Abstract: Significant progress has been made in understanding the pre-symptomatic phase of amyotrophic lateral sclerosis. While much is still unknown, advances in other neurodegenerative diseases offer valuable insights. Indeed, it is increasingly clear that the well-recognized clinical syndromes of Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, spinal muscular atrophy and frontotemporal dementia are also each preceded by a pre-symptomatic or prodromal period of varying duration, during which the underlying disease process unfolds, with associated compensatory changes and loss of inherent system redundancy. Key insights from these diseases highlight opportunities for discovery in amyotrophic lateral sclerosis. The development of biomarkers reflecting amyloid and tau has led to a shift in defining Alzheimer’s disease based on inferred underlying histopathology. Parkinson’s disease is unique among neurodegenerative diseases in the number and diversity of non-genetic biomarkers of pre-symptomatic disease, most notably REM sleep behaviour disorder. Huntington’s disease benefits from an ability to predict the likely timing of clinically manifest disease based on age and CAG-repeat length alongside reliable neuroimaging markers of atrophy. Spinal muscular atrophy clinical trials have highlighted the transformational value of early therapeutic intervention, and studies in frontotemporal dementia illustrate the differential role of biomarkers based on genotype. Similar advances in amyotrophic lateral sclerosis would transform our understanding of key events in pathogenesis, thereby dramatically accelerating progress towards disease prevention. Deciphering the biology of pre-symptomatic amyotrophic lateral sclerosis relies on a clear conceptual framework for defining the earliest stages of disease. Clinically manifest amyotrophic lateral sclerosis may emerge abruptly, especially among those who harbour genetic mutations associated with rapidly progressive amyotrophic lateral sclerosis. However, the disease may also evolve more gradually, revealing a prodromal period of mild motor impairment preceding phenoconversion to clinically manifest disease. Similarly, cognitive and behavioural impairment, when present, may emerge gradually, evolving through a prodromal period of mild cognitive impairment or mild behavioural impairment before progression to amyotrophic lateral sclerosis. Biomarkers are critically important to studying pre-symptomatic amyotrophic lateral sclerosis and essential to efforts to intervene therapeutically before clinically manifest disease emerges. The use of non-genetic biomarkers, however, presents challenges related to counselling, informed consent, communication of results and limited protections afforded by existing legislation. Experiences from pre-symptomatic genetic testing and counselling, and the legal protections against discrimination based on genetic data, may serve as a guide. Building on what we have learned—more broadly from other pre-symptomatic neurodegenerative diseases and specifically from amyotrophic lateral sclerosis gene mutation carriers—we present a road map to early intervention, and perhaps even disease prevention, for all forms of amyotrophic lateral sclerosis.

Abstract: Background: Patients with beta-thalassemia may need to start receiving regular red blood cell transfusions as early as infancy. In the absence of iron chelation therapy, frequent transfusions cause iron to accumulate in the body, which can lead to morbidity, organ damage, and death. However, in very young children, current practice is to delay chelation therapy until receipt of 10-20 transfusions, or until the patient's serum ferritin (SF) level has reached 1000 μg/L, due to concerns over excessive iron depletion observed with the parenteral iron chelator deferoxamine. Unfortunately, this delay may increase the risk of iron accumulation in endocrine glands such as the pancreas, pituitary, and thyroid, where toxicities could manifest later in life. The START study (NCT03591575) evaluated the safety and efficacy of the oral iron chelator deferiprone (DFP) in children with transfusion-dependent beta-thalassemia who did not yet meet the criteria for starting chelation therapy as per standard practice. Methods: Infants and children who had started on a regular blood transfusion regimen, received a minimum of 2 transfusions, and whose SF level was between 200 and 600 μg/L were randomly assigned 1:1 to receive either (DFP) oral solution or a matching volume of placebo until their SF levels exceeded 1000 μg/L at 2 consecutive visits or they completed 12 months of therapy, whichever occurred first. The dosage of DFP was initiated at 25 mg/kg/day and increased to 50 mg/kg/day after 2 weeks; based on iron load, the dosage was then increased to 75 mg/kg/day for some patients. All adverse events (AEs) were reported and assessed for causality. Efficacy was assessed by monthly SF measurements to monitor iron load, with the primary efficacy endpoint being the percentage of patients in each group whose SF was still below the 1000 μg/L threshold. Once withdrawn, the patients were to receive standard chelation therapy, as recommended by their primary care physician. Results: The study enrolled 64 patients; 32 in each group. The mean (SD) age was 3.03 (2.42) years in the DFP group and 2.63 (1.70) years in the placebo group; the participants were 62.5% and 65.6% male in the DFP and placebo groups, respectively. There were no statistical group differences in the baseline demographics. The primary reason for withdrawal was SF levels that exceeded 1000 μg/L at 2 consecutive visits, which occurred in 25% of patients receiving DFP compared with 63% of patients receiving placebo (P=0.0051). After completing 12 months of treatment, 65.6% of patients receiving DFP had a SF level & lt;1000 mg/L compared with 37.5% receiving placebo (P=0.0446). The percentage of patients who reached the 1000 mg/L SF threshold increased more rapidly in the placebo group compared with the DFP group, and the difference in rates between the 2 groups was significant (P=0.0407). A summary of adverse events (AEs) is shown in Table 1. There were no significant group differences in the number of overall AEs (P=1.0000), serious AEs (P=0.4258), or the number of AEs that were considered to be at least possibly related to the study treatment (P=1.0000). Two patients receiving DFP withdrew from the study due to AEs: 1 patient experienced agranulocytosis and 1 patient experienced neutropenia of moderate severity and both patients recovered. Conclusions: Initiation of DFP chelation therapy at a lower threshold of SF values than currently recommended was safe and efficacious in preventing iron overload in most transfusion-dependent children. After 12 months of treatment, the number of patients below the SF threshold was significantly higher in the DFP group compared with the placebo group. Moreover, there was a significant difference in the number of patients who withdrew due to elevated SF levels in the placebo group (62.5%) compared with the DFP group (25%). The safety and tolerability profile of DFP administered for up to 12 months in infants and young children was comparable to the profile established in older age groups and there were no instances of iron depletion. Disclosures: This study was sponsored by Chiesi Global Rare Diseases, and medical writing support was provided by Kelsey Hodge-Hanson, PhD, of Oxford PharmaGenesis Inc., Newtown, PA, and funded by Chiesi. Figure 1 Figure 1. Disclosures Fradette: Chiesi Canada Corp: Current Employment. Lee: Chiesi Canada Corp: Current Employment. Temin: Chiesi Canada Corp: Current Employment. Tricta: Chiesi Canada Corp: Current Employment. Rozova: Chiesi Canada Corp: Current Employment. Hamdy: Novartis: Honoraria; Roche: Honoraria; NovoNordisk: Honoraria; Bayer: Honoraria; Takeda: Honoraria; Amgen: Honoraria; ApoPharma: Honoraria.

Abstract: Children with sickle cell disease (SCD) who have their disease managed with frequent blood transfusions often require iron chelation therapy to prevent iron overload. Deferoxamine (DFO) is an iron chelator approved for pediatric use that is often administered via infusion; however, postmarketing research revealed that adherence to treatment in pediatric populations is a key challenge experienced by patients and caregivers due to the burdensome nature of the administration route. Deferiprone (DFP), an oral iron chelator, has recently been approved as a first-line treatment for transfusional iron overload in pediatric and adult patients with SCD and other anemias. We previously reported that DFP is noninferior to DFO in patients with SCD and iron overload (as assessed by liver iron concentration [LIC]) and has an acceptable safety profile. Here, we report a subgroup analysis of the FIRST (NCT02041299) study to assess whether the efficacy and safety of DFP are comparable to DFO in children with SCD. In this phase 4, multicenter, 2-arm, randomized, open-label study, eligible patients were randomized in a 2:1 ratio to receive DFP or DFO for 12 months. The subgroup analysis included children (2-16 years of age) with SCD or another rare anemia who were treated for transfusional iron overload. Children received either DFP orally tid or DFO by subcutaneous infusion 5-7 days a week. Iron load was monitored during the trial and dosage adjustments were allowed when necessary. The primary efficacy endpoint was the change in LIC from baseline to month 12, and data were analyzed for all patients who had a baseline and a follow-up LIC assessment (efficacy population). Absolute neutrophil counts were assessed weekly for the first 6 months, and then every 2 weeks until the end of the study. Additional safety assessments were done monthly with analysis including all patients who received at least 1 dose of the study drug (safety population). Statistical significance between DFP- and DFO-treated groups was calculated via t-test for continuous variables and Fisher's exact test for discrete variables. Of the 228 patients in the safety population, 128 (n=86 in DFP; n=42 in DFO) were children. Five children withdrew from the study due to adverse events (AEs) and 19 withdrew for other reasons. Most children in each treatment group (DFP, 75.6 %; DFO, 80.9%) had a primary diagnosis of SCD (HbS); the remainder had another form of anemia that required chronic transfusions. At the time of first exposure, mean ages (SD) in the DFP- and DFO-treated groups were 9.9 (3.7) years and 10.9 (3.0) (P=0.09), respectively. There were no significant differences between the DFP- and DFO-treatment groups in sex (males 59.3% vs 57.1%; P=0.85), ethnicity (P=0.68), or race (P=0.34). Children treated with DFP or DFO showed no significant differences in overall incidence of AEs (P=0.77) (including neutropenias (P=0.30)), severe AEs (P=0.10), serious AEs (P=0.16), or withdrawals due to an AE (P=0.17). However, a difference in the overall incidence of nonserious AEs considered at least possibly related to DFP treatment (59.3% vs 33.3%; P=0.01) was found. Table 1 shows the most common (≥5%) AEs in children by treatment group. The only individual AE for which the rate was significantly higher in the DFP group vs the DFO group was elevated liver enzymes (P=0.03), a known transient reaction to DFP that typically resolves with continued DFP therapy. In DFP-treated children, there were no AEs observed that had not been previously reported in other patient populations; 1 child developed agranulocytosis; and children & lt;6 years of age treated with DFP demonstrated a comparable safety profile to that of older children (6-16 years of age) treated with DFP. In the efficacy population, after 12 months of treatment, there was no significant difference in the mean (SD) LIC change from baseline in children treated with DFP (n=78) compared to DFO (n=40) (-3.39 ± 4.24 mg/g vs -2.99 ± 3.16 mg/g, respectively; P=0.57). This subgroup analysis of children receiving chronic transfusion therapy for SCD or other anemias corroborates previous findings that treatment with DFP is comparable to DFO in reducing LIC. No new safety concerns were observed in children that have not been previously noted in other populations. Thus, the present findings may benefit children and their healthcare providers when considering effective iron chelation therapy that may also address treatment-adherence concerns. Figure 1 Figure 1. Disclosures Hamdy: Amgen: Honoraria; Bayer: Honoraria; Novartis: Honoraria; ApoPharma: Honoraria; NovoNordisk: Honoraria; Roche: Honoraria; Takeda: Honoraria. Kwiatkowski: Terumo BCT: Research Funding; Sangamo: Research Funding; Bluebird Bio: Research Funding; Novartis: Research Funding; ApoPharma: Research Funding; Agios: Honoraria; Silence Therapeutics: Honoraria; Celgene: Honoraria; Imara: Other: Consultancy Fees; Bluebird Bio: Other: Consultancy Fees. Kanter: Fulcrum Therapeutics, Inc.: Consultancy; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Forma: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Agios: Honoraria, Membership on an entity's Board of Directors or advisory committees; Beam: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sanofi: Honoraria, Membership on an entity's Board of Directors or advisory committees; Graphite Bio: Consultancy; GuidePoint Global: Honoraria; Fulcrum Tx: Consultancy. Lee: Chiesi Canada Corp: Current Employment. Temin: Chiesi Canada Corp: Current Employment. Fradette: Chiesi Canada Corp: Current Employment. Tricta: Chiesi Canada Corp: Current Employment.

Abstract: Long-term safety and efficacy data on the iron chelator deferiprone in sickle cell disease (SCD) and other anemias are limited. FIRST-EXT was a 2-year extension study of FIRST (Ferriprox in Patients With Iron Overload in Sickle Cell Disease Trial), a 1-year, randomized noninferiority study of deferiprone vs deferoxamine in these populations. Patients who entered FIRST-EXT continued to receive, or were switched to, deferiprone. Altogether, 134 patients were enrolled in FIRST-EXT (mean age: 16.2 years), with mean (SD) exposure to deferiprone of 2.1 (0.8) years over the 2 studies. The primary end point was safety. Secondary end points were change in liver iron concentration (LIC), cardiac T2∗, serum ferritin (SF), and the proportion of responders (≥20% improvement in efficacy measure). The most common adverse events considered at least possibly related to deferiprone were neutropenia (9.0%) and abdominal pain (7.5%). LIC (mg/g dry weight) decreased over time, with mean (SD) changes from baseline at each time point (year 1, −2.64 [4.64] ; year 2, −3.91 [6.38]; year 3, −6.64 [7.72] , all P  & lt; .0001). Mean SF levels (μg/L) decreased significantly after year 2 (−771, P = .0008) and year 3 (−1016, P = .0420). Responder rates for LIC and SF increased each year (LIC: year 1, 46.5%; year 2, 57.1%; year 3, 66.1%; SF: year 1, 35.2%; year 2, 55.2%; year 3, 70.9%). Cardiac T2∗ remained normal in all patients. In conclusion, long-term therapy with deferiprone was not associated with new safety concerns and led to continued and progressive reduction in iron load in individuals with SCD or other anemias. The trial was registered at www.clinicaltrials.gov as #NCT02443545.