; M. van Marwijk-Kooy; Hans-Juergen Salwender; M. H. J. Van Oers; Ron Schaafsma; R Naumann; Harm Sinnige; Igor W. Blau; M Delforge; O. de Weerdt; P. Wijermans; S. Wittebol; U. Duersen; Edo Vellenga; H. Goldschmidt

Thalidomide as part of initial treatment of multiple myeloma improves pre- and post-transplant response by increasing the proportion of patients achieving a very good partial response. 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<0.001). Complete remission (CR) and very good partial remission (VGPR) were also higher after TAD. After High Dose melphalan 200mg/m2 response was comparable in both arms, 76% and 79% respectively. However, CR plus VGPR were significantly higher in the patients randomized to TAD (49% vs. 32%, p<0.001). CTC grade 3–4 adverse events were similar in both arms.


Blood | 2010

Gemtuzumab ozogamicin as postremission treatment in AML at 60 years of age or more: results of a multicenter phase 3 study

Bob Löwenberg; Joachim Beck; Carlos Graux; Wim L.J. van Putten; Harry C. Schouten; Leo F. Verdonck; Augustin Ferrant; Pieter Sonneveld; Mojca Jongen-Lavrencic; Marie von Lilienfeld-Toal; Bart J. Biemond; Edo Vellenga; Dimitri A. Breems; Hilde de Muijnck; Ron Schaafsma; Gregor Verhoef; Hartmut Döhner; Alois Gratwohl; Thomas Pabst; Gert J. Ossenkoppele; Johan Maertens

In older patients with acute myeloid leukemia (AML), the prevention of relapse has remained one of the major therapeutic challenges, with more than 75% relapses after complete remission. The anti-CD33 immunotoxin conjugate gemtuzumab ozogamicin (GO) has shown antileukemic remission induction activity in patients with relapsed AML. Patients with AML or refractory anemia with excess blasts in first complete remission attained after intensive induction chemotherapy were randomized between 3 cycles of GO (6 mg/m(2) every 4 weeks) or no postremission therapy (control) to assess whether GO would improve outcome. The 2 treatment groups (113 patients receiving GO vs 119 control patients) were comparable with regard to age (60-78 years, median 67 years), performance status, and cytogenetics. A total of 110 of 113 received at least 1 cycle of GO, and 65 of 113 patients completed the 3 cycles. Premature discontinuation was mainly attributable to incomplete hematologic recovery or intercurrent relapse. Median time to recovery of platelets 50 x 10(9)/L and neutrophils 0.5 x 10(9)/L after GO was 14 days and 20 days. Nonhematologic toxicities were mild overall, but there was 1 toxic death caused by liver failure. There were no significant differences between both treatment groups with regard to relapse probabilities, nonrelapse mortality, overall survival, or disease-free survival (17% vs 16% at 5 years). Postremission treatment with GO in older AML patients does not provide benefits regarding any clinical end points. The HOVON-43 study is registered at The Netherlands Trial Registry (number NTR212) and at http://www.controlled-trials.com as ISRCTN77039377.


British Journal of Haematology | 2011

Platelet doubling after the first azacitidine cycle is a promising predictor for response in myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML) and acute myeloid leukaemia (AML) patients in the Dutch azacitidine compassionate named patient programme.

Lieke H. van der Helm; Canan Alhan; Pierre W. Wijermans; Marinus van Marwijk Kooy; Ron Schaafsma; Bart J. Biemond; Aart Beeker; Mels Hoogendoorn; Bastiaan P. van Rees; Okke de Weerdt; Jurgen Wegman; Ward J. Libourel; Sylvia A. Luykx-de Bakker; Monique C. Minnema; Rolf E. Brouwer; Fransien Croon-de Boer; Matthijs Eefting; Kon-Siong G. Jie; Jan Koedam; Nic J. G. M. Veeger; Edo Vellenga; Gerwin Huls

The efficacy of azacitidine in the treatment of high‐risk myelodysplastic syndromes (MDS), chronic myelomonocytic leukaemia (CMML) and acute myeloid leukaemia (AML) (20–30% blasts) has been demonstrated. To investigate the efficacy of azacitidine in daily clinical practice and to identify predictors for response, we analysed a cohort of 90 MDS, CMML and AML patients who have been treated in a Dutch compassionate named patient programme. Patients received azacitidine for a median of five cycles (range 1–19). The overall response rate (complete/partial/haematological improvement) was 57% in low risk MDS, 53% in high risk MDS, 50% in CMML, and 39% in AML patients. Median overall survival (OS) was 13·0 (9·8–16·2) months. Multivariate analysis confirmed circulating blasts [Hazard Ratio (HR) 0·48, 95% confidence interval (CI) 0·24–0·99; P = 0·05] and poor risk cytogenetics (HR 0·45, 95% CI 0·22–0·91; P = 0·03) as independent predictors for OS. Interestingly, this analysis also identified platelet doubling after the first cycle of azacitidine as a simple and independent positive predictor for OS (HR 5·4, 95% CI 0·73–39·9; P = 0·10). In conclusion, routine administration of azacitidine to patients with variable risk groups of MDS, CMML and AML is feasible, and subgroups with distinct efficacy of azacitidine treatment can be identified.


Leukemia | 2018

Bortezomib before and after high-dose therapy in myeloma: long-term results from the phase III HOVON-65/GMMG-HD4 trial

H. Goldschmidt; Henk M. Lokhorst; Elias K. Mai; B. van der Holt; I. W. Blau; Sonja Zweegman; Katja Weisel; Edo Vellenga; Michael Pfreundschuh; M. J. Kersten; C Scheid; Sandra Croockewit; Reinier Raymakers; Dirk Hose; Anna Potamianou; Anna Jauch; Jens Hillengass; Marian Stevens-Kroef; Marc S. Raab; Annemiek Broijl; Hans-Walter Lindemann; G. Bos; P Brossart; M. van Marwijk Kooy; Paula F. Ypma; Ulrich Duehrsen; Ron Schaafsma; Uta Bertsch; Thomas Hielscher; Le Jarari

The Dutch-Belgian Cooperative Trial Group for Hematology Oncology Group-65/German-speaking Myeloma Multicenter Group-HD4 (HOVON-65/GMMG-HD4) phase III trial compared bortezomib (BTZ) before and after high-dose melphalan and autologous stem cell transplantation (HDM, PAD arm) compared with classical cytotoxic agents prior and thalidomide after HDM (VAD arm) in multiple myeloma (MM) patients aged 18–65 years. Here, the long-term follow-up and data on second primary malignancies (SPM) are presented. After a median follow-up of 96 months, progression-free survival (censored at allogeneic transplantation, PFS) remained significantly prolonged in the PAD versus VAD arm (hazard ratio (HR)=0.76, 95% confidence interval (95% CI) of 0.65–0.89, P=0.001). Overall survival (OS) was similar in the PAD versus VAD arm (HR=0.89, 95% CI: 0.74–1.08, P=0.24). The incidence of SPM were similar between the two arms (7% each, P=0.73). The negative prognostic effects of the cytogenetic aberration deletion 17p13 (clone size ⩾10%) and renal impairment at baseline (serum creatinine >2 mg dl−1) on PFS and OS remained abrogated in the PAD but not VAD arm. OS from first relapse/progression was similar between the study arms (HR=1.02, P=0.85). In conclusion, the survival benefit with BTZ induction/maintenance compared with classical cytotoxic agents and thalidomide maintenance is maintained without an increased risk of SPM.


Bone Marrow Transplantation | 2011

Prognostic factors and outcome in relapsed multiple myeloma after nonmyeloablative allo-SCT: a single center experience.

Monique C. Minnema; S van Dorp; N W C J van de Donk; F Schouten; Marie José Kersten; Jules Llm Coenen; H Schouten; Sonja Zweegman; Ron Schaafsma; H M Lokhorst

For relapsed multiple myeloma (MM) patients, allo-SCT is a possible treatment option, but recent data obtained using a nonmyeloablative (NMA) conditioning regimen are scarce. We retrospectively collected data from 38 relapsed MM patients who received a NMA allo-SCT from October 2001 to January 2008. In total, 18 patients (48%) were transplanted using a matched unrelated donor. The median follow-up is 2.3 years. In 16 patients (42%) the response improved and eight patients (21%) were rapidly progressive within 6 months after allo-SCT. In total, 15 patients (39%) were in CR after allo-SCT. The median PFS was 1.4 years (range, 0.1–4.9), and having a CR after allo-SCT or having chronic GVHD resulted in longer PFS. Median OS was 3.1 years (range, 0.2–7.2) and again having a CR after allo-SCT or chronic GVHD was associated with a better OS. Six patients (16%) have died from treatment-related diseases. These results indicate that NMA allo-SCT is a treatment option in relapsed MM patients and that results may be improved by strategies that enhance the CR rate after allo-SCT.


Clinical Lymphoma, Myeloma & Leukemia | 2009

B152 First Analysis of HOVON-65/GMMG-HD4 Randomized Phase III Trial Comparing Bortezomib, Doxorubicin, Dexamethasone (PAD) vs. VAD as Induction Treatment Prior to High-dose Melphalan (HDM) in Patients with Newly Diagnosed Multiple Myeloma (MM)

Pieter Sonneveld; L Eljarari; Hans-Juergen Salwender; Sonja Zweegman; Edo Vellenga; B. van der Holt; Ingo G. H. Schmidt-Wolf; Uta Bertsch; Joerg Schubert; I. W Blau; G. S. K Jie; Berna Beverloo; Anna Jauch; Dirk Hose; Ron Schaafsma; M. J. Kersten; Michel Delforge; O. de Weerdt; R. van der Griend; P. Wijermans; Harry Martin; H Van der Velde; H M Lokhorst; H. Goldschmidt

The randomized, open-label, phase III trial HOVON-65/GMMG-HD4 was designed to evaluate the efficacy of bortezomib prior to HDM for response and progression-free survival (PFS) in patients with newly diagnosed MM. The trial was performed in 75 referral centers in the Netherlands and Belgium (HOVON group) and Germany (GMMG group). Patients with Salmon & Durie (SD) stage II or III, age 18-65 years inclusive, were randomly assigned to 3 cycles of VAD (vincristine 0.4 mg, adriamycine 9 mg/m2 days 1-4, dexamethasone 40 mg days 1-4, 9-12, and 17-20) or PAD (bortezomib 1.3 mg/m2 days 1,4,8,11, adriamycine 9 mg/m2 days 1-4, dexamethasone 40 mg days 1-4, 9-12, and 17-20). No thrombosis prophylaxis was given. Stem cells were mobilized using the CAD regimen, including cyclophosphamide 1000 mg/m2 iv day 1, and G-CSF. After induction therapy, all patients were to receive 1 or 2 cycles of high-dose melphalan (HDM) 200 mg/m2 with autologous stem cell rescue followed by maintenance with thalidomide 50 mg daily (VAD arm) or bortezomib, 1.3 mg/m2 once every 2 weeks (PAD arm) for 2 years. Between May 4, 2005 and May 16, 2008, 833 patients were randomized. After the trial was closed, we here report the planned interim analysis data on response after induction and HDM-1 of the initial 300 (150 per arm) randomized patients. The 2 randomization arms were equal for SD stage of disease, ISS stage, and distribution of chromosomal abnormalities. 137 patients (91%) completed PAD or 136 (91%) completed VAD and 132 patients (88%) in each arm completed HDM-1. Full dose bortezomib could be administered in 95% (PAD1), 89% (PAD2) and 85% (PAD3) of patients. Successful stem cell apheresis was achieved in all 137 PAD treated patients who received CAD mobilization . Peripheral polyneuropathy CTC grade 3-4 during PAD vs VAD was 16% vs 6%, while DVT/pulmonary embolism was diagnosed in 3% during VAD and 4% during PAD. Responses were assessed according to EBMT criteria including VGPR and nCR after PAD/VAD, after HDM-1 and best response on protocol treatment. Complete Response (CR/nCR), Very Good Partial Response (VGPR) and Partial Response (PR) in both arms were compared by logistic regression (table 1). Deletion of chromosome 13q or presence of t(4;14) did not have a significant impact on VGPR or (n)CR. We conclude that PAD induces significantly more PR+VGPR+(n)CR as compared with VAD, and that this effect is sustained after HDM-1.


Case Reports | 2014

Pulmonary leucostasis syndrome presented by unilateral pulmonary infiltrates.

Ronald Jan Trof; Ron Schaafsma; Bert Beishuizen

Summary A 48-year-old woman presented with suspected acute myelogenous leukaemia with a leucocyte count of 80×109/L. On admission, she had high fever and shortness of breath. Chest X-ray demonstrated unilateral consolidations of right lung suggestive for pneumonia and broad spectrum antibiotics were started. Her condition rapidly deteriorated and despite the clinical diagnosis of pulmonary leucostasis and treatment with leucapheresis the patient died within 2 days after admission from progressive respiratory failure and multiorgan failure. Autopsy showed diffuse leucostasis in the pulmonary capillaries. The present case illustrates that pulmonary leucostasis may be presented by unilateral chest X-ray abnormalities and without clear neurological symptoms (headache and blurred vision). Clinicians should be aware of this since delayed treatment may increase mortality.


Clinical Lymphoma, Myeloma & Leukemia | 2009

A046 HOVON-50 Final Analysis of Thalidomide Combined with Adriamycin, Dexamethasone, and HDM

H. Lokhorst; B. van der Holt; Sonja Zweegman; P.A. von dem Borne; G. Bos; Sandra Croockewit; J.J. Cornelissen; M. van Oers; Ron Schaafsma; Harm Sinnige; M. Delforge; O. de Weerdt; P. Wijermans; S. Wittebol; Asiong Jie; Edo Vellenga; Henriette W Berenschot; Pieter Sonneveld

Patient characteristics were as follows: 27 men, 14 women; median age, 61 years (range, 41-70 years); isotype (21 IgG, 12 IgA, 6 light chain only, 2 nonsecretory); and Durie-Salmon stage (31 stage III, 8 stage II, 2 stage I). Thirty-four patients who were at least 18 months from HDT were compared with a control group that received the same induction (VAD/ZDex) and HDT but without any thalidomide maintenance at our institution. CDT treated and control groups had similar disease isotype, Durie-Salmon stage, and response to HDT after 3 months. Results: Median duration of CDT consolidation was 4 months (range, 1-6 months). Cyclophosphamide dose was reduced in 20 (49%) patients because of grade 2 neutropenia. Median thalidomide dose was 100 mg daily. Fifteen (37%) patients developed grade 1 neuropathy. Two (5%) patients withdrew because of adverse side effects. There were no incidences of febrile neutropenia or DVT. Median follow-up from HDT is 31 months (range, 8-54 months) in CDT-treated patients and 42 months (range, 19-102 months) in the control group. CDT consolidation improved depth of response to HDT. VGPR/CR rate was increased from 33% (11 patients) at 3 months following HDT to 55% (18 patients) at 12 months. No improvement in depth of response was seen in the control group. Median PFS was longer in CDT treated patients (24 months vs. 17 months control group; P = .02). Conclusion: CDT consolidation following HDT is safe and well tolerated and improves depth of response.

Collaboration


Dive into the Ron Schaafsma's collaboration.

Top Co-Authors

Avatar

Edo Vellenga

University Medical Center Groningen

View shared research outputs
Top Co-Authors

Avatar

Sonja Zweegman

VU University Medical Center

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Pieter Sonneveld

Erasmus University Rotterdam

View shared research outputs
Top Co-Authors

Avatar

B. van der Holt

Erasmus University Rotterdam

View shared research outputs
Top Co-Authors

Avatar

Mels Hoogendoorn

Medisch Centrum Leeuwarden

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Geert A. Huls

University Medical Center Groningen

View shared research outputs
Researchain Logo
Decentralizing Knowledge