Untreated bleeds in people with hemophilia A in a noninterventional study and intrapatient comparison after initiating emicizumab in HAVEN 1-3.

Background: Bleeding in people with hemophilia A can be life threatening, and intra-articular bleeds can result in joint damage. Most clinical studies focus on treated bleeds, while bleeds not treated with coagulation factor(s) (untreated bleeds) are underreported. Objectives: We assessed the incidence of untreated bleeds during a noninterventional study (NIS) wherein people with hemophilia A, with or without factor VIII (FVIII) inhibitors, were managed according to standard practice. Patients/Methods: Using the Bleed and Medication Questionnaire, we prospectively collected data from three cohorts: Cohort A, adults/adolescents (age ≥12 years) with FVIII inhibitors; Cohort B, children (aged <12 years) with FVIII inhibitors; Cohort C, adults/adolescents without FVIII inhibitors. Untreated bleeds were analyzed for site, frequency, and etiology of bleeding and compared with those during emicizumab prophylaxis in the same individuals after transferring to a Phase III HAVEN trial. Results: In the 221 participants enrolled in the NIS (Cohort A, n = 103; Cohort B, n = 24; Cohort C, n = 94), the incidence of untreated bleeds was approximately 40% of all bleeds in people with FVIII inhibitors and 26.2% in adolescents/adults without inhibitors. Approximately 70% of treated bleeds and approximately 54% of untreated bleeds in adults/adolescents were in joints. Untreated joint bleeds were less common (7.1%) in children. Overall, intra-individual comparisons showed reduced treated/untreated bleeds following transition from standard to emicizumab prophylaxis. Conclusion: A significant proportion of bleeding events are untreated in people with hemophilia A. There is a need to further understand why bleeds remain untreated and to capture such events in clinical studies.

Effect of emicizumab prophylaxis on bone and joint health markers in people with haemophilia A without factor VIII inhibitors in the HAVEN 3 study.

INTRODUCTION: Emicizumab prophylaxis significantly reduces bleeding events; however, the associated impact on bone/joint health is unknown. AIM: To explore the effect of emicizumab prophylaxis on bone/joint health in people with haemophilia A (PwHA) without FVIII inhibitors enrolled in HAVEN 3 (NCT02847637). METHODS: Haemophilia joint health scores (HJHS; v2.1) were evaluated at baseline and Weeks 49 and 97 in PwHA receiving emicizumab (n = 134), and at baseline and Weeks 49, 73 and 97 in PwHA who switched to emicizumab after 24 weeks of no prophylaxis (n = 17). Bone and joint biomarkers were measured in 117 PwHA at baseline and at Weeks 13, 25, 49 and 73. RESULTS: HJHS was lower for PwHA who were previously on FVIII prophylaxis, aged <40 years or had no target joints at baseline compared with PwHA who were receiving no prophylaxis, aged ≥40 years or with target joints. Clinically significant mean (95% confidence interval) improvements from baseline of -2.13 (-3.96, -.29) in HJHS joint-specific domains were observed at Week 49 in PwHA with at least one target joint at study entry (n = 71); these changes were maintained through Week 97. Improvements in HJHS from baseline were also observed for PwHA aged 12-39 years. Biomarkers of bone resorption/formation, cartilage degradation/synthesis, and inflammation did not change significantly during emicizumab prophylaxis. CONCLUSIONS: Clinically relevant improvements in HJHS were observed in younger PwHA and those with target joints after 48 weeks of emicizumab in HAVEN 3. Biomarkers of bone/joint health did not show significant changes during 72 weeks of emicizumab prophylaxis.

A Model-Based Framework to Inform the Dose Selection and Study Design of Emicizumab for Pediatric Patients With Hemophilia A.

Emicizumab is a bispecific antibody mimicking the cofactor function of activated coagulation factor VIII to prevent bleeds in patients with hemophilia A. The dose selection for the first-in-child phase III study of emicizumab was addressed by pediatric pharmacokinetic prediction using an adult/adolescent population pharmacokinetic model developed in phase I-I/II studies. The model was modified to incorporate functions describing the age-dependent increase in body weight (BW) with or without clearance maturation to account for the differences in emicizumab pharmacokinetics between adults/adolescents and children. A minimal dose anticipated to achieve in children the same target efficacious exposure as for adults/adolescents was identified when considering BW and clearance maturation. It was the same BW-based dose as for adults/adolescents and was selected for the starting dose for the pediatric study. Whether considering clearance maturation or not in addition to BW led to uncertainty in the pediatric pharmacokinetic prediction and dose selection, which informed implementation of a dose-adapting scheme in the study design. Exposure matching to adults/adolescents was ultimately achieved in children with the starting dose, indicating that consideration of clearance maturation in addition to BW provided adequate pediatric pharmacokinetic predictions for emicizumab. This pharmacokinetic finding in conjunction with exposure-response information served as a basis for the efficacy demonstrated in children, avoiding a time-consuming process for exploring an optimal pediatric dose of emicizumab. This experience indicates that a model-based framework helped optimize the pediatric dose selection and study design, thereby streamlining the development process with extrapolation, of emicizumab for children.

The effect of emicizumab prophylaxis on long-term, self-reported physical health in persons with haemophilia A without factor VIII inhibitors in the HAVEN 3 and HAVEN 4 studies.

INTRODUCTION: Severe haemophilia A (HA) has a major impact on health-related quality of life (HRQoL). AIM: Assess the impact of emicizumab on HRQoL in persons with severe HA (PwHA) without factor VIII (FVIII) inhibitors in the phase 3 HAVEN 3 and 4 studies. METHODS: This pooled analysis examines the HRQoL of PwHA aged ≥ 18 years treated with emicizumab prophylaxis via Haemophilia-Specific Quality of Life Questionnaire for Adults (Haem-A-QoL) and EuroQoL 5-Dimensions 5-levels (EQ-5D-5L). In particular, changes from baseline in Haem-A-QoL 'Physical Health' (PH) domain and 'Total Score' (TS) are evaluated. RESULTS: Among 176 evaluable participants, 96 (55%) had received prior episodic treatment and 80 (45%) prophylaxis; 70% had ≥ 1 target joint and 51% had experienced ≥ 9 bleeds in the previous 24 weeks. Mean Haem-A-QoL PH and TS improved after emicizumab initiation. Mean (standard deviation) -12.0 (21.26)- and -8.6 (12.57)-point improvements were observed in PH and TS from baseline to Week 73; Week 73 scores were 27.9 (24.54) and 22.0 (14.38), respectively. Fifty-four percent of participants reported a clinically meaningful improvement in PH scores (≥ 10 points) by Week 73. Subgroups with poorer HRQoL prior to starting emicizumab (i.e. receiving episodic treatment, ≥ 9 bleeds, target joints) had the greatest improvements in PH scores, and corresponding reductions in missed workdays; change was not detected among those previously taking prophylaxis. No change over time was detected by the EQ-5D-5L questionnaire. CONCLUSIONS: Emicizumab prophylaxis in PwHA without FVIII inhibitors resulted in persistent and meaningful improvements in Haem-A-QoL PH and less work disruption than previous treatment.

Long-term outcomes with emicizumab prophylaxis for hemophilia A with or without FVIII inhibitors from the HAVEN 1-4 studies.

Prophylaxis with emicizumab, a subcutaneously administered bispecific humanized monoclonal antibody, promotes effective hemostasis in persons with hemophilia A (PwHAs). The primary efficacy, safety, and pharmacokinetics of emicizumab were reported previously, but long-term data were limited. Here, data from 401 pediatric and adult PwHAs with/without factor VIII (FVIII) inhibitors who were enrolled in the phase 3 HAVEN 1, HAVEN 2, HAVEN 3, and HAVEN 4 studies (NCT02622321, NCT02795767, NCT02847637, NCT03020160) have been pooled to establish a long-term efficacy, safety, and pharmacokinetics profile. Across a median efficacy period of 120.4 weeks (interquartile range, 89.0-164.4) (data cutoff 15 May 2020), the model-based treated annualized bleed rate (ABR) was 1.4 (95% confidence interval [CI], 1.1-1.7). ABRs declined and then stabilized at <1 in an analysis of 24-week treatment intervals; at weeks 121 to 144 (n = 170), the mean treated ABR was 0.7 (95% CI, 0-5.0). During weeks 121 to 144, 82.4% of participants had 0 treated bleeds, 97.6% had ≤3 treated bleeds, and 94.1% reported no treated target joint bleeds. Bleeding into target joints decreased substantially. Emicizumab was well tolerated, and no participant discontinued because of adverse events beyond the 5 previously described. This data cutoff includes the previously reported 3 thrombotic microangiopathies (one in the PwHA with fatal rectal hemorrhage) and 2 thromboembolic events, all associated with activated prothrombin complex concentrate use, as well as a myocardial infarction and a venous device occlusion. With 970.3 patient-years of exposure, emicizumab prophylaxis maintained low bleed rates in PwHAs of all ages with/without FVIII inhibitors and remains well tolerated, with no new safety concerns identified.

Pharmacokinetics and Pharmacodynamics of Emicizumab in Persons with Hemophilia A with Factor VIII Inhibitors: HAVEN 1 Study.

Emicizumab, a bispecific monoclonal antibody, bridges activated factor IX (FIXa) and FX, replacing the function of missing FVIIIa to restore effective hemostasis in persons with hemophilia A (PwHA). Here we assess pharmacokinetic (PK) and pharmacodynamic (PD) biomarkers in PwHA with FVIII inhibitors in the Phase III HAVEN 1 study (NCT02622321). Blood samples from 112 PwHA receiving 1.5 mg/kg once-weekly subcutaneous emicizumab were analyzed at central laboratories. Emicizumab concentrations for PK analysis were measured via validated immunoassay. PD effects were assessed using FVIII chromogenic activity assay containing human factors (Hyphen Biophen FVIII:C), and by FXIa-triggered thrombin generation (TG). Activated partial thromboplastin time (aPTT), prothrombin time (PT), antigen levels of FIX and FX, fibrinogen, D-dimer, and prothrombin fragment 1.2 (PF1.2) levels were determined. Emicizumab trough concentrations ≥ 50 µg/mL were maintained throughout the study. FVIII-like activity and TG (peak height) correlated with emicizumab concentrations and remained above 20 U/dL and 100 nM, respectively, with a weekly maintenance dose, theoretically converting persons with severe hemophilia A to a mild disease phenotype. aPTT was normalized at subtherapeutic concentrations of emicizumab. Plasma concentrations of target antigens FIX and FX were not significantly affected by emicizumab treatment; nor were fibrinogen, PT (international normalized ratio), D-dimer, or PF1.2. The PK profile of once-weekly emicizumab in HAVEN 1 provides sustained therapeutic plasma levels, consistent with population PK models. Both the PK profile and the PD and safety biomarkers are consistent with the established efficacy of emicizumab prophylaxis in PwHA with FVIII inhibitors.

Outcomes in children with hemophilia A with inhibitors: Results from a noninterventional study.

BACKGROUND: Data regarding management of pediatric persons with hemophilia A (PwHA) with factor VIII (FVIII) inhibitors are limited. This prospective noninterventional study (NCT02476942) evaluated annualized bleeding rates (ABRs), safety, and health-related quality of life (HRQoL) in pediatric PwHA with FVIII inhibitors. PROCEDURE: PwHA aged <12 years with current FVIII inhibitors and high-titer inhibitor history were enrolled. Participants remained on usual treatment; no interventions were applied. Outcomes included ABR, safety, and HRQoL. RESULTS: Twenty-four PwHA aged 2-11 years (median 7.5) were enrolled and monitored for 8.7-44.1 weeks (median 23.4). In the episodic (n = 10) and prophylactic (n = 14) groups, respectively, 121 of 185 (65.4%) and 101 of 186 (54.3%) bleeds were treated using activated prothrombin complex concentrate (aPCC) and/or recombinant activated FVII (rFVIIa). ABRs (95% confidence interval) were 19.4 (13.2-28.4) and 18.5 (14.2-24.0) for treated bleeds, and 32.7 (20.5-52.2) and 33.1 (22.4-48.9) for all bleeds, respectively. Most prophylactic group participants (92.9%) were prescribed aPCC; 50% adhered to their prescribed treatment regimen. Adherence to prophylactic rFVIIa was not assessed. Serious adverse events included hemarthrosis (12.5%) and mouth hemorrhage (12.5%); the most common nonserious adverse event was viral upper respiratory tract infection (12.5%). HRQoL showed functional impairment at baseline; scores remained stable throughout, with little intergroup variation. CONCLUSIONS: ABRs remained high in pediatric PwHA with inhibitors receiving standard treatment. This study demonstrates the need for more effective treatments, with reduced treatment burden, to prevent bleeds, increase prophylaxis adherence, and improve patient outcomes.

A phase 2 PK/PD study of andexanet alfa for reversal of rivaroxaban and edoxaban anticoagulation in healthy volunteers.

As with any anticoagulant, factor Xa (FXa) inhibitors are associated with a risk of major bleeding. Andexanet alfa is a recombinant modified human FXa lacking enzymatic activity, developed for reversal of FXa inhibitor-induced anticoagulation. In two phase 2, randomized, double-blind, placebo-controlled, single-center studies, different regimens of andexanet alfa were administered to healthy volunteers after therapeutic anticoagulation with rivaroxaban or edoxaban, and multiple anticoagulation reversal and safety end points were evaluated. Andexanet alfa rapidly and effectively reversed anticoagulation with both rivaroxaban and edoxaban. Within 2 minutes after bolus, anti-FXa activity decreased significantly, with maximum decreases of ≈93% (P < .05) and ≈82% (P < .05), respectively, compared with placebo. The stoichiometric ratios of andexanet alfa:total anticoagulant at maximum reversal of anti-FXa activity ranged from 1:1 to 1.3:1 for rivaroxaban and 1.41:1 to 2.58:1 for edoxaban. Sustained normalization of thrombin generation for ≈2 hours and sustained decrease in unbound anticoagulant (maximum ≈80%) for up to ≈4 hours following completion of andexanet alfa administration, compared with placebo, were observed when andexanet was administered as a bolus or as a bolus followed by continuous infusion. Andexanet alfa was well tolerated, and there were no serious adverse events or thrombotic events. Andexanet alfa has been approved in the United States and Europe for reversal of anticoagulation in patients treated with rivaroxaban or apixaban who experience life-threatening or uncontrolled bleeding. These studies were registered with clinicaltrials.gov (#NCT03578146 and #NCT03551743).

A multicenter, open-label phase 3 study of emicizumab prophylaxis in children with hemophilia A with inhibitors.

Emicizumab, a bispecific humanized monoclonal antibody, bridges activated factor IX (FIX) and FX to restore the function of missing activated FVIII in hemophilia A. Emicizumab prophylaxis in children with hemophilia A and FVIII inhibitors was investigated in a phase 3 trial (HAVEN 2). Participants, previously receiving episodic/prophylactic bypassing agents (BPAs), were treated with subcutaneous emicizumab: 1.5 mg/kg weekly (group A), 3 mg/kg every 2 weeks (group B), or 6 mg/kg every 4 weeks (group C). Pharmacokinetics, safety, and efficacy (including an intraindividual comparison of participants from a noninterventional study) were evaluated. Eighty-five participants aged <12 years were enrolled. In group A (n = 65), the annualized rate of treated bleeding events (ABRs) was 0.3 (95% confidence interval [CI], 0.17-0.50), and 77% had no treated bleeding events. Intraindividual comparison of 15 participants who previously took BPA prophylaxis showed that emicizumab prophylaxis reduced the ABR by 99% (95% CI, 97.4-99.4). In groups B (n = 10) and C (n = 10), ABRs were 0.2 (95% CI, 0.03-1.72) and 2.2 (95% CI, 0.69-6.81), respectively. The most frequent adverse events were nasopharyngitis and injection-site reactions; no thrombotic events occurred. Two of 88 participants developed antidrug antibodies (ADAs) with neutralizing potential, that is, associated with decreased emicizumab plasma concentrations: 1 experienced loss of efficacy, and, in the other, ADAs disappeared over time without intervention or breakthrough bleeding. All other participants achieved effective emicizumab plasma concentrations, regardless of the treatment regimen. Emicizumab prophylaxis has been shown to be a highly effective novel medication for children with hemophilia A and inhibitors. This trial was registered at www.clinicaltrials.gov as #NCT02795767.

Safety analysis of rFVIIa with emicizumab dosing in congenital hemophilia A with inhibitors: Experience from the HAVEN clinical program.

BACKGROUND: Recombinant activated factor VII (rFVIIa; eptacog alfa activated, NovoSeven® , Novo Nordisk A/S) is a bypassing agent used in congenital hemophilia A patients with inhibitors. Emicizumab (Hemlibra® ; F Hoffmann-La Roche Ltd) is a recombinant, humanized, bispecific monoclonal antibody used for routine prophylaxis in patients with congenital hemophilia A with inhibitors. Concomitant use of the hemostatic agents rFVIIa and emicizumab carries a theoretical increased risk of thrombotic complications. Roche and Novo Nordisk collaboratively analyzed all available data on the use of rFVIIa in patients receiving emicizumab prophylaxis in the Study to Evaluate the Efficacy, Safety, and Pharmacokinetics of Prophylactic Emicizumab Versus no Prophylaxis in Hemophilia A Participants With Inhibitors (HAVEN) clinical development program. OBJECTIVE: Obtain further insights into the concomitant clinical use and safety of rFVIIa and emicizumab. METHODS: The initial individual rFVIIa dose, dosing intervals and cumulative dosing were evaluated in the HAVEN 1, HAVEN 2, and HAVEN 4 trials. All adverse events reported in each of the three trials in patients treated with rFVIIa, including available narratives, were assessed. RESULTS: The vast majority of bleeds occurred in HAVEN 1. When rFVIIa was used to treat a bleeding episode, a 100 ± 20 µg/kg dose was used to initiate treatment in the majority of cases. The dosing interval, as well as cumulative dosing were consistent with prescribing information and current practice. No serious adverse events, no thrombotic microangiopathy cases, or thromboembolic events were assessed to be associated with rFVIIa when used in conjunction with emicizumab prophylaxis in the HAVEN trials. CONCLUSION: rFVIIa use in the context of emicizumab prophylaxis does not change the rFVIIa safety profile as described in the product information.

Health-related quality of life and health status in persons with haemophilia A with inhibitors: A prospective, multicentre, non-interventional study (NIS).

INTRODUCTION: Real-world data (RWD) on health-related outcomes in persons with haemophilia A (PwHA) provide insights into patient needs and can guide clinical study design. A global, prospective, non-interventional study (NIS; NCT02476942) collected detailed RWD on bleeding outcomes, health-related quality of life (HRQoL) and health status in PwHA treated per local routine clinical practice. AIM: To report HRQoL and health status in the adult/adolescent PwHA with inhibitors cohort in the NIS. METHODS: This cohort enrolled PwHA aged ≥12 years with high-titre factor VIII inhibitor history. Participants remained on their usual treatment (no protocol-specified interventions). Health-related outcomes: Haemophilia Quality of Life Questionnaire for Adults (Haem-A-QoL), Haemophilia-specific Quality of Life Questionnaire for Children Short Form (Haemo-QoL SF), EuroQol 5-Dimensions 5-Levels (EQ-5D-5L) index utility score (IUS) and visual analogue scale (EQ-VAS). RESULTS: One hundred three participants were enrolled on episodic (n = 75) or prophylactic treatment (n = 28); median (range) age, 31 (12-75) years; median (range) observation time, 26 (4-70) weeks. Haem-A-QoL scores indicated impairments in HRQoL aspects; comparable between episodic/prophylactic regimens and relatively consistent over time. Haemo-QoL SF scores with both regimens varied over time, and appeared poorer with episodic than prophylactic treatment. IUS and EQ-VAS were comparable between regimens, stable over time and lower on bleeding days. Mean proportions of missed work and school days were 16% and 23%, respectively; mean (standard deviation) number of days hospitalized was 3.2 (8.8) (comparable between groups). CONCLUSIONS: These RWD demonstrate that PwHA with inhibitors have impaired HRQoL, despite standard treatment, and that more effective treatment options are needed.

Efficacy, safety, and pharmacokinetics of emicizumab prophylaxis given every 4 weeks in people with haemophilia A (HAVEN 4): a multicentre, open-label, non-randomised phase 3 study.

BACKGROUND: Emicizumab, a subcutaneously administered, humanised, bispecific, monoclonal antibody, is approved to treat people with haemophilia A of all ages with and without coagulation factor VIII (FVIII) inhibitors. HAVEN 4 assessed emicizumab prophylaxis administered as one dose every 4 weeks in adults and adolescents with haemophilia A, regardless of FVIII inhibitor status. METHODS: In this phase 3, multicentre, open-label, two-stage study, patients aged 12 years and older with severe congenital haemophilia A (<1% of normal FVIII activity in blood) or haemophilia A with FVIII inhibitors, undergoing treatment with either FVIII concentrates or bypassing agents were recruited from three sites in Japan and Spain for a run-in cohort, and from 17 sites in Australia, Belgium, Japan, Poland, Spain, and the USA for a subsequent expansion cohort. Participants in the run-in and expansion cohorts were given emicizumab subcutaneously 6 mg/kg every 4 weeks for 24 weeks or more; for patients in the expansion cohort this regimen was preceded by four loading doses of 3 mg/kg once weekly. In the run-in cohort, we assessed pharmacokinetics after single and multiple (every 4 weeks) subcutaneous administration of 6 mg/kg emicizumab and safety. In the expansion cohort, the efficacy endpoint was efficacy of prophylactic emicizumab in maintaining adequate bleed prevention, assessed in all patients who received at least one dose of emicizumab and reported as annualised bleed rates for treated bleeds, all bleeds (treated and untreated), treated spontaneous bleeds, treated joint bleeds, and treated target joint bleeds. Safety was assessed in all participants given emicizumab. This study is registered with ClinicalTrials.gov, number NCT03020160, and is ongoing. FINDINGS: Between Jan 30, 2017, and Feb 27, 2017, seven patients were enrolled into the initial run-in cohort, which confirmed the expected pharmacokinetic profile and safety of the regimen based on model-based simulations, providing sufficient evidence for opening of the expansion cohort (n=41), which was recruited and enrolled between May 24, 2017, and June 30, 2017. The annualised rate of treated bleeds was 2·4 (95% CI 1·4-4·3). 23 (56·1%; 95% CI 39·7-71·5) of 41 reported no treated bleeds and 37 (90%; 76·9-97·3) reported zero to three treated bleeds. The annualised bleed rate was 4·5 (95% CI 3·1-6·6) for all bleeds, 0·6 (0·3-1·5), for treated spontaneous bleeds, 1·7 (0·8-3·7) for treated joint bleeds, and 1·0 (0·3-3·3) for treated target joint bleeds. The most frequent treatment-related adverse event was injection-site reaction (nine [22%] of 41 patients). We observed no thrombotic events or development of de-novo antidrug antibodies with neutralising potential or FVIII inhibitors. INTERPRETATION: Emicizumab given once every 4 weeks showed clinically meaningful bleed control while being well tolerated. This regimen could improve patient care by decreasing treatment burden and increasing adherence to effective prophylaxis, potentially decreasing the development of secondary complications for people with haemophilia A. FUNDING: F Hoffmann-La Roche and Chugai Pharmaceutical.

Bleeding events and safety outcomes in persons with haemophilia A with inhibitors: A prospective, multi-centre, non-interventional study.

INTRODUCTION: Prospectively collected, real-world data on bleeds, haemophilic treatment and safety outcomes in persons with haemophilia A (PwHA) with factor VIII (FVIII) inhibitors are limited. A prospective, global, multi-centre, non-interventional study (NIS; NCT02476942) collected detailed real-world data in PwHA treated per local routine clinical practice. AIM: To characterize bleeding rates, haemophilic treatment practices, prophylaxis adherence and adverse events (AEs) in adult/adolescent PwHA with inhibitors in the NIS. METHODS: Participants aged ≥12 years with congenital haemophilia A/documented high-titre FVIII inhibitor history were enrolled. Participants remained on their usual treatment; no interventions were applied. RESULTS: Overall, 103 PwHA with inhibitors enrolled, (median [range] age 31 [12-75] years) and were monitored for median (range) 26.0 (4.1-69.6) weeks. In the episodic (n = 75) and prophylactic (n = 28) treatment groups, respectively, 1244 and 325 bleeds were reported, and 528 (42.4%) and 104 (32.0%) were not treated; annualized bleeding rates (ABRs; 95% confidence interval) were 18.6 (15.2-22.8) and 14.9 (10.5-21.2) for treated bleeds, and 32.7 (27.3-39.1) and 25.0 (18.4-34.0) for all bleeds. Coagulation products used included activated prothrombin complex concentrate (aPCC) and/or recombinant activated FVII. Among participants prescribed aPCC prophylaxis, 35.0% adhered to both prescribed frequency of aPCC administration and prescribed dose. Serious AEs of haemarthrosis and muscle haemorrhage were reported; most common AEs were arthralgia, viral upper respiratory tract infection and pyrexia. CONCLUSIONS: ABRs (treated bleeds and all bleeds) remain high on standard treatment; this prospective NIS demonstrates the need for more effective treatments for PwHA with inhibitors to reduce/prevent bleeds, with potential to improve prophylaxis adherence and further improve outcomes.

Emicizumab Prophylaxis in Patients Who Have Hemophilia A without Inhibitors.

BACKGROUND: Emicizumab is a bispecific monoclonal antibody that bridges activated factor IX and factor X to replace the function of missing activated factor VIII, thereby restoring hemostasis. In a phase 3, multicenter trial, we investigated its use as prophylaxis in persons who have hemophilia A without factor VIII inhibitors. METHODS: We randomly assigned, in a 2:2:1 ratio, participants 12 years of age or older who had been receiving episodic treatment with factor VIII to receive a subcutaneous maintenance dose of emicizumab of 1.5 mg per kilogram of body weight per week (group A) or 3.0 mg per kilogram every 2 weeks (group B) or no prophylaxis (group C). The primary end point was the difference in rates of treated bleeding (group A vs. group C and group B vs. group C). Participants who had been receiving factor VIII prophylaxis received emicizumab at a maintenance dose of 1.5 mg per kilogram per week (group D); intraindividual comparisons were performed in those who had participated in a noninterventional study. RESULTS: A total of 152 participants were enrolled. The annualized bleeding rate was 1.5 events (95% confidence interval [CI], 0.9 to 2.5) in group A and 1.3 events (95% CI, 0.8 to 2.3) in group B, as compared with 38.2 events (95% CI, 22.9 to 63.8) in group C; thus, the rate was 96% lower in group A and 97% lower in group B (P<0.001 for both comparisons). A total of 56% of the participants in group A and 60% of those in group B had no treated bleeding events, as compared with those in group C, who all had treated bleeding events. In the intraindividual comparison involving 48 participants, emicizumab prophylaxis resulted in an annualized bleeding rate that was 68% lower than the rate with previous factor VIII prophylaxis (P<0.001). The most frequent adverse event was low-grade injection-site reaction. There were no thrombotic or thrombotic microangiopathy events, development of antidrug antibodies, or new development of factor VIII inhibitors. CONCLUSIONS: Emicizumab prophylaxis administered subcutaneously once weekly or every 2 weeks led to a significantly lower bleeding rate than no prophylaxis among persons with hemophilia A without inhibitors; more than half the participants who received prophylaxis had no treated bleeding events. In an intraindividual comparison, emicizumab therapy led to a significantly lower bleeding rate than previous factor VIII prophylaxis. (Funded by F. Hoffmann-La Roche and Chugai Pharmaceutical; HAVEN 3 ClinicalTrials.gov number, NCT02847637 .).

A Pharmacometric Approach to Substitute for a Conventional Dose-Finding Study in Rare Diseases: Example of Phase III Dose Selection for Emicizumab in Hemophilia A.

BACKGROUND: Emicizumab (ACE910) is a bispecific antibody mimicking the cofactor function of activated coagulation factor VIII. In phase I-I/II studies, emicizumab reduced the bleeding frequency in patients with severe hemophilia A, regardless of the presence of factor VIII inhibitors, at once-weekly subcutaneous doses of 0.3, 1, and 3 mg/kg. METHODS: Using the phase I-I/II study data, population pharmacokinetic and repeated time-to-event (RTTE) modeling were performed to quantitatively characterize the relationship between the pharmacokinetics of emicizumab and reduction in bleeding frequency. Simulations were then performed to identify the minimal exposure expected to achieve zero bleeding events for 1 year in at least 50% of patients and to select the dosing regimens to be tested in phase III studies. RESULTS: The RTTE model adequately predicted the bleeding onset over time as a function of plasma emicizumab concentration. Simulations suggested that plasma emicizumab concentrations of ≥  45 µg/mL should result in zero bleeding events for 1 year in at least 50% of patients. This efficacious exposure provided the basis for selecting previously untested dosing regimens of 1.5 mg/kg once weekly, 3 mg/kg every 2 weeks, and 6 mg/kg every 4 weeks for phase III studies. CONCLUSIONS: A pharmacometric approach guided the phase III dose selection of emicizumab in hemophilia A, without conducting a conventional dose-finding study. Phase III studies with the selected dosing regimens are currently ongoing. This case study indicates that a pharmacometric approach can substitute for a conventional dose-finding study in rare diseases and will streamline the drug development process.

Emicizumab Prophylaxis in Hemophilia A with Inhibitors.

BACKGROUND: Emicizumab (ACE910) bridges activated factor IX and factor X to restore the function of activated factor VIII, which is deficient in persons with hemophilia A. This phase 3, multicenter trial assessed once-weekly subcutaneous emicizumab prophylaxis in persons with hemophilia A with factor VIII inhibitors. METHODS: We enrolled participants who were 12 years of age or older. Those who had previously received episodic treatment with bypassing agents were randomly assigned in a 2:1 ratio to emicizumab prophylaxis (group A) or no prophylaxis (group B). The primary end point was the difference in bleeding rates between group A and group B. Participants who had previously received prophylactic treatment with bypassing agents received emicizumab prophylaxis in group C. RESULTS: A total of 109 male participants with hemophilia A with inhibitors were enrolled. The annualized bleeding rate was 2.9 events (95% confidence interval [CI], 1.7 to 5.0) among participants who were randomly assigned to emicizumab prophylaxis (group A, 35 participants) versus 23.3 events (95% CI, 12.3 to 43.9) among those assigned to no prophylaxis (group B, 18 participants), representing a significant difference of 87% in favor of emicizumab prophylaxis (P<0.001). A total of 22 participants in group A (63%) had zero bleeding events, as compared with 1 participant (6%) in group B. Among 24 participants in group C who had participated in a noninterventional study, emicizumab prophylaxis resulted in a bleeding rate that was significantly lower by 79% than the rate with previous bypassing-agent prophylaxis (P<0.001). Overall, 198 adverse events were reported in 103 participants receiving emicizumab prophylaxis; the most frequent events were injection-site reactions (in 15% of participants). Thrombotic microangiopathy and thrombosis were reported in 2 participants each (in the primary analysis) who had received multiple infusions of activated prothrombin complex concentrate for breakthrough bleeding. No antidrug antibodies were detected. CONCLUSIONS: Emicizumab prophylaxis was associated with a significantly lower rate of bleeding events than no prophylaxis among participants with hemophilia A with inhibitors. (Funded by F. Hoffmann-La Roche and Chugai Pharmaceutical; HAVEN 1 ClinicalTrials.gov number, NCT02622321 .).

Pictilisib for oestrogen receptor-positive, aromatase inhibitor-resistant, advanced or metastatic breast cancer (FERGI): a randomised, double-blind, placebo-controlled, phase 2 trial.

BACKGROUND: Inhibition of phosphatidylinositol 3-kinase (PI3K) is a promising approach to overcome resistance to endocrine therapy in breast cancer. Pictilisib is an oral inhibitor of multiple PI3K isoforms. The aim of this study is to establish if addition of pictilisib to fulvestrant can improve progression-free survival in oestrogen receptor-positive, endocrine-resistant breast cancer. METHODS: In this two-part, randomised, double-blind, placebo-controlled, phase 2 study, we recruited postmenopausal women aged 18 years or older with oestrogen receptor-positive, HER2-negative breast cancer resistant to treatment with an aromatase inhibitor in the adjuvant or metastatic setting, from 123 medical centres across 21 countries. Part 1 included patients with or without PIK3CA mutations, whereas part 2 included only patients with PIK3CA mutations. Patients were randomly allocated (1:1 in part 1 and 2:1 in part 2) via a computer-generated hierarchical randomisation algorithm to daily oral pictilisib (340 mg in part 1 and 260 mg in part 2) or placebo starting on day 15 of cycle 1, plus intramuscular fulvestrant 500 mg on day 1 and day 15 of cycle 1 and day 1 of subsequent cycles in both groups. In part 1, we stratified patients by presence or absence of PIK3CA mutation, primary or secondary aromatase inhibitor resistance, and measurable or non-measurable disease. In part 2, we stratified patients by previous aromatase inhibitor treatment for advanced or metastatic disease or relapse during or within 6 months of an aromatase inhibitor treatment in the adjuvant setting and measurable or non-measurable disease. All patients and those administering treatment and assessing outcomes were masked to treatment assignment. The primary endpoint was progression-free survival in the intention-to-treat population for both parts 1 and 2 and also separately in patients with PIK3CA-mutated tumours in part 1. Tumour assessment (physical examination and imaging scans) was investigator-assessed and done at screening and after 8 weeks, 16 weeks, 24 weeks, and 32 weeks of treatment from day 1 of cycle 1 and every 12 weeks thereafter. We assessed safety in as-treated patients who received at least one dose of study medication. This trial is registered with ClinicalTrials.gov, number NCT01437566. FINDINGS: In part 1, between Sept 27, 2011, and Jan 11, 2013, we randomly allocated 168 patients to the pictilisib (89 [53%]) or placebo (79 [47%]) group. In part 2, between March 18, 2013, and Jan 2, 2014, we randomly allocated 61 patients to the pictilisib (41 [67%]) or placebo (20 [33%]) group. In part 1, we found no difference in median progression-free survival between the pictilisib (6·6 months [95% CI 3·9-9·8]) and placebo (5·1 months [3·6-7·3]) group (hazard ratio [HR] 0·74 [95% CI 0·52-1·06]; p=0·096). We also found no difference when patients were analysed according to presence (pictilisib 6·5 months [95% CI 3·7-9·8] vs placebo 5·1 months [2·6-10·4]; HR 0·73 [95% CI 0·42-1·28]; p=0·268) or absence (5·8 months [3·6-11·1] vs 3·6 months [2·8-7·3]; HR 0·72 [0·42-1·23]; p=0·23) of PIK3CA mutation. In part 2, we also found no difference in progression-free survival between groups (5·4 months [95% CI 3·8-8·3] vs 10·0 months [3·6-13·0]; HR 1·07 [95% CI 0·53-2·18]; p=0·84). In part 1, grade 3 or worse adverse events occurred in 54 (61%) of 89 patients in the pictilisib group and 22 (28%) of 79 in the placebo group. 19 serious adverse events related to pictilisib treatment were reported in 14 (16%) of 89 patients. Only one (1%) of 79 patients reported treatment-related serious adverse events in the placebo group. In part 2, grade 3 or worse adverse events occurred in 15 (36%) of 42 patients in the pictilisib group and seven (37%) of 19 patients in the placebo group. Four serious adverse events related to pictilisib treatment were reported in two (5%) of 42 patients. One treatment-related serious adverse event occurred in one (5%) of 19 patients in the placebo group. INTERPRETATION: Although addition of pictilisib to fulvestrant did not significantly improve progression-free survival, dosing of pictilisib was limited by toxicity, potentially limiting its efficacy. For future assessment of PI3K inhibition as an approach to overcome resistance to hormonal therapy, inhibitors with greater selectivity than that of pictilisib might be needed to improve tolerability and potentially increase efficacy. No further investigation of pictilisib in this setting is ongoing. FUNDING: F Hoffmann-La Roche.

First-in-human phase I study of pictilisib (GDC-0941), a potent pan-class I phosphatidylinositol-3-kinase (PI3K) inhibitor, in patients with advanced solid tumors.

PURPOSE: This first-in-human dose-escalation trial evaluated the safety, tolerability, maximal-tolerated dose (MTD), dose-limiting toxicities (DLT), pharmacokinetics, pharmacodynamics, and preliminary clinical activity of pictilisib (GDC-0941), an oral, potent, and selective inhibitor of the class I phosphatidylinositol-3-kinases (PI3K). PATIENTS AND METHODS: Sixty patients with solid tumors received pictilisib at 14 dose levels from 15 to 450 mg once-daily, initially on days 1 to 21 every 28 days and later, using continuous dosing for selected dose levels. Pharmacodynamic studies incorporated (18)F-FDG-PET, and assessment of phosphorylated AKT and S6 ribosomal protein in platelet-rich plasma (PRP) and tumor tissue. RESULTS: Pictilisib was well tolerated. The most common toxicities were grade 1-2 nausea, rash, and fatigue, whereas the DLT was grade 3 maculopapular rash (450 mg, 2 of 3 patients; 330 mg, 1 of 7 patients). The pharmacokinetic profile was dose-proportional and supported once-daily dosing. Levels of phosphorylated serine-473 AKT were suppressed >90% in PRP at 3 hours after dose at the MTD and in tumor at pictilisib doses associated with AUC >20 h·µmol/L. Significant increase in plasma insulin and glucose levels, and >25% decrease in (18)F-FDG uptake by PET in 7 of 32 evaluable patients confirmed target modulation. A patient with V600E BRAF-mutant melanoma and another with platinum-refractory epithelial ovarian cancer exhibiting PTEN loss and PIK3CA amplification demonstrated partial response by RECIST and GCIG-CA125 criteria, respectively. CONCLUSION: Pictilisib was safely administered with a dose-proportional pharmacokinetic profile, on-target pharmacodynamic activity at dose levels ≥100 mg and signs of antitumor activity. The recommended phase II dose was continuous dosing at 330 mg once-daily.

The endothelial-specific regulatory mutation, Mvwf1, is a common mouse founder allele.

Mvwf1 is a cis-regulatory mutation previously identified in the RIIIS/J mouse strain that causes a unique tissue-specific switch in the expression of an N-acetylgalactosaminyltransferase, B4GALNT2, from intestinal epithelium to vascular endothelium. Vascular B4galnt2 expression results in aberrant glycosylation of von Willebrand Factor (VWF) and accelerated VWF clearance from plasma. We now report that 13 inbred mouse strains share the Mvwf1 tissue-specific switch and low VWF phenotype, including five wild-derived strains. Genomic sequencing identified a highly conserved 97-kb Mvwf1 haplotype block shared by these strains that encompasses a 30-kb region of high nucleotide sequence divergence from C57BL6/J flanking B4galnt2 exon 1. The analysis of a series of bacterial artificial chromosome (BAC) transgenes containing B4galnt2 derived from the RIIIS/J or C57BL6/J inbred mouse strains demonstrates that the corresponding sequences are sufficient to confer the vessel (RIIIS/J) or intestine (C57BL6/J)-specific expression patterns. Taken together, our data suggest that the region responsible for the Mvwf1 regulatory switch lies within an approximately 30-kb genomic interval upstream of the B4galnt2 gene. The observation that Mvwf1 is present in multiple wild-derived strains suggests that this locus may be retained in wild mouse populations due to positive selection. Similar selective pressures could contribute to the high prevalence of von Willebrand disease in humans.