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

Abstract [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. Disclosures Nogami: 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.

Download Full-text

Natural History Of Inhibitor Recurrence Following Successful Immune Tolerance Induction

Blood ◽

10.1182/blood.v122.21.1106.1106 ◽

2013 ◽

Vol 122 (21) ◽

pp. 1106-1106 ◽

Cited By ~ 2

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.

Download Full-text

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

Blood ◽

10.1182/blood-2019-132021 ◽

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.

Download Full-text

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 ◽

10.1182/blood-2018-99-114408 ◽

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.

Download Full-text

Immune Tolerance Induction Using Rfviiifc (Eloctate)

Blood ◽

10.1182/blood.v126.23.3531.3531 ◽

2015 ◽

Vol 126 (23) ◽

pp. 3531-3531 ◽

Cited By ~ 2

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.

Download Full-text

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 ◽

10.1182/blood.v122.21.575.575 ◽

2013 ◽

Vol 122 (21) ◽

pp. 575-575 ◽

Cited By ~ 1

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.

Download Full-text

Identification of a Factor X-Interactive Site on the Factor VIII A2 Domain

Blood ◽

10.1182/blood.v128.22.3760.3760 ◽

2016 ◽

Vol 128 (22) ◽

pp. 3760-3760

Author(s):

Masahiro Takeyama ◽

Keiji Nogami ◽

Shoko Furukawa ◽

Midori Shima

Keyword(s):

Board Of Directors ◽

Binding Affinity ◽

Research Funding ◽

Cross Linking ◽

Functional Evaluation ◽

Dependent Manner ◽

Wild Type ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

A2 Domain

Abstract We have experienced a case of acquired hemophilia A with inhibitor recognizing only a factor (F) VIII A2 epitope, and reported the inhibitory mechanism for disappearing FVIII activity (Blood, 124, 4226, 2014). In summary, the patient's inhibitor IgG bound to FVIII A2N (residue 372-562) fragment and inhibited Arg372 cleavage in FVIII by FXa, suggesting that FX(a) bound to FVIII A2 domain. ELISA-based assay showed that FVIII A2 fragment bound to FX (Kd; 338 nM). We hypothesized that FVIII A2 residues 400-429 might be FX binding site according to the 3-D model of FVIII molecule, and prepared synthetic peptides (400-409, 409-419, and 420-429). The 400-409 peptide inhibited the FVIII A2-FX interaction, suggesting that the 400-409 region contributed to FX-interactive site. In this current study, we further performed the localization of a FX-interactive site on the 400-409 region in the A2 domain. A purified FXa generation assay demonstrated the 400-409 peptide decreased the generation of FXa in a dose-dependent manner up to 38% of 100 μM (Ki; 23 ± 9 nM). In comparison, scrambled peptide of 400-409 decreased up to 10% of 100 μM. These data demonstrated that the 400-409 peptide inhibited the generated FXa, suggesting the 400-409 region contributed to regulate the coagulation function. Covalent cross-linking was observed between the biotinylated 400-409 peptide and FX following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) using SDS-PAGE. This cross-linking formation was blocked by the addition of unlabeled 400-409 peptide. N-terminal sequence analysis of the peptide-FX product demonstrated that two sequential residues (Lys408 and Ser409) could not be detected, supporting that two residues participate in cross-link formation. To confirm the significance of these residues in A2 domain for FX-binding, the mutant forms of the A2 domain, converted to alanine, were expressed in BHK system and purified. Compared with wild type FVIII (Kd; 10 ± 3 nM), the binding affinity of Ser409Ala FVIII mutant for FX was no significant difference (Kd; 14 ± 1 nM) on SPR-based assay. Lys408Ala or Lys408Ala/Ser409Ala double FVIII mutant, however, decreased the binding affinity by 3.6~4.3-fold (Kd; 36 ± 7 or 43 ± 2 nM, respectively), suggesting contribution of Lys408Ala to the binding interaction. For the functional evaluation of the association with FVIII mutants to FX, a FXa generation assay was repeated. Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant reacted with varying concentrations of FX decreased by 1.2~1.6-fold (Km; 53 ± 12, 69 ± 15, or 65 ± 15 nM, respectively) compared to wild type FVIII (Km; 43 ± 9 nM), supporting a contribution of these mutants to Km and overall catalytic efficiency. Vmax values were largely unaffected by the mutations with most values within approximately 30% of the wild-type value. On the other hand, Kcat/Km value of Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant were decreased by 0.5~0.7-fold (Kcat/Km; 1.0, 1.3, or 0.9 nM-1min-1, respectively) compared to wild type FVIII (Kcat/Km; 1.8 nM-1min-1), suggesting low catalytic efficacy of Lys408Ala and Ser409Ala. These results indicate that the 400-409 region in the FVIII A2 domain, and in particular Lys408 and Ser409, may contribute to a unique FX-interactive site. Disclosures Nogami: Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding. Shima:Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.

Download Full-text

ACE910 Facilitates Its Hemostatic Effect with the Lower Concentration of Factor X Than That Required for Factor VIIa-Driven Coagulation

Blood ◽

10.1182/blood.v126.23.1077.1077 ◽

2015 ◽

Vol 126 (23) ◽

pp. 1077-1077 ◽

Cited By ~ 1

Author(s):

Koji Yada ◽

Keiji Nogami ◽

Takehisa Kitazawa ◽

Kunihiro Hattori ◽

Midori Shima

Keyword(s):

Board Of Directors ◽

Normal Level ◽

Research Funding ◽

Poor Response ◽

Employment Equity ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

Hemostatic Effect ◽

Equity Ownership ◽

Dose Dependent

Abstract The hemostatic effect of bypassing agents such as recombinant (r) factor (F)VIIa and activated prothrombin complex concentrates (aPCC) for hemophilia A with inhibitors (HA-inh) is not always stable (Berntope, Haemophilia 2009). The mechanism(s) of its instability remain unclear, however. We have recently reported the HA-inh case showing the attenuated responsiveness to aPCC (Ogiwara, Int J Hematol. 2014). Some groups reported the hemostatic effects of the complex concentrates of FVIIa and FX (Shirahata, Haemophilia 2012) in HA-inh, suggesting that FX would play the key role in the hemostatic effect by FVIIa. ACE910, a humanized bispecific antibody to FIXa and FX mimicking the functions of FVIIIa, exerting FXase activities without FVIII(a) (Kitazawa, Nature Medicine 2012). In this study, we attempted to elucidate the dependency on FX of the FVIIa- and/or ACE910-driven coagulation. Firstly, the global hemostatic potentials in the whole blood samples obtained from the four HA-inh cases (Case 1, 2, 3 and 4) under perioperative hemostatic treatment with the intermittent administration of rFVIIa every 2-3hr were evaluated by Ca2+-triggered viscoelastometric assay with ROTEM. The first infusion of rFVIIa shortened CT (from 5,087 ± 1,261 to 1,157 ± 208 sec) and increased MCF (from 17 ± 8.7 to 58.8 ± 1.3 mm) in each case. Additional rFVIIa after the 7th administration in Case 1, the 13th in Case 2 and the 12th in Case 3 little affected CT and MCF as well as clinical symptom, indicative of poor responsiveness, while Case 4 showed the improvement of the parameters even after the frequent infusion of rFVIIa, identified as a responsive case. Thrombin generation (TG) triggered by TF (1pM) or TF (1pM) together with ellagic acid (0.3μM) was evaluated in the plasma from the cases with poor response. Peak thrombin (PeakTh) was little changed between pre- and post-additional infusion of rFVIIa in the cases with poor response, similar to the pattern of ROTEM. The level of FX antigen measured by an ELISA in the plasma was 90.5 ± 9.6 nM, showing 67% of normal control (~140 nM), of little difference among the four cases at the first administration of rFVIIa, while that in Case 1, 2 or 3 at the 7th, 13th or 12th administration, respectively, decreased to 39.1 ± 7.0 nM, equivalent to ~45% of that (86.8 ± 12.9 nM) kept in the responsive Case 4. Addition of FX (300nM) in the plasma of poor response to rFVIIa ex vivo increased PeakTh to ~80% of normal control, suggesting that FVIIa-driven hemostatic effect would be dependent upon FX. Furthermore, to investigate the FX-dependency of FVIIa- and ACE910-driven coagulation, TG in the reconstituted HA-inh model plasmas consisting of FX-deficient plasma in which FVIII was inactivated by an anti-FVIII polyclonal antibody (10BU/ml) with/without rFVIIa (50 and 150 nM) or ACE910 (10, 30 and 60 μg/ml) was evaluated in the presence of various concentrations of FX (f.c. 0 - 300 nM). The control experiment without rFVIIa or ACE910 showed the FX dose-dependent increase of PeakTh. In the plasmas with FX ranged from 50 to 300nM, PeakTh improved to almost normal level by rFVIIa as well as ACE910. Of note, with the lower concentration of FX (10-20 nM), PeakTh improved to almost normal level in the presence of ACE910, increased by 38 ± 2.4%, 45 ± 1.7% and 48 ± 0.8% compared to those in its absence, respectively, in an ACE910 dose-dependent manner, whilst the presence of rFVIIa little affected TG compared to those in its absence. Taken together, ACE910 could exert its hemostatic effect with the lower amount of FX than that required for the rFVIIa-driven coagulation. Disclosures Yada: Chugai Pharmaceutical Co., ltd: Research Funding. Nogami:Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding; Chugai: Membership on an entity's Board of Directors or advisory committees. Kitazawa:Chugai Pharmaceutical Co., Ltd: Employment, Equity Ownership, Patents & Royalties. Hattori:Chugai Pharmaceutical Co., Ltd: Employment, Equity Ownership, Patents & Royalties. Shima:Biogen: Honoraria, Research Funding; Bayer: Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Chugai Pharmaceutical Co., Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Baxalta: Honoraria, Research Funding; Novo Nordisk: Honoraria, Research Funding; Kaketsuken: Honoraria.

Download Full-text

Shift to Anti-Fibrinolysis on the Administration of L-Asparaginase (L-Asp) during Induction Therapy for Pediatric Acute Lymphoblastic Leukemia (ALL)

Blood ◽

10.1182/blood.v128.22.5156.5156 ◽

2016 ◽

Vol 128 (22) ◽

pp. 5156-5156

Author(s):

Takashi Ishihara ◽

Keiji Nogami ◽

Tomoko Matsumoto ◽

Yasufumi Takeshita ◽

Akitaka Nomura ◽

...

Keyword(s):

Board Of Directors ◽

Induction Therapy ◽

Research Funding ◽

The Other ◽

Induction Phase ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

Hepatic Synthesis ◽

Coagulation And Fibrinolysis

Abstract Introduction: Thromboembolism is a serious complication associated with ALL. The use of central venous catheter and treatment protocols involving corticosteroids and L-Asp is assumed as important thrombogenic factors at the induction phase. In particular, L-Asp has profound effects on hepatic synthesis of pro-, anti-coagulant and fibrinolytic factors. In this study, we hypothesized that change of coagulation and fibrinolytic function contributes to hyper-coagulation condition during the induction phase with L-Asp. In order to clarify this, we evaluated the dynamic change in coagulation and fibrinolysis by simultaneous measurement of both thrombin and plasmin generation assay (T/P-GA). Patients: Twenty-seven pediatric patients with newly diagnosed ALL were enrolled from Aug. 2014 to Oct. 2015 at 3 hospitals in Japan. All cases had no thrombotic predisposition. Eighteen cases (66.7%) (BCP-ALL; n=17, T-ALL; n=1) received Berlin-Frankfürt-Münster (BFM)-95 oriented induction therapy included prednisolone (and dexamethasone for T-ALL), vincristine, daunorubicin, and E.coli L-Asp (a total of 8 doses of 5,000 U/m2). The others (BCP-ALL; n=8, T-ALL; n=1) received Japan Association of childhood Leukemia Study (JACLS) ALL02 oriented induction therapy included prednisolone, dexamethasone, vincristine, daunorubicin, cyclophosphamide and E.coli L-Asp (a total of 6 doses of 6,000 U/m2). Methods: The individual hemostatic parameters were monitored by fibrinogen (Fbg), FDP, AT, TAT and PIC. Additionally, the global functions of coagulation and fibrinolysis were evaluated using T/P-GA established by our group [Matsumoto et al. TH 2013]. This assay was initiated by the addition of a mixture of optimized concentrations of tissue factor and tissue-type plasminogen activator. Thrombin and plasmin generation were monitored simultaneously using individual fluorescent substrates in separate microtiter wells. Standard curves were set using purified alpha-thrombin and plasmin. Patients' plasmas were collected at the following points, T0; pre-phase of L-Asp, T1; intermittent phase of L-Asp, T2; post-phase of L-Asp, and T3; post-induction phase. Endogenous potentials of thrombin generation (T-EP) for coagulant activity and plasmin peak levels (P-Peak) of plasmin generation for fibrinolytic activity were selected as parameters for evaluation in this study. A ratio of T-EP and P-Peak of patients' plasmas to those of control normal plasma were calculated. Results: All cases obtained first remission, and none of them developed coagulopathy. Six cases received FFP transfusion for low Fbg level, whilst 21 cases received AT supplement for low AT level. Fbg showed a median of 170, 99.0, 99.0 and 328 mg/dl at T0, T1, T2 and T3, respectively, whilst the other individual parameters showed relatively unchanged. T-EP revealed a median of 1,126, 1,059, 1,175, 1,343 and 1,132 nM, whilst P-Peak showed a median of 6.67, 4.54, 4.12, 5.50 and 5.77 nM for T0, T1, T2, T3 and control plasma, respectively, indicating the elevated T-EP ratios and reduced P-Peak ratios (Fig. 1). The most significant difference in both ratios demonstrated a median of 1.5-fold (range, 1.0 to 2.6) at T2, consistent with the lowest Fbg levels. The FFP transfusion group showed significantly lower T-EP ratios than non-transfusion group at T1 (a median of 0.87 vs. 1.01, P=0.041) and T2 (a median of 0.96 vs. 1.07, P=0.009), whilst P-Peak ratios revealed no significant changes. The AT supplement group showed no significant changes of both ratios. Conclusion: The results from decreased Fbg and unchanged FDP might reveal the hepatic synthesis disorder of Fbg, whilst the results from T/P-GA showed that their hemostatic dynamics appear likely to be thrombotic tendency, since their coagulation state was hyper-coagulation and anti-fibrinolysis at post-phase of L-Asp. These results suggest that the impaired balance of coagulation and fibrinolysis due to L-Asp therapy might play an important role of a thrombotic complication at induction phase. On the other hand both conventional FFP transfusion and AT supplement therapy might not dramatically repair this unbalance state. A further research would be required to examine the role of coagulant and fibrinolytic function using T/P-GA in the pathogenesis of coagulopathy associated with L-Asp therapy in order to establish the optimal supportive therapy. Figure 1 The Changes of Both T-EP and P-Peak Ratios Figure 1. The Changes of Both T-EP and P-Peak Ratios Disclosures Nogami: F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Matsumoto:Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Patents & Royalties, Research Funding. Shima:Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding.

Download Full-text

Mechanism of Tissue Factor (TF) Enhancing Factor (F)VIII Activity on FXa Generation in Initial Phase of Coagulation and Interaction Between TF and FVIII C2 Domain

Blood ◽

10.1182/blood.v128.22.1391.1391 ◽

2016 ◽

Vol 128 (22) ◽

pp. 1391-1391 ◽

Cited By ~ 1

Author(s):

Furukawa Shoko ◽

Keiji Nogami ◽

Kenichi Ogiwara ◽

Midori Shima

Keyword(s):

Board Of Directors ◽

Tissue Factor ◽

Initial Velocity ◽

Research Funding ◽

Solid Phase ◽

Transmembrane Protein ◽

C2 Domain ◽

Advisory Committees ◽

Chugai Pharmaceutical ◽

Initiation Phase

Abstract In the cell-based coagulation model, factor (F)VIIa complex with tissue factor (TF) initiates the blood coagulation by generating FXa as the extrinsic tenase complex and activates FIX which composes the intrinsic tenase complex. We demonstrated that FVIIa/TF directly activated FVIII in an early coagulation phase (Soeda, JTH, 2010), and TF enhanced the intrinsic tenase activity via possible interaction with FVIIIa (Ogiwara, ASH, 2010). In this study, we clarified the enhancing mechanism of intrinsic tenase activity in the TF-related up-regulation of FVIII, and identified the TF-interactive region on FVIII. To explore the enhancing mechanism of TF for FVIII regulation, we performed the FXa generation assay with various amounts of FVIII or thrombin-mediated FVIIIa, constant FIXa (1 nM), FX (300 nM) and phospholipid vesicles (PL; 20 µM) in the presence of recombinant lipidated TF (rTF, Innovin®). The Km value for FVIII in the presence of rTF was ~2.4-fold lower than that its absence (Km; 5.6±0.5, 13.3±3.7 nM, respectively, p<0.05). Similarly, the Km for FVIIIa in the presence of TF was ~1.5-fold lower than that in its absence (Km; 6.3±0.6 nM, 9.7±1.6 nM, respectively, p<0.05), supporting that the presence of TF could promote the FXa-catalyzed activation of FVIII and FVIIIa-dependent generation of intrinsic FXa. To further evaluate the effect of TF on FVIII-dependent FXa generation, the FXa generation assay with FVIIa/TF-activated FVIIIa (FVIIIa-VIIa/TF) was also performed. The initial velocity on FXa generation with FVIIIa-VIIa/TF was 22.6 nM/min. However, the initial velocity on FXa generation with FVIIIa-VIIa/TF by addition of FVIIa-inhibitor (E-76), not to generate FVIIa/TF-dependent FXa, was 3.4 nM/min, and that with FVIII alone was 0.05 nM/min. In addition, the initial velocity with FVIIa/TF alone was 10.4 nM/min. These findings supported that the TF increased FXa generation greater than the additive effect of FVIII-dependent and FVIIa/TF-dependent FXa generation in early initiation phase of coagulation prior to thrombin generation. Since tissue factor pathway inhibitor (TFPI) is present in physiological circulating whole blood, a similar experiment on FXa generation assay was repeated under the presence of TFPI, estimated to be present at 0.5 nM in the pre-coagulant state or at 15 nM in the coagulant state in circulating blood. The initial velocity on FXa generation with FVIIIa-VIIa/TF was reduced by the presence of 0.5 or 15 nM TFPI (17.9 and 12.6 nM/min, respectively). By contrast, the initial velocity on FVIIIa-VIIa/TF-dependent FXa generation with addition of FVIIa inhibitor was little reduced by 0.5 nM TFPI, whilst was reduced by 15 nM TFPI (3.5 and 2.5 nM/min, respectively). These findings supported that the TFPI possibly didn't inhibit TF on the enhanced intrinsic tenase on association with FVIII in the pre-coagulant state. We further reported that TF enabled FXa to activate FVIII, irrespective of von Willebrand factor (VWF), and the direct association of rTF and non-lipidated TF with FVIII (Furukawa, ISTH, 2015). Since TF is transmembrane protein, however, we performed a surface plasmon resonance (SPR)-based assay (BIAcore®) and solid phase-based ELISA to identify the interactive region(s) on FVIII to recombinant soluble TF (sTF; Altor BioScience), a portion of TF outside of the PL membrane. An SPR-based assay revealed the direct binding of intact FVIII, LCh (a3-A3C1C2, A3C1C2) subunit, C2 domain to immobilized sTF (Kd; 2.3±0.6, 5.8±1.0, 10.5±3.5, 11.8±0.5 nM, respectively). The intact HCh, A1 or A2 domain to sTF failed to bind, however. A non-equilibrium ELISA also revealed that sTF bound to immobilized C2 domain with moderate affinity (Kdapp; 16.9±2.2 nM), and the interaction was dependent on ionic strength and Ca2+. In addition, the presence of VWF significantly competitively inhibited the C2 and sTF binding by ~90% (IC50; 5.7 µg/ml) at the maximal concentration employed, suggesting that the C2 domain-TF interaction could activate FVIII by FXa even in the presence of VWF. We concluded that it might be possible that TF enhanced the FVIII-mediated FXa generation by not only FVIIa but also FXa, additionally this enhancing mechanism might not be suppressed by TFPI in the initiation phase of coagulation. Furthermore, TF might function to FVIII activation, irrespective of presence of VWF, by the binding to C2 domain through the competition with VWF. Disclosures Nogami: Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Shima:Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.

Download Full-text

French National Retrospective Cohort of Hairy-Cell Leukemias: Risk of Second Malignancies after 10 Years of Follow-up

Blood ◽

10.1182/blood-2019-127560 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1537-1537

Author(s):

Jérôme Paillassa ◽

Edouard Cornet ◽

Stephanie Noel ◽

Cecile Tomowiak ◽

Aline Schmidt ◽

...

Keyword(s):

Board Of Directors ◽

Research Funding ◽

Retrospective Cohort ◽

Hematological Malignancies ◽

Hematological Malignancy ◽

Solid Cancer ◽

Advisory Committees ◽

History Of ◽

History Of Cancer

Introduction: Hairy-cell leukemia (HCL) is a chronic B-cell lymphoproliferative disorder with a favorable outcome thanks to treatment with purine analogues (PNA) like cladribine and pentostatin. Here, we updated the French national retrospective cohort of HCL after 10 years of follow-up, in order to evaluate the risk of second cancers in these patients. Methods: Data were collected up to June 2018 through a questionnaire sent to the members of the Société Française d'Hématologie, and centralized in the cohort database. We described the second malignancies observed during the follow-up, distinguishing second 'solid' cancers from second hematological malignancies. Then, using a Fine and Gray model, we performed a multivariate analysis in order to identify second cancer risk factors. Finally, to evaluate the excess of cancers in our cohort in comparison with the French general population, we calculated the standardized incidence ratio (SIR). Results: 279 patients (pts) from 19 centers were included in our retrospective cohort. The median age was 59 years old (range 29-88). 21% had an infectious disease at diagnosis, 23% had a familial history of cancer and 11% a personal history of cancer before HCL diagnosis. The median number of lines of treatments was 1 (0-7). PNA (cladribine or pentostatin) were the first therapeutic choice in frontline (75% of pts) and at relapse (69%). With a median follow-up of 127 months (2-413), the median overall survival for the overall study population was 328 months (95% CI 299-357) and the median relapse-free survival (RFS) was 136 months (95% CI 109-163). Pts treated with cladribine or pentostatin in first line had a statistically significant better RFS than pts treated with 'other' treatments (log rank test, p < 0.001). The 10-year cumulative incidence of relapse was 39% (95% CI 33-46). Pts who received treatments other than PNA in first line had a higher risk of relapse (Gray's test, p < 0.001). For pts receiving PNA in first and second lines, there was no difference in outcomes between those who switched PNA and those who did not. In this cohort, we observed 68 second malignancies during the follow-up: 49 solid cancers (most prevalent: prostate and non-melanoma skin cancers) and 19 hematological malignancies (most prevalent: monoclonal gammopathy of undetermined significance (MGUS) and myelodysplastic syndromes (MDS)). The median onset of second cancer, second solid cancer and second hematological malignancy from HCL diagnosis was 81 months, 99 months and 78 months, respectively. The median age at diagnosis of cancer, solid cancer and hematological malignancy was 70, 69 and 77 years old, respectively. Considering death as a competing risk, the 10-year cumulative incidence of cancer, solid cancer and hematological malignancy was 15% (95% CI 11-19), 11% (95% CI 7.2-15), and 5.0% (95% CI 2.8-8.2), respectively. In multivariate analyses, IFN treatment was associated with a decreased risk for all cancers (Fine and Gray regression model, subdistribution Hazard Ratio (sdHR) 0.53 (95% CI 0.29-0.97); p = 0.038), a familial history of cancer was a risk factor for solid cancers (sdHR 2.12 (95% CI 1.15-3.91); p = 0.017), a personal history of cancer was a risk factor for hematological malignancies (sdHR 3.47 (95% CI 1.14-10.55); p = 0.028). Even after excluding non-melanoma skin cancers and MGUS, there was an excess of cancers (SIR = 2.22), solid cancers (SIR = 1.81) and hematological malignancies (SIR = 6.67). Conclusions: In this updated real-world retrospective cohort with a long follow-up and most pts treated with PNA, we highlighted the importance and the excess of second cancers in HCL patients, in particular hematological malignancies. Figure Disclosures Paillassa: Janssen: Other: Bibliography board with young hematologists. Thieblemont:Roche: Honoraria, Research Funding; Gilead: Honoraria; Novartis: Honoraria; Kyte: Honoraria; Janssen: Honoraria; Celgene: Honoraria; Cellectis: Membership on an entity's Board of Directors or advisory committees. Hermine:AB Science: Membership on an entity's Board of Directors or advisory committees. Feugier:janssen: Honoraria, Research Funding, Speakers Bureau; gilead: Honoraria, Research Funding, Speakers Bureau; roche: Honoraria, Research Funding, Speakers Bureau; abbvie: Honoraria, Research Funding, Speakers Bureau. Troussard:Innate Pharma: Consultancy, Membership on an entity's Board of Directors or advisory committees; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Roche: Other: Research Support; Sysmex: Other: Research Support.

Download Full-text