Safety and Efficacy of B-domain Deleted Third Generation Recombinant Factor VIII (GreenGene F™) in Korean Patients with Hemophilia A: Data from a Post-marketing Surveillance Study.

BACKGROUND: New B-domain deleted third generation recombinant factor VIII (FVIII; GreenGene F™, beroctocog alfa) was launched in 2010. We determined safety and efficacy of GreenGene F™ during routine clinical practice in patients with hemophilia A over a period of 12 months. METHODS: From July 2010 to July 2014, a total of 136 hemophilia A patients were enrolled in a post-marketing surveillance (PMS) study. Among them, 134 patients were assessed for drug safety and 114 patients were analyzed for drug efficacy. Patients with differing hemophilia A severities and medical histories were monitored during 12 months of prophylactic and/or on-demand therapy. RESULTS: Among 134 patients evaluated, 85 (63.4%) had severe hemophilia. Ninety-two received a total of 1,266,077 units for prophylaxis, and 42 received 516,491 units for bleeding episodes. Three patients developed inhibitors. In 112 previously treated patients, one patient (0.9%) developed inhibitor after intensive FVIII treatment for surgery. Among 22 previously untreated patients, inhibitors were observed in 2 infants (9.1%). Overall, there were a total of 47 adverse events (other than inhibitors) of all types in 30 patients (22.4%), 11 in 10 patients (7.5%) of which were considered showing serious adverse events (SAEs); most of which were hemorrhages at different sites. None of the SAEs were judged as product related. An excellent/good efficacy rate of 91.3% for hemostasis and 89.4% for hemorrhage prevention was recorded. CONCLUSION: The results of this PMS study support the use of GreenGene F™ as safe and efficacious in hemorrhage prevention and treatment of hemophilia A. These results are consistent with the findings from previously published GreenGene F™ studies.

Epidemiology and clinical long-term outcome of childhood aplastic anemia in Korea for 15 years: retrospective study of the Korean Society of Pediatric Hematology Oncology (KSPHO).

PURPOSE: Aplastic anemia (AA) is a rare hematologic disease characterized by pancytopenia and hypocellular marrow. The Korean Society of Pediatric Hematology Oncology investigated retrospectively the incidence, survival, and transfusion independency according to treatment strategies in AA. METHODS: All the questionnaires were sent to members for medical records. We collected and analyzed 702 available data. RESULTS: The male and female ratio was 1.2, and the median age at diagnosis was 9.3 years. The annual incidence of Korean children with AA was 5.16 per million per year. Constitutional anemia was diagnosed in 44 children. In acquired AA, causes were identified in 39 children. Severe AA (SAA) at initial diagnosis was more common than nonsevere AA. The overall survival was 47.8% with supportive care, 68.1% with immunosuppressive therapy (IST), and 81.8% with hematopoietic stem cell transplantation. In IST, response rate was 65.7%, and relapse rate after response was 54.4% within a median of 23.0 months. The factors with overall survival were severity of disease in supportive care, severity and response in IST, donor type, graft failure, and posttransplant events in hematopoietic stem cell transplantation. CONCLUSIONS: Long-term outcome in AA was dependent on treatment strategies. These Korean results may help research and prospective international clinical trials for childhood AA.

Efficacy of tandem high-dose chemotherapy and autologous stem cell rescue in patients over 1 year of age with stage 4 neuroblastoma: the Korean Society of Pediatric Hematology-Oncology experience over 6 years (2000-2005).

The efficacy of tandem high-dose chemotherapy and autologous stem cell rescue (HDCT/ASCR) was investigated in patients with high-risk neuroblastoma. Patients over 1 yr of age who were newly diagnosed with stage 4 neuroblastoma from January 2000 to December 2005 were enrolled in The Korean Society of Pediatric Hematology-Oncology registry. All patients who were assigned to receive HDCT/ASCR at diagnosis were retrospectively analyzed to investigate the efficacy of single or tandem HDCT/ASCR. Seventy and 71 patients were assigned to receive single or tandem HDCT/ASCR at diagnosis. Fifty-seven and 59 patients in the single or tandem HDCT group underwent single or tandem HDCT/ASCR as scheduled. Twenty-four and 38 patients in the single or tandem HDCT group remained event free with a median follow-up of 56 (24-88) months. When the survival rate was analyzed according to intent-to-treat at diagnosis, the probability of the 5-yr event-free survival+/-95% confidence intervals was higher in the tandem HDCT group than in the single HDCT group (51.2+/-12.4% vs. 31.3+/-11.5%, P=0.030). The results of the present study demonstrate that the tandem HDCT/ASCR strategy is significantly better than the single HDCT/ASCR strategy for improved survival in the treatment of high-risk neuroblastoma patients.

Safety and effectiveness of Rixubis in patients with hemophilia B: a real-world, prospective, postmarketing surveillance study in South Korea.

BACKGROUND: Rixubis (recombinant factor IX, nonacog gamma) is indicated for the control and prevention of bleeding episodes, perioperative management, and routine prophylaxis in hemophilia B patients. This real-world, postmarketing surveillance study aimed to evaluate the safety and effectiveness of Rixubis in adult and pediatric hemophilia B patients in South Korea. METHODS: This prospective, observational, multicenter study (clinicaltrials.gov identifier: NCT029 22231) was conducted in hemophilia B patients between April 2015 and April 2019, who were observed for up to 6 months after the initiation of Rixubis treatment. Safety was evaluated based on the number and severity of adverse events (AEs) and serious AEs (SAEs). Hemostatic effectiveness was assessed by physicians and patients by using a four-point scale and rated as excellent, good, fair, or no response based on treatment type. RESULTS: In all, 58 patients were enrolled from four centers by seven physicians during the study period. The safety and effectiveness analysis sets included 57 and 54 patients, respectively. Overall, 11 AEs were reported in eight patients (14.0%), of which three were SAEs and occurred in three patients (5.3%). All 11 AEs were reported as unexpected and mild in severity, with no anaphylactic reaction, and 10 AEs (90.9%) resolved. The majority of AEs (10) were unrelated to Rixubis. Of the 142 hemostatic effectiveness assessments, 123 (86.6%) were reported as good or excellent. CONCLUSION: Rixubis demonstrated an acceptable safety and effectiveness profile in the treatment of bleeding, perioperative management, and prophylaxis in hemophilia B patients in a real-world setting in South Korea.

Long-term course of anti-factor VIII antibody in patients with hemophilia A at a single center.

BACKGROUND: Immune tolerance induction (ITI) can reduce inhibitors against factor VIII concentrates by 70-80%. In this study, we elucidated the characteristics of inhibitors and attempted to determine the proper indications and timing for ITI. METHODS: Subjects included hemophilia A patients registered at the Korea Hemophilia Foundation from 1991 through 2014. Inhibitors were classified as persistent and transient. Patients were classified into groups according to peak inhibitor titer: low (<2 BU/mL), moderate (2 to <5 BU/mL), high (5 to <10 BU/mL), and very high titer (≥10 BU/mL). RESULTS: Overall, 350 (21.4%) of 1,634 hemophilia A patients developed inhibitors at least once. Of these, 100 (6.1%) and 250 (15.3%) patients developed persistent and transient inhibitors, respectively. For transient inhibitors, the median peak titer was 1.0 BU/mL, persistent for median of 11.0 months (10.0, 8.0, 13.0, and 19.0 months in the low, moderate, high, and very high titer transient inhibitor groups, respectively). Overall, 95.8% (215), 72.2% (17), 52.4% (21), and 21.7% (97) of patients in the low, moderate, high, and very high titer groups became inhibitor-negative spontaneously, without ITI. CONCLUSION: Given the spontaneous disappearance of inhibitors and high cost of ITI, it is worthwhile to postpone ITI for 11 months unless the peak inhibitor titer is greater than 10 BU/mL.

Immune tolerance induction in patients with severe hemophilia A with inhibitors.

BACKGROUND: Inhibitory antibodies to factor VIII (FVIII) are an important complication when managing patients with hemophilia A. Immune tolerance induction (ITI) has been regarded as a useful method for eradicating inhibitors. We report the results of a retrospective study in Korean patients with hemophilia A who underwent ITI. METHODS: We reviewed the records of patients with hemophilia A with inhibitors who underwent ITI from March 2004 to December 2014. ITI was started with FVIII concentrates at 100 IU/kg, 3 times per week. The dose of FVIII was reduced according to the inhibitor titer and recovery of FVIII. Inhibitor elimination was defined as the time taken to achieve a negative inhibitor assay with no anamnestic response and normal FVIII recovery and/or normal half-life. RESULTS: In total, 17 patients with severe hemophilia A were evaluated. Complete tolerance was achieved in 14 of 17 patients (83%). The mean peak inhibitor titer before ITI was 38.4 BU/mL. The mean treatment duration was 26.2 months. The mean duration between inhibitor detection and ITI was 5.1 years in the complete tolerance group and 10.8 years in the partial tolerance and failed group. CONCLUSION: This study shows that ITI can be an effective and well-tolerated method for eradicating inhibitors. Possible influencing factors for ITI success were age at the start of ITI treatment and duration after inhibitor detection. More research to provide further insight about other factors and conditions is needed.

Recombinant urate oxidase (Rasburicase) for the treatment of hyperuricemia in pediatric patients with hematologic malignancies: Results of a compassionate prospective multicenter study in Korea.

BACKGROUND: Hyperuricemia accompanying tumor lysis syndrome is a serious complication in neoplasia with rapid proliferation and destruction. To confirm the efficacy of recombinant urate oxidase (rasburicase) and its safety profile, a phase IV compassionate use prospective study was performed in Korean pediatric patients with hematologic malignancies. PROCEDURE: Rasburicase was administered at 0.2 mg/kg/day once daily for 3-5 days (twice daily allowed during the first 72 hr) by intravenous route for hyperuricemia (uric acid > 7.5 mg/dl). The study period was 5 weeks and consisted of a baseline assessment within 48 hr before the administration of rasburicase, 3-5 days of assessment during treatment and a follow-up assessment at 4 weeks after its final administration. RESULTS: The uric acid endpoint (< or =7.0 mg/dl) was reached in 97.3% (36/37) of the patients and uric acid levels were significantly reduced in all patients (P < 0.001). Drug related toxicities were mild and reversible without any grade 4 or serious adverse event associated with rasburicase. CONCLUSION: This study confirms that rasburicase is a safe and effective agent for the treatment of hyperuricemia associated with hematologic malignancies in pediatric patients.

Bulbous urethra involved in perineal extraskeletal myxoid chondrosarcoma in a child.

Extraskeletal myxoid chondrosarcoma is a rare soft-tissue sarcoma that usually occurs in deep soft tissues, especially those of the proximal extremities and limb girdles, but is rare in children. We present an unusual case of a tumor arising in the perineum and involving the bulbous urethra in a 21-month-old boy. The patient was treated with surgical excision and urethroplasty followed by combination chemotherapy.