Ongoing Extension Study Research Articles

Natural Compounds as Inhibitors of Aβ Peptide and Tau Aggregation.

Neurodegenerative conditions like Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) encompass disorders characterized by the degeneration of neurons in specific circumstances. The quest for novel agents to influence these diseases, particularly AD, has unearthed various natural compounds displaying multifaceted activities and diverse pharmacological mechanisms. Given the ongoing extensive study of pathways associated with the accumulation of neurofibrillary aggregates and amyloid plaques, this paper aims to comprehensively review around 130 studies exploring natural products. These studies focus on inhibiting the formation of amyloid plaques and tau protein tangles, with the objective of potentially alleviating or delaying AD.

Safety and efficacy of givinostat in boys with Duchenne muscular dystrophy (EPIDYS): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

Duchenne muscular dystrophy, the most common childhood muscular dystrophy, is caused by dystrophin deficiency. Preclinical and phase 2 study data have suggested that givinostat, a histone deacetylase inhibitor, might help to counteract the effects of this deficiency. We aimed to evaluate the safety and efficacy of givinostat in the treatment of Duchenne muscular dystrophy. This multicentre, randomised, double-blind, placebo-controlled, phase 3 trial was done at 41 tertiary care sites in 11 countries. Eligible participants were ambulant, male, and aged at least 6 years, had a genetically confirmed diagnosis of Duchenne muscular dystrophy, completed two four-stair climb assessments with a mean of 8 s or less (≤1 s variance), had a time-to-rise of at least 3 s but less than 10 s, and had received systemic corticosteroids for at least 6 months. Participating boys were randomly assigned (2:1, allocated according to a list generated by the interactive response technology provider) to receive either oral givinostat or matching placebo twice a day for 72 weeks, stratified by concomitant steroid use. Boys, investigators, and site and sponsor staff were masked to treatment assignment. The dose was flexible, based on weight, and was reduced if not tolerated. Boys were divided into two groups on the basis of their baseline vastus lateralis fat fraction (VLFF; measured by magnetic resonance spectroscopy): group A comprised boys with a VLFF of more than 5% but no more than 30%, whereas group B comprised boys with a VLFF of 5% or less, or more than 30%. The primary endpoint compared the effects of givinostat and placebo on the change in results of the four-stair climb assessment between baseline and 72 weeks, in the intention-to-treat, group A population. Safety was assessed in all randomly assigned boys who received at least one dose of study drug. When the first 50 boys in group A completed 12 months of treatment, an interim futility assessment was conducted, after which the sample size was adapted using masked data from the four-stair climb assessments. Furthermore, the starting dose of givinostat was reduced following a protocol amendment. This trial is registered with ClinicalTrials.gov, NCT02851797, and is complete. Between June 6, 2017, and Feb 22, 2022, 359 boys were assessed for eligibility. Of these, 179 were enrolled into the study (median age 9·8 years [IQR 8·1-11·0]), all of whom were randomly assigned (118 to receive givinostat and 61 to receive placebo); 170 (95%) boys completed the study. Of the 179 boys enrolled, 120 (67%) were in group A (81 givinostat and 39 placebo); of these, 114 (95%) completed the study. For participants in group A, comparing the results of the four-stair climb assessment at 72 weeks and baseline, the geometric least squares mean ratio was 1·27 (95% CI 1·17-1·37) for boys receiving givinostat and 1·48 (1·32-1·66) for those receiving placebo (ratio 0·86, 95% CI 0·745-0·989; p=0·035). The most common adverse events in the givinostat group were diarrhoea (43 [36%] of 118 boys vs 11 [18%] of 61 receiving placebo) and vomiting (34 [29%] vs 8 [13%]); no treatment-related deaths occurred. Among ambulant boys with Duchenne muscular dystrophy, results of the four-stair climb assessment worsened in both groups over the study period; however, the decline was significantly smaller with givinostat than with placebo. The dose of givinostat was reduced after an interim safety analysis, but no new safety signals were reported. An ongoing extension study is evaluating the long-term safety and efficacy of givinostat in patients with Duchenne muscular dystrophy. Italfarmaco.

Exploring concurrent validity of the CLN2 Clinical Rating Scale: Comparison to PedsQL using cerliponase alfa clinical trial data.

The CLN2 Clinical Rating Scale evaluates disease progression in CLN2 disease, an ultra-rare, neurodegenerative disorder with late infantile onset. To validate the Clinical Rating Scale, a comparison with the Pediatric Quality of Life Inventory (PedsQL) was conducted utilising clinical trial data investigating cerliponase alfa use in CLN2 disease. Linear regression and mixed effects models were used to investigate the relationship between the Clinical Rating Scale and PedsQL using open-label, single-arm, phase 1/2 (NCT01907087) and ongoing extension study (NCT02485899) data of 23 children with CLN2 disease treated with cerliponase alfa for ≥96 weeks. Correlations between the four Clinical Rating Scale domains were low. Linear mixed effects analyses showed significant correlation between PedsQL and Clinical Rating Scale (Total score or motor-language [ML] score adjusted p-values <0.05), driven by the relationship with the PedsQL Physical domain. A statistically significant relationship was identified between the Clinical Rating Scale motor domain and PedsQL (Total score: adjusted p-value = 0.048, parameter estimate [PE] = 8.10; Physical domain score: adjusted p-value = 0.012; PE = 13.79). Each domain of the Clinical Rating Scale provides unique information on disease state. Validity of the scale is supported by its relationship with the PedsQL. Among the four domains of the Clinical Rating Scale, motor has the highest correlation to PedsQL, suggesting motor function as a driver of patients' quality of life. The lack of association between the remaining domains of the Clinical Rating Scale and PedsQL suggests that additional disease-specific measures may be needed to fully capture the quality of life impact of CLN2 disease. NCT01907087, NCT02485899.

The Development of Ofatumumab, a Fully Human Anti-CD20 Monoclonal Antibody for Practical Use in Relapsing Multiple Sclerosis Treatment.

The importance of B cells in multiple sclerosis (MS) has been demonstrated through the advent of B-cell-depleting anti-CD20 antibody therapies. Ofatumumab is the first fully human anti-CD20 monoclonal antibody (mAb) developed and tested for subcutaneous (SC) self-administration at monthly doses of 20mg, and has been approved in the US, UK, EU, and other regions and countries worldwide for the treatment of relapsing MS. The development goal of ofatumumab was to obtain a highly efficacious anti-CD20 therapy, with a safety and tolerability profile that allows for self-administration by MS patients at home and a positive benefit-risk balance for use in the broad relapsing MS population. This development goal was enabled by the unique binding site, higher affinity to B cells, and higher potency of ofatumumab compared to previous anti-CD20 mAbs; these properties of ofatumumab facilitate rapid B-cell depletion and maintenance with a low dose at a low injection volume (20mg/0.4ml). The high potency in turn enables the selective targeting of B cells that reside in the lymphatic system via subcutaneous (SC) administration. Through a comprehensive dose-finding program in two phase 2 studies (one intravenous and one SC) and model simulations, it was found that safety and tolerability can be further improved, and the risk of systemic injection-related reactions (IRRs) minimized, by avoiding doses≥30mg, and by reaching initial and rapid B-cell depletion via stepwise weekly administration of ofatumumab at Weeks 0, 1, and 2 (instead of a single high dose). Once near-complete B-cell depletion is reached, it can be maintained by monthly doses of 20mg/0.4ml. Indeed, in phase 3 trials (ASCLEPIOS I/II), rapid and sustained near-complete B-cell depletion (largely independent of body weight, race and other factors) was observed with this dosing regimen, which resulted in superior efficacy of ofatumumab versus teriflunomide on relapse rates, disability worsening, neuronal injury (serum neurofilament light chain), and imaging outcomes. Likely due to its fully human nature, ofatumumab has a low immunogenic risk profile-only 2 of 914 patients receiving ofatumumab in ASCLEPIOS I/II developed anti-drug antibodies-and this may also underlie the infrequent IRRs (20% with ofatumumab vs. 15% with the placebo injection in the teriflunomide arm) that were mostly (99.8%) mild to moderate in severity. The overall rates of infections and serious infections in patients treated with ofatumumab were similar to those in patients treated with teriflunomide (51.6% vs. 52.7% and 2.5% vs. 1.8%, respectively). The benefit-risk profile of ofatumumab was favorable compared to teriflunomide in the broad RMS population, and also in the predefined subgroups of both recently diagnosed and/or treatment-naïve patients, as well as previously disease-modifying therapy-treated patients. Interim data from the ongoing extension study (ALITHIOS) have shown that long-term treatment with ofatumumab up to 4years is well-tolerated in RMS patients, with no new safety risks identified. In parallel to the phase 3 trials in which SC administration was carried out with a pre-filled syringe, an autoinjector pen for more convenient self-administration of the ofatumumab 20mg dose was developed and is available for use in clinical practice.

Abstract 12690: Mavacamten Treatment in Patients With Obstructive and Nonobstructive Hypertrophic Cardiomyopathy: A Pooled Safety Analysis of 5 Clinical Trials

Introduction: Mavacamten, a cardiac myosin inhibitor, is approved by the US FDA for the treatment of adults with symptomatic obstructive HCM. We present results from an integrated analysis of pooled mavacamten safety data from clinical studies in patients (pts) with obstructive and nonobstructive HCM. Methods: Pts who received ≥1 dose of mavacamten in phase 2 and 3 studies (PIONEER-HCM [end of study date: Jan 12, 2018]; MAVERICK-HCM [Jan 7, 2020]; EXPLORER-HCM [Jul 1, 2020]) and ongoing extension studies (PIONEER-OLE and MAVA-LTE [data cut-off date: Aug 31, 2021]) comprised the pooled analysis population. Results: Data were pooled from a total of 314 unique pts with obstructive (n=260) or nonobstructive (n=54) HCM. Baseline characteristics are shown in the Table. Cumulative time on study (parent + extension) was ≥6 mo for 91% of pts. The mean cumulative duration of mavacamten exposure was 20.2 mo (range: 0.3, 42.5; median: 20.7 mo); 5.4% of pts permanently discontinued treatment due to treatment-emergent adverse events (TEAEs). Total cumulative exposure was 527.6 pt-yrs, and the median average daily dose of mavacamten was 5.7 mg. Generally similar proportions of pts on mavacamten vs placebo experienced grade ≥3, serious, or drug-related TEAEs; few pts experienced TEAEs that led to study discontinuation or drug interruption ( Table ). The exposure-adjusted incidence of adjudicated events in EXPLORER-HCM and MAVA-LTE of heart failure and new-onset atrial fibrillation were 1.42 and 3.07 per 100 pt-yrs, respectively. As previously reported, 4 deaths occurred across studies: 3 in the mavacamten arm due to TEAEs (bacterial endocarditis, cardiac arrest, and acute myocardial infarction [all, n=1]), with none considered related to study drug, and 1 in the placebo arm (sudden death). Conclusion: Integrated evaluation of existing trial data in HCM show that mavacamten is safe and generally well tolerated, irrespective of the presence of obstruction and across multiple doses.

RF09 | PSAT70 Comparison of Prednisolone Versus Modified-release Hydrocortisone (Efmody) in the Treatment of Congenital Adrenal Hyperplasia (CAH)

Abstract Background Prednisolone and prednisone have a longer plasma elimination half-life after oral administration than hydrocortisone: 2.1 to 3.5 vs ∼1.5hrs1,2. For this reason, prednis(ol)one has been used in Congenital Adrenal Hyperplasia (CAH) by giving a dose in the evening to try to prevent the overnight rise in adrenal androgens. Modified-release hydrocortisone (MRHC) capsules, (Efmody, Diurnal Ltd, Cardiff UK), replicate the cortisol diurnal rhythm and improve the control of CAH compared to standard glucocorticoid therapy3. This post-hoc sub-analysis examines CAH control in MRHC treated patients switched from prednis(ol)one. Methods We reviewed the data of all patients taking prednis(ol)one in the randomised study of standard treatment versus MRHC3: 39 classic CAH patients on prednis(ol)one (alone or combined with hydrocortisone) (36 prednisolone; 3 prednisone) were randomised either to continue prednis(ol)one or switched to MRHC at the same hydrocortisone dose equivalent (HDE=prednisolone dose x5). Patients were assessed after 4 weeks following which blinded dose titration according to 17OHP and A4 control was performed to bring 17OHP into the optimal range (&amp;lt;36 nmol/l) and A4 into the reference range. After 24 weeks, 31 patients from the prednis(ol)one prior therapy group participated in an ongoing MHRC single arm extension study with 28 patients completing 18 months follow up. Control of CAH was defined as a 0900h 17OHP &amp;lt;36 nmol/l. Results Median baseline dose (HDE) was 30mg (n=39), androgen control was 56%. In patients randomised to MRHC (n=18), 39% were controlled at baseline and 94% at 4 weeks without dose adjustment. At 24 weeks, after androgen-control guided titration, the HDE dose in the prednis(ol)one group was 34mg, and in the MRHC group 27.5mg, with control being 71% and 94%, respectively. Percentage inhibition of 9am 17OHP from the levels at baseline to that at 24 weeks in the prednis(ol)one group was 32% and in the MRHC group 91%. In this study period there were no adrenal crises in the MRHC group and one in the prednis(ol)one group. MRHC-treated patients in the extension study were further titrated according to clinician assessment, at interim analysis the median MRHC dose was 20mg (median reduction 10mg) and 82% of patients were controlled at 18 months (n=28). In the ongoing extension study of all patients on MRHC (221 patient years), there were 12 adrenal crises in 5 patients (5.4/100 patient years). Conclusions Control of CAH is better on MRHC than prednisolone: 94% vs 39%; and the dose of MRHC can be down titrated to an adrenal replacement dose whilst maintaining control in the majority (82%) of patients.

33-OR: ADA Presidents' Select Abstract: Glycemic Outcomes over 12 Months in Very Young Children with the Omnipod 5 Automated Insulin Delivery (AID) System

The Omnipod 5 AID System is a tubeless hybrid closed-loop system with on-body operation and customizable glucose targets. Safe and effective system use was demonstrated in children aged 2-5.9y with type 1 diabetes (T1D) during a 3-mo pivotal study. To evaluate durability of glycemic benefit, we analyzed results from 9mo of an ongoing extension study, totaling 12mo of system use. In the pivotal study, participants used the system for 3mo at home, after 14d of their standard therapy (ST, pump or multiple daily injections) . They were then invited to participate in the extension study. Safety endpoints were occurrence of severe hypoglycemia (SH) and diabetic ketoacidosis (DKA) . Glycemic outcomes were A1C and percent time in ranges (TIR 70-180 mg/dL, TBR &amp;lt;70 mg/dL, TAR &amp;gt;180 mg/dL) during 3-mo AID intervals compared with ST. All pivotal trial participants (N=80) , aged (mean±SD) 4.7±1.0y with T1D duration 2.3±1.1y and total daily insulin of 14±4U (range: 5.3-27U) at baseline, enrolled in the extension. Improved outcomes were observed for up to 12mo, including lower A1C and greater TIR during each AID interval compared with ST (all p&amp;lt;0.05, Table) . There were no episodes of DKA or SH in the 12-mo study. The safety and improved glycemic outcomes from the initial 3mo pivotal study persisted for an additional 9mo, indicating the potential long-term benefit of the Omnipod 5 System in very young children with T1D. Disclosure D.Desalvo: Consultant; Dexcom, Inc., Insulet Corporation, Research Support; Insulet Corporation. D.W.Hansen: None. T.T.Ly: Employee; Insulet Corporation, Stock/Shareholder; Insulet Corporation. Omnipod 5 in preschoolers study group: n/a. B.W.Bode: Advisory Panel; CeQur SA, MannKind Corporation, Medtronic, Novo Nordisk, Zealand Pharma A/S, Consultant; Bigfoot Biomedical, Inc., Research Support; Abbott, Beta Bionics, Inc., Dexcom, Inc., Diasome, Dompé, Eli Lilly and Company, Insulet Corporation, IQVIA Inc., Jaeb Center for Health Research, Medtronic, Novo Nordisk, Provention Bio, Inc., REMD Biotherapeutics, Sanvita Medical, Senseonics, ViaCyte, Inc., Speaker's Bureau; Abbott, Boehringer Ingelheim International GmbH, Eli Lilly and Company, Insulet Corporation, MannKind Corporation, Novo Nordisk, Sanofi, Xeris Pharmaceuticals, Inc., Stock/Shareholder; AgaMatrix, Glytec, LLC. G.P.Forlenza: Advisory Panel; Lilly, Medtronic, Consultant; Dexcom, Inc., Insulet Corporation, Tandem Diabetes Care, Inc., Research Support; Dexcom, Inc., Insulet Corporation, Medtronic, Tandem Diabetes Care, Inc. L.M.Laffel: Advisory Panel; Medtronic, Roche Diabetes Care, Consultant; Boehringer Ingelheim International GmbH, Dexcom, Inc., Dompé, Insulet Corporation, Janssen Pharmaceuticals, Inc., Lilly Diabetes, Novo Nordisk, Provention Bio, Inc. B.A.Buckingham: Advisory Panel; Arecor, Lilly Diabetes, Medtronic, Other Relationship; Insulet Corporation, Research Support; Insulet Corporation, Lilly Diabetes, Medtronic. A.B.Criego: Advisory Panel; Insulet Corporation, Other Relationship; Medscape, Sanofi, Research Support; Abbott Diabetes, Dexcom, Inc., Insulet Corporation, Medtronic. M.Schoelwer: Other Relationship; Dexcom, Inc., Research Support; Insulet Corporation, Medtronic, Tandem Diabetes Care, Inc. S.A.Macleish: Advisory Panel; Insulet Corporation. J.Sherr: Advisory Panel; Bigfoot Biomedical, Inc., Cecelia Health, Insulet Corporation, Medtronic, Vertex Pharmaceuticals Incorporated, Consultant; Insulet Corporation, Lexicon Pharmaceuticals, Inc., Research Support; Dexcom, Inc., Insulet Corporation, Jaeb Center for Health Research, JDRF, Medtronic, National Institute of Diabetes and Digestive and Kidney Diseases, Speaker's Bureau; Lilly Diabetes. Funding Insulet Corporation

Mitapivat (AG-348) Demonstrates Safety, Tolerability, and Improvements in Anemia, Hemolysis, Oxygen Affinity, and Hemoglobin S Polymerization Kinetics in Adults with Sickle Cell Disease: A Phase 1 Dose Escalation Study

Background. Hemoglobin S (HbS) polymerization causes red cell sickling, hemolysis, and vaso-occlusion, key pathological features of sickle cell disease (SCD). Mitapivat (AG-348) has potential as an oral anti-sickling agent in SCD via increasing glycolytic activity, which reduces intracellular levels of 2,3-diphosphoglycerate (2,3-DPG) in parallel with increasing adenosine triphosphate (ATP). Reducing 2,3-DPG decreases HbS polymerization, while increasing ATP improves red cell membrane integrity. Here, we report the complete results of our single-center Phase 1 study of multiple ascending doses of mitapivat in subjects with SCD.Methods. We enrolled adult subjects (age ≥ 18 years) with confirmed SCD (HbSS) and baseline Hb ≥ 7 g/dL; with no recent transfusions, erythropoietin therapy, or changes in SCD-specific therapies including hydroxyurea (HU) and L-glutamine. Subjects received either 3 or 4 ascending dose levels of mitapivat (5 mg BID, 20 mg BID, 50 mg BID, 100 mg BID) for 2 weeks' duration each, followed by a 12-15 day drug taper. Safety and tolerability were assessed by frequency and severity of adverse events (AEs) and changes in hemoglobin (Hb) level and hemolytic markers. For each dose level, pharmacokinetics (PK), pharmacodynamics (PD; 2,3-DPG and ATP levels), and markers of oxygen (O 2) affinity (p50) and HbS polymerization (t50) were assessed pre-dose, post-dose, at end of taper, and at end of study. p50 is the partial pressure of O 2 at which 50% of the hemes in the Hb molecule have O 2 bound; t50 is the time at which 50% of erythrocytes are sickled in response to gradual deoxygenation with nitrogen to a final O 2 partial pressure of 38 torr.Results. Out of 17 subjects enrolled, 16 escalated to 50 mg BID. One subject, withdrawn 3 days after starting the study for a pre-existing pulmonary embolus, was not evaluable for response. After a protocol amendment, 9/10 eligible subjects completed the 100 mg BID dose level; 1 subject self-discontinued treatment after completing 3 dose levels. Mean age of the 17 subjects was 39 years (range 23-55 years); 11 were male, and 12 were on HU. Mitapivat was well tolerated; the most commonly reported drug-related AEs were insomnia (n=6 subjects, Grades 1-2), arthralgia (n=3, Grades 1-2), and hypertension (n=3, Grades 1-3). Six serious AEs (SAEs) were reported in 6/17 subjects, including 4 vaso-occlusive crises (VOCs), 1 non-VOC-related pain, and 1 pre-existing pulmonary embolism; 2/6 SAEs were deemed possibly drug-related. Of the 4 VOCs, 2 occurred during drug taper and were possibly drug-related, and 2 occurred during the 28-day safety follow up post-treatment in the setting of known VOC triggers.In 16 evaluable subjects, a dose-dependent decrease in mean 2,3-DPG levels and increase in mean ATP levels were consistently observed, followed by a return to near baseline by end of study (Figure 1A-B). There was a mean decrease in p50 and increase in t50 (Figure 1D-E), indicating increased oxygen affinity and slower sickling, respectively. The mean Hb increase at the 50 mg BID dose level was 1.2 g/dL (range -0.3-2.9 g/dL; Figure 1C). Over half (9/16, 56.3%) of subjects achieved a Hb response, defined as a ≥ 1 g/dL increase in Hb at any dose level compared to baseline. Subjects also experienced a mean reduction in the hemolytic markers of lactate dehydrogenase, total serum bilirubin, absolute reticulocyte count, and aspartate aminotransferase during the dose escalation period (Figure 1F-I), though responses were variable. Mean corpuscular volume (MCV) and HbF levels remained relatively stable throughout the study, supporting the notion that hydroxyurea exposure remained stable throughout the treatment period.Conclusion. During a 6-8 week treatment period, mitapivat demonstrated an acceptable safety and tolerability profile at multiple ascending dose levels in subjects with SCD. Mitapivat improved anemia, reduced markers of hemolysis, decreased 2,3-DPG and increased ATP levels, improved oxygen affinity, and decreased sickling rate, signaling its potential to improve clinically meaningful outcomes in SCD. Long-term disease modifying effects of mitapivat treatment in SCD are being evaluated in an ongoing extension study (ClinicalTrials.gov NCT04610866). [Display omitted] DisclosuresIyer: Novartis: Current equity holder in publicly-traded company; Agios Pharmaceuticals: Current Employment, Current holder of stock options in a privately-held company. Mangus: Agios Pharmaceuticals, Inc.: Current Employment, Current equity holder in publicly-traded company; Bristol-Myers Squibb: Current equity holder in publicly-traded company. Kung: Agios Pharmaceuticals, Inc.: Current Employment, Current holder of stock options in a privately-held company. Dang: Agios Pharmaceuticals, Inc.: Current Employment, Current holder of stock options in a privately-held company. Kosinski: Agios Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Hawkins: Bristol-Myers Squibb: Current equity holder in publicly-traded company; Agios: Current equity holder in publicly-traded company.

Long-Term Cardiac, Vascular and Hypertensive Safety of Bosutinib in Patients with Philadelphia Chromosome-Positive (Ph+) Leukemia Resistant or Intolerant to Prior Therapy

Long-Term Cardiac, Vascular and Hypertensive Safety of Bosutinib in Patients with Philadelphia Chromosome-Positive (Ph+) Leukemia Resistant or Intolerant to Prior Therapy

Bosutinib (BOS) for chronic phase (CP) chronic myeloid leukemia (CML) after imatinib (IMA) failure: ≥8-y update of a phase I/II study.

7549 Background: BOS is approved for newly diagnosed CP CML and CML resistant/intolerant to prior therapy. In a phase I/II study, BOS showed durable efficacy and manageable toxicity in patients (pts) with CP CML after IMA failure. We report an ≥8-y update of this phase I/II and ongoing extension study. Methods: Pts with CP CML resistant/intolerant to IMA (CP2L) or IMA + dasatinib and/or nilotinib (CP3L) or with accelerated/blast phase (AP/BP) CML or Philadelphia chromosome+ acute lymphoblastic leukemia with prior tyrosine kinase inhibitor (TKI) therapy (ADV) received BOS starting at 500 mg/d. Results: 54/284 (19%) CP2L pts were still on BOS after ≥9 y and 8/119 (7%) CP3L and 5/167 (3%) ADV pts after ≥8 y; 61 CP2L pts discontinued BOS since y 5 and 21 CP3L and 12 ADV pts since y 4. Overall, the most common reason for discontinuation was disease progression/lack of efficacy in CP2L (27%), CP3L (42%) and ADV (50%) pts; last dose before discontinuation was ≥500 mg/d in 59 (21%), 28 (24%) and 46 (28%) pts, respectively. In CP2L pts, median (range) of follow-up was 54 (1–155) mo, treatment duration 26 (&lt;1–155) mo and dose intensity 438 (87–599) mg/d; responses were durable (Table) and overall survival (OS) at 9 y was 74% vs 84% at 5 y. OS at 8 y was 69% in CP3L, 54% in AP CML and 23% in BP CML pts vs 78%, 59% and 23% at 4 y. 55 CP2L, 29 CP3L and 98 ADV pts died on study (10, 3 and 2 since the 4/5-y reports); 15, 5 and 3 had on-treatment transformations to AP/BP. Most common new treatment-emergent adverse events since y 5 in CP2L pts were pleural effusion (n=13), arthralgia (n=12) and increased blood creatinine (n=11). Conclusions: After ≥8 y, BOS continued to show durable efficacy and no new safety signals in pts with CP CML on long-term treatment, providing further support for BOS use after prior TKIs. Clinical trial information: NCT00261846 and NCT01903733 . [Table: see text]

1169Interim analysis of data from a long-term, extension trial of tafamidis meglumine in patients with transthyretin amyloid cardiomyopathy

Abstract Background Transthyretin amyloid cardiomyopathy (ATTR-CM), is an underdiagnosed, fatal disease caused by the deposition of transthyretin amyloid fibrils in the heart leading to heart failure. The Transthyretin Cardiomyopathy Clinical Trial (ATTR-ACT), an international, multi-center, double-blind, placebo-controlled, randomized study, demonstrated the efficacy and safety of tafamidis treatment for patients with ATTR-CM due to variant (ATTRm) or wild-type (ATTRwt) TTR. Purpose This is a pooled analysis of data from ATTR-ACT and interim data from the ongoing, long-term, extension study to evaluate longer term data on the efficacy of tafamidis in patients with ATTR-CM. Methods Patients who completed ATTR-ACT (which had a duration of 30 months) were eligible to be enrolled in a long-term, extension study in which patients either continued to receive tafamidis meglumine at the same dose (the tafamidis/tafamidis [T/T] group) or, for patients previously treated with placebo, were randomised (in a 1:2 ratio) to tafamidis meglumine 20 mg or 80 mg (the placebo/tafamidis [P/T] group) for up to 60 months. The primary efficacy outcome was all-cause mortality. This analysis combined data from the completed ATTR-ACT with interim data from the extension study (cut-off date: 15 Feb, 2018), and included patients treated with tafamidis meglumine across the two studies with a median follow up of 36 months. Results All-cause mortality was significantly lower in the T/T group (n=264; 88 events, 33.3%) compared with the P/T group (n=177; 88 events, 50.3%); hazard ratio (95% CI), 0.64 (0.47, 0.85); P=0.001. In the subgroup of ATTRwt patients, all-cause mortality was significantly reduced in the T/T group (55/201; 27.4%) compared with the P/T group (60/134; 44.8%); 0.64 (0.44, 0.92); P=0.002. In the 106 (24.0%) ATTRm patients, there was a trend towards a reduction in all-cause mortality in the T/T group (33/63; 52.4%) compared with the P/T group (29/43; 67.4%); 0.66 (0.39, 1.09); P=0.17. In patients who were NYHA Class I or II at baseline, all-cause mortality was significantly reduced in the T/T group (38/186; 20.4%) compared with the P/T group (45/114; 39.5%); 0.49 (0.32, 0.75); P=0.001. In those patients with more severe symptoms at baseline (NYHA Class III), there were fewer deaths in the T/T group (50/78; 64.1%) compared with the P/T group (44/63; 69.8%); 0.80 (0.53, 1.21), but this difference was not statistically significant (P=0.50). Conclusions In ATTR-ACT, tafamidis was shown to significantly improve survival, functional capacity, and quality of life in patients with ATTR-CM. This pooled analysis with data from the ongoing extension study further supports the efficacy of tafamidis in patients over a longer period of time and the importance of early diagnosis and treatment. Acknowledgement/Funding This study was sponsored by Pfizer.

Second-Line Bosutinib in Patients with Chronic Phase Chronic Myeloid Leukemia (CP CML) Resistant or Intolerant to Prior Imatinib: An 8-Year Update

Bosutinib is an orally active, dual SRC/ABL tyrosine kinase inhibitor (TKI) approved for treating adult patients with chronic phase, accelerated phase (AP), or blast phase (BP) Philadelphia chromosome-positive (Ph+) CML with resistance or intolerance to prior therapy. In an open-label, phase 1/2 study (NCT00261846), second-line bosutinib demonstrated durable hematologic and cytogenetic responses and good tolerability in patients with Ph+ CP CML who were imatinib resistant (IM-R) or imatinib intolerant (IM-I) (Cortes, Am J Hematol, 2016). Here we report a 96-month update of this study and its ongoing extension study (NCT01903733).Adult patients with Ph+ CP CML who were resistant or intolerant to first-line imatinib were included in this analysis. 195 IM-R and 89 IM-I patients received bosutinib starting at 500 mg/d. Median age (range) was 53 yr (18-91 yr), time from CML diagnosis was 3.7 yr (0.1-15.1 yr), treatment duration was 25.6 mo (0.2-133 mo), and follow-up duration was 53.7 mo (0.5-133 mo). Bosutinib dose was increased to 600 mg/d in 13% of patients. For the last enrolled IM-R and IM-I patients, time from first dose of bosutinib to data cutoff was 96.5 mo and 94.2 mo, respectively. At 8 yr, 26% of patients were still receiving bosutinib.Major cytogenetic response (MCyR) was achieved by 60% of patients in both groups (Table). Median duration of MCyR was not reached as of the minimum follow-up, and the Kaplan-Meier probability of maintaining MCyR at 8 yr was 60% (IM-R) and 75% (IM-I). Complete cytogenetic response (CCyR) was achieved by 49% (IM-R) and 51% (IM-I) of patients. Median duration CCyR was not reached as of the minimum follow-up, and the Kaplan-Meier probability of maintaining CCyR at 8 yr was 57% (IM-R) and 69% (IM-I) of patients. On-treatment transformation to accelerated phase or blast phase occurred in 7% (IM-R) and 2% (IM-I) of patients with no new events since the 5-yr follow-up. The cumulative incidence of on-treatment progression or death at 8 yr was 28% (IM-R) and 11% (IM-I), respectively (Table). Overall survival at 8 yr on study was 75% for the IM-R group and 87% for the IM-I group.Dose delays due to adverse events (AEs) occurred in 133 (68%) and 76 (85%) of IM-R and IM-I patients, resulting in median cumulative treatment delays of 25 d and 27 d, respectively. Dose reductions due to AEs occurred in 93 (48%) and 54 (61%) of IM-R and IM-I patients, respectively. Median cumulative duration of dose reduction was 357 d and 267 d, and median time to dose reduction was 49 d and 54 d in the IM-R and IM-I cohorts, respectively. By 8 yr, treatment was discontinued in 141 (72%) and 69 (78%) of IM-R and IM-I patients, respectively. The most common reasons for discontinuation were disease progression (23%) and AEs (16%) in the IM-R cohort, and AEs (42%) and patient request (13%) in the IM-I cohort. In the IM-R cohort, the most frequent AEs leading to permanent treatment discontinuation were thrombocytopenia (4%), increased ALT (2%), and diarrhea (2%). In the IM-I cohort the most frequent AEs leading to permanent treatment discontinuation were thrombocytopenia (11%), neutropenia (5%), increased ALT (3%), and rash (3%). Among the 40 patients (21%) in the IM-R cohort who died on study, the most frequent reasons for death were disease progression (12%) and AEs unrelated to study drug (7%). For the 11 patients (12%) in the IM-I cohort who died on study, the most frequent reasons were disease progression (7%) and unknown (3%). No patients died due to an AE related to study drug and 13 patients (5%) died within 30 days of last dose. Five subjects died since the 5-yr follow-up; 3 within 30 days of last dose.These long-term (8-yr) data are consistent with previous findings associating second-line bosutinib therapy with similar rates of durable major cytogenetic responses in the majority of patients with imatinib-resistant and imatinib-intolerant CP CML. Most AEs could be managed through temporary treatment interruptions and dose reductions. [Display omitted] DisclosuresBrümmendorf:Novartis: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding. Gambacorti-Passerini:BMS: Consultancy; Pfizer: Consultancy, Honoraria, Research Funding. Pagnano:Roche: Speakers Bureau; Amgen: Consultancy; Bristol-Meirs Squibb: Consultancy, Speakers Bureau; Novartis: Consultancy. Aguiar:Pfizer: Employment, Equity Ownership. Leip:Pfizer: Employment, Equity Ownership. Cortes:Teva: Research Funding; Pfizer: Consultancy, Research Funding; Novartis Pharmaceuticals Corporation: Consultancy, Research Funding; ImmunoGen: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Sun Pharma: Research Funding; ARIAD: Consultancy, Research Funding.

Profiling and Comparing the Immunogenicity of a Novel Single-Chain FVIII Molecule (rVIII-SingleChain) for the Treatment of Hemophilia a

Hemophilia A is an X-linked bleeding disorder caused by mutations in the gene encoding the Factor VIII coagulation protein (FVIII). Bleeding episodes in patients are reduced by prophylactic therapy or treated acutely using recombinant or plasma derived FVIII. These treatments have substantially improved the outcome of hemophilia. More recently long-acting recombinant FVIII concentrates have become available in the clinic, but hemophilia A patients still require the repeated intravenous injections frequently 2-3 times per week. Furthermore, the development of inhibitors which are associated with significant mortality and morbidity remains a serious complication for approximately 30% of patients with severe hemophilia A, highlighting the need for new FVIII products with reduced immunogenicity. The development of recombinant FVIII molecules with a lower inhibitor risk profile would present an important advance in the care of patients with hemophilia A. rVIII-SingleChain (AFSTYLATM), is the first and only single-chain molecule purposely designed to provide key features such as increased dosing intervals and high clinical efficacy. The present study has focused on evaluating the immunogenic profile of rVIII-SingleChain in comparison to other rFVIII products (both full length and B-domain-truncated/deleted). Several key characteristics have been identified: The highly pure and homogeneous rVIII-SingleChain with a covalently linked heavy chain and light chain is less likely to contain dissociated FVIII chains (or fragments thereof) that cannot bind to von Willebrand Factor (VWF) and are thus available for uptake by antigen presenting cells (APC). The high degree of sulphation of the predicted six tyrosine sulphation sites in rVIII-SingleChain (as compared to other rFVIII molecules) not only provides a basis for optimal functionality but also (with respect to Tyr1680) ensures maximal VWF binding of the majority of rVIII-SingleChain molecules. The improved binding of rVIII-SingleChain to VWF as compared to full-length rFVIII may more effectively reduce antigen uptake and processing by antigen-presenting cells. In this regard, rVIII-SingleChain pre-complexed with plasma-derived VWF, is less efficiently internalized by human monocyte-derived dendritic cells (MoDCs) as compared to several rFVIII products tested. Further, in a ProImmune ProPresent® antigen presentation assay to identify potentially immunogenic regions in rVIII-SingleChain as compared to full length rFVIII protein revealed a lower number of HLA-DR/DP/DQ-restricted epitopes derived from rVIII-SingleChain as compared to the full length rFVIII protein (33 c.f. 47 for DR; 24 c.f. 32 for DP and 26 c.f. 32 for DQ). In addition, when compared to BDD-rFVIII comparators in the ProImmune ProReveal® T cell stimulation assay, rVIII-SingleChain was found to contain fewer HLA-DR/DP/DQ-restricted epitopes derived from the linker region that triggered T-cell proliferation (15% as compared to 25-35% for the comparators). Collectively, these features should contribute to the reduced immunogenic potential of rVIII-SingleChain. Importantly, these pre-clinical studies are supported by findings from the completed rVIII-SingleChain clinical studies in previously treated patients (PTPs) in which no inhibitor development has been observed. In summary, the immunogenicity of rVIII-SingleChain has been extensively characterized in PTPs over 28,418 exposure days equivalent to more than 233 treatment years. As of 01 August 2016, no PTP subject has developed inhibitors after being exposed to rVIII-SingleChain. All available data support the hypothesis that the unique structural attributes of rVIII-SingleChain may translate into reduced immunogenicity when used for replacement therapy in patients with hemophilia A. The previously untreated patient (PUP) arm in the ongoing extension study is designed to generate data that are necessary to prove this significant clinical benefit. rVIII-SingleChain could potentially offer hemophilia A patients a recombinant product with an inhibitor risk profile that is more favorable than that of currently available products. DisclosuresMaraskovsky:CSL Limited: Employment. Verhagen:CSL Limited: Employment. Huynh:CSL Limited: Employment. Baz Morelli:CSL Limited: Employment. Schmidbauer:CSL Behring: Employment. Zollner:CSL Behring: Employment. Powell:CSL Behring: Employment. St Ledger:CSL Behring: Employment. Veldman:CSL Behring: Employment. Hofmann:CSL Behring: Employment.

Efmoroctocog Alfa: A Review in Haemophilia A.

Efmoroctocog alfa (Elocta(®), Eloctate(®), Eloctate™), a first-in-class recombinant factor VIII-Fc fusion protein (rFVIIIFc), has an extended half-life compared with conventional factor VIII (FVIII) preparations, including recombinant FVIII (rFVIII) products. It is approved for the treatment and prophylaxis of bleeding in patients with haemophilia A in multiple countries worldwide. Data accumulated from pivotal phase III studies (A-LONG in adults and adolescents aged ≥12years; Kids A-LONG in children aged <12years) and their ongoing extension study (ASPIRE) have demonstrated the long-term effectiveness of efmoroctocog alfa for the treatment of acute bleeding episodes, perioperative management and routine prophylaxis in previously treated males with severe haemophilia A. Among patients on individualized efmoroctocog alfa prophylaxis who had previously received FVIII prophylaxis, all but one of those aged ≥12years and three-quarters of those aged <12years reduced their injection frequency compared with their pre-study regimen. FVIII replacement therapy with efmoroctocog alfa was generally well tolerated in previously treated patients, with no evidence of increased immunogenicity. The safety and efficacy of FVIII replacement therapy with efmoroctocog alfa in previously untreated males aged <6years with severe haemophilia A are currently being evaluated. Although there are no direct, head-to-head studies, the available clinical trial evidence indicates that efmoroctocog alfa provides an effective alternative to conventional FVIII preparations (including rFVIIIs) for the management of haemophilia A. Moreover, by reducing the frequency of injections required, it has the potential to reduce treatment burden, and hence improve adherence to prophylaxis.

A.06 Ataluren: an overview of clinical trial results in nonsense mutation Duchenne Muscular Dystrophy (nmDMD)

Background: Ataluren is the first drug to treat the underlying cause of nmDMD. Methods: Phase 2 and 3 studies of ataluren in nmDMD were reviewed, with efficacy and safety/tolerability findings summarized. Results: Ataluren nmDMD trials include: a Phase 2a proof-of-concept study (N=38); a Phase 2b randomized controlled trial (RCT) (N=174); an ongoing US-based open-label safety extension study (N=108); an ongoing non-US-based open-label safety/efficacy extension study (N=94); and a Phase 3 RCT, ACT DMD (N=228), whose primary endpoint was change in six-minute walk distance (6MWD) over 48 weeks. The proof-of-concept study demonstrated increased dystrophin production in post-treatment muscle biopsies from ataluren-treated patients with nmDMD. The Phase 2b results demonstrated an ataluren treatment effect in 6MWD, timed function tests, and other measures of physical functioning, The Phase 3 ACT DMD results demonstrated an ataluren treatment effect in patients with nmDMD in both primary and secondary endpoints, particularly in those with a baseline 6MWD of 300-400m. Ataluren was consistently well-tolerated in all three trials, as well as in the ongoing extension studies. Trial findings will be presented in detail. Conclusions: The totality of the results demonstrates that ataluren enables nonsense mutation readthrough in the dystrophin mRNA, producing functional dystrophin and slowing disease progression.Supported by: PTC Therapeutics Inc.

Safety, pharmacokinetics, and pharmacodynamics of ivacaftor in patients aged 2–5 years with cystic fibrosis and a CFTR gating mutation (KIWI): an open-label, single-arm study

Ivacaftor has been shown to be a safe, effective treatment for cystic fibrosis in patients aged 6 years or older with a CFTR gating mutation. We aimed to assess the safety, pharmacokinetics, and pharmacodynamics of ivacaftor in children aged 2-5 years. In the two-part KIWI study, we enrolled children aged 2-5 years weighing 8 kg or more with a confirmed diagnosis of cystic fibrosis and a CFTR gating mutation on at least one allele from 15 hospitals in the USA, UK, and Canada. Participants received oral ivacaftor 50 mg (if bodyweight <14 kg) or 75 mg (if bodyweight ≥14 kg) every 12 h for 4 days in part A (to establish the short-term safety of doses for subsequent assessment in part B), and then for 24 weeks in part B (to assess safety and longer-term pharmacodynamics). Children could participate in both or just one part of the study. Primary outcomes were pharmacokinetics and safety, analysed in all patients who received at least one dose of ivacaftor. Secondary outcomes were absolute change from baseline in sweat chloride concentrations and bodyweight, body-mass index (BMI), and height Z scores, and pharmacokinetic parameter estimation of ivacaftor. This study is registered with ClinicalTrials.gov, number NCT01705145. Between Jan 8, 2013, and March 1, 2013, nine patients were enrolled onto part A of the study, all of whom completed the 4 day treatment period, and eight of whom took part in part B. Between June 28, 2013, and Sept 26, 2013, 34 patients were enrolled in part B, 33 of whom completed the 24 week treatment period. All patients received at least one dose of ivacaftor. Results of ivacaftor pharmacokinetics suggested that exposure was similar to that reported in adults (median Cmin were 536 ng/mL for the 50 mg dose; 580 ng/mL for the 75 mg dose; median ivacaftor AUC values were 9840 ng × h/mL and 10 200 ng × h/mL, respectively). Common adverse events in part B included cough (in 19 [56%] of 34 patients) and vomiting (in ten [29%]). Five (15%) patients had liver function test (LFT) results that were more than eight times higher than the upper limit of normal, four of whom had study drug interrupted, and one of whom had study drug discontinued. Six (18%) of 34 patients had seven serious adverse events; a raised concentration of transaminases was the only serious adverse event regarded as related to ivacaftor and the only adverse event that resulted in study treatment discontinuation. At week 24, in patients for whom we had data, sweat chloride had changed from baseline by a mean of -46·9 mmol/L (SD 26·2, p<0·0001), weight Z score by 0·2 (0·3; p<0·0001), BMI Z score by 0·4 (0·4, p<0·0001), and height Z score by -0·01 (0·3; p=0·84). Ivacaftor at doses of 50 mg and 75 mg seems to be safe in children aged 2-5 years with cystic fibrosis with a gating mutation followed up for 24 weeks, although the frequency of elevated LFTs suggests that monitoring should be frequent in young children, particularly those with a history of elevated LFTs. Results of an ongoing extension study assessing durability of these effects and longer-term safety are warranted. Vertex Pharmaceuticals Incorporated.

Long-Term Use of Coagulation Factor IX (Recombinant) Albumin Fusion Protein (rIX-FP) in Previously Treated Patients with Hemophilia B in the Prolong-9FP Program

A fusion protein genetically linking recombinant human coagulation FIX with recombinant human albumin (rIX-FP) has been developed with an improved PK profile, improving hemophilia B treatment by allowing less frequent dosing than required with standard plasma-derived (pd) and recombinant (r) FIX products. The PROLONG-9FP clinical program has evaluated the use of rIX-FP for prophylaxis and on-demand treatment of bleeding in patients with severe hemophilia B. The clinical program is comprised of 5 clinical studies, including four completed studies (a Phase I pharmacokinetic (PK) study, a Phase II study, and two Phase III studies in adults and children), and an ongoing extension study, which includes previously untreated patients. Over 100 subjects from 42 hemophilia treatment centers in 12 countries have participated in the PROLONG-9FP clinical program. Here, we report on the long-term safety and efficacy of rIX-FP in 15 subjects who have continuously participated in 3 clinical studies (Phase II, Phase III and the on-going Phase III extension studies) over a period of 4 years.Subjects began either weekly prophylaxis treatment or on-demand treatment with rIX-FP in the Phase II 2004 study, and continued that treatment regimen in the Phase III 3001 study. The Phase III global study evaluated safety and efficacy of rIX-FP for prophylaxis treatment (PT) of every 7-, 10- and 14-days and on-demand treatment (ODT) of bleeding episodes. Subjects in the on-demand arm received only ODT for 6 months and then switched to 7-day PT. Subjects in the prophylaxis arm received 7-day PT for 6 months, and eligible subjects switched to 10- or 14-day PT interval. Upon completion of the 3001 study, subjects entered the on-going extension study 3003 and either continued the treatment regimen or switched to a longer prophylaxis interval of 10-, 14- or 21-days. Within subject comparisons of the annualized spontaneous bleeding rates (AsBR), total ABR over time and other efficacy parameters between regimens will be presented.Long-term use of rIX-FP is safe and well-tolerated. No subjects developed inhibitors to FIX or antibodies to rIX-FP during the 4 year treatment period, with a mean of 180 exposure days (EDs) for PT subjects and 125 EDs for ODT subjects. ABR decreased over time with rIX-FP prophylaxis, and longer treatment intervals were possible with no increase in consumption. DisclosuresLubetsky:CSL Behring: Consultancy. Martinowitz:CSL Behring: Honoraria, Speakers Bureau. Voigt:CSL Behring: Employment. Wolko:CSL Behring: Employment. Jacobs:CSL Behring: Employment. Santagostino:Biotest: Speakers Bureau; Kedrion: Speakers Bureau; Roche: Speakers Bureau; Octapharma: Speakers Bureau; Novo Nordisk: Speakers Bureau; Baxter/Baxalta: Speakers Bureau; Bayer: Speakers Bureau; Biogen/Sobi: Speakers Bureau; Pfizer: Research Funding, Speakers Bureau; CSL Behring: Speakers Bureau.

Efficacy and Safety Results of Prolong-9FP Clinical Program of Recombinant Fusion Protein Linking Coagulation Factor IX with Albumin (rIX-FP) in Previously Treated Patients with Hemophilia B

▪A fusion protein genetically linking recombinant human coagulation FIX with recombinant human albumin (rIX-FP) has been developed with an improved PK profile, thus improving hemophilia B treatment by allowing less frequent dosing.Two Phase 3 studies (CSL654-3001 and CSL654-3002) were completed. CSL654-3001 study evaluated safety and efficacy of rIX-FP for prophylaxis treatment (PT) of every 7-, 10- and 14-day and on-demand (ODT) of bleeding episodes in 63 previously treated patients (PTP), 12-61 years of age with hemophilia B (FIX ≤ 2%). Subjects in the on-demand arm received only ODT for 6 months and then switched to every 7-day PT. Subjects in the prophylaxis arm received every 7-day PT, and eligible subjects switched to every 10- or 14-day PT for approximately 12-18 months. Annualized spontaneous bleeding rates (AsBR) were compared between ODT and PT periods (in on-demand arm), and between 7-day PT and 10- or 14-day PT (in prophylaxis arm). CSL654-3002 study evaluated safety and efficacy of rIX-FP for weekly prophylaxis regimen in 27 previously treated patients younger than 12 years with hemophilia B (FIX ≤ 2%) for approximately 12 months. Annualized spontaneous bleeding rates (AsBR) were calculated. The median annualized spontaneous bleeding rate were all 0.00 for all treatment interval (7-day, 10-day or 14-day) and in both studies age groups (1-11 years and 12-65 years) during the two completed phase 3 studies.Seventy-six subjects from both studies continued their prophylaxis regimen in the on-going extension study. In addition, subjects (including children), switched to longer treatment intervals of 10-day, 3 times per month or 14-day or lowered their weekly prophylaxis dose. Nine subjects switched to 21-day treatment interval with 100 IU/kg rIX-FP. As of 28 July 2015, at least 50 subjects (PTP) had achieved 100 EDs without developing an inhibitor to FIX or antibodies to rIX-FP. The long term safety and efficacy of rIX-FP will be presented. This presentation includes the new information regarding the change to longer than 7-day treatment regimens in the extension study, among those subjects (1-61 years of age) that previously participated in the lead in studies.Conclusion: The Prolong - 9FP clinical programdemonstrated the clinical efficacy of rIX-FP for routine prophylaxis every 7-, 10- and 14-day treatment intervals. Routine prophylaxis once every 21 days may be effective in preventing bleeding episodes in a selected patient population. In addition, rIX-FP demonstrated favorable long-term safety and tolerability. DisclosuresSantagostino:Novo Nordisk: Speakers Bureau; Bayer: Speakers Bureau; CSL Behring: Speakers Bureau; Baxter/Baxalta: Speakers Bureau; Pfizer: Research Funding, Speakers Bureau; Biogen/Sobi: Speakers Bureau; Biotest: Speakers Bureau; Kedrion: Speakers Bureau; Octapharma: Speakers Bureau; Roche: Speakers Bureau. Voigt:CSL Behring: Employment. Wolko:CSL Behring: Employment. Cole:CSL Behring: Employment. Li:CSL Behring: Employment. Jacobs:CSL Behring: Employment.

Perioperative Management of Hemostasis with Recombinant FIX Fc Fusion Protein in Subjects Undergoing Surgery in the B-YOND Study

Background: The phase 3 B-LONG (adults/adolescents ≥12 years of age) and Kids B-LONG (children <12 years of age) studies demonstrated the safety and efficacy of recombinant FIX Fc fusion protein (rFIXFc) for the control and prevention of bleeding episodes in subjects with severe hemophilia B (FIX levels ≤2 IU/dL). Eligible subjects from either study could continue rFIXFc treatment in the ongoing extension study, B-YOND, during which surgical procedures were allowed.Aims: To describe rFIXFc efficacy and safety in B-YOND subjects undergoing surgery.Methods: B-YOND subjects who underwent surgery received an investigator-determined rFIXFc regimen. Major surgery endpoints included rFIXFc dosing, investigator/surgeon assessment of hemostatic response (4-point scale: excellent, good, fair, poor/none), blood loss, number of transfusions, and safety. For minor surgeries, hemostatic response and dosing are summarized. Surgeries performed up to cutoff for the interim analysis (17 October 2014) were included. For safety analyses, the surgery subgroup included subjects who underwent major surgery during B-YOND and those who underwent major surgery in the parent study but had their surgical/rehabilitation period during B-YOND.Results: Fifteen major surgeries were performed in 8 subjects (7 adults/adolescents and 1 child <12 years of age), most commonly orthopedic procedures (9/15 surgeries). In adults/adolescents undergoing major surgery, the median total rFIXFc dose on the day of surgery was 135.92 IU/kg (range, 60.6-317.9 IU/kg); 12 of these 14 surgeries required a single rFIXFc infusion to maintain hemostasis during surgery. The number of adults and adolescents undergoing major surgery who required an infusion decreased from Day 0 to Day 14. A single rFIXFc infusion of 99.43 IU/kg was required on the day of surgery for the single major surgery in a pediatric subject (tonsillectomy). Of 15 major surgeries, 14 surgeries were assessed for hemostatic response to rFIXFc and all were rated as excellent (n = 13, including the single pediatric surgery) or good (n = 1). Among 12 major surgeries with estimates, blood loss ranged from 0-1,000 mL intraoperatively and 0-1,000 mL postoperatively (for the single pediatric subject, blood loss was 50 mL intraoperatively and 0 mL postoperatively). One additional subject had an estimated intraoperative blood loss of 5,000 mL during liver transplantation and was the only subject who required transfusion (6 units of packed cells, 4 units of platelet concentrate, and 4 units of fresh frozen plasma intraoperatively), consistent with previously reported blood loss for this procedure in the general population (Yuasa et al. Transfusion 2005;45:879). Hemostatic response for this surgery was rated as excellent. No subject reported a bleeding episode during the postoperative/rehabilitation period. Among 12 subjects in the surgery subgroup (8 with major surgery during B-YOND; 4 with major surgery in B-LONG and a surgical/rehabilitation period during B-YOND), 3 subjects (25%) reported ≥1 adverse event (AE) during the perioperative management period. One subject who underwent major surgery experienced 2 serious AEs (anal sphincter atony and epididymitis; considered unrelated to treatment) during the perioperative management period. All AEs were assessed by the investigator as unrelated to treatment and resolved.Of 25 minor surgeries performed in 17 adults/adolescents (none in children), approximately half were dental procedures (12/25 surgeries). No rFIXFc was administered on the day of surgery for 2 minor surgeries. For the other 23 surgeries, the median number of rFIXFc infusions was 1.0 (range, 1-3) and the median total dose of rFIXFc was 79.84 IU/kg (range, 38.5-200.0). Hemostatic response was assessed in 10 of 25 minor surgeries; all were rated as excellent (n = 9) or good (n = 1).Summary/Conclusion: Hemostasis with rFIXFc during surgery was rated favorably by investigators/surgeons, with comparable blood loss to what would be expected for subjects without hemophilia. Taken together with results from the B-LONG and Kids B-LONG studies, these data indicate that rFIXFc is well-tolerated and efficacious for the management of perioperative hemostasis in individuals with severe hemophilia B. DisclosuresOzelo:Baxter: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novo Nordisk: Research Funding, Speakers Bureau; Biogen: Research Funding. Mahlangu:Bayer, CSL, Novo Nordisk, and Biogen: Research Funding, Speakers Bureau; Biotest: Speakers Bureau; Roche: Research Funding; Amgen: Speakers Bureau. Perry:Novo Nordisk: Consultancy, Membership on an entity's Board of Directors or advisory committees; Biogen: Consultancy, Honoraria. Yuan:Biogen: Employment, Equity Ownership. Cristiano:Biogen: Employment, Equity Ownership. Mei:Biogen: Employment, Equity Ownership.

Luspatercept (ACE-536) Reduces Disease Burden, Including Anemia, Iron Overload, and Leg Ulcers, in Adults with Beta-Thalassemia: Results from a Phase 2 Study

Background. Luspatercept is a fusion protein (modified activin receptor IIB-IgG Fc) being investigated for the treatment of anemias with ineffective erythropoiesis. In beta-thalassemia, imbalanced production of alpha and beta globin chains in erythroid precursors inhibits late-stage erythroid differentiation, leading to anemia, ineffective erythropoiesis (IE), and dysregulated iron homeostasis. Luspatercept promotes late-stage erythroid differentiation, corrects ineffective erythropoiesis, and reduces alpha globin aggregates, hemolysis, and disease complications including iron overload in a beta-thalassemia mouse model (Suragani R, Blood 2014). Aims. This is an ongoing, phase 2, multicenter, open-label, dose-finding study to evaluate luspatercept in adults with transfusion-dependent (TD) or non-transfusion dependent (NTD) beta-thalassemia. Efficacy outcomes include erythroid response including Hb increase in NTD patients and reduction in RBC transfusion burden in TD patients, and reduction in liver iron concentration (LIC) by MRI in both TD and NTD patients. Methods. Inclusion criteria included age ≥ 18 yr and either TD (defined as ≥4 RBC units transfused in the 8 weeks prior to first dose, confirmed over 6 months) or NTD (defined as &lt;4 RBC units transfused in the 8 weeks prior to first dose) with baseline Hb &lt;10.0 g/dL. Luspatercept was administered SC every 3 weeks for up to 5 doses (12 weeks) with an 8-week follow-up (20 weeks total). Six sequential cohorts (n=up to 6 each) were treated at escalating dose levels from 0.2 to 1.25 mg/kg and an expansion cohort (n=30) is ongoing with starting dose level 0.8 mg/kg and individual dose titration. Patients who completed the core study may have been eligible to enroll in an ongoing 24-month extension study. Results. Preliminary data (as of 10-Apr-2015) were available for 39 patients, 35 patients from dose escalation, and 4 patients from the expansion. Median age was 40 yr, ranging from 20-57 yr, and 82% had prior splenectomy. TD patients (n=14). Transfusion burden prior to treatment ranged from 4 to 12 units/12 weeks. Ten of 14 (71%) patients were treated for ≥12 weeks and were evaluable for the primary endpoint of ≥20% reduction in transfusion burden. All 10 of these patients responded with &gt;40% reduction in transfusion burden over any 12-week period during the study. Reduction in transfusion burden correlated with reduction in LIC. Two of the 3 TD patients with baseline LIC ≥7 mg/g dw (all on iron chelation therapy) had a reduction in LIC at 16 weeks (-2.0 and -4.7 mg/g dw). NTD patients (n=25). Median baseline Hb was 8.4 g/dL (range 6.5-9.6 g/dL). Four of 8 (50%) patients in the 0.8-1.25 mg/kg dose groups achieved the primary endpoint of increase in Hb ≥1.5 g/dL sustained for ≥2 weeks, compared with 0 of 17 (0%) patients in the 0.2-0.6 mg/kg dose groups. Four of eight (50%) patients in the 0.8-1.25 mg/kg dose groups had a mean increase in Hb ≥1.0 g/dL sustained for ≥12 weeks, compared with 5 of 17 (29%) patients in the 0.2-0.6 mg/kg dose groups. Eight of 12 (67%) NTD patients with baseline LIC ≥5 mg/g dw (including 6 patients on iron chelation therapy) had a reduction of at least 1 mg/g dw in LIC at 16 weeks; reduction in LIC correlated with increase in hemoglobin. All 3 patients with chronic leg ulcers at baseline (2 NTD, 1 TD) had substantial, rapid healing, evident within 6 weeks after the first dose of luspatercept. Luspatercept was generally well tolerated, with no related serious adverse events reported to date. Adverse events were mostly mild-moderate; most frequent related adverse events (&gt;10% patients) were bone pain, myalgia, headache and asthenia. Longer-term treatment data from the extension study for TD and NTD patients will be presented. Conclusions. Luspatercept treatment for up to 3 months was well-tolerated, increased Hb levels in NTD patients, and decreased transfusion requirement in TD patients with beta-thalassemia. Both TD and NTD patients also had decreases in LIC, and healing of leg ulcers occurred in 3 of 3 patients. These treatment effects represent a significant reduction in disease burden for patients with beta-thalassemia. Phase 3 studies of luspatercept in beta-thalassemia are planned. Disclosures Piga: Celgene Corporation: Honoraria; Acceleron Pharma: Research Funding. Zhang:Acceleron: Employment. Bellevue:Acceleron: Employment. Wilson:Acceleron: Employment. Laadem:Celgene Corporation: Employment. Sherman:Acceleron Pharma: Employment. Attie:Acceleron: Employment.