Abstract: Background: Pyruvate Kinase (PK) deficiency is the most common enzyme defect of the glycolytic pathway causing hereditary non-spherocytic hemolytic anemia. Patients have a broad phenotypic spectrum, ranging from mild anemia to transfusion dependence, and there is wide variation in transfusion practices and decisions about splenectomy. No prior studies have reported on the use of validated health related quality of life (HRQoL) measures in this population. Aim: To describe patient reported outcomes including general HRQoL and fatigue in adults with PK deficiency and the correlation with clinical and laboratory features. Methods: Patients were enrolled on the PK Deficiency Natural History Study, a prospective 30 site international study. All patients had molecularly confirmed PK deficiency. Adults (n=132), ages ≥18 years, completed the EuroQol-5D (high index equivalent to better QoL), PROMIS Fatigue Short Form 7a (high scores equivalent to higher fatigue), and the Functional Assessment of Cancer Therapy-Anemia (FACT-An, high scores equivalent to less fatigue) surveys at enrollment and annually. Timing of administration was convenience based. Survey data were analyzed according to proprietary scoring guidelines. Tests of association were performed using Fisher's exact test (categorical) and Wilcoxon rank sum test (continuous). Regular transfusions were defined as ≥6 transfusions in 12 months. Genotypes were grouped as two missense mutations (M/M), one missense/one non-missense (M/NM), or two non-missense mutations (NM/NM)); non-missense included deletions or other drastic variants. The minimal important difference (MID) for the FACT-An has been reported as 7 points (Cella et al, J Pain Symptom Manage 2002). P-values 〈 0.05 were considered statistically significant. Results: At enrollment, 128 adults completed the FACT-An with a median total score of 156 (IQR 122-190). Patients receiving regular transfusions reported significantly lower FACT-An scores than those who were not regularly transfused (median 129 vs 156, p=0.004) with significantly lower scores for physical, emotional, and functional well-being and anemia sub-scores (Table). This difference also surpassed the MID. However, non- regularly transfused patients with hemoglobin (Hb) 〈 8 g/dl did not report significantly different scores than those with Hb≥ 8 g/dl (p=0.75). There were also no significant differences in FACT-An scores by splenectomy status or age. The FACT-An score differences were greater than the MID for patients with iron overload (ferritin 〉 1000 ng/dL or chelation), higher number of lifetime transfusions, and two missense mutations. Females reported significantly lower scores than males (median 143 vs. 160, p=0.006) with significantly lower anemia sub-scores (p=0.0009). FACT-An surveys completed at the one year follow-up time point validated these findings. EuroQol-5D scores (n=124) at enrollment were similar to the healthy population (median PK deficiency index score 0.88; healthy population index mean 0.88, Shaw et al, Medical Care 2005). No significant differences were found by Hb level, splenectomy status, transfusion status, or genotype group. The median PROMIS fatigue T score (n=66) was 52.1 (IQR 40.5-63.7). Similar to the FACT-An survey data, PROMIS fatigue scores were significantly worse in patients who were regularly transfused (67.0 vs 52.4, p=0.02). PROMIS fatigue scores were also significantly worse in patients ≥40 years old (p=0.05) and females (p=0.01). Conclusions: Using the FACT-An and PROMIS Fatigue measures, patients with PK deficiency who are regularly transfused report significantly more fatigue and worse HRQoL compared with those who are not transfused. Important differences were also seen by iron status and mutation group using the FACT-An. Patients report similar fatigue levels regardless of Hb level, which suggests that symptoms, rather than Hb value alone, should be factored into clinical decision making. In contrast to anemia related HRQoL scores, overall HRQoL scores using validated generic measures in patients with PK deficiency show no differences compared with the healthy population, suggesting that disease-specific measures may better detect the effects of PK deficiency on HRQoL. Disclosures Van Beers: Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Glader:Agios Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees. Despotovic:AmGen: Research Funding; Novartis: Research Funding; Sanofi: Consultancy. Kwiatkowski:bluebird bio: Consultancy, Honoraria, Research Funding; Agios Pharmaceuticals: Consultancy, Research Funding; Novartis: Research Funding; Apopharma: Research Funding; Terumo: Research Funding. Thompson:La Jolla Pharmaceutical: Research Funding; Baxalta/Shire: Research Funding; Novartis: Research Funding; Celgene: Research Funding; bluebird bio: Consultancy, Research Funding; Biomarin: Research Funding; Amgen: Research Funding. Newburger:TransCytos LLC: Consultancy; Janssen Research & Development, LLC: Consultancy, Honoraria; X4 Pharmaceutics: Consultancy, Honoraria. Ravindranath:AGIOS: Other: Site Investigator for Pyruvate Kinase Deficiency. Sheth:Terumo Corporation: Research Funding; Novartis: Research Funding; La Jolla Pharmaceutical Company: Research Funding; Celgene Corporation: Consultancy, Research Funding; Bluebird Bio: Consultancy. Grace:Agios Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees; Agios Pharmaceuticals: Research Funding; Agios Pharmaceuticals: Consultancy.

Abstract: Introduction: Pyruvate kinase (PK) deficiency causes a defect in the glycolytic pathway, leading to a hereditary hemolytic anemia. Management is supportive and consists of splenectomy, transfusions, and chelation therapy. Aim: To better understand the comorbidity and complication profile of adults with PK deficiency, and the extent to which transfusion frequency contributes, the objectives of this study were to (1) quantify the prevalence of comorbidities and complications according to transfusion history and (2) compare the types and rates of select comorbidities and complications with the general population. Methods: Data were obtained from the enrollment survey of the PK Deficiency Natural History Study (NHS), a longitudinal, retrospective and prospective cohort study in which clinical, laboratory, transfusion, and radiologic data were collected; all participants were confirmed to have 2 mutations in the PKLR gene. Patients (n=122) were eligible for this analysis if they were ≥18 years of age and had sufficient data on transfusion history to enable classification into 1 of 3 cohorts: "Ever Regularly Transfused" (ERT, defined as ≥6 transfusions in any 12-month period), "Never Regularly Transfused" (NRT, defined as having ≥1 lifetime transfusion but never having 〉 4 transfusions in any 12-month period), or "Never Transfused" (NT). To contextualize the findings, the frequencies of select conditions were compared with an age- and gender-matched cohort of individuals from the insured, general US population who did not have any hemolytic anemia diagnoses and had ≥5 years of continuous enrollment in the Truven MarketScan administrative claims database. The NHS reported lifetime prevalence rates, whereas rates obtained from the MarketScan data were based on diagnosis and procedure codes over varying look-back periods; therefore, to minimize bias, we limited PK deficiency vs. general population comparisons to (1) chronic conditions that require lifetime management and would thus still be recorded in claims data years after initial diagnosis, and/or (2) conditions for which a diagnosis/procedure date was available in the NHS and could be matched in time to the average 8-year look-back period for the general population. Frequencies were compared across mutually exclusive cohorts using Fisher's exact 2-tailed tests of significance. Results: ERT (n=65), NRT (n=30), and NT patients (n=27) had a mean age of 34.2, 39.5, and 37.2 years at enrollment, respectively (not significant [ns]), with 46.2%, 56.7%, and 59.3%, respectively, being male (ns). ERT patients trended toward being more likely than NT patients to be Amish and have the homozygous R479H splice variant (30.8% vs 11.1% [p=0.064] ) but were significantly less likely to have a missense/missense PKLR genotype (32.3% vs 70.4% [p=0.001]). Compared with the general population, patients with PK deficiency had significantly higher rates of splenectomy, cholecystectomy, osteoporosis, liver cirrhosis, pulmonary hypertension, and current prophylactic antibiotic and anticoagulant use (Table). Rates of splenectomy, cholecystectomy, and osteoporosis were significantly higher in patients with PK deficiency, regardless of transfusion cohort, and both ERT and NRT patients had significantly higher rates of liver cirrhosis than individuals from the general population. A gradient was seen across transfusion cohorts for other conditions. Notably, 83.1% of ERT patients, 50.0% of NRT patients, and 25.9% of NT patients had a history of liver iron overload. ERT patients were also significantly more likely than NRT and NT patients to have had a splenectomy, cholecystectomy, and/or thrombosis, and to currently use prophylactic antibiotics. Findings were consistent when the analysis was restricted to non-Amish patients with PK deficiency. Conclusions: Patients with PK deficiency have higher rates of select comorbidities and complications than age- and gender-matched individuals who do not have PK deficiency. Even patients with PK deficiency who have never been transfused are at increased risk of complications of the disease and its treatment. Disclosures Boscoe: Agios Pharmaceuticals, Inc.: Employment, Equity Ownership. Yan:Agios Pharmaceuticals, Inc.: Consultancy. Hedgeman:IBM Watson Health: Employment. van Beers:Agios Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Research Funding; RR Mechatronics: Research Funding. Al-Samkari:Agios: Consultancy, Research Funding; Dova: Consultancy, Research Funding; Moderna: Consultancy. Barcellini:Incyte: Consultancy; Alexion: Consultancy, Speakers Bureau; Agios Pharmaceuticals, Inc.: Consultancy; Novartis: Speakers Bureau; Apellis: Consultancy; bioverativ: Consultancy. Eber:Agios Pharmaceuticals, Inc.: Consultancy. Glader:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Rothman:Agios: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Pfizer: Consultancy, Honoraria, Research Funding. Kuo:Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy; Celgene: Consultancy; Novartis: Consultancy, Honoraria; Pfizer: Consultancy. Kwiatkowski:Agios: Consultancy; bluebird bio, Inc.: Consultancy, Research Funding; Imara: Consultancy; Apopharma: Research Funding; Novartis: Research Funding; Celgene: Consultancy; Terumo: Research Funding. Ravindranath:Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Neufeld:Octapharma, Shire Pharmaceuticals (Baxalta), Novo Nordisk, Celgene, NHLBI/NIH: Research Funding; Octapharma, Agios, Acceleron, Grifols, Pfizer, CSL Behring, Shire Pharmaceuticals (Baxalta), Novo Nordisk, ApoPharma, Genentech, Novartis, Bayer Healthcare: Consultancy; Octapharma: Other: study investigator, NuProtect study (Octapharma-sponsored). Holzhauer:Agios Pharmaceuticals, Inc.: Consultancy. Verhovsek:Sickle Cell Disease Association of Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Canadian Haemoglobinopathy Association: Membership on an entity's Board of Directors or advisory committees; Vertex: Consultancy; Sickle Cell Awareness Group of Ontario: Membership on an entity's Board of Directors or advisory committees. Kunz:Novartis: Membership on an entity's Board of Directors or advisory committees. Sheth:Apopharma: Other: Clinical trial DSMB; Celgene: Consultancy; CRSPR/Vertex: Other: Clinical Trial Steering committee. Despotovic:Novartis: Research Funding; Dova: Honoraria. Grace:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding.

Abstract: Background: Pyruvate kinase deficiency (PKD) is the most common cause of chronic hereditary non-spherocytic hemolytic anemia. The spectrum of disease in PKD is broad, ranging from an incidentally discovered mild anemia to a severe transfusion-dependent anemia. Splenectomy partially ameliorates the anemia and reduces the transfusion burden in the majority of patients. Because hemoglobin poorly correlates with symptoms in PKD, transfusion requirements are typically used clinically to classify disease severity with those who are regularly transfused despite splenectomy recognized as the most severely affected subgroup. Aim: To compare demographics, complications, and laboratory results between the most severely-affected PKD patients (those that are splenectomized and regularly transfused) with non-regularly transfused splenectomized PKD patients. Methods: After ethics committee approval, patients were enrolled on the PKD Natural History Study, a prospective 30 site international study. All patients had molecularly confirmed PKD. Only splenectomized patients were included in the analysis. Transfusion frequency was observed over a 3-year period. Patients were divided into two groups based on transfusion frequency: the severe phenotype group was defined as those who receive regular transfusions (≥6 discrete red cell transfusion episodes per year) and the control group did not receive regular transfusions. Phenotype stability over the 3-year period was also assessed. Results: 154 splenectomized patients with PKD were included: 30 patients in the severe PKD phenotype group and 124 patients in the comparison PKD group. Results of the analysis comparing the two groups are described in the Table. Severely affected patients were more likely to be female (77% versus 51%, p=0.013), older at the time of splenectomy (median age: 5 versus 3.6, p=0.011), have iron overload (93% vs. 51%, p & lt;0.0001), have received chelation therapy (90% vs. 42%, p & lt;0.0001), and had more lifetime transfusions (median: 77 versus 15, p & lt;0.0001). Rates of other PKD complications including pulmonary hypertension, extramedullary hematopoiesis, liver cirrhosis, endocrinopathy, and bone fracture appear similar between the two groups. Laboratory values, including hemoglobin, total bilirubin, normalized PK enzyme activity, and median absolute reticulocyte count appear similar between the two groups. The underlying genetic mutation patterns (missense mutations versus non-missense mutations) were also similar between the groups. Phenotype stability over time was highly variable: of the patients with a severe phenotype at enrollment, 62% had a severe phenotype during the first follow-up year and 39% had a severe phenotype at the second follow-up year. Conclusions: Patients with PKD who are regularly transfused despite splenectomy appeared to have similar rates of PKD-associated complications (except for iron overload) and similar relevant laboratory values and genotypes when compared to those who are not regularly transfused after splenectomy. The similarity observed between severe phenotype patients and comparison patients with PKD may result from a protective effect of transfusion (e.g. reduction of bone fractures and extramedullary hematopoiesis) or could suggest transfusion-dependence is an artificial signifier of disease severity, reflective of provider practices and patient symptoms rather than an actual distinct phenotype. Transfusion requirements in severe PKD appear to fluctuate significantly over time. Disclosures Al-Samkari: Dova: Consultancy, Research Funding; Agios: Consultancy, Research Funding; Moderna: Consultancy. van Beers:RR Mechatronics: Research Funding; Agios Pharmaceuticals, Inc.: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Research Funding. Barcellini:Agios: Consultancy, Other: Advisory board; Apellis: Consultancy; Incyte: Consultancy, Other: Advisory board; Bioverativ: Consultancy, Other: Advisory board; Novartis: Research Funding, Speakers Bureau; Alexion: Consultancy, Research Funding, Speakers Bureau. Eber:Agios Pharmaceuticals, Inc.: Consultancy. Glader:Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Chonat:Alexion: Other: advisory board; Agios Pharmaceuticals, Inc.: Other: advisory board. Kuo:Pfizer: Consultancy; Novartis: Consultancy, Honoraria; Celgene: Consultancy; Agios: Consultancy; Alexion: Consultancy, Honoraria; Apellis: Consultancy; Bioverativ: Other: Data Safety Monitoring Board; Bluebird Bio: Consultancy. Despotovic:Dova: Honoraria; Novartis: Research Funding; Amgen: Research Funding. Kwiatkowski:Celgene: Consultancy; Terumo: Research Funding; Apopharma: Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Agios: Consultancy; Imara: Consultancy; Novartis: Research Funding. Thompson:Baxalta: Research Funding; Novartis: Consultancy, Research Funding; bluebird bio, Inc.: Consultancy, Research Funding; Celgene: Consultancy, Research Funding. Ravindranath:Agios Pharmaceuticals, Inc.: Other: I am site PI on several Agios-sponsored studies, Research Funding. Rothman:Pfizer: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Agios: Honoraria, Research Funding. Verhovsek:Sickle Cell Awareness Group of Ontario: Membership on an entity's Board of Directors or advisory committees; Sickle Cell Disease Association of Canada: Membership on an entity's Board of Directors or advisory committees, Research Funding; Canadian Haemoglobinopathy Association: Membership on an entity's Board of Directors or advisory committees; Vertex: Consultancy. Kunz:Novartis: Membership on an entity's Board of Directors or advisory committees. Sheth:CRSPR/Vertex: Other: Clinical Trial Steering committee; Apopharma: Other: Clinical trial DSMB; Celgene: Consultancy. London:United Therapeutics: Consultancy; ArQule, Inc: Consultancy. Grace:Novartis: Research Funding; Agios Pharmaceuticals, Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Abstract: Pyruvate kinase (PK) deficiency is a rare recessive congenital hemolytic anemia caused by mutations in the PKLR gene. This study reports the molecular features of 257 patients enrolled in the PKD Natural History Study. Of the 127 different pathogenic variants detected, 84 were missense and 43 non‐missense, including 20 stop‐gain, 11 affecting splicing, five large deletions, four in‐frame indels, and three promoter variants. Within the 177 unrelated patients, 35 were homozygous and 142 compound heterozygous (77 for two missense, 48 for one missense and one non‐missense, and 17 for two non‐missense variants); the two most frequent mutations were p.R510Q in 23% and p.R486W in 9% of mutated alleles. Fifty‐five (21%) patients were found to have at least one previously unreported variant with 45 newly described mutations. Patients with two non‐missense mutations had lower hemoglobin levels, higher numbers of lifetime transfusions, and higher rates of complications including iron overload, extramedullary hematopoiesis, and pulmonary hypertension. Rare severe complications, including lower extremity ulcerations and hepatic failure, were seen more frequently in patients with non‐missense mutations or with missense mutations characterized by severe protein instability. The PKLR genotype did not correlate with the frequency of complications in utero or in the newborn period. With ICCs ranging from 0.4 to 0.61, about the same degree of clinical similarity exists within siblings as it does between siblings, in terms of hemoglobin, total bilirubin, splenectomy status, and cholecystectomy status. Pregnancy outcomes were similar across genotypes in PK deficient women. This report confirms the wide genetic heterogeneity of PK deficiency.