Natural History Of Inhibitor Recurrence Following Successful Immune Tolerance Induction

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1106-1106 ◽  
Author(s):  
Ana G. Antun ◽  
Paul Monahan ◽  
Marilyn J. Manco-Johnson ◽  
Michael Callaghan ◽  
Guy Young ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Immune Tolerance ◽  
Half Life ◽  
Research Funding ◽  
Tolerance Induction ◽  
Advisory Committees ◽  
Immune Tolerance Induction ◽  
Baxter Healthcare ◽  
Inhibitor Titer

Abstract Introduction The formation of Factor VIII (FVIII) inhibitory antibodies is a major complication of hemophilia A. Currently immune tolerance induction (ITI) is successful in up to 70% of patients. Outside of the International Immune Tolerance Registry, where 6 of 128 patients had a recurrent inhibitor between 1 and 6 years, little is known about the probability of inhibitor recurrence following successful ITI. Objective To determine the probability of inhibitor recurrence and the influence of adherence to post-ITI prophylaxis on inhibitor recurrence following successful ITI. Methods All persons with hemophilia A (FVIII level < 50%) who completed ITI (defined as inhibitor titer <0.6 BU/ml) between 1/1/1998 and 8/15/2010 at 12 U.S. Hemophilia Treatment Centers were identified. Demographic and clinical characteristics were obtained through review of subject medical records and included age at start of ITI, race, ethnicity, hemophilia severity, peak inhibitor titer prior to the start of ITI and ITI regimen. For those subjects where tolerance was confirmed with measurement of FVIII half-life > 6 hours and/or FVIII recovery > 66% in addition to inhibitor titer < 0.6 BU/ml, information was also collected on post-ITI prophylaxis regimen, adherence to post-ITI prophylaxis, and the presence of a recurrent inhibitor titer (≥ 0.6 BU/ml) or last inhibitor titer prior to 8/15/2011. Adherence during the 6 months prior to inhibitor recurrence or last inhibitor titer was determined by review of pharmacy and infusion logs compared with prescribed treatment regimen. Follow-up time started when the subject was considered tolerized (normalized half-life or recovery if half-life not performed) and ended at the time of inhibitor recurrence or the last recorded inhibitor titer. Estimates of the probability of remaining inhibitor-free at 1, 3 and 5 years were calculated with the Kaplan-Meier method. The association between adherence (completing >80% of prescribed infusions vs. < 80% of prescribed infusions) and inhibitor recurrence was assessed using the chi-square test. Results Eighty-three male subjects were enrolled. The median age at start of ITI was 3.3 years (range: 0.08 - 39). The majority of the subjects were white (73%) and non-Hispanic (73.5%). Seventy-one (85.6%) had severe hemophilia. The median peak inhibitor titer was 8.5 BU/ml (range: 0.6 - 950). Four subjects (5%) had a prior unsuccessful course of ITI. FVIII alone was used in 85% of subjects. Sixty-seven (80.7%) met criteria for tolerance and 64 had follow-up data available, with a median follow up time of 3.4 years (range: 0.08-12.4). Forty-four subjects (68.7%) remained tolerant without a recurrent inhibitor titer after a median 4.7 years (range: 0.25-12.4) of follow-up. Twenty subjects (31.3%) had at least one inhibitor titer ≥ 0.6 BU/ml after a median of 1.6 years (range 0.08-5.7). The probability of recurrent inhibitor at 1 year is 0.15 (95% CI: [0.05, 0.20]); at 3 years is 0.30 (95% CI: [0.2, 0.4]) and 5 years is 0.35 (95% CI: [0.2, 0.5]) (Figure 1). Four subjects discontinued post-ITI prophylaxis anywhere from 6 months to greater than 6 years after tolerance was achieved, of whom 2 (50%) developed a recurrent inhibitor. Of those that remained on post-ITI prophylaxis, 41 subjects (64.1%) were adherent (took >80% of prescribed infusions) to their post-ITI prophylaxis regimen, of whom 13 (31.7%) developed a recurrent inhibitor. Twenty-three (35.9%) who were non-adherent (took <80% of the prescribed infusions) of which 7 (30.4%) subjects developed a recurrent inhibitor; no statistically significant association was found between adherence and inhibitor-free status (p=0.92). Conclusion ITI is currently the most effective treatment to eradicate FVIII inhibitors, however 5 years after completion, 30-35% of patients will have at least one inhibitor titer ≥ 0.6 BU/ml. A recurrent inhibitor is unlikely after 5 years. Adherence to post-ITI prophylaxis does not appear to be a major driver of inhibitor recurrence. It is imperative to elucidate the factors that influence the durability of successful ITI to improve quality of life and cost of treatment in these patients. Disclosures: Monahan: Baxter: Consultancy, Honoraria, Research Funding, travel support, travel support Other; Bayer: Honoraria, Membership on an entity’s Board of Directors or advisory committees; Novo Nordisk: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria; Prolor Biotech: Research Funding; Asklepios: Consultancy, Research Funding, travel support Other. Manco-Johnson:Eisai: Research Funding; Novo Nordisk: Membership on an entity’s Board of Directors or advisory committees; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees; Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees; CSL Behring: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Bayer HealthCare: Membership on an entity’s Board of Directors or advisory committees, Research Funding. Carpenter:Novo Nordisk: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Grifols: Honoraria, Research Funding. Kruse-Jarres:Bayer HealthCare: Consultancy; Biogen IDEC: Consultancy; Grifols: Consultancy; Kedrion: Consultancy; Novo Nordisk: Consultancy; Baxter Healthcare: Consultancy. Ragni:Novo Nordisk: Research Funding; Merck: Research Funding; CSL Behring: Research Funding; Bayer: Research Funding; Baxter: Research Funding; Tacere Benitec: Consultancy; Smith Kline Glaxo: Consultancy, Research Funding; Bristol Myers Squibb: Consultancy, Research Funding; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding. Kempton:Novo Nordisk: Research Funding; Baxter Healthcare: Membership on an entity’s Board of Directors or advisory committees.

scholarly journals Low-Dose Immune Tolerance Induction for Hemophilia a Children with Poor-Risk High-Titer Inhibitors

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1122-1122
Author(s):  
Zekun Li ◽  
Zhenping Chen ◽  
Xiaoling Cheng ◽  
Xinyi Wu ◽  
Li Gang ◽  
...  
Keyword(s):  
Success Rate ◽  
Board Of Directors ◽  
Immune Tolerance ◽  
Low Dose ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Advisory Committees ◽  
Immune Tolerance Induction ◽  
Inhibitor Titer

Background: Low-dose immune tolerance induction (ITI) +/- immunosuppression as a practical ITI strategy in China showed a relatively satisfactory success rate and economic advantages in pilot study. However, the outcome still needs to be verified by larger cohort. Aim: To report the efficacy of this low-dose ITI +/- immunosuppression strategy in hemophilia A children ≥ 10 BU. Methods: This was a single center, prospective study in 53 hemophilia A subjects from Sep 2016 to Apr 2019. All subjects having ≥ 10 BU receiving ~50IU/kg FVIII every other day using domestic intermediate purity pdFVIII/VWF products, either alone or in combination with rituximab and prednisone judging by inhibitors and ITI response. Results: Finally, 46 subjects received this strategy at a median of 3.2 (IQR, 2.3-6.5) years old, their pre-ITI inhibitor titer was median 30.0 (range, 10.1-416) BU. Analysis at median 15.1 (range 3.0-34.4) months follow-up, success (inhibitor <0.6BU) was achieved in 32 (69.6%) subjects, partial success (inhibitor <5BU but >0.6BU) in 11 (23.9%) subjects, and failure in 5 (10.9%) subjects. Between subjects administered ITI-alone and ITI- immunosuppression, no significant difference was observed in time to success (median 8.5; IQR 6.7-11.7 vs 10.2; IQR 5.1-25.1, P=0.164). The mean monthly bleeding rate on ITI was 0.49 which declined 59.3% compared with pre-ITI period. Subjects administered ITI-immunosuppression (0.54 ± 0.46) was higher than ITI-alone (0.42 ± 0.69) although with no significantly difference (P=0.089). Seven (21.9%) subjects experienced inhibitor recurrence, 4 subjects treated with ITI-alone, 3 with ITI-immunosuppression. Recurrence occurred at a median of 4.8 (range, 2.8-10.8) months after successful ITI with inhibitor titer transiently rising to median 0.7 (range, 0.7-1.5) BU. Conclusion: This low-dose ITI +/- immunosuppression therapy in subjects with pre-ITI inhibitor ≥ 10 BU showed a success rate similar to other high/intermediate-dose regimen for the whole inhibitor patients. The subjects treated with ITI-immunosuppression did not showed higher recurrence at present, while a longer time follow-up is still needed. Disclosures Poon: Roche: 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; Bioverativ/Sanofi: Consultancy, Membership on an entity's Board of Directors or advisory committees; World Federation of Hemophilia: Other: Not-for-profit organization affiliation: volunteer ; Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Participation in sponsored research; CSL-Behring: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Grant Funding; Bayer: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Grant Funding; Takeda/Shire: Consultancy, Membership on an entity's Board of Directors or advisory committees; Octapharma: Consultancy, Membership on an entity's Board of Directors or advisory committees.

scholarly journals Immune Tolerance Induction Using Rfviiifc (Eloctate)

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 3531-3531 ◽  
Author(s):  
Lynn M. Malec ◽  
Margaret V Ragni ◽  
Janna M. Journeycake ◽  
Michelle Alabek
Keyword(s):  
Board Of Directors ◽  
Immune Tolerance ◽  
Half Life ◽  
Research Funding ◽  
Hemophilia A ◽  
Central Venous Access ◽  
Tolerance Induction ◽  
Severe Hemophilia ◽  
Advisory Committees ◽  
Immune Tolerance Induction

Abstract Introduction: Inhibitor formation affects approximately 30% of individuals with severe hemophilia A. The eradication of inhibitors using immune tolerance induction (ITI) remains the mainstay of therapy, although typically requires daily high-dose factor VIII via a port for up to a year. Extended half-life recombinant factor VIII Fc fusion protein (rFVIIIFc, Eloctate¨) has a half-life extension 1.5-fold longer than standard recombinant FVIII (rFVIII), reducing treatment frequency, and also induces regulatory T cell response to FVIII in animal models. We hypothesized that rFVIIIFc would provide more effective ITI, specifically shortening ITI, than rFVIII. We describe ITI with rFVIIIFc in three patients with severe hemophilia A. Methods: Immune tolerance induction was initiated with rFVIIIFc (Eloctate) in three children with severe hemophilia A and an anti-FVIII inhibitor. Dosing was per MD discretion with family agreement, and performed by central venous access device or intravenous infusion via heplock. Follow-up was scheduled every 6-8 weeks, with planned determination of FVIII half-life once the anti-FVIII fell to <0.6 B.U. Tolerance was a priori defined as achieving anti-FVIII <0.6 B.U. and half-life, t½ >6 hours. FVIII half-life was determined by one-stage FVIII:C assay on citrate samples drawn pre- and 10 minutes, 1, 2, 4, and 6 hours post-infusion of a single dose of rFVIIIFc. Once a t½ >6 hours was documented, incremental reduction to 50 IU/kg every other day or three times weekly, once there was evidence of maintenance of inhibitor neutralization and a >6 hour FVIII:C half-life. Results: Immune tolerance induction was initiated with rFVIIIFc at a dose of 100-200 IU/kg rFVIIIFc via central venous access device every other day or three times weekly per MD discretion in three children with severe hemophilia A and in anti-FVIII inhibitor > 5 B.U. (Table 1). Two patients had F8 genetic testing. In two patients, Pt 1 and Pt 3, this was the initial ITI course, and in the third child (Pt 2) this was salvage ITI after failing to achieve tolerance due to noncompliance with daily rFVIII ITI taper regimen. In two rFVIIIFc ITI was begun when anti-FVIII was < 10 B.U. Historic peak titers were 16-422 B.U. The time to anti-FVIII tolerance was 4-12 weeks Discussion: Immune tolerance induction was successful in three children with inhibitors using rFVIIIFc, including a child previously failing rFVIII ITI. The time to anti-FVIII=0 was 4-12 weeks, significantly shorter than with current rFVIII ITI. There were no adverse effects. These data indicate that rFVIIIFc safely and effectively induced immune tolerance to FVIII in children with inhibitors. Whether ITI may be accomplished more rapidly with rFVIIIFc, and the optimal dose for ITI will require prospective studies. A prospective observational study of rFVIIIFc ITI pre- and post-ITI T cell responses in children with hemophilia and inhibitors, the H emophilia I nhibitor R esponse to E loctate (HIRE) Study, is underway. Table 1. Immune Tolerance Induction with rFVIIIFc in Hemophilia A Inhibitor Patients Patient (Pt) Hemophilia Severity F8 Gene Mutation Age at Anti-FVIII Detection Peak Anti-FVIII Titer Initial ITI Dose Time toAnti-FVIII = 0 Current Anti-FVIII 1 <0.01 IU/ml Intron 22 inversion 13 months 32 B.U. 200 IU/kg QOD 12 weeks 0 B.U. 2 < 0.01 IU/ml Exon 18 nonsense variant 9 months 422 B.U. 200 IU/kg 3x/week 4 weeks 0 B.U. 3 <0.01 IU/ml Not available 10 years 16 B.U. 100 IU/kg QOD 11 weeks 0 B.U. Disclosures Malec: Baxter: Research Funding; Biogen: Research Funding. Ragni:Pfizer: Research Funding; Tacere Benitec: Membership on an entity's Board of Directors or advisory committees; Baxalta: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Research Funding; Dimension: Research Funding; Vascular Medicine Institute: Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL Behring: Research Funding; SPARK: Research Funding; Biomarin: Research Funding; Genentech Roche: Research Funding; Bayer: Research Funding; Biogen: Research Funding; Alnylam: Research Funding. Journeycake:CSL, Baxalta, NovoNordisk: Consultancy; ATHN: Research Funding; Biogen: Speakers Bureau; ATHN: Membership on an entity's Board of Directors or advisory committees.

Durability of ITI Utilizing Rfviiifc

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3793-3793
Author(s):  
Margaret V. Ragni ◽  
Lynn M. Malec ◽  
Janna M. Journeycake
Keyword(s):  
Immune Tolerance ◽  
Half Life ◽  
Research Funding ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Severe Hemophilia ◽  
Immune Tolerance Induction ◽  
Viii Inhibitor ◽  
Inhibitor Titer

Introduction: The eradication of inhibitors using immune tolerance induction (ITI) remains the mainstay of therapy in patients with severe hemophilia A who develop inhibitors. The long-acting recombinant factor VIII Fc fusion protein, rFVIIIFc (Eloctate™), which is safe and effective in the prevention and treatment of bleeding events, may promote tolerance to FVIII as shown in preclinical animal models and an inhibitor prone child, as Fc suppresses immunoregulatory Tcells to proteins to which Fc is attached. We therefore previously hypothesized rFVIIIFc would provide effective ITI, specifically shortening and simplifying ITI, and have previously described successful inhibitor eradication in three patients. Long-term follow-up data after successful ITI in patients with severe hemophilia remains limited. In the International Immune Tolerance Induction study, at 1-year follow-up, 6 of 66 subjects who had achieved tolerance demonstrated evidence of relapse at a median of 9.5 months. Of these 6 subjects, 1 had a measurable inhibitor titer and 5 had reduced FVIII recovery. We aim to provide follow-up data on our cohort of patients who had successful inhibitor eradication utilizing rFVIIIFc for ITI. Methods: Immune tolerance induction was initiated in three patients with severe hemophilia A and anti-VIII >5 B.U., in two as initial ITI (Pt. 1, 3), and one as salvage (Pt. 2) after failing to achieve ITI with standard rFVIII due to poor compliance. Follow-up was scheduled every 6-8 weeks, with planned determination of FVIII half-life once the anti-FVIII fell to <0.6 B.U. Tolerance was a priori defined as achieving anti-FVIII <0.6 B.U., FVIII recovery of at least 60%, and half-life (t½) >6 hours. Once a t½ >6 hours was documented, incremental reduction to rFVIIIFc occurred. Patients continued to be followed by their local HTC as per standard of care. Results: ITI was initiated with rFVIIIFc at a dose of 100-200 IU/kg rFVIIIFc every other day or three times weekly per MD discretion. The time to initial anti-FVIII <0.6 B.U. was 4-12 weeks. Patient 1 and 2 were able to achieve tolerance, with a FVIII recovery of at least 60%, and half-life (t½) >6 hours, at weeks 18 and 17, respectively, after initiation of ITI. Patient 3 has improved but is not yet fully tolerized, as evidenced by 57% recovery and a t½ of approximately 7 hours. Anti-VIII inhibitor titers remain negative at 15, 16 and 15 months, from the initiation of ITI in patients 1, 2, and 3 respectively. Patients 1 and 2 have been able to decrease their post ITI prophylaxis dosing regimen to 80 IU/kg and 65 IU/kg three times a week while maintaining a FVIII trough of >1%. No patients were maintained on bypassing prophylaxis during ITI and no patients have experienced hemarthroses or other major bleeding event since the initiation of ITI. Discussion: Immune tolerance induction was successful in three children with inhibitors using rFVIIIFc, including a child previously failing rFVIII ITI. The time to anti-FVIII=0 was 4-12 weeks, significantly shorter than with current rFVIII ITI. At a mean duration of follow up of 15.3 months, all patients achieved an anti-VIII inhibitor titer of 0 B.U. Repeat pharmacokinetics studies will be available at planned subsequent follow-up visit. To date, these data indicate that rFVIIIFc safely and effectively induced immune tolerance to FVIII in three children with inhibitors, and has provided durable and continuing immune tolerance to FVIII. Whether rFVIIIFc ITI will be successful and durable in a larger cohort of children with severe hemophilia A will require prospective studies. A prospective observational study of rFVIIIFc ITI pre- and post-ITI T cell responses in children with hemophilia and inhibitors, the Hemophilia Inhibitor Response to Eloctate (HIRE) Study, has begun recruitment. Disclosures Ragni: SPARK: Research Funding; Shire: Consultancy; Novo Nordisk: Research Funding; Genentech: Research Funding; CSL Behring: Research Funding; Biomarin: Consultancy; Biogen: Consultancy, Research Funding; Baxalta: Research Funding; Alnylam Pharmaceuticals: Consultancy, Research Funding; Tacere Benitec: Consultancy; Vascular Medicine Institute: Research Funding; OPKO: Research Funding. Malec:Vascular Medicine Institute: Research Funding; Biogen: Research Funding; Baxalta: Research Funding; Biogen: Consultancy. Journeycake:CSL: Consultancy; Biogen: Consultancy; Baxalta/Shire: Consultancy.

scholarly journals Treatment of Haemophilia a (HA) Patients with Inhibitors: Immune Tolerance Induction with a Single Factor VIII/Von Willebrand Factor Concentrate in an Observational Immune Tolerance Induction Study (ObsITI)

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2482-2482
Author(s):  
C. Escuriola Ettingshausen ◽  
Erik Berntorp ◽  
Yesim Dargaud ◽  
Zeynep Gutowski ◽  
Claude Negrier ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Von Willebrand Factor ◽  
Immune Tolerance ◽  
Research Funding ◽  
Tolerance Induction ◽  
Advisory Committees ◽  
Immune Tolerance Induction ◽  
Inhibitor Titre ◽  
Von Willebrand ◽  
Willebrand Factor

Abstract Introduction and objectives: Development of neutralising inhibitors against factor VIII (FVIII) is one of the most serious and costly complications in the treatment of HA. An ongoing international, open-label, uncontrolled, multicentre observational study, ObsITI (ClinicalTrials.gov. NCT 02207894) started in 2005 to assess immune tolerance induction (ITI), the standard of care in patients with inhibitors. The study evaluates patient- and therapy-related variables on ITI course, outcome and morbidity in HA patients with inhibitors. ObsITI satellite studies additionally look at other factors related to tolerisation. Methods and Materials: As of February 2018, 193 patients from 20 countries undergoing ITI have been recruited in ObsITI. 152 patients completed the study and 41 are ongoing. A subgroup of more than 80 prospective patients were treated exclusively during the complete ITI course with a single plasma-derived (pd) FVIII concentrate that contains von Willebrand factor (VWF) in a VWF/FVIII ratio of 0.4 (Octapharma AG). According to the recommended Bonn protocol, low responders at ITI start received 50-100 IU FVIII kg-1 daily, or every other day; high responders received 100 IU FVIII kg-1 every 12 hours. Results: In this ongoing study, the majority of patients treated with the pdFVIII/VWF product achieved a negative inhibitor titre. ITI outcome was significantly correlated with the bleeding rate during ITI, the peak titre during ITI, the inhibitor titre at start of ITI >10 BU, and the number of poor prognosis factors. Conclusion: Treatment with this particular pdFVIII/VWF concentrate, mainly according to the Bonn protocol, resulted in a high ITI success rate in HA patients with inhibitors and corroborates previously published success rates (77.1% complete/partial success in 48 inhibitor patients undergoing ITI with the same product). Disclosures Escuriola Ettingshausen: SOBI: Honoraria, Research Funding; Shire: Honoraria, Research Funding; Biotest: Honoraria, Research Funding; Octapharma: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Novo Nordisk: Honoraria; Roche: Honoraria; Grifols: Honoraria; Pfizer: Honoraria; LFB: Honoraria. Berntorp:Octapharma: Consultancy; CSL Behring: Consultancy; Shire: Consultancy, Other: honoraria for lecturing . Negrier:Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Octapharma: Honoraria, Research Funding; CSL Behring: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; LFB: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sobi/Bioverativ: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Baxalta/Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Honoraria, Research Funding. Pavlova:Novo Nordisk: Honoraria; Octapharma: Honoraria. Oldenburg:Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees; Grifols: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; Biogen Idec: Honoraria, Membership on an entity's Board of Directors or advisory committees; Shire: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Octapharma: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novo Nordisk: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL Behring: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Biotest: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bayer: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Swedish Orphan Biovitrum: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.

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

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4923-4923
Author(s):  
Miguel A. Escobar ◽  
Linda Shaffer ◽  
Mark Holguin ◽  
Timothy McCavit ◽  
Sandeep K. Rajan ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Immune Tolerance ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Advisory Committees ◽  
Immune Tolerance Induction ◽  
Off Label ◽  
Inhibitor Titer ◽  
Antihemophilic Factor ◽  
Partial Success

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.

Prompt Immune Tolerance Induction at Inhibitor Diagnosis Regardless of Titer May Increase Overall Success in Hemophilia A With Inhibitors: Experience of Two US Centers

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 575-575 ◽  
Author(s):  
Charles T Nakar ◽  
Marilyn J. Manco-Johnson ◽  
Alice Lail ◽  
Sharyne M. Donfield ◽  
Jennifer Maahs ◽  
...  
Keyword(s):  
Board Of Directors ◽  
Research Funding ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Time Interval ◽  
Advisory Committees ◽  
Immune Tolerance Induction ◽  
Bayer Healthcare ◽  
Inhibitor Titer ◽  
Partial Success

Abstract Introduction Immune tolerance induction (ITI) for patients (pts) with hemophilia A with inhibitors is the only modality known to effectively eradicate inhibitors with an overall reported success of ∼60-80%. One debate concerns the optimal time to start ITI; recent guidelines recommend delaying ITI until inhibitor titer is <10 Bethesda units (BU). Aim We report results of an analytic project to determine the success of ITI relative to time from inhibitor detection to ITI initiation. Methods Data was collected retrospectively at 2 US hemophilia centers on pts with severe/moderate (≤5%) factor VIII (FVIII) deficiency undergoing ITI including time interval from inhibitor detection to ITI start, inhibitor titer and outcome. High-dose ITI was practiced by both centers (i.e. ≥100 IU/kg/day). Success, partial success and failure were defined practically with success as a negative inhibitor titer and ability to use FVIII concentrate routinely for treatment and prevention of bleeding; partial success was an inhibitor titer <5 BU with ability to use FVIII concentrate to treat bleeding episodes; failure as ongoing ITI >3 years without achieving success/partial success or discontinuation of ITI. IRB approvals were obtained at both centers for this data analysis. Pts were first divided into low responding inhibitor (LRI) and high responding inhibitor (HRI) based on peak inhibitor titer; the HRI subgroup was further subdivided based on time to start ITI, including within 1 month, 1-6 months and greater than 6 months. The HRI subgroup starting ITI within 1 month was analyzed based on pre-ITI inhibitor titer. Results Fifty eight male pts with adequate ITI history documentation were included; 55 (95%) were severe (<1%), 3 moderately deficient (1-3%). Forty-seven pts (48%) were Caucasian, 6 Hispanic, 2 African American, 2 Asian and 1 Native American. Outcome is summarized in Table 1. Overall, 49 of 58 pts (84%) underwent successful ITI. Low responding Inhibitors: Among 19 (33%) pts with LRI, ITI success was 100%. Most pts with LRI 15/19 (79%) started ITI within 1 month from inhibitor detection. High responding inhibitors: Among 39 (67%) pts with HRI, 30/39 (77%) achieved tolerance, 1 achieved partial success and continued ITI, 1 was ongoing, 7 pts failed. The 39 pts with HRI were further subdivided based on time to ITI start. ITI start within 1 month of detection: Twenty three pts started ITI within 1 month from detection; 21 achieved success (91%), 1 partially succeeded and 1 failed. Eight of 10 pts (80%) with a pre-ITI titer <10 BU achieved success, 1 partially succeeded and 1 failed. All 13 pts (100%) starting ITI with pre-ITI inhibitor titer ≥ 10 BU achieved success. ITI start > 6 months: Eleven pts had an interval > 6 months until ITI start; 7 (64%) achieved success and 4 (36%) failed. Conclusions These results suggest that the time interval from inhibitor detection to start of ITI may play a critical role in outcome. A titer ≥10 BU did not influence outcome in pts where ITI was utilized within 1 month, supporting this approach in contrast to the commonly accepted practice of delaying ITI start until a titer <10 BU is achieved. Pts may benefit from prompt ITI regardless of current inhibitor titer and are not subjected to wait periods where bleeding is more likely to occur. Prompt ITI should be considered a viable therapeutic option in newly identified inhibitor pts regardless of current inhibitor titer. Disclosures: Manco-Johnson: Bayer HealthCare: Membership on an entity’s Board of Directors or advisory committees, Research Funding; CSL Behring: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees; Novo Nordisk: Membership on an entity’s Board of Directors or advisory committees; Eisai: Research Funding. Maahs:Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau; Biogen Idec: Membership on an entity’s Board of Directors or advisory committees; Novo Nordisk: Membership on an entity’s Board of Directors or advisory committees, Speakers Bureau. Shapiro:Baxter BioScience: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Novo Nordisck: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Bayer Healthcare: Membership on an entity’s Board of Directors or advisory committees, Research Funding; Biogen Idec: Consultancy, Membership on an entity’s Board of Directors or advisory committees, Research Funding; Chugai Pharma: Consultancy; Kedrion Biopharma: Consultancy, Research Funding; Cangene Pharmaceuticals: Research Funding; CSL Behring: Research Funding; Octopharma: Research Funding; PTC Therapeutics: Research Funding; Eli Lilly: Research Funding.

scholarly journals Immune Tolerance Induction with Simoctocog Alfa (Nuwiq®) in Six Patients with Severe Haemophilia a and FVIII Inhibitors

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 5037-5037
Author(s):  
Neha Bhatnagar ◽  
Kate Khair ◽  
Ri Liesner ◽  
Alice Wilkinson ◽  
Larisa Belyanskaya
Keyword(s):  
Immune Tolerance ◽  
Half Life ◽  
Research Funding ◽  
Poor Prognosis ◽  
Case Series ◽  
Tolerance Induction ◽  
Haemophilia A ◽  
Severe Haemophilia ◽  
Immune Tolerance Induction ◽  
Inhibitor Titre

Abstract Introduction and Objective: Inhibitors to coagulation factor VIII (FVIII) are the most serious complication of haemophilia A treatment. Previously untreated patients (PUPs) are at the greatest risk of inhibitors, which generally occur within the first 20 exposure days (ED) to FVIII. Immune tolerance induction (ITI) is the only clinically proven strategy for eradication of inhibitors. We present a case series of six PUPs with severe haemophilia A and inhibitors who underwent ITI with simoctocog alfa (Nuwiq®), a 4th generation human cell-line-derived recombinant FVIII approved for treatment of haemophilia A. Materials and Methods: Six male PUPs with severe haemophilia A who developed FVIII inhibitors after treatment with simoctocog alfa were started on ITI with simoctocog alfa. Primarily, we assessed the success of simoctocog alfa in patients with inhibitors. Success of ITI was determined based on undetectable inhibitor titre (< 0.6 BU/ml), FVIII recovery ≥ 66% and half-life ≥ 6 hours. Secondary objectives were to assess bleeding rate, tolerability and safety in patients with inhibitors treated with simoctocog alfa ITI. Results: The age of the patients at the start of ITI ranged from 8 to 186 months. Four of the patients were Caucasian, and two were African. All patients had a F8 mutation associated with high risk of ITI failure and two patients had an additional risk factor for ITI failure. The number of EDs prior to inhibitor development ranged from 9 to 33, and the peak inhibitor titre ranged from 0.9 to 114 BU. For ITI, five patients were treated with 100 IU/kg simoctocog alfa daily, and one with 90 IU/kg every other day. One patient achieved complete tolerisation and is now on prophylaxis at normal doses, having achieved an undetectable inhibitor titre after 9 months. This was despite an inhibitor titre ≥ 10 BU/mL at ITI start, which is considered a poor prognosis factor for ITI success. Three other patients achieved an undetectable inhibitor titre after 1, 6 and 18 months of ITI, and FVIII recovery has normalised but half-life remains short and they are on weaning doses as the half-life extends. One patient discontinued ITI with simoctocog alfa after 15 months due to an increasing inhibitor level. This patient was 15 years old at ITI start, and older age is associated with poor ITI outcome. Additionally, his haemophilia A was untreated for 15 years, during which time he developed severe arthropathy. One patient, who started ITI 3 months ago, has an ongoing inhibitor titre and continues on ITI with simoctocog alfa. Conclusions: In a case series of six patients treated with simoctocog alfa for ITI, who all had poor prognosis factors for ITI success, four patients (67%) to date have achieved an undetectable inhibitor titre. These data suggest that ITI with simoctocog alfa may be an effective treatment approach in haemophilia A patients with inhibitors. Disclosures Khair: Shire, SOBI, Pfizer, Roche, Novo Nordisk, Octapharma: Speakers Bureau; shire, SOBI, Pfizer, Roche: Research Funding. Liesner:Roche: Research Funding; Novo Nordisk: Research Funding, Speakers Bureau; Baxalta: Consultancy, Research Funding; Bayer: Consultancy, Research Funding; Octapharma: Consultancy, Other: Clinical study investigator for NuProtect Study (Octapharma sponsored), Research Funding, Speakers Bureau; Sobi: Speakers Bureau. Belyanskaya:Octapharma AG: Employment.

scholarly journals Outcome of Immune Tolerance Induction Using an Extended Half-Life Clotting Factor Concentrate — Recombinant Factor VIII Fc (Eloctate™) — a Report from India

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2494-2494
Author(s):  
Aby Abraham ◽  
Shashikant Apte ◽  
Chandrakala Shamukhaiah ◽  
Fouzia N. ◽  
Kannan Subramaniam ◽  
...  
Keyword(s):  
Median Duration ◽  
Immune Tolerance ◽  
Half Life ◽  
Tolerance Induction ◽  
The Other ◽  
Clotting Factor ◽  
Immune Tolerance Induction ◽  
Inhibitor Titre ◽  
History Of ◽  
Inhibitor Titer

Abstract The development of inhibitors is the most serious adverse effect of replacement theray with clotting factor concentrates (CFC) in hemophilia. Its eradication is also difficult, usually requiring months of frequent exposure to high doses of the CFC - immune tolerance induction (ITI). There is limited data on use of extended half-life (EHL) CFC for ITI. A limited program of ITI was made possible in India with some of the rFVIIIFc (Eloctate™) provided through the humanitarian aid program of the World Federation of Hemophilia. This report summarizes the interim outcome of ITI in these patients treated at three centers participating in this program. ITI with rFVIIIFc was offered to patients with hemophilia A and significant inhibitors. The CFC dose used ranged from 50 IU/kg, 3x/week, to 200 IU/kg per day, depending on the weight, convenience and early response as well as availability of rFVIIIFc. All patients completing at least 10 weeks of ITI are included in this analysis. Bethesda assay was done every 2-4 weeks. Successful ITI was defined as a negative Bethesda assay with a FVIII recovery of >60%. Patients received either FEIBA or rVIIa for breakthrough bleeds. Thirty eight patients were included in this analysis. The median age at initiation of ITI was 15 years (range:2 -39). Nine (24%) patients had a family history of inhibitors. The median age at which inhibitors developed was 11 years (range:0.6 -38). Nine (24%) patients had history of surgery prior to onset of inhibitor. Ten patients (26%) had exposure to only plasma derived factors. All patients were on episodic CFC replacement therapy except two (5%) who were receiving low-dose prophylaxis prior to inhibitor development. The median exposures to FVIII was 20 (range:2-80) and duration of inhibitors prior to ITI was 2 years (range:0.1 - 20). The median highest inhibitor titre recorded prior to ITI was 19 BU (range:4-1177). Only 3 patients had their maximum inhibitor titer below 5BU. The median inhibitor titre at the time of starting ITI was 10.4 BU (range: 0.6-1177). The median peak inhibitor titer after starting ITI was 40.4 BU (range:3.5-13933). Out of the 38, 17 (45%) patients achieved a negative inhibitor status after ITI for a median duration of 23 weeks (range: 10-64). Among the 17 patients who had successful ITI, the median duration of ITI required to achieve negative inhibitor status was 20 weeks (range:10-60). Among the other 21 patients who had persistence of inhibitors, 4 were included in other clinical trials, 3 discontinued due to personal reasons while the other 14 are continuing ITI based on availability of appropriate EHL CFC. Among these patients with persistence of inhibitors, the last inhibitor titer was 6.4 BU (range:0.9-9240) after a median of 26 weeks of ITI (range:11-64). The median number of breakthrough bleeds during ITI was 1 (range:0-12), being 1 (range:0-6) among responders and 1 (range:0-12) among those with persistence of inhibitors. A comparison of the group which responded within this duration of ITI and those who did not respond is shown in the table. Older age and the peak inhibitor titer prior to ITI were the two significant variables which affected early outcome of ITI. These data show that EHL rFVIIIFc can be effective in ITI with nearly 45% of patients achieving a negative inhibitor titer within 1 year and with responses starting as early as 1 month and nearly half of them within 4 months. There was also a relatively low median annualized bleed rate during ITI. More patients need to be treated with different doses of rFVIIIFc to assess its potential in ITI and to determine the optimal protocols but the initial data is promising. Disclosures No relevant conflicts of interest to declare.

scholarly journals The Atlanta Protocol: Immune Tolerance Induction in Pediatric Patients with Hemophilia a and Inhibitors on Emicizumab

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 634-634 ◽  
Author(s):  
Glaivy M. Batsuli ◽  
Karen L. Zimowski ◽  
Kelly Tickle ◽  
Shannon L. Meeks ◽  
Robert F. Sidonio
Keyword(s):  
Clinical Evaluation ◽  
Immune Tolerance ◽  
Half Life ◽  
Research Funding ◽  
Pediatric Patients ◽  
Hemophilia A ◽  
Tolerance Induction ◽  
Advisory Board ◽  
Third Generation ◽  
Immune Tolerance Induction

Abstract Introduction: The formation of neutralizing anti-factor VIII (fVIII) antibodies, called inhibitors, is a challenging complication in hemophilia A care. While novel non-factor therapies significantly reduce bleeding symptoms in patients with hemophilia A and inhibitors, the absence of fVIII tolerance remains unchanged. Additionally, there are concerns regarding the hemostatic efficacy and safety of bypassing agents necessary for the management of breakthrough bleeds in patients with inhibitors on these novel therapies. Immune tolerance induction (ITI) remains the primary method for eradicating inhibitors and restoring the hemostatic response to fVIII. Here we report on the response to ITI in pediatric patients following initiation of the bispecific humanized monoclonal antibody Emicizumab. Methods: Patients between the ages of 1 - 11 years old with hemophilia A and an active inhibitor (≥0.6 Bethesda Units (BU)/mL) treated at the Emory Pediatric Hemophilia Treatment Center were included in this analysis. In general, ITI was initiated after four weekly loading doses of Emicizumab with standard or extended half-life recombinant (rfVIII) or plasma-derived (pdfVIII) fVIII at 100 units/kg three times per week. Factor choice was determined by the fVIII product used for the ITI attempt prior to initiation of Emicizumab or a standard half-life third generation rfVIII product if no prior ITI attempts. FVIII pharmacokinetics during ITI including the estimated fVIII half-life, fVIII incremental recovery of expected, and inhibitor titers were measured with chromogenic-based assays using bovine reagents. Bleeding symptoms and treatment regimens for bleeds/procedures were also monitored. Results: Eight patients are currently receiving ITI according to this Atlanta Protocol. Details regarding this cohort are outlined in Table 1. Three of the 8 patients required central venous access for ITI fVIII infusions. These eight patients have historical peak inhibitor titers, defined as the highest inhibitor titer prior to this ITI regimen, ranging from 2.0 - 198 BU/mL. Four patients have just recently started ITI. The other 4 patients (patients 1, 2, 4, and 5) have been treated with Emicizumab and ITI for a median duration of 15 weeks (range 13-18 weeks). Two of the 4 patients are on ITI with a standard half-life third generation rfVIII product, 1 is on a standard half-life third generation B domain deleted (BDD) rfVIII product, and 1 is on an extended half-life (EHL) rfVIII-Fc fusion product. Their last measured inhibitor titers after initiation of ITI range from 0.3 - 3.7 chromogenic BU (CBU). All inhibitor titers declined with the start of ITI, and none of the 4 patients experienced an amnestic response (Figure 1). The fVIII incremental recovery improved in 3 of the 4 patients from a median of 30% of expected (range 17-69%) prior to Emicizumab with ITI to 85% of expected (range 67-85%) at the last clinical evaluation. The 1 patient remaining has an fVIII incremental recovery <10% of expected at the last clinical evaluation. Only one patient has required treatment with a single dose of recombinant activated factor VII (rfVIIa) for a right knee hemarthrosis during ITI without complication. There were 3 additional mild bleeding symptoms in 2 patients that did not require intervention including 1 trauma-induced forehead hematoma that self-resolved and 2 episodes self-resolving epistaxis lasting <5 minutes. Two of the 4 patients reported no bleeding symptoms. There were no episodes of thrombosis or thrombotic microangiopathy. Conclusions: This is the first report detailing the Atlanta Protocol for ITI in hemophilia A patients with inhibitors receiving Emicizumab prophylaxis. Although early, these results suggest that ITI can be safely administered in these patients and is able to achieve continued improvement in clinical indicators of tolerance. Disclosures Batsuli: Bayer: Other: Advisory Board; Genentech: Other: Advisory Board; Octapharma: Other: Advisory Board. Zimowski:National Hemophilia Association/Shire: Other: Funding for clinical fellowship in Hemostasis/Thrombosis. Meeks:Bioverativ: Other: Advisory Board; Bayer: Other: Advisory Board; CSL Behring: Other: Advisory Board; Catalyst Biosciences: Other: Advisory Board; Genentech: Other: Advisory Board; HEMA Biologics: Other: Advisory Board; Shire: Other: Advisory Board; Pfizer: Research Funding. Sidonio:Genentech: Other: Advisory Board, Research Funding; Bioverativ: Other: Advisory Board, Research Funding; Biomarin: Other: Advisory Board; Novo Nordisk: Other: Advisory Board; Octapharma: Other: Advisory Board; Grifols: Other: Advisory Board, Research Funding; Uniqure: Other: Advisory Board; CSL Behring: Other: Advisory Board; Shire: Other: Advisory Board, Research Funding; Kedrion: Research Funding.

scholarly journals Immune Tolerance Induction for FIX Inhibitors Using Combined B and T Cell Immune Modulation Therapy in Severe Hemophilia B

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1193-1193 ◽  
Author(s):  
Yasmina L. Abajas ◽  
Paul Edward Monahan ◽  
Brenda Nielsen ◽  
Pia Petrini ◽  
Susanna Ranta ◽  
...  
Keyword(s):  
Nephrotic Syndrome ◽  
Median Time ◽  
Immune Tolerance ◽  
Research Funding ◽  
Immune Modulation ◽  
Tolerance Induction ◽  
Factor Ix ◽  
Hemophilia B ◽  
Inhibitor Titer

Abstract Introduction Development of an inhibitor to Factor IX is a potentially life-threatening complication that occurs in 2-4% of severe hemophilia B patients. Attempt to eradicate these neutralizing alloantibodies with immune tolerance induction (ITI) regimens using prolonged repeated exposure to FIX fails to induce tolerance in ~70% of cases, and is limited by severe complications including FIX hypersensitivity and nephrotic syndrome. Cases of FIX ITI with immunosuppressive drugs have been reported infrequently. In light of increased understanding of the role of active T lymphocyte regulation of clotting factor-directed B lymphocyte-mediated humoral immunity, an approach combining immune modulating agents and frequent FIX infusions was reported by Beutel, et al (Haemostaseologie, 2009; 2014). We report a multi-institutional retrospective experience with combination immune modulation therapy (CIT), including B cell suppression with anti-CD20 monoclonal antibody Rituximab and T cell modulation using mycophenylate mofetil (MMF) with FIX ITI in 11 males with severe congenital hemophilia B. Methods The originally published regimen of Beutel, et al involves a 50 day course including FIX 100 IU/kg twice daily, rituximab 375 mg/m2 x 4 doses, mycophenolate (MMF) 300 mg/m2/dose daily, dexamethasone 6 mg/m2/dose pulses and IVIG 1 g/kg x 6 doses. Following individual Institutional Review Board approval, data on 11 patients was contributed by the INPH investigators and via outreach internationally and collected retrospectively using a uniform data collection form. Cases were included in the CIT series if the combination of FIX, rituximab and MMF was used. Approaches varied in the concomitant use of IVIG and pulse corticosteroids (dexamethasone or prednisone). Results CIT was the first immune tolerance therapy for 9/11 patients. Patients were 14-222 months of age at time of CIT, with a median time from inhibitor diagnosis to CIT 20 (range 0-207) months. Median historical peak inhibitor titer prior to initiation of CIT was 3.2 (range 1-42) BU/ml. Inhibitor titers at the initiation of CIT ranged from undetectable to 7 BU/ml. Eighty-onepercent of patients had a history of FIX hypersensitivity reaction. Prior to initiation of therapy, 27% of the patients underwent FIX desensitization during the initial course. The patients received FIX BID (9/11 patients) or QD (2/11 patients), 4 doses of rituximab 375 mg/m2, MMF for a minimum of 49 days (varying duration from 49-1247 days). IVIG was infused in 10/11 patients, with most receiving 3-7 doses during each course of CIT. 6/11 patients received between 2-10 courses of pulse corticosteroids during a CIT course. Each course of CIT achieved disappearance of the titer of FIX inhibitor at a median time of 1 month (range 1-41 months) Hypersensitivity reactions did not limit the courses of CIT, but did recur with inhibitor recurrence in 1 patient. Recurrence occurred in 6/11 patients at a median time of 11 months from time of CIT, in some cases soon after documented B cell recovery with a median inhibitor titer of 1.8 (range 0.7-7) BU/ml. In cases of recurrence, a negative inhibitor titer was achieved again in 1 patient by increasing FIX dose and in 4 patients who received additional courses of CIT. Repeat recurrence was seen in these patients following repeat CIT, although at low titer with a median of 1 BU/ml (range 1-4), allowing ongoing management with FIX in 3 of the 4. Overall, patients have had a median follow-up of 61 months following CIT, 9/11 patients are currently managed with factor IX for prophylaxis and bleeding, while 2/11 use bypassing agents. The most common complication was hospitalization for central venous catheter-related bacterial infection that occurred from < 1 to > 12 months after the use of rituximab in 3/11 patients. Nephrotic syndrome occurred in 3/11 patients. In each case, nephrotic syndrome responded to corticosteroids or re-initiation of CIT and FIX could be resumed. Conclusions FIX ITI with CIT targeting both B and T cells in hemophilia B is an effective means of achieving a negative inhibitor titer with tolerable safety in this series, allowing return to use of FIX for hemostasis and prophylaxis in most patients. Although recurrence is common and longer follow up is needed, when compared to the experience with using FIX alone, outcomes appear to be improved using CIT with FIX ITI as an initial approach. Disclosures Abajas: Bayer: Honoraria; CSL Limited: Honoraria. Allen:Shire: Employment, Equity Ownership. Oldenburg:Pfizer: Honoraria, Research Funding; Biogen: Honoraria, Research Funding; CSL Behring: Honoraria, Research Funding; Grifols: Honoraria, Research Funding; Octapharma: Honoraria, Research Funding; Bayer: Consultancy, Honoraria, Research Funding; Shire: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Biotest: Honoraria, Research Funding; Roche: Honoraria, Research Funding; Swedish Orphan Biovitrum: Honoraria, Research Funding; Novo Nordisk: Honoraria, Research Funding.

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