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Featured researches published by Onder Arslan.


The New England Journal of Medicine | 2017

Blinatumomab versus Chemotherapy for Advanced Acute Lymphoblastic Leukemia

Hagop M. Kantarjian; Anthony S. Stein; Nicola Gökbuget; Adele K. Fielding; Andre C. Schuh; Josep Maria Ribera; Andrew Wei; Hervé Dombret; Robin Foà; Renato Bassan; Onder Arslan; Miguel A. Sanz; Julie Bergeron; Fatih Demirkan; Ewa Lech-Maranda; Alessandro Rambaldi; Xavier Thomas; Heinz-August Horst; Monika Brüggemann; Wolfram Klapper; Brent L. Wood; Alex Fleishman; Dirk Nagorsen; Chris Holland; Zachary Zimmerman; Max S. Topp

Background Blinatumomab, a bispecific monoclonal antibody construct that enables CD3‐positive T cells to recognize and eliminate CD19‐positive acute lymphoblastic leukemia (ALL) blasts, was approved for use in patients with relapsed or refractory B‐cell precursor ALL on the basis of single‐group trials that showed efficacy and manageable toxic effects. Methods In this multi‐institutional phase 3 trial, we randomly assigned adults with heavily pretreated B‐cell precursor ALL, in a 2:1 ratio, to receive either blinatumomab or standard‐of‐care chemotherapy. The primary end point was overall survival. Results Of the 405 patients who were randomly assigned to receive blinatumomab (271 patients) or chemotherapy (134 patients), 376 patients received at least one dose. Overall survival was significantly longer in the blinatumomab group than in the chemotherapy group. The median overall survival was 7.7 months in the blinatumomab group and 4.0 months in the chemotherapy group (hazard ratio for death with blinatumomab vs. chemotherapy, 0.71; 95% confidence interval [CI], 0.55 to 0.93; P=0.01). Remission rates within 12 weeks after treatment initiation were significantly higher in the blinatumomab group than in the chemotherapy group, both with respect to complete remission with full hematologic recovery (34% vs. 16%, P<0.001) and with respect to complete remission with full, partial, or incomplete hematologic recovery (44% vs. 25%, P<0.001). Treatment with blinatumomab resulted in a higher rate of event‐free survival than that with chemotherapy (6‐month estimates, 31% vs. 12%; hazard ratio for an event of relapse after achieving a complete remission with full, partial, or incomplete hematologic recovery, or death, 0.55; 95% CI, 0.43 to 0.71; P<0.001), as well as a longer median duration of remission (7.3 vs. 4.6 months). A total of 24% of the patients in each treatment group underwent allogeneic stem‐cell transplantation. Adverse events of grade 3 or higher were reported in 87% of the patients in the blinatumomab group and in 92% of the patients in the chemotherapy group. Conclusions Treatment with blinatumomab resulted in significantly longer overall survival than chemotherapy among adult patients with relapsed or refractory B‐cell precursor ALL. (Funded by Amgen; TOWER ClinicalTrials.gov number, NCT02013167.)


Journal of Viral Hepatitis | 2004

Lamivudine prophylaxis for prevention of chemotherapy-induced hepatitis B virus reactivation in hepatitis B virus carriers with malignancies.

Ramazan Idilman; Mutlu Arat; Ender Soydan; Murat Törüner; Irfan Soykan; Hakan Akbulut; Onder Arslan; Muhit Ozcan; Ahmet R Turkyilmaz; Mithat Bozdayi; Selim Karayalcin; D. H. Van Thiel; Ali Özden; Meral Beksac; Hamdi Akan

Summary.  Although hepatitis B virus (HBV) reactivation in HBV carriers undergoing immunosuppressive therapy is clearly documented, the role of antiviral prophylaxis in such individuals is still controversial. The aim of this study was to determine the efficacy of lamivudine prophylaxis in HBV carriers with haemato/oncological malignancies, who receive chemotherapy. Eighteen HBV carriers with malignancy, who were candidates for chemotherapy, were enrolled. Eight subjects (three with leukaemia, four with lymphoma and one with multiple myeloma) were enrolled for prophylactic lamivudine therapy. The remaining 10 patients (six with leukaemia, three with lymphoma and one with breast cancer) were not treated with lamivudine and were used as a control. Lamivudine was administered beginning on the same day as the chemotherapy and was maintained for a year after chemotherapy was discontinued. No HBV‐related mortality was observed in either group. In the lamivudine‐treated group, none of the subjects had clinical, biochemical or serological evidence of HBV reactivation during the time they were receiving chemotherapy and after their chemotherapy was discontinued. In contrast, five of the 10 HBV carriers not receiving lamivudine therapy experienced a reactivation of HBV infection. This reactivation of HBV was observed during the chemotherapy in four with one individual experiencing a HBV activation 12 months after chemotherapy was discontinued. No lamivudine‐related major adverse effects were observed. Hence prophylactic lamivudine treatment in HBV carriers with haemato/oncological malignancy receiving chemotherapy prevents chemotherapy‐induced HBV reactivation.


British Journal of Haematology | 2002

Mobilization of peripheral blood stem cells with chemotherapy and recombinant human granulocyte colony-stimulating factor (rhG-CSF): a randomized evaluation of different doses of rhG-CSF.

Taner Demirer; Meltem Ayli; Muhit Ozcan; Nazan Günel; Rauf Haznedar; Mehmet Daglı; Turgay Fen; Yasemin Genç; Suleyman Dincer; Onder Arslan; Gunhan Gurman; S. Demirer; Gülsüm Özet; Akin Uysal; Nahide Konuk; Osman Ilhan; Haluk Koç; Hamdi Akan

Summary. To date, no randomized study has compared different doses of recombinant human granulocyte colony‐stimulating factor (rhG‐CSF) following submyeloablative mobilization chemotherapy. Therefore, we evaluated the effect of different doses of rhG‐CSF following mobilization chemotherapy on yields of CD34+ peripheral blood stem cells (PBSC). Fifty patients were randomized to receive 8 (n = 25) versus 16 µg/kg/d (n = 25) of rhG‐CSF following mobilization chemotherapy. The median number of CD34+ cells collected after 8 µg/kg/d of rhG‐CSF was 2·36 × 106/kg (range, 0·21–7·80), compared with 7·99 (2·76–14·89) after 16 µg/kg/d (P < 0·001). Twenty out of 25 (80%) patients in the low‐dose and 23 out of 25 (92%) in the high‐dose rhG‐CSF arm underwent high‐dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT). Median days to white blood cell engraftment in patients mobilized with 8 µg/kg and 16 µg/kg of rhG‐CSF were 12 (10–20) and 9 (8–11) respectively (P < 0·001). There was no difference between the two groups regarding the other parameters of peritransplant morbidity: days to platelet engraftment (P = 0·10), number of red blood cell (P = 0·56) and platelet transfusions (P = 0·22), days of total parenteral nutrition requirement (P = 0·84), fever (P = 0·93) and antibiotics (P = 0·77), and number of different antibiotics used (P = 0·58). These data showed that higher doses of rhG‐CSF following submyeloablative mobilization chemotherapy were associated with a clear dose–response effect based on the collected cell yields. Based on the parameters of peritransplant morbidity, 8 µg/kg/d was as effective as 16 µg/kg/d except for a rapid neutrophil engraftment in the high‐dose arm. Therefore, in routine clinical practice, despite some advantage in the use of higher doses of rhG‐CSF, lower doses may be used for PBSC collections following chemotherapy‐based mobilization regimens in this cost‐conscious era.


Bone Marrow Transplantation | 1997

Hepatitis B virus infection in allogeneic bone marrow transplantation

C. Üstün; Haluk Koç; S Karayalçın; Gülen Akyol; Gunhan Gurman; Osman Ilhan; Hamdi Akan; Muhit Ozcan; Onder Arslan; Nahide Konuk; Akin Uysal; Meral Beksac

Fourty-four patients who underwent allogeneic bone marrow transplantation (alloBMT) were studied for hepatitis B virus (HBV)-related complications. The mean follow-up period was 15.3 months. Positivity for HBV surface antigen (HBsAg) was observed in 10 patients (22.7%) throughout the study. Four of the 10 patients were HBsAg carriers before alloBMT, while the remaining six became HBsAg(+) after alloBMT. During the follow-up period (from 6 months to 45 months), an elevation in serum ALT activity was observed in the four carriers when immunosuppression was reduced or withdrawn. All of the four HBsAg carriers developed hepatitis, but none of them died of liver failure due to HBV. Only one death due to GVHD and diabetic ketoacidosis was observed in this group. Two of the four carriers received marrow from anti-HBs positive donors and one of them cleared HBsAg from his serum via adoptive immunity 8 months after transplantation. The remaining six patients acquired HBV after alloBMT, but we were unable to demonstrate the source of HBV. Five of them had a moderate increase in serum ALT activity while the other patient had a normal ALT. Two patients seroconverted to anti-HBs spontaneously. Two patients died during the follow-up, one due to intracranial hemorrhage and the other due to GVHD and accompanying pulmonary infection. The rest of the study group (34 patients) remained HBsAg(−) throughout the study. Two of them had an HBsAg(+) donor, but neither developed HBV infection in their follow-up period. The acquisition rate of HBV infection was relatively low in recipients who were positive for anti-HBs compared to those who were negative for anti-HBs (8 vs 19%). Anti-HBs positivity remained for a longer period in recipients who received marrow from anti-HBs positive donors compared to those recipients who had anti-HBs negative donors (median 12 vs 3 months). We think that HBV is a frequent cause of liver dysfunction in alloBMT patients where HBV infection is endemic. Whether the disease is in the form of reactivation of HBsAg-positive recipients, or is acquired from unknown sources in recipients who never had contact with the virus, the course of the disease is not fatal. Silent serologic changes can be demonstrated if viral serologic markers are sought serially. Among them, the disappearance of serum anti-HBs may be important as it increases the risk of HBV contamination in recipients.


Bone Marrow Transplantation | 2001

Aerobic bacterial and fungal infections in peripheral blood stem cell transplants

G. Aksu; Mz Ruhi; Hamdi Akan; S Bengisun; C. Üstün; Onder Arslan; H. Ozenci

Allogeneic and autologous peripheral blood stem cell transplants are frequently complicated by infections. This study was performed to evaluate early and late infections in 74 patients who underwent peripheral blood stem cell transplantation (PBSCT). Fifty-eight patients received allogeneic and 16 autologous PBSCT. All patients received fluconazole, ciprofloxacin and acyclovir prophylaxis. 93.1% of alloPBSCT patients and 87.5% of autoPBSCT patients developed fever. Febrile episodes were commonly seen in the week of transplantation (66%). There was a median of 3 days with fever in alloPBSCT, and 2 days in autoPBSCT. Period of neutropenia was 15 days for AlloPBSCT and 12 days for AutoPBSCT. The microbiological identification rate was 47% (32/68). Gram-positive infections dominated the early period (50%) and Gram-negative bacterial infections dominated the late period (50%). All our patients had Hickman-type catheters and 26 infections involving catheters were seen. Sixteen occurred in the early, and 10 in the late period. Ten of 14 (71.4%) late bacterial infections were catheter-related. The dominance of Gram-positive infections and high rates of methicillin resistance warranted the use of vancomycin extensively. Surveillance cultures were found to be useful in selected patients. Although slime factor is an important virulence factor, there was no difference between slime factor positive and negative coagulase-negative staphylococci isolated during infections. In conclusion, febrile episodes are the most frequent complication of PBSCT and Gram-positive microorganisms remain the main pathogen in these patients because of catheter use, mucositis and ciprofloxacin prophylaxis. Methicillin resistance is increasing and glycopeptides remain the only choice for treating such infections. Although the infection rate is high, measures taken to prevent and treat infections result in very low rates of mortality from infection in PBSCT patients. Bone Marrow Transplantation (2001) 27, 201–205.


Transfusion Science | 1999

The impact of the CD34+ cell dose on engraftment in allogeneic peripheral blood stem cell transplantation.

Osman Ilhan; Onder Arslan; Mutlu Arat; Meral Beksac; Hamdi Akan; Muhit Ozcan; Gunhan Gurman; Nahide Konuk; Akin Uysal; Haluk Koç

Forty-five patients who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) were evaluated in order to investigate any relationship between CD34+ cell dose given and hematological recovery. Granulocyte counts > 1.0 x 10(9)/L and platelet > 50 x 10(9)/L were considered as hematological recovery. Three different regimens were used for mobilization, by adjusting the recombinant granulocyte colony stimulating factor (rhG-CSF, Roche) dose. The first group (n = 3), whose donors mobilized with 5 micrograms/kg/d s.c. rhG-CSF received a mean of 5.9 x 10(6)/kg (95% confidence interval for mean (CI); 2.4-9.3) CD34+ cells. The second group (n = 37), mobilized with 10 micrograms/kg/d s.c. rhG-CSF and the third group (n = 5) mobilized with 15 micrograms/kg/d s.c. rhG-CSF, received a mean of 5.7 x 10(6)/kg (95% CI; 4.6-6.75) and 6.56 x 10(6)/kg (95% CI; 4.57-8.55) CD34+ cells, respectively. CD34+ cell dose was 5.82 x 10(6)/kg (95% CI; 4.97-6.68) for all the patients. All patients received rhG-CSF from day +1 until attaining granulocyte count > 1.0 x 10(9)/L for three consecutive days. Median granulocyte and platelet engraftment days for the whole group was 15 (range; 11-44) and 14 (11-54) days respectively. There was a close correlation (r = -0.301, p < 0.05) between the CD34+ cell dose and granulocyte recovery for the whole group. When these analyses were performed separately within groups, this correlation was also found significant for the first group (r = -0.99, p < 0.05) for granulocyte recovery. On the contrary the same analysis did not reach significance for the other groups, nor for platelet recovery for the whole group (r = 0.039, p = 0.821). We calculated a minimum dose of 4 x 10(6)/kg CD34+ cells for a safe alloPBSCT. There was no difference between patients who received more than 5 x 10(6)/kg CD34+ cells, and those who received more than 2 x 10(6)/kg and less than 5 x 10(6)/kg CD34+ cells. In conclusion, we have demonstrated a correlation between the CD34+ cell dose given and faster hematological recovery for alloPBSCT patients.


Transfusion | 2004

Hb content-based transfusion policy successfully reduces the number of RBC units transfused.

Onder Arslan; Selami Kocak Toprak; Mutlu Arat; Yasemin Kayalak

BACKGROUND: RBC transfusions should be based on Hb content of the products instead of units. As high as a 50‐percent difference in Hb content can be encountered between two units. In this study, 500 mL of whole blood (WB)‐generated RBCs according to their total Hb content was used to decrease the number of units ordered by using a new software called Hemosoft.


European Journal of Cardio-Thoracic Surgery | 2009

Five-year follow-up after transepicardial implantation of autologous bone marrow mononuclear cells to ungraftable coronary territories for patients with ischaemic cardiomyopathy

Ahmet Ruchan Akar; Serkan Durdu; Mutlu Arat; Mustafa Kilickap; Nuriye Ozlem Kucuk; Onder Arslan; Isinsu Kuzu; Ümit Özyurda

OBJECTIVE Cell therapy for patients with ischaemic cardiomyopathy (IC) is still an open issue. We aimed to assess the long-term safety and therapeutic potency of autologous bone marrow mononuclear cell (ABMMNC) implantation into ungraftable coronary artery (UCA) territories in patients with IC. METHODS Bone marrow was aspirated from the iliac crest, and transepicardial ABMMNC implantation (n=25, 24 men, aged 57+/-7 years) as an adjunct to coronary artery bypass grafting (CABG) was performed into an area of reversible ischaemia within the territory of UCA (1.29+/-0.09 x 10(9) ABMMNCs). Control group (n=25, 23 men, aged 59+/-7 years) underwent incomplete CABG due to poor target vessel graftability. The study protocol consisted of coronary angiography, stress echocardiography, nuclear imaging and Holter monitoring at baseline and follow-up. The mean follow-up time was 988+/-423 days. RESULTS There was no difference between the groups regarding postoperative complications and outcome. Overall 5-year survival for the ABMMNC group was 79+/-10%, and 71+/-12% for the controls (p=0.48). Left ventricular ejection fraction (LVEF) at baseline was 24.8+/-3.7 versus 25.9+/-3.1 in the ABMMNC group and the controls, respectively. After 6 months, mean global LVEF increased to 36.3+/-7.4 (p<0.001) versus 31.4+/-4.1 (p=0.001), respectively. A significant difference was noted in delta LVEF between the groups (p<0.001, 95% confidence interval (CI): 3.4-8.9) at 6 months, and (p=0.001, 95% CI: 2.0-7.4) at 1 year. Accordingly, perfusion scores in UCA segments detected by single-photon emission computed tomography (SPECT) improved with ABMMNC therapy to 18.0+/-24.4 from 7.1+/-25.7 (p=0.001 vs control UCA segments). CONCLUSION Cellular therapy for IC within UCA could augment myocardial perfusion and contractility but does not improve overall survival. No adverse events were detected after cell therapy at mid-term follow-up.


Transfusion Science | 2000

National survey of hemapheresis practice in Turkey (1998)

Osman Ilhan; Necdet Üskent; Onder Arslan; Mutlu Arat; Fahir Özkalemkaş; Gülyüz Öztürk; Sevgi B. Kalayoǧlu; Ahmet Özet; Murat Tombuloǧlu; Fikret Arpaci; Ercument Ovali; Sema Anak

The Turkish Apheresis Group has maintained a national registry for apheresis activities since 1997. The hemapheresis practice of Turkey in 1998 is summarized in brief detail in this article. A total of 30, 136 apheresis procedures were performed at 31 different apheresis centers. At 10 centers, 145 peripheral blood stem cell (PBSC) apheresis were performed on 82 patients in allogeneic setting and at 17 centers, 981 PBSC apheresis were performed on 271 patients in autologous setting. Frequently observed adverse effects during PBSC apheresis were mild tremor and chills, paresthesia and nausea in 15% of the patients and donors. Vascular access complications, particularly observed in autologous setting due to central venous catheters were encountered in 10% of the procedures. Eight hundred and sixty-nine therapeutic plasma exchange procedures were performed at 21 centers on 172 patients, most commonly for neurological disorders and thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS). Therapeutic cytapheresis procedures like leukapheresis, plateletapheresis and erythrocyte apheresis were performed especially for cytoreduction in myeloproliferative disorders. A total of 204 cytapheresis procedures (66% leukapheresis, 33% plateletapheresis and 1% erythrocytapheresis) were performed on 134 patients in 15 centers. Donor plateletapheresis was the most used apheresis procedure, reaching a total of 28.016 in 1998. Many university hospitals and a few state hospitals are performing above-mentioned apheresis procedures with great success and acceptable side effects. According to these data we are planning prospective trials and will establish National Standards of Practice.


Clinical Transplantation | 2003

Hepatitis B virus vaccination of recipients and donors of allogeneic peripheral blood stem cell transplantation

Ramazan Idilman; C. Üstün; Selim Karayalcin; Aslihan Aktemel; Ahmet R Turkyilmaz; Muhit Ozcan; Onder Arslan; A. Mithat Bozdayi; David H. Van Thiel; Hamdi Akan

Abstract: Background: The aim of this study was to determine the role of hepatitis B virus (HBV) vaccination as defined by the seroconversion to hepatitis B surface antibody (anti‐HBs) positivity in peripheral blood stem cell transplants.

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Mutlu Arat

Istanbul Bilim University

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