Rescue Immune Tolerance Induction Research Articles

Immune Tolerance Induction Experience from a Single Institute in the United Arab Emirates

Background: Immune tolerance induction (ITI) is the gold standard approach for eradicating inhibitors and increasing patient tolerance to factor VIII. The success rate of ITI may vary depending on patient variables and factors relating to the pattern of treatment for the induction of immune tolerance. Children with recently diagnosed inhibitors are the best candidates for ITI, and those with favourable expected results should be offered ITI as soon as inhibitors are identified. Recombinant factor VIII Fc fusion protein has proved a therapeutic advantage in patients with high factor VIII inhibitor titers AIMS AND OBJECTIVES: To evaluate the clinical characteristics and outcomes of ten hemophilic pediatric patients who underwent ITI therapies to eliminate FVIII inhibitors at Tawam Hospital, UAE MATERIALS AND METHODS: The data of ten hemophilia A children aged 2–7 years with high inhibitor titers who underwent ITI therapy at Tawam Hospital, UAE, were retrospectively collected for this case series. A comparison of bleeds before and after the ITI therapy was also made. Patients with either failed or partially successful primary ITI therapy underwent rescue ITI therapy. Data analysis was performed using SPSS version 26. RESULTS: Full success was achieved in 60% (6/10) of the patients, 10% (1/10) achieved partial success, whereas 30% (3/10) failed the primary ITI therapy. The rescue ITI therapy was successful in 50% (2/4) of the patients and the remaining 50% (2/4) achieved partial success [Table 2]. The rescue ITI was successful in 66% (2/3) of those patients who received Elocta and partially successful in 33% (1/3) CONCLUSION: ITI therapy is the gold standard for the eradication of antibodies against FVIII. The patients with good expected outcomes should be offered ITI as soon as the inhibitors are confirmed. The use of extended half life rFVIIIFc demonstrated therapeutic benefit, particularly in challenging ITI patients with high inhibitor titers

Efficacy of rFVIIIFc for First-Time Immune Tolerance Induction (ITI) Therapy: Final Results from the Global, Prospective VerITI-8 Study

Efficacy of rFVIIIFc for First-Time Immune Tolerance Induction (ITI) Therapy: Final Results from the Global, Prospective VerITI-8 Study

Emerging benefits of Fc fusion technology in the context of recombinant factor VIII replacement therapy.

Although the primary reason for recombinant factor VIII Fc fusion protein (rFVIIIFc) development was to reduce treatment burden associated with routine prophylaxis, new evidence suggests additional benefits of Fc fusion technology in the treatment of people with haemophilia A. Preclinical research has been utilized to characterize the potential immunomodulatory properties of rFVIIIFc, including an ability to reduce inflammation and induce tolerance to factor VIII. This has since been expanded into clinical research in immune tolerance induction (ITI) with rFVIIIFc, results of which suggest the potential for rapid tolerization in first‐time ITI patients and therapeutic benefit in patients undergoing rescue ITI. The potential for improved joint health through the anti‐inflammatory properties of rFVIIIFc has also been suggested. In addition, a new avenue of research into the role of rFVIIIFc in promoting bone health in patients with haemophilia A, potentially through reduced osteoclast formation, has yielded encouraging results that support further study. This review summarizes the existing preclinical and clinical studies of immunomodulation and tolerization with rFVIIIFc, as well as studies in joint and bone health, to elucidate the potential benefits of rFVIIIFc in haemophilia A beyond the extension of factor VIII half‐life.

Immune Tolerance Induction (ITI) with a Plasma-Derived Factor VIII for Patients with Hemophilia a and Inhibitors: A Retrospective Study

Introduction: A serious complication in hemophilia A is the formation of inhibitors to clotting factors. The primary means for eradicating inhibitors is immune tolerance induction (ITI) therapy. Antihemophilic factor (human) (Koate®-DVI) is a purified dried concentrate indicated for the treatment of hemophilia A with insufficient activity of Factor VIII (FVIII). Although other plasma-derived concentrates containing von Willebrand factor have been utilized successfully for ITI, studies evaluating this product for ITI therapy have not been published. An evaluation of patient- and treatment-related factors associated with outcomes following primary or rescue ITI with antihemophilic factor (human) in patients with hemophilia A and inhibitors was conducted in this retrospective multicenter chart review project. Methods: An evaluation of medical records of 13 inhibitor patients treated with antihemophilic factor (human) for primary or rescue ITI therapy between January 1, 2012, and July 31, 2017, was conducted in five US hemophilia treatment centers. To be eligible for inclusion, patients were required to have a diagnosis of hemophilia A of any severity level, inhibitor to FVIII at the time of treatment initiation with antihemophilic factor (human), and ongoing treatment with antihemophilic factor (human) for primary or rescue ITI. Data were de-identified and analyzed descriptively. Outcome measures were defined, per the International Immune Tolerance consensus recommendations, as "complete success" (inhibitor titer <0.6 Bethesda Units [BU] at 33 months of ITI, FVIII recovery ≥66% and half-life ≥6 hours), "partial success" (a reduction in inhibitor titer to <5 BU mL with FVIII recovery <66% and/or FVIII half-life <6 hours associated with clinical response to FVIII therapy not followed by a treatment-limiting anamnestic rise in inhibitors to >5 BU mL), or "failure" (neither complete nor partial success). Results: All (N=13) patients who met the inclusion criteria were males with severe hemophilia, with the exception of one with moderate hemophilia. Six patients were African American, four were Hispanic, two Caucasian, and one was Asian. They were diagnosed with inhibitors between the ages of 8 months and 39 years and were 5 to 53 years old upon ITI with antihemophilic factor (human). Ten of 13 patients (76.9%) had successful ITI; seven with complete success and three with partial success (Table). Three patients failed ITI. As primary therapy, complete success was obtained with all but one of the six patients treated with antihemophilic factor (human). These six patients were all older than 7 at the initiation of ITI, a risk factor for poor ITI. Seven of the 13 total patients had a combined previous 12 attempts at ITI with other products (plasma derived and/or recombinant). Of these seven rescue patients, ITI with antihemophilic factor (human) was completely successful in two and partially successful in three. Adverse events reported once in separate patients during treatment with antihemophilic factor (human) included catheter infection, portal infection, bacteremia, peritonitis due to a ruptured appendix, and complications in treatment. One patient had several adverse events, including cellulitis at the port site, abdominal wall hematoma, right thumb fracture and hematoma, and left shoulder hemarthrosis. Conclusions: While retrospective data has limitations, real-world evidence demonstrates that ITI with antihemophilic factor (human) concentrate can be successful or partially successful in diverse populations of moderately complex patients with hemophilia A and inhibitors. The data suggest that antihemophilic factor (human) may be most appropriate for patients when used as primary ITI, as even patients older than 7 years achieved complete success. Additional patients need to be evaluated to make a definitive conclusion regarding the impact of age on success of ITI therapy in addition to other risk factors. Disclosures Escobar: Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; Takeda: Consultancy, Membership on an entity's Board of Directors or advisory committees; National Hemophilia Foundation: Consultancy, Membership on an entity's Board of Directors or advisory committees; Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees. Rajan:Bayer, Octapharma: Consultancy, Honoraria, Research Funding, Speakers Bureau. Amega:Kedrion Biopharma: Employment. OffLabel Disclosure: Koate is not approved to treat vWD, nor, cTTP however, based on some published reports using kotae for these indications, we are anticipating those type of off label inquiries. I will clearly disclose to the participants that these are off label indications.

Real-World Data of Immune Tolerance Induction Using rFVIIIFc in Subjects With Severe Hemophilia A With Inhibitors at High Risk for ITI Failure

Real-World Data of Immune Tolerance Induction Using rFVIIIFc in Subjects With Severe Hemophilia A With Inhibitors at High Risk for ITI Failure

Innowacyjna metoda prowadzenia ITI za pomocą preparatu czynnika VIII z frakcją Fc u pacjentów z hemofilią A z obecnością inhibitora czynnika VIII – przegląd literaturowy

Eradication of factor VIII inhibitors using Immune tolerance induction (ITI) treatment is the standard of care for severe haemophilia A patients presenting with factor VIII inhibitors, but is not always effective. A description of the potential immunological tolerance effect of the IgG Fc domain of recombinant factor VIII Fc fusion protein (rFVIIIFc), as well as published experience with rFVIIIFc for ITI in patients with severe haemophilia A and high-titre inhibitors. Review of published literature describing cases of ITI with rFVIIIFc in patients with severe haemophilia A and high-titre inhibitors between November 2015 and June 2018. Four publications has been found. Of 56 patients with haemophilia A who presented with FVIII inhibitors, 28 achieved a negative Bethesda titre (< 0.6) after ITI treatment using rFVIIIFc. Additional patients continued on rFVIIIFc ITI at the time of publication, while a few were reported to have switched to bypass therapy alone or other factors . For those still undergoing ITI, longer follow-up is needed to determine final outcomes. No adverse events were reported. Based on literature review, preliminary evidence of FVIIIFc use in high risk, first-time ITI suggests rapid time to tolerization. For rescue ITI, rFVIIIFc showed therapeutic benefit in some patients who previously failed ITI. These findings give hope but highlight the need for further evaluation in ongoing clinical trials.

Recombinant factor VIII Fc fusion protein for immune tolerance induction in patients with severe haemophilia A withinhibitors-A retrospective analysis.

Immune tolerance induction (ITI) is the gold standard for eradication of factor VIII inhibitors in severe haemophilia A; however, it usually requires treatment for extended periods with associated high burden on patients and healthcare resources. Review outcomes of ITI with recombinant factor VIII Fc fusion protein (rFVIIIFc) in patients with severe haemophilia A and high-titre inhibitors. Multicentre retrospective chart review of severe haemophilia A patients treated with rFVIIIFc for ITI. Of 19 patients, 7 were first-time ITI and 12 were rescue ITI. Of 7 first-time patients, 6 had at least 1 high-risk feature for ITI failure. Four of 7 first-time patients were tolerized in a median of 7.8months. The remaining 3 patients continue on rFVIIIFc ITI. Of 12 rescue patients, 7 initially achieved a negative Bethesda titre (≤0.6) in a median of 3.3months, 1 had a decrease in Bethesda titre and continues on rFVIIIFc ITI and 4 have not demonstrated a decrease in Bethesda titre. Of these 4, 3 continue on rFVIIIFc ITI and 1 switched to bypass therapy alone. Two initially responsive patients transitioned to other factors due to recurrence. Overall, 16 of 19 patients remain on rFVIIIFc (prophylaxis or ITI). For those still undergoing ITI, longer follow-up is needed to determine final outcomes. No adverse events reported. Recombinant factor VIII Fc fusion protein demonstrated rapid time to tolerization in high-risk first-time ITI patients. For rescue ITI, rFVIIIFc showed therapeutic benefit in some patients who previously failed ITI with other products. These findings highlight the need to further evaluate the use of rFVIIIFc for ITI.

Long-term outcome of haemophilia A patients after successful immune tolerance induction therapy using a single plasma-derived FVIII/VWF product: the long-term ITI study.

Immune tolerance induction (ITI) is a standard intervention to eradicate inhibitors in haemophilic patients. However, information on the long-term condition of patients who eradicated the inhibitor totally or partially after ITI is scarce. To perform a long-term follow-up to describe the status of patients reported as ITI success in the G-ITI study. This was an international, multicentre, observational, retrospective study of the 57 haemophilic patients who were reported as ITI success in the G-ITI study. Demographics and post-ITI clinical data recorded until January 2015 were extracted from the medical records. A descriptive analysis was undertaken. Forty-four patients were evaluable. Post-ITI follow-up was 9.1 years in average. Thirty-seven target joints were affected in 21 patients; 38 patients presented bleeding with a mean of 1.0 ± 1.2 episodes year-1 , most of them (271/330) treated with Fanhdi® (Grifols). Around half of the patients underwent at least one surgical procedure. Most venous access complications were of expected nature, requiring hospital stay in practically all cases. Fanhdi was used in 42 patients as the regular haemophilia treatment after ITI, mainly prophylactically. Three patients (6.8%) who were being treated with Fanhdi (prophylaxis), Kogenate (prophylaxis) and Emoclot (on demand), respectively, showed inhibitor relapse (at 29, 53 and 13 months after ITI, with 0.9, 3.65 and 12.5 BU respectively). All of them were successfully tolerized after rescue ITI. After ITI success, all patients continued with regular successful FVIII treatment for haemophilia for more than 9 years. The few inhibitor relapses were successfully overcome after rescue ITI.

Long-Term Follow-up of Hemophilia a Patients Who Previously Showed Complete or Partial Success in Immune Tolerance Induction Therapy with a Single Plasma-Derived FVIII/VWF Product: Long-Term ITI Study

IntroductionInhibitor development against infused FVIII is a serious complication in hemophilia A that greatly increases the risk of developing major bleeding episodes. Immune tolerance induction (ITI) is the standard therapy for the management and eradication of inhibitors and return to effective FVIII therapy. Little evidence exists on the long-term status of patients who eradicated the inhibitor totally or partially by ITI. Therefore, the aim of this study is to investigate the clinical status and sustainability of tolerance in patients who succeeded on ITI therapy.MethodsThe Long-term ITI study was an international, multicenter, observational, retrospective study performed on hemophilia A patients who received primary or rescue ITI therapy using a single pdFVIII/VWF concentrate (Fanhdi®, Grifols, Spain) and who showed partial or total success in the Grifols-ITI study (Oldenburg J et al. Haemophilia 2014;20:83, Rangarajan S et al. J Thromb Haemost 2013;11 suppl 2;1081). In the G-ITI study, 60 patients from Germany, Italy and Spain showed a success rate of 85% and nine other G-ITI patients from UK obtained a 78% of ITI success. Demographics and clinical data relevant for the Long-term ITI study were extracted from the medical records of eligible patients. Primary endpoints were to describe the long-term status and post-ITI outcomes (including comorbidities, joint status, bleeding episodes, inhibitor relapses, venous access complications, hospitalizations and surgeries). Secondary endpoints included regular hemophilia therapy as well adjuvant and concomitant therapy used. Statistical analysis performed was descriptive.ResultsForty-four out of the 57 eligible patients signed the informed consent and were included in the study. The mean follow up period after ITI success was 9.3 ±3.3 years (range: 2.1-17.7). At least one co-morbidity was reported in 17 (38.6%) patients, which included liver and lung cancer, hypertension, liver disease, hepatitis C and HIV infection. Twenty-one (47.7%) patients had a total of 37 affected -joints of which 5 patients had 2 affected joints, 1 patient had 3 affected joints and 3 patients had 4 affected joints. In 38 (86.4%) patients at least 1 bleeding episode was reported (mean annual bleeding rate: 1.0±1.2; range 0.1-3.9). A total of 330 bleeding episodes were described, of which 271 were treated with Fanhdi. Four (9.0%) patients had inhibitor relapse. Of those, 2 patients did not attempt rescue ITI because in one case the inhibitor (0.5 BU) disappeared after the next infusion with Fanhdi, and the other was considered of low titer (3.5 BU). The 2 patients who attempted rescue ITI (one under prophylaxis with Kogenate and the other treated on demand with Emoclot at the time of inhibitor relapse) were both successfully tolerized, one completely after 3.9 months of ITI with Fanhdi and the other partially after 9.1 months of ITI with Haemate P. Twenty venous access complications were reported in 10 (22.7%) patients. Thirty-nine surgical/invasive procedures were reported in 22 (50.0%) patients, 37 procedures requiring extra treatment with FVIII (Fanhdi), 25 of them for more than 3 days and 14 for more than 5 days. Hospitalizations reported were 79, 17 of them due to bleeding, 18 due to venous access complications, 33 due to surgical/invasive procedures, and 11 due to other reasons. Treatment product for hemophilia after ITI success was always Fanhdi in 29 (65.9%) patients, while 13 (29.5%) other patients were first treated with Fanhdi and then switched to other FVIII products, and 2 patients were immediately switched post-ITI to other FVIII products. The most common regimen used was prophylaxis (42 patients, 95.4%), and the most common treatment frequency was every 48 hours (16 patients, 36.4%). The FVIII dose ranged from 20 to 85 IU/Kg. Use of NSAIDs was reported for 6 patients and immunesuppressors for 5 patients.ConclusionsAfter an average of more than 9 years of post-ITI success follow up of patients participating in the G-ITI Study, all of them continue with regular FVIII treatment for hemophilia. The few inhibitor relapses were successfully overcome. DisclosuresJiménez-Yuste:Baxter, Bayer, CSL-Behring, Grifols, Novo Nordisk, Octapharma and Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau. Oldenburg:Baxter, Bayer, Biogen Idec, Biotest, CSL-Behring, Grifols, Novo Nordisk, Octapharma, Swedish Orphan Biovitrum and Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau. Rangarajan:Baxter, Grifols, Biotest and Pfizer: Consultancy, Honoraria, Research Funding, Speakers Bureau. Peiró:Grifols: Employment. Santagostino:Bayer, Baxter, Pfizer, CSL Behring, Novo-Nordisk, Sobi/Biogen, Octapharma, Kedrion, Roche and Grifols: Consultancy, Honoraria, Research Funding, Speakers Bureau.

Outcome of the Japanese Immune Tolerance Induction (ITI) Registry and Predictors of Successful ITI

[Background] Immune tolerance induction (ITI) therapy is the only therapeutic approach that can eradicate factor (F)VIII and FIX inhibitors in patients with hemophilia A (HA) and B (HB), respectively. Although results of several retrospective cohort studies have been published, predictors of successful outcome are still debated. Nonetheless, little information is so far available in terms of large ITI cohort in non-Caucasian countries.[Aim] In this study, we performed a retrospective cohort study on ITI therapy carried out for Japanese hemophilia patients with inhibitors to understand the status of practice on this therapy in Japan and to study the predictors of successful outcome.[Methods] As of March 31, 2015, the registry of ITI therapy in Japanese hemophilia patients had received reports on 155 HA patients (140 severe type, high responder 69.1%) and 7 HB patients (7 severe type, high responder 42.5%) who have undergone this therapy from 45 hospitals including Hemophilia Treatment Centers since 2000. The ITI outcome was centrally reviewed. The success of ITI was defined as an undetectable inhibitor for 2 successive measurements, and the salvage ITI was defined as any rescue ITI regimen by using von Willebrand factor-containing FVIII concentrates.[Results] Among the completed ITI courses, the overall success rate of ITI therapy was 71.2% (94/132) and 83.3% (5/6) for HA and HB patients, respectively. Cumulated ITI success rates of 50% and 80% for HA patients were achieved at 1.6 and 4.3 years after the inhibitor diagnosis, and 0.6 and 2.3 years after the initiation of ITI, respectively. Significant predictors for success of ITI in HA were (i) low responding inhibitors (success 35/37 (94.5%)) compared to high responding inhibitors (59/93 (63.4%); p <0.0001), (ii) shorter intervals from inhibitor diagnosis to the initiation of ITI (success (S): 1.85±3.52 vs failure (F): 3.38±3.77 years; p =0.02), (iii) lower historical peak titers on pre-ITI (S: 24.9±55.2 vs F: 132±295 BU/ml; p =0.04), and (iv) lower peak inhibitor titers on-ITI (S: 72.4±231 vs F: 916±1,307 BU/ml; p <0.01). However, outcome was not significantly different (p =0.77) between high dose regimens (>90 IU/kg, 7 days/wk) and low dose regimens (<75 IU/kg, 3 days/wk). Also, either FVIII products (plasma-derived or recombinant) at the initiation or the insertion of central venous access devise (CVAD) did not affect the outcome (p =0.32 and 0.85). Although the outcome prediction was difficult for HB because of low number of the cases registered, success rate was much higher than those of previous reports. The success rate of salvage ITI was 50% (6/12) for HA. The significant predictive parameter for outcome was only the age at the initiation of salvage ITI (p =0.03). The inhibitor relapsed in 6 cases, and all cases were HA patients (4.5% 6/140). In 86 cases with insertion of CVAD, the catheter-related infection was complicated in 21 cases (12.9%).[Conclusion] This study underscores the importance of initiating the ITI as early as possible after the diagnosis of inhibitor and the low response of inhibitor titer before and during the ITI to maximize the success of the treatment for Japanese hemophilia patients. DisclosuresNogami:Chugai: Membership on an entity's Board of Directors or advisory committees; Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding. Taki:Biogen, Baxalta, Bayer, Novo, Pfizer: Honoraria; Biogen, Baxalta, NovoNordisk, CSL-Behring, Kaketsuken, Chugai: Research Funding. Matsushita:Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Baxalta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Biogen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; CLS-Behling: Research Funding; Japan Blood Products Organization: Honoraria, Research Funding; Kyowa-Kirin: Honoraria, Research Funding; Octapharma AG: Honoraria; Sysmex: Speakers Bureau; Seamens: Speakers Bureau; Nihon Pharmaceutical: Honoraria, Research Funding, Speakers Bureau; Kaketsuken: Honoraria, Research Funding, Speakers Bureau; Asahi Kasei Pharma: Honoraria, Research Funding, Speakers Bureau; Eisai: Research Funding; Novartis Pharma: Honoraria, Speakers Bureau; Bayer Healthcare: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Novo Nordisk Pharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Chugai Pharmaceutical Co., Ltd.: Research Funding. Hanabusa:Novo Nordisk, Baxalta, Bayer, Pfizer, Biogen, and KaketsuKen: Honoraria; Novo Nordisk, Baxalta, KaketsuKen, and Biogen: Membership on an entity's Board of Directors or advisory committees. Shima:Pfizer: Honoraria, Research Funding; Kaketsuken: Honoraria; Biogen: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; Baxalta: Honoraria, Research Funding.

ITI choice for the optimal management of inhibitor patients - from a clinical and pharmacoeconomic perspective.

The development of alloantibody inhibitors against factor VIII (FVIII) represents the most significant complication of haemophilia care. Inhibitors tend to develop early in the course of treatment in about 20-30% of patients with severe haemophilia who receive on-demand or prophylactic FVIII therapy. Many factors are associated with inhibitor formation, including disease severity, major FVIII gene defects, family history and non-Caucasian race, as well as age at first treatment, intensity of early treatment, use of prophylaxis and product choice. As these latter treatment-related variables are modifiable, they provide opportunity to minimize inhibitor incidence at the clinical level. Data from the Bonn Centre in Germany have indicated an overall success rate of 78% for immune tolerance induction (ITI) therapy, with a failure rate of 15% and with some treatments either ongoing (3%) or withdrawn (4%). Similarly, data from the G-ITI study, the largest international multicentre ITI study using a single plasma-derived (pd) FVIII/von Willebrand factor (VWF) product, have demonstrated success rates (complete and partial) in primary and rescue ITI of 87% and 74%, respectively, with 85% of poor prognosis patients achieving success. Favourable clinical results based on success rates and time to tolerization continue to be reported for use of pdFVIII/VWF in ITI, with pdFVIII/VWF having a particular role in patients who require rescue ITI and those with a poor prognosis for success. Data from prospective, randomized, controlled clinical studies, such as RES.I.ST (Rescue Immune Tolerance Study), are eagerly awaited. Another factor to consider with ITI therapy is cost; preliminary data from an updated decision analytic model have provided early evidence that ITI has an economic advantage compared with on-demand or prophylactic therapy.

Primary and rescue immune tolerance induction in children and adults: a multicentre international study with a VWF‐containing plasma‐derived FVIII concentrate

Most studies on immune tolerance induction (ITI) therapy in haemophilia A patients are focused on primary ITI in children. Here we report on the ITI outcome in a large retrospective cohort, including adults and patients with rescue ITI, treated with a pdFVIII/VWF concentrate. Retrospective data from haemophilic patients (FVIII< 2%) with inhibitors from 22 centres in Spain, Italy and Germany, who underwent primary or rescue ITI with pdFVIII/VWF concentrate, were collected. Complete success (CS), partial success (PS) and failure were defined based on the criteria of the consensus recommendations of the 2006 International ITI Workshop. A total of 41 cases of primary ITI (32 children and 9 adults) and 19 cases of rescue ITI (17 children and 2 adults) were evaluated. Success (CS+PS) rate of 87% was achieved in primary ITI and 74% in the higher risk profile of rescue ITI. Eight of nine (85%) patients with poorest prognosis (three or more of the known risk factors of poor response to ITI) achieved success (CS+PS). CS of 100% was observed in eight primary ITI patients with titre at start of ITI ≤2.5 BU and inhibitor peak ≤25 BU. The favourable response rates in primary and rescue ITI in children and in adult patients, even in the presence of poor prognostic factors, should be encouraged for broadening the indication of immune tolerance therapy in haemophilia A patients with inhibitors.

More than a decade of international experience with a pdFVIII/VWF concentrate in immune tolerance

Approximately 20-30% of patients with severe haemophilia A develop alloantibodies ('inhibitors') to infused FVIII rendering use of such replacement therapy ineffective. Once an inhibitor emerges, immune tolerance induction (ITI) is the standard treatment. ITI involves giving regular doses of FVIII concentrate to eradicate the inhibitor and achieve immunogenic acceptance of administered FVIII. In the early 2000s, a retrospective analysis of inhibitor patients treated at a single centre in Germany indicated that success rates were higher when patients were treated with von Willebrand factor (VWF)-containing plasma-derived FVIII (pdFVIII/VWF) concentrate compared with recombinant or non-VWF-containing pdFVIII products. Importantly, pdFVIII/VWF as rescue therapy was able to convert 8 of 10 patients who had failed primary ITI with recombinant or non-VWF-containing pdFVIII product. A subsequent study from Italy in patients with poor prognostic factors for ITI success also reported good success rates with pdFVIII/VWF as rescue therapy (53% success; 41% partial success). The Grifols-Immune Tolerance Induction (G-ITI) Study represents the largest group of haemophilia A inhibitor patients treated with a single pdFVIII/VWF concentrate (Alphanate(®)/Fanhdi(®)) to be reported to date. Data have been collected for 95 patients who underwent primary or rescue ITI at 46 centres in Europe and the US. Currently, published data are available for 33 patients in the US cohort (11 centres), and data from the European cohort are being analysed. Both groups contained patients with poor prognostic factors and most patients received a high-dose regimen (≥ 100 IU pdFVIII/VWF kg(-1) daily). As expected, the success rate was better for primary vs. rescue ITI and for patients with good vs. poor prognostic factors. However, more than half the patients in the US cohort receiving rescue ITI achieved success (33% complete success; 20% partial success). These results should encourage clinicians to consider the use of pdFVIII/VWF concentrates for rescue ITI. Published outcomes data from the total global G-ITI cohort (95 patients) are awaited with anticipation.

Rescue and Primary ITI in Children and Adults with a Single FVIII/VWF Product

AbstractAbstract 1174 IntroductionInhibitors are the most serious complication of hemophilia A (HA) treatment. Current optimal intervention for inhibitor eradication is immune tolerance induction (ITI), the goal of which is for the patient to resume therapy with FVIII. Basic and clinical research have strongly supported that VWF containing FVIII concentrates may be less immunogenic and are effective in primary ITI as well as for rescue ITI for those who fail to develop tolerance with recombinant proteins. ObjectiveTo assess the outcome of rescue and primary ITI in children (<18 years old) and adults with a single FVIII/VWF product (Fanhdi®, Grifols, Barcelona, Spain). MethodsRetrospective data from HA patients (FVIII< 2%) with inhibitors from 22 centers in Spain, Italy and Germany, who underwent primary or rescue ITI with FVIII/VWF concentrate were evaluated. Success, partial success and failure were defined based on the criteria of the consensus recommendations of the 2006 International ITI Workshop. ResultsThe largest international multicenter study on ITI using a single product has evaluated 41 cases of primary ITI (32 children and 9 adults) and 19 cases of rescue ITI (17 children and 2 adults).Table 1illustrates the overall response rates for children and adults.Table 1Primary ITIRescue ITIChildren (n = 49)Complete Success = 21 (65%)Complete Success = 6 (35%)Primary ITI – n = 32 (65%)Partial Success = 7 (22%)Partial Success = 6 (35%)Rescue ITI – n = 17 (35%)Failure = 4 (13%)Failure = 5 (30%)Adults (n = 11)Complete Success = 5 (56%)Complete Success = 1 (50%)Primary ITI – n = 9 (82%)Partial Success = 3 (33%)Partial Success = 1 (50%)Rescue ITI – n = 2 (18%)Failure = 1 (11%)Failure = 0Table 2describes the rescue and primary ITI outcome for high risk patients. Risk factors for poor response include: failure of a previous ITI, inhibitor peak >200 BU, age at ITI start >7 years old, titer ≥ 10 BU at ITI start and >24 months between diagnosis and start of ITI.Table 2Number of risk factors012345Primary ITI (n=41)Complete success127*2410Partial success212310Failure04*2000Rescue ITI (n=19)Complete success000430Partial success0013*12Failure011111*Time from diagnosis to ITI start not available in 1 patient (this risk factor is not considered in that patient). ConclusionThe response rate of 87% (CS+PS) in primary ITI exceeds that previously reported with any product class. The response rate (CS+PS) of 74% in the higher risk profile of rescue ITI is what one might expect for primary ITI. These excellent results, using a single VWF containing FVIII product, should encourage the use of this class of product for immune tolerance. Acknowledgments:The authors acknowledge Grifols financial support of the study. The authors also acknowledge Drs Jeffrey Spears and Roser Peiro, Grifols, for their editorial assistance in preparation of the abstract. Disclosures:Aledort:Grifols: Advisory Board Other, Honoraria; Kedrion: Advisory Board, Advisory Board Other; Baxter: DSMB, DSMB Other; Octapharma: DSMB, DSMB Other. Off Label Use: This FVIII is not licensed for ITI - nor is any other product. Oldenburg:d and e: Baxter, Bayer, Biotest, CSL-Behring, Grifols, Inspiration, NovoNordisk, Octapharma, Pfizer e: Biogen IDec, Swedish Orphan Biovitrum: Honoraria, Research Funding. Santagostino:Bayer, Baxter, Pfizer, CSL Behring, Novo Nordisk, Biotest, Kedrion and Grifols: Speakers Bureau; Pfizer, Baxter, Bayer, CSL Behring, Kedrion, Grifols and Novo Nordisk: Consultancy; Novo Nordisk and Pfizer: Research Funding. Jimenez Yuste:Grifols, Baxter, Pfizer, NovoNordisk: Advisory Board Other, Consultancy.

The use of a single von Willebrand factor-containing, plasma-derived FVIII product in hemophilia A immune tolerance induction: the US experience.

Inhibitors are a serious complication for patients with severe hemophilia A. Immune tolerance induction (ITI) is the primary method for eradicating these inhibitors. The role of type of concentrate and in particular the use of von Willebrand factor-containing, plasma-derived factor VIII (VWF/pd-FVIII) concentrate in primary or rescue ITI remains unclear. To report retrospective collection of data on the use of a single VWF/pd-FVIII concentrate in primary and rescue ITI. Retrospective chart review of hemophilia A inhibitor patients at 11 US institutions who received VWF/pd-FVIII concentrate in primary or rescue ITI. Primary ITI was carried out in eight inhibitor patients with a 75% complete and partial success. Secondary ITI was carried out in 25 inhibitor patients, with 52% attaining complete or partial success. This report represents the largest group of primarily pediatric, high-titer inhibitor patients treated with a single VWF/pd-FVIII concentrate. It adds retrospective data to the use of VWF-containing plasma-derived factor VIII concentrate in primary and rescue ITI, particularly in those patients with characteristics of poor response to ITI.

第VIII因子/フォン・ヴィレブランド因子製剤による救済免疫寛容導入療法により部分的成功に達したインヒビター陽性血友病Aの1例

第VIII因子/フォン・ヴィレブランド因子製剤による救済免疫寛容導入療法により部分的成功に達したインヒビター陽性血友病Aの1例