The use of reduced DOAC doses in atrial fibrillation patients does not always lead to good anticoagulation levels and avoid adverse events.

BACKGROUND: The MAS study (Blood Advances 2024) showed that a high proportion of Italian AF patients treated with direct oral anticoagulants (DOACs) receive reduced doses. This sub-analysis of MAS data aimed to analyze the effects of reduced (appropriate or not)- or standard-dose use on DOAC activity assessed at baseline and the occurrence of thrombotic or bleeding complications during follow-up. METHODS: The MAS study design, the methods for DOAC measurement, the results, and the adverse events during follow-up, are described in detail elsewhere. RESULTS: Seven hundred AF patients (42 % of the total 1657) received a reduced dose (considered inappropriate in 140 [20 %]). They were older, more frequently women, with lower body mass index (BMI), hemoglobin levels, and creatinine clearance. They more often had cerebral or cardiovascular diseases, were taking more medications, with higher scores for thrombotic or bleeding risk. Despite the use of low doses, 133 (19.0 %) patients had high standardized C-trough DOAC levels and experienced a high proportion of bleeding events (8.3 % per year). Conversely, some patients (4.7 %) had very low levels, resulting in a high incidence of thrombotic events (6.7 % per year). No difference was detected if the reduced dose was appropriate or not. CONCLUSION: The unpredictable, highly variable inter-individual anticoagulant effect of DOACs may lead to either too low or too high anticoagulant levels, increasing the risk of thrombotic or bleeding events. This is particularly relevant for patients with high-risk conditions, such as those chosen for reduced-dose treatment. Further studies are needed to investigate this important clinical issue.

Real-World Efficacy and Safety of Plasma-Derived Von Willebrand Factor-Containing Factor VIII Concentrates in Patients With Von Willebrand Disease in Italy.

Plasma-derived von Willebrand factor-containing factor VIII concentrates (pd-VWF/FVIII-C) are the mainstay of treatment in von Willebrand disease (VWD). Real-world data on efficacy and safety of these pd-VWF/FVIII-C are required. To retrospectively evaluate the efficacy and safety of pd-VWF/FVIII-C (Fanhdi® and Alphanate®, Grifols) in clinical practice in Italy. A multicentric, observational, retrospective study at 10 Italian centers was conducted. Eligible patients diagnosed with inherited VWD (ISTH criteria) were treated with either Fanhdi® or Alphanate® for bleeding episodes, prevention of surgical bleeding and secondary long-term prophylaxis (SLTP) according to clinical practice with medical records collected from January 2007 to December 2019. Efficacy/safety of pd-VWF/FVIII-C was assessed according to FDA-agreed objective criteria following regulatory procedures. Fifty-seven patients (M/F: 21/36) were enrolled in the study with the following VWD types: VWD1 (n = 29, 52%), VWD2A (n = 10, 18%), VWD2B (n = 7, 12%), VWD2M (n = 2, 4%), VWD2N (n = 1, 2%), VWD2 unclassified (n = 1, 2%), and VWD3 (n = 7, 12%). These pd-VWF/FVIII-C were used to manage 58 bleeding episodes (n = 24 patients), 100 surgeries (n = 47 patients), and 7 SLTP (n = 6 patients). Global clinical efficacy with these pd-VWF/FVIII-C was reported to be excellent/good in 85% of bleeding episodes, 98% of surgeries, and 100% of SLTP. As far as safety, no adverse-drug-related episodes, immunogenic or thrombotic events were reported. This study confirmed that Fanhdi® and Alphanate® were effective and safe in the management of bleeding episodes, the prevention of bleeding during surgeries and for SLTP in Italian patients with inherited VWD.

MORE EARLY BLEEDS ASSOCIATED WITH HIGH BASELINE DIRECT ORAL ANTICOAGULANT LEVELS IN ATRIAL FIBRILLATION: THE MAS STUDY.

Treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) patients is effective and safe. However, bleeding complications still occur. Whether the measurement of DOAC levels may further improve treatment efficacy and safety is still an open issue. In the "Measure and See" (MAS) Study (#NCT03803579) venous blood was collected 15-30 days after DOAC initiation in AF patients who were then followed for one year to record the occurrence of major and clinically relevant non-major bleeding. DOAC plasma levels were measured in one laboratory, and results were kept blind to patients and treating doctors. Trough DOAC levels were assessed in 1657 patients [957 (57.7%) and 700 treated with standard and low-dose, respectively]. Fifty bleeding events were recorded during 1606 years of follow-up (3.11% pt/yrs). Fifteen bleeding events (4.97% pt/yrs) occurred in patients with C-trough standardized values in the highest activity class (> 0.50); whereas 35 events (2.69% pt/yrs) occurred in those with values in the two lower classes ( 0.50, p= 0.0401). Increasing DOAC levels and low-dose DOAC use were associated with increased bleeding risk in the first three months of treatment. 19% of patients receiving low doses had standardized activity values in the highest class. More bleeding occurred in patients treated with low (4.3% pt/yrs) than standard (2.2% pt/yrs; p= 0.0160) dose DOAC. Early measurement of DOAC levels in AF patients identified many subjects with high activity levels despite the low doses use and had more bleeding risk during the first 3 months of treatment.

Long-term pharmacodynamic and clinical effects of twice- versus once-daily low-dose aspirin in essential thrombocythemia: The ARES trial.

Patients with essential thrombocythemia (ET) are treated with once-daily low-dose aspirin to prevent thrombosis, but their accelerated platelet turnover shortens the antiplatelet effect. The short-term Aspirin Regimens in EsSential Thrombocythemia trial showed that twice-daily aspirin dosing restores persistent platelet thromboxane (TX) inhibition. However, the long-term pharmacodynamic efficacy, safety and tolerability of twice-daily aspirin remain untested. We performed a multicenter, randomized, open-label, blinded-endpoint, phase-2 trial in which 242 patients with ET were randomized to 100 mg aspirin twice- or once-daily and followed for 20 months. The primary endpoint was the persistence of low serum TXB2, a surrogate biomarker of antithrombotic efficacy. Secondary endpoints were major and clinically relevant non-major bleedings, serious vascular events, symptom burden assessed by validated questionnaires, and in vivo platelet activation. Serum TXB2 was consistently lower in the twice-daily versus once-daily regimen on 10 study visits over 20 months: median 3.9 ng/mL versus 19.2 ng/mL, respectively; p < .001; 80% median reduction; 95% CI, 74%-85%. No major bleeding occurred. Clinically relevant non-major bleedings were non-significantly higher (6.6% vs. 1.7%), and major thromboses lower (0.8% vs. 2.5%) in the twice-daily versus once-daily group. Patients on the twice-daily regimen had significantly lower frequencies of disease-specific symptoms and severe hand and foot microvascular pain. Upper gastrointestinal pain was comparable in the two arms. In vivo platelet activation was significantly reduced by the twice-daily regimen. In patients with ET, twice-daily was persistently superior to once-daily low-dose aspirin in suppressing thromboxane biosynthesis and reducing symptom burden, with no detectable excess of bleeding and gastrointestinal discomfort.

A rescue approach in refractory diffuse large B-cell lymphoma with obinutuzumab-redirected cytokine-induced killer cells: a first-in-human case report.

Not available.

D-dimer and risk of venous thromboembolism recurrence: Comparison of two studies with similar designs but different laboratory and clinical results.

BACKGROUND: D-dimer testing may help deciding the duration of anticoagulation in subjects at high risk of venous thromboembolism (VTE) recurrence. Two management studies on this issue have been published (DULCIS in 2014 and APIDULCIS in 2022). They had similar designs but had important different results. Aim of this article is to compare their results. METHODS: Both studies were finalized to extend anticoagulation [with vitamin K anticoagulants (VKAs) in DULCIS or apixaban 2.5 mg BID (kindly provided by BMS-Pfizer Collaboration) in APIDULCIS] only in patients with positive D-dimer results. RESULTS: More D-dimer assays resulted positive in APIDULCIS than in DULCIS (61.1 % vs 47.7 %, respectively; p < 0.0001). While only 4 (0.5 %) refused low dose apixaban in APIDULCIS, the 22.6 % of patients with positive D-dimer refused to resume VKAs in DULCIS; their rates of recurrence were 187 and 8.8 per 100 person-years, respectively (incidence rate ratio [IRR]: 21.2). The incidence of bleeding was low in those receiving apixaban vs those who resumed VKAs (0.4 vs 2.3 per 100 person-years, respectively; IRR 0.17;). While the recurrence rate was low and similar in the studies in subjects who resumed anticoagulation, it was significantly higher in APIDULCIS than in DULCIS in those who stopped anticoagulation for negative D-dimer (5.6 vs 3.0 per 100 person-years, respectively; IRR 1.9). CONCLUSION: The low dose Apixaban for extended VTE treatment is effective and safe, and well accepted by patients. Why subjects who stopped anticoagulation for negative D-dimer had a higher recurrence rate in APIDULCIS than in DULCIS remains to be explained.

Thrombotic events associated with low baseline direct oral anticoagulant levels in atrial fibrillation: the MAS study.

ABSTRACT: Although effective and safe, treatment with direct oral anticoagulants (DOAC) in atrial fibrillation (AF) is still associated with thrombotic complications. Whether the measurement of DOAC levels may improve treatment efficacy is an open issue. We carried out the observational, prospective, multicenter Measure and See (MAS) study. Blood was collected 15 to 30 days after starting DOAC treatment in patients with AF who were followed-up for 1 year. Plasma samples were centralized for DOAC level measurement. Patients' DOAC levels were converted into drug/dosage standardized values to allow a pooled analysis in a time-dependent, competitive-risk model. The measured values were transformed into standardized values (representing the distance of each value from the overall mean) by subtracting the DOAC-specific mean value from the original values and dividing by the standard deviation. Trough and peak DOAC levels were assessed in 1657 and 1303 patients, respectively. In total, 21 thrombotic complications were recorded during 1606 years of follow-up (incidence of 1.31% of patients per year). Of 21 thrombotic events, 17 occurred in patients whose standardized activity levels were below the mean of each DOAC (0); the incidence was the highest (4.82% of patients per year) in patients whose standardized values were in the lowest class (-1.00 or less). Early measurement of DOAC levels in patients with AF allowed us to identify most of the patients who, having low baseline DOAC levels, subsequently developed thrombotic complications. Further studies are warranted to assess whether thrombotic complications may be reduced by measuring baseline DOAC levels and modifying treatment when indicated. This trial was registered at www.ClinicalTrials.gov as #NCT03803579.

A real-life study of daratumumab-bortezomib-dexamethasone (D-VD) in lenalidomide exposed/refractory multiple myeloma patients: a report from the Triveneto Myeloma Working Group.

Treatment of lenalidomide refractory (Len-R) multiple myeloma (MM) patients still represents an unmet clinical need. In the last years, daratumumab-bortezomib-dexamethasone (D-VD) combination was extensively used in this setting, even though only a small fraction of Len-R patients was included in the pivotal trial. This real-life study aimed to evaluate the efficacy and safety of the D-VD regimen in a cohort that exclusively enrolled Len exposed or refractory MM patients. The study cohort included 57 patients affected by relapsed/refractory MM. All patients were previously exposed to Len, with 77.2% being refractory. The overall response rate (ORR) was 79.6% with 43% of cases obtaining at least a very good partial response (VGPR). The D-VD regimen showed a favorable safety profile, with low frequency of grade 3-4 adverse events, except for thrombocytopenia observed in 21.4% of patients. With a median follow-up of 13 months, median progression-free survival (PFS) was 17 months. No significant PFS differences were observed according to age, ISS, LDH levels, type of relapse, and high-risk FISH. Len exposed patients displayed a PFS advantage as compared to Len refractory patients (29 vs 16 months, p = 0.2876). Similarly, patients treated after Len maintenance showed a better outcome as compared to patients who had received a full-dose Len treatment (23 vs 13 months, p = 0.1728). In conclusion, our real-world data on D-VD combination showed remarkable efficacy in Len-R patients, placing this regimen as one of the standards of care to be properly taken into account in this MM setting.

von Willebrand factor neutralizing and non-neutralizing alloantibodies in 213 subjects with type 3 von Willebrand disease enrolled in 3WINTERS-IPS.

BACKGROUND: Type 3 von Willebrand disease (VWD) is the most severe form of this disease owing to the almost complete deficiency of von Willebrand factor (VWF). Replacement therapy with plasma-derived products containing VWF or recombinant VWF rarely cause the development of alloantibodies against VWF that may be accompanied by anaphylactic reactions. OBJECTIVE: The objective of this study was to assess the prevalence of anti-VWF alloantibodies in subjects with type 3 VWD enrolled in the 3WINTERS-IPS. METHODS: An indirect in-house enzyme-linked immunosorbent assay has been used to test all the alloantibodies against VWF. Neutralizing antibodies (inhibitors) have been tested with a Bethesda-based method by using a VWF collagen binding (VWF:CB) assay. Samples positive for anti-VWF antibodies were further tested with Bethesda-based methods by using the semiautomated gain-of-function glycoprotein-Ib binding (VWF:GPIbM) and a VWF antigen (VWF:Ag) enzyme-linked immunosorbent assay. RESULTS: In total, 18 of the 213 (8.4%) subjects tested positive for anti-VWF antibodies and 13 of 213 (6%) had VWF:CB inhibitors. These 13 were among the 18 with anti-VWF antibodies. Of the 5 without VWF:CB inhibitors, 3 had non-neutralizing antibodies, 1 only inhibitor against VWF:GPIbM, and one could not be tested further. Ten of the 13 subjects with VWF:CB inhibitors also had VWF:GPIbM inhibitors, 6 of whom also had VWF:Ag inhibitors. Subjects with inhibitors were homozygous for VWF null alleles (11/14), homozygous for a missense variant (1/14), or partially characterized (2/14). CONCLUSIONS: Anti-VWF antibodies were found in 8.4% of subjects with type 3 VWD, whereas neutralizing VWF inhibitors were found in 6%, mainly in subjects homozygous for VWF null alleles. Because inhibitors may be directed toward different VWF epitopes, their detection is dependent on the assay used.

IDEAL study: A real-world assessment of pattern of use and clinical outcomes with recombinant coagulation factor IX albumin fusion protein (rIX-FP) in patients with haemophilia B in Italy.

INTRODUCTION: Factor IX replacement therapy is used for treatment and prophylaxis of bleeding in haemophilia B. rIX-FP is an extended half-life albumin-fusion protein, which, in clinical studies, has demonstrated prolonged dosing intervals up to 21 days for routine prophylaxis, providing therapeutic benefit. AIMS: To describe dosing frequency and consumption (primary endpoint), efficacy and safety of rIX-FP treatment during routine clinical practice in Italy. METHODS: Patients with moderate/severe haemophilia B on prophylaxis with rIX-FP for ≥6 months, were enrolled in this observational study from October 2017 to February 2019 and followed-up for 2 years. Descriptive analysis included prospective and retrospective data (12 months prior to switching to rIX-FP). RESULTS: Data were collected from 59 male patients (median age 30.1 years) enrolled by 23 Italian centres. Of them, 50 were on prophylaxis during the entire observation period and completed the study. The infusion frequency changed from 2-3 times/week in 86.0% of patients with previous treatment, to less than once a week in 84.0% of patients treated with rIX-FP at the 2nd-year follow-up. The annual number of infusions decreased by about 70%, whereas the mean FIX activity trough level increased from 3.8% to 14.4% (mean > 10% in all the infusion regimens). Median Annualised Bleeding Rate of .0 was achieved across all prophylaxis regimens. Subjects with zero bleedings increased from 66.0% to 78.0% with rIX-FP. CONCLUSION: Treatment with rIX-FP reduced infusion frequency, while providing higher FIX trough levels with substantial benefit in terms of annualised bleeding rate and a good safety profile.

Oral anticoagulant management of patients with mechanical heart valves at the Salam Centre of Khartoum: Observations on quality of anticoagulation and thrombotic risk.

INTRODUCTION: Rheumatic heart disease with mechanical heart valve (MHV) replacement is common in Africa. However, MHV requires long-life anticoagulation and managing this can be challenging. METHODS AND RESULTS: We report data of a prospective observational study conducted between August 2018 and September 2019 in MHV patients in the Salam Centre for Cardiac Surgery built in Khartoum, by Emergency, an Italian Non-Governmental Organization, to evaluate the quality of anticoagulation control and the risk of thrombotic complications. RESULTS: We studied 3647 patients (median age 25.1 years; 53.9 % female). Median Time in Therapeutic Range (TTR) was 53 % (interquartile range 37 % to 67 %) and 70 thrombotic events (rate 1.8 × 100 pt-years [95 % CI 1.38-2.23]) were recorded. Among patients in the first quartile of TTR (≤37 %), we recorded 34/70 (48.6 %) of all thrombotic events (rate 3.7 × 100 pt-years [95 % CI 2.5-5.1]), with a high mortality rate (2.2 × 100 pt-years [95 % CI 1.3-3.3]). In patients with guideline-recommended TTR (≥65 %) the event rate was 0.8 × 100 pt-years for thrombotic events [95 % CI 0.3-1.5] and 0.4 × 100 pt-years for mortality [95 % CI 0.1-0.9]. Multivariable analysis showed that having a TTR in the lowest quartile (≤37 %) and being noncompliant are significantly associated with increased thrombotic risk. Aspirin use or different valve type did not influence the thrombotic risk. Almost 40 % of all thromboembolic complications could have been potentially prevented by further improving VKA management to obtain a TTR > 37 %. CONCLUSION: The thrombotic risk of MHV patients on VKAs living in a low-income country like Sudan is associated with low quality of anticoagulation control. Efforts should be made to decrease the number of non-compliant patients and to reach a guideline-recommended TTR of ≥65 %.

D-dimer and reduced-dose apixaban for extended treatment after unprovoked venous thromboembolism: the Apidulcis study.

D-dimer assay is used to stratify patients with unprovoked venous thromboembolism (VTE) for the risk of recurrence. However, this approach was never evaluated since direct oral anticoagulants are available. With this multicenter, prospective cohort study, we aimed to assess the value of an algorithm incorporating serial D-dimer testing and administration of reduced-dose apixaban (2.5 mg twice daily) only to patients with a positive test. A total of 732 outpatients aged 18 to 74 years, anticoagulated for ≥12 months after a first unprovoked VTE, were included. Patients underwent D-dimer testing with commercial assays and preestablished cutoffs. If the baseline D-dimer during anticoagulation was negative, anticoagulation was stopped and testing repeated after 15, 30, and 60 days. Patients with serially negative results (286 [39.1%]) were left without anticoagulation. At the first positive result, the remaining 446 patients (60.9%) were given apixaban for 18 months. All patients underwent follow-up planned for 18 months. The study was interrupted after a planned interim analysis for the high rate of primary outcomes (7.3%; 95% confidence interval [CI], 4.5-11.2), including symptomatic proximal deep vein thrombosis (DVT) or pulmonary embolism (PE) recurrence, death for VTE, and major bleeding occurring in patients off anticoagulation vs that in those receiving apixaban (1.1%; 95% CI, 0.4-2.6; adjusted hazard ratio [HR], 8.2; 95% CI, 3.2-25.3). In conclusion, in patients anticoagulated for ≥1 year after a first unprovoked VTE, the decision to further extend anticoagulation should not be based on D-dimer testing. The results confirmed the high efficacy and safety of reduced-dose apixaban against recurrences. This trial was registered at www.clinicaltrials.gov as #NCT03678506.

Recurrence after stopping anticoagulants in women with combined oral contraceptive-associated venous thromboembolism: A systematic review and meta-analysis.

The risk of recurrence after discontinuation of anticoagulation for a combined oral contraceptive (COC)-associated venous thromboembolism (VTE) is unclear. Therefore, we conducted a systematic review and meta-analysis to estimate the incidence of recurrent VTE among women with COC-associated VTE, unprovoked VTE and to compare the incidence of recurrent VTE between the two groups. The Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Embase Classic +Embase and Medline ALL to July 2020 and citations from included studies were searched. Randomized controlled trials, prospective cohort studies and meta-analyses of these study types were selected. The analysis was conducted by random-effects model. Nineteen studies were identified including 1537 women [5828 person-years (PY)] with COC-associated VTE and 1974 women (7798 PY) with unprovoked VTE. Studies were at low risk of bias. The incidence rate of VTE recurrence was 1.22/100 PY [95% confidence interval (CI) 0.92-1.62, I2  = 6%] in women with COC-associated VTE, 3.89/100 PY (95% CI 2.93-5.17, I2  = 74%) in women with unprovoked VTE and the unadjusted incidence rate ratio was 0.34 (95% CI 0.26-0.46, I2  = 3%). The recurrence risk in women after COC-associated VTE is low and lower than after an unprovoked VTE.

Intracranial Haemorrhage in Haemophilia Patients Is Still an Open Issue: The Final Results of the Italian EMO.REC Registry.

Background: Intracranial hemorrhage (ICH) is a highly serious event in patients with haemophilia (PWH) which leads to disability and in some cases to death. ICH occurs among all ages but is particularly frequent in newborns. Aim: The primary aim was to assess the incidence and mortality due to ICH in an Italian population of PWH. Secondary aims were to evaluate the risk factors for ICH, the role of prophylaxis, and the clinical management of patients presenting ICH. Methods: A retrospective-prospective registry was established in the network of the Italian Association of Haemophilia Centers to collect all ICHs in PWH from 2009 to 2019 reporting clinical features, treatments, and outcomes. Results: Forty-six ICHs were collected from 13 Centers. The ICHs occurred in 15 children (10 < 2 years), and in 31 adults, 45.2% of them with mild hemophilia. Overall, 60.9% patients had severe haemophilia (15/15 children). Overall ICH incidence (×1000 person/year) was 0.360 (0.270−0.480 95% CI), higher in children <2 years, 1.995 (1.110−3.442 95% CI). Only 7/46 patients, all with severe haemophilia, had received a prophylactic regimen before the ICH, none with mild. Inhibitors were present in 10.9% of patients. In adult PWHs 17/31 suffered from hypertension; 85.7% of the mild subjects and 29.4% of the moderate/severe ones (p < 0.05). ICH was spontaneous in the 69.6% with lower rate in children (46.7%). Surgery was required in 21/46 patients for cerebral hematoma evacuation. Treatment with coagulation factor concentrates for at least three weeks was needed in 76.7% of cases. ICH was fatal in 30.4% of the cases. Of the survivors, 50.0% became permanently disabled. Only one-third of adult patients received long term prophylaxis after the acute treatment. Conclusion: The results from our Registry confirm the still high incidence of ICH in infants <2 years and in adults, particularly in mild PWHs presenting hypertension and its unfavorable outcomes. The majority of PWHs were treated on-demand before ICH occurred, suggesting the important role of prophylaxis in preventing such life-threatening bleeding.

Rivaroxaban for the treatment of noncirrhotic splanchnic vein thrombosis: an interventional prospective cohort study.

Heparins and vitamin K antagonists are the mainstay of treatment of splanchnic vein thrombosis (SVT). Rivaroxaban is a potential alternative, but data to support its use are limited. We aimed to evaluate the safety and efficacy of rivaroxaban for the treatment of acute SVT. In an international, single-arm clinical trial, adult patients with a first episode of noncirrhotic, symptomatic, objectively diagnosed SVT received rivaroxaban 15 mg twice daily for 3 weeks, followed by 20 mg daily for an intended duration of 3 months. Patients with Budd-Chiari syndrome and those receiving full-dose anticoagulation for >7 days prior to enrollment were excluded. Primary outcome was major bleeding; secondary outcomes included death, recurrent SVT, and complete vein recanalization within 3 months. Patients were followed for a total of 6 months. A total of 103 patients were enrolled; 100 were eligible for the analysis. Mean age was 54.4 years; 64% were men. SVT risk factors included abdominal inflammation/infection (28%), solid cancer (9%), myeloproliferative neoplasms (9%), and hormonal therapy (9%); 43% of cases were unprovoked. JAK2 V617F mutation was detected in 26% of 50 tested patients. At 3 months, 2 patients (2.1%; 95% confidence interval, 0.6-7.2) had major bleeding events (both gastrointestinal). One (1.0%) patient died due to a non-SVT-related cause, 2 had recurrent SVT (2.1%). Complete recanalization was documented in 47.3% of patients. One additional major bleeding event and 1 recurrent SVT occurred at 6 months. Rivaroxaban appears as a potential alternative to standard anticoagulation for the treatment of SVT in non-cirrhotic patients. This trial was registered at www.clinicaltrials.gov as #NCT02627053 and at eudract.ema.europa.eu as #2014-005162-29-36.

Turoctocog alfa pegol (N8-GP) in severe hemophilia A: Long-term safety and efficacy in previously treated patients of all ages in the pathfinder8 study.

Background: N8-GP (turoctocog alfa pegol; Esperoct) is a glycoPEGylated human recombinant factor VIII (FVIII). Objectives: Pathfinder8 (NCT01480180) was a phase 3, multinational, open-label, nonrandomized trial to investigate the long-term safety and efficacy of N8-GP in people of all ages with severe hemophilia A previously treated with N8-GP. Patients/Method: Patients were recruited from the completed phase 3 pathfinder2 and pathfinder5 trials to receive intravenous N8-GP prophylaxis for up to 104 weeks, administered every 7 days, twice weekly, or three times weekly. Primary and secondary end points were the number of adverse events (AEs) reported and efficacy of treatment, respectively. Results: Overall, 160 patients were exposed to N8-GP for a mean of 179 exposure days and 681 calendar days (≈1.9 years) per patient. In total, 119 patients experienced 510 AEs, corresponding to a rate of 1.71 AEs per patient-year of exposure; 97.5% of AEs were mild or moderate in severity, and no AEs led to withdrawal. No patients developed FVIII inhibitors during the trial. The Poisson estimate of mean annualized bleeding rate for all bleeds (excluding surgery) and across all regimens was 1.10 (median, 0.00), and for spontaneous bleeds was 0.61 (median, 0.00). Most (55.6%) patients experienced no bleeds that required FVIII treatment (excluding perioperative bleeds). The estimated hemostatic success rate for the treatment of 322 bleeding episodes (excluding surgery) was 95.8%, including missing values as failure. Conclusions: Long-term prophylactic use of N8-GP appeared safe and efficacious across all age groups in people with severe hemophilia A previously treated with N8-GP.