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Rohr F, Burton B, Dee A, Harding CO, Lilienstein J, Lindstrom K, MacLeod E, Rose S, Singh R, van Calcar S, Whitehall K. Evaluating change in diet with pegvaliase treatment in adults with phenylketonuria: Analysis of phase 3 clinical trial data. Mol Genet Metab 2024; 141:108122. [PMID: 38184920 DOI: 10.1016/j.ymgme.2023.108122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 01/09/2024]
Abstract
Phenylketonuria (PKU), a genetic disorder characterized by phenylalanine hydroxylase (PAH) deficiency and phenylalanine (Phe) accumulation, is primarily managed with a protein-restricted diet and PKU-specific medical foods. Pegvaliase is an enzyme substitution therapy approved for individuals with PKU and uncontrolled blood Phe concentrations (>600 μmol/L) despite prior management. This analysis assessed the effect of pegvaliase on dietary intake using data from the Phase 3 PRISM-1 (NCT01819727), PRISM-2 (NCT01889862), and 165-304 (NCT03694353) clinical trials. Participants (N = 250) had a baseline diet assessment, blood Phe ≥600 μmol/L, and had discontinued sapropterin; they were not required to follow a Phe-restricted diet. Outcomes were analyzed by baseline dietary group, categorized as >75%, some (>0% but ≤75%), or no protein intake from medical food. At baseline, mean age was 29.1 years, 49.2% were female, mean body mass index was 28.4 kg/m2, and mean blood Phe was 1237.0 μmol/L. Total protein intake was stable up to 48 months for all 3 baseline dietary groups. Over this time, intact protein intake increased in all groups, and medical protein intake decreased in those who consumed any medical protein at baseline. Of participants consuming some or >75% medical protein at baseline, 49.1% and 34.1% were consuming no medical protein at last assessment, respectively. Following a first hypophenylalaninemia (HypoPhe; 2 consecutive blood Phe measurements <30 μmol/L) event, consumption of medical protein decreased and consumption of intact protein increased. Substantial and sustained Phe reductions were achieved in all 3 baseline dietary groups. The probability of achieving sustained Phe response (SPR) at ≤600 μmol/L was significantly greater for participants consuming medical protein versus no medical protein in an unadjusted analysis, but no statistically significant difference between groups was observed for probability of achieving SPR ≤360 or SPR ≤120 μmol/L. Participants with alopecia (n = 49) had longer pegvaliase treatment durations, reached HypoPhe sooner, and spent longer in HypoPhe than those who did not have alopecia. Most (87.8%) had an identifiable blood Phe drop before their first alopecia episode, and 51.0% (n = 21/41) of first alopecia episodes with known duration resolved before the end of the HypoPhe episode. In conclusion, pegvaliase treatment allowed adults with PKU to lower their blood Phe, reduce their reliance on medical protein, and increase their intact and total protein intake. Results also suggest that HypoPhe does not increase the risk of protein malnutrition in adults with PKU receiving pegvaliase.
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Affiliation(s)
| | - Barbara Burton
- Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA.
| | - Anne Dee
- BioMarin Pharmaceutical Inc., Novato, CA, USA.
| | | | | | | | - Erin MacLeod
- Children's National Rare Disease Institute, Washington, DC, USA.
| | - Sarah Rose
- BioMarin Pharmaceutical Inc., Novato, CA, USA.
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Burton BK, Clague GE, Harding CO, Kucuksayrac E, Levy DG, Lindstrom K, Longo N, Maillot F, Muntau AC, Rutsch F, Zori RT. Long-term comparative effectiveness of pegvaliase versus medical nutrition therapy with and without sapropterin in adults with phenylketonuria. Mol Genet Metab 2024; 141:108114. [PMID: 38142628 DOI: 10.1016/j.ymgme.2023.108114] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 12/26/2023]
Abstract
Phenylketonuria is characterized by intellectual disability and behavioral, psychiatric, and movement disorders resulting from phenylalanine (Phe) accumulation. Standard-of-care treatment involves a Phe-restricted diet plus medical nutrition therapy (MNT), with or without sapropterin dihydrochloride, to reduce blood Phe levels. Pegvaliase is an injectable enzyme substitution treatment approved for adult patients with blood Phe >600 μmol/L despite ongoing management. A previous comparative effectiveness analysis using data from the Phase 3 PRISM trials of pegvaliase (NCT01819727 and NCT01889862) and the Phenylketonuria Demographics, Outcomes and Safety Registry (PKUDOS; NCT00778206) suggested that pegvaliase was more effective at lowering mean blood Phe levels than sapropterin + MNT or MNT alone at 1 and 2 years of treatment. The current work augments and complements the previous analysis by including additional follow-up from the completed studies, robust methods reflecting careful consideration of issues with the distribution of Phe, and alternative methods for adjustment that are important for control of potential confounding in comparative effectiveness. Median blood Phe levels were lower, and median intact protein intakes were higher, in the pegvaliase group (n = 183) than in the sapropterin + MNT (n = 82) and MNT (n = 67) groups at Years 1, 2, and 3. In the pegvaliase group, median blood Phe levels decreased from baseline (1244 μmol/L) to Year 1 (535 μmol/L), Year 2 (142 μmol/L), and Year 3 (167 μmol/L). In the sapropterin + MNT group, median blood Phe levels decreased from baseline (900 μmol/L) to Year 1 (588 μmol/L) and Year 2 (592 μmol/L), and increased at Year 3 (660 μmol/L). In the MNT group, median blood Phe levels decreased slightly from baseline (984 μmol/L) to Year 1 (939 μmol/L) and Year 2 (941 μmol/L), and exceeded baseline levels at Year 3 (1157 μmol/L). The model-estimated proportions of participants achieving blood Phe ≤600 μmol/L were 41%, 100%, and 100% in the pegvaliase group at Years 1, 2, and 3, respectively, compared with 55%, 58%, and 38% in the sapropterin + MNT group and 5%, 16%, and 0% in the MNT group. The estimated proportions of participants achieving more stringent blood Phe targets of ≤360 μmol/L and ≤120 μmol/L were also higher in the pegvaliase group than in the other groups at Years 2 and 3. Overall, our results indicate that, compared with standard therapy, pegvaliase induces a substantial, progressive, and sustained decrease in blood Phe levels - to a much greater extent than sapropterin + MNT or MNT alone - which is expected to improve long-term outcomes in patients with phenylketonuria.
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Affiliation(s)
| | | | | | | | - Drew G Levy
- BioMarin Pharmaceutical Inc., Novato, CA, USA
| | | | | | - François Maillot
- Service de Médecine Interne, CHRU et Université de Tours, Tours, France
| | - Ania C Muntau
- University Children's Hospital, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Frank Rutsch
- Department of General Pediatrics, Münster University Children's Hospital, Münster, Germany
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Vos EN, Demirbas D, Mangel M, Gozalbo MER, Levy HL, Berry GT. The treatment of biochemical genetic diseases: From substrate reduction to nucleic acid therapies. Mol Genet Metab 2023; 140:107693. [PMID: 37716025 DOI: 10.1016/j.ymgme.2023.107693] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/18/2023]
Abstract
Newborn screening (NBS) began a revolution in the management of biochemical genetic diseases, greatly increasing the number of patients for whom dietary therapy would be beneficial in preventing complications in phenylketonuria as well as in a few similar disorders. The advent of next generation sequencing and expansion of NBS have markedly increased the number of biochemical genetic diseases as well as the number of patients identified each year. With the avalanche of new and proposed therapies, a second wave of options for the treatment of biochemical genetic disorders has emerged. These therapies range from simple substrate reduction to enzyme replacement, and now ex vivo gene therapy with autologous cell transplantation. In some instances, it may be optimal to introduce nucleic acid therapy during the prenatal period to avoid fetopathy. However, as with any new therapy, complications may occur. It is important for physicians and other caregivers, along with ethicists, to determine what new therapies might be beneficial to the patient, and which therapies have to be avoided for those individuals who have less severe problems and for which standard treatments are available. The purpose of this review is to discuss the "Standard" treatment plans that have been in place for many years and to identify the newest and upcoming therapies, to assist the physician and other healthcare workers in making the right decisions regarding the initiation of both the "Standard" and new therapies. We have utilized several diseases to illustrate the applications of these different modalities and discussed for which disorders they may be suitable. The future is bright, but optimal care of the patient, including and especially the newborn infant, requires a deep knowledge of the disease process and careful consideration of the necessary treatment plan, not just based on the different genetic defects but also with regards to different variants within a gene itself.
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Affiliation(s)
- E Naomi Vos
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America; Manton Center for Orphan Disease Research, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - Didem Demirbas
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America; Manton Center for Orphan Disease Research, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - Matthew Mangel
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - M Estela Rubio Gozalbo
- Department of Pediatrics and Clinical Genetics, Maastricht University Medical Centre+, P. Debyelaan 25, 6229 HX Maastricht, the Netherlands; GROW, Maastricht University, Minderbroedersberg 4-6, 6211 LK Maastricht, the Netherlands; MetabERN: European Reference Network for Hereditary Metabolic Disorders, Udine, Italy; UMD: United for Metabolic Diseases Member, Amsterdam, the Netherlands.
| | - Harvey L Levy
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America.
| | - Gerard T Berry
- Division of Genetics & Genomics, Boston Children's Hospital; and Department of Pediatrics, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States of America; Manton Center for Orphan Disease Research, Boston Children's Hospital, 300 Longwood Avenue, Boston, MA 02115, United States of America.
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Adams AD, Fiesco-Roa MÓ, Wong L, Jenkins GP, Malinowski J, Demarest OM, Rothberg PG, Hobert JA. Phenylalanine hydroxylase deficiency treatment and management: A systematic evidence review of the American College of Medical Genetics and Genomics (ACMG). Genet Med 2023; 25:100358. [PMID: 37470789 DOI: 10.1016/j.gim.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/08/2022] [Accepted: 12/08/2022] [Indexed: 07/21/2023] Open
Abstract
PURPOSE Elevated serum phenylalanine (Phe) levels due to biallelic pathogenic variants in phenylalanine hydroxylase (PAH) may cause neurodevelopmental disorders or birth defects from maternal phenylketonuria. New Phe reduction treatments have been approved in the last decade, but uncertainty on the optimal lifespan goal Phe levels for patients with PAH deficiency remains. METHODS We searched Medline and Embase for evidence of treatment concerning PAH deficiency up to September 28, 2021. Risk of bias was evaluated based on study design. Random-effects meta-analyses were performed to compare IQ, gestational outcomes, and offspring outcomes based on Phe ≤ 360 μmol/L vs > 360 μmol/L and reported as odds ratio and 95% CI. Remaining results were narratively synthesized. RESULTS A total of 350 studies were included. Risk of bias was moderate. Lower Phe was consistently associated with better outcomes. Achieving Phe ≤ 360 μmol/L before conception substantially lowered the risk of negative effect to offspring in pregnant individuals (odds ratio = 0.07, 95% CI = 0.04-0.14; P < .0001). Adverse events due to pharmacologic treatment were common, but medication reduced Phe levels, enabling dietary liberalization. CONCLUSIONS Reduction of Phe levels to ≤360 μmol/L through diet or medication represents effective interventions to treat PAH deficiency.
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Affiliation(s)
- April D Adams
- Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX; Division of Maternal-Fetal Medicine, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Moisés Ó Fiesco-Roa
- Programa de Maestría y Doctorado en Ciencias Médicas, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico; Laboratorio de Citogenética, Instituto Nacional de Pediatría, Mexico City, Mexico
| | | | | | | | | | - Paul G Rothberg
- Department of Pathology & Laboratory Medicine, University of Rochester Medical Center, Rochester, NY
| | - Judith A Hobert
- University of Utah School of Medicine, Salt Lake City, UT; ARUP Laboratories, Salt Lake City, UT
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Cunningham A, Rohr F, Splett P, Mofidi S, Bausell H, Stembridge A, Kenneson A, Singh RH. Nutrition management of PKU with pegvaliase therapy: update of the web-based PKU nutrition management guideline recommendations. Orphanet J Rare Dis 2023; 18:155. [PMID: 37349772 DOI: 10.1186/s13023-023-02751-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/18/2023] [Indexed: 06/24/2023] Open
Abstract
BACKGROUND The web-based GMDI/SERN PKU Nutrition Management Guideline, published before approval of pegvaliase pharmacotherapy, offers guidance for nutrition management of individuals with phenylketonuria (PKU) treated with dietary therapy and/or sapropterin. An update of this guideline aims to provide recommendations that improve clinical outcomes and promote consistency and best practice in the nutrition management of individuals with PKU receiving pegvaliase therapy. Methodology includes: formulation of a research question; review, critical appraisal, and abstraction of peer-reviewed studies and unpublished practice literature; expert input through Delphi surveys and a Nominal Group process; and external review by metabolic experts. RESULTS Recommendations, summary statements, and strength of evidence are included for each of the following topics: (1) initiating a pegvaliase response trial, (2) monitoring therapy response and nutritional status, (3) managing pegvaliase treatment after response to therapy, (4) education and support for optimal nutrition with pegvaliase therapy, and (5) pegvaliase therapy during pregnancy, lactation, and adolescence. Findings, supported by evidence and consensus, provide guidance for nutrition management of individuals receiving pegvaliase therapy for PKU. Recommendations focus on nutrition management by clinicians, as well as the challenges for individuals with PKU as a result of therapy changes. CONCLUSIONS Successful pegvaliase therapy allows the possibility for individuals with PKU to consume an unrestricted diet while still maintaining the benefits of blood phenylalanine control. This necessitates a perspective change in education and support provided to individuals in order to achieve healthy nutrient intake that supports optimal nutritional status. The updated guideline, and companion Toolkit for practical implementation of recommendations, is web-based, allowing for utilization by health care providers, researchers, and collaborators who advocate and care for individuals with PKU. These guidelines are meant to be followed always taking into account the provider's clinical judgement and considering the individual's specific circumstances. Open access is available at the Genetic Metabolic Dietitians International ( https://GMDI.org ) and Southeast Regional Genetics Network ( https://managementguidelines.net ) websites.
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Affiliation(s)
- Amy Cunningham
- Hayward Genetics Center, Tulane University School of Medicine, 1430 Tulane Ave SL-31, New Orleans, LA, USA.
| | | | | | - Shideh Mofidi
- Maria Fareri Children's Hospital/Westchester, New York Medical College, Hawthorne, NY, USA
| | - Heather Bausell
- Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL, USA
| | - Adrya Stembridge
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Aileen Kenneson
- Department of Human Genetics, Emory University, Atlanta, GA, USA
| | - Rani H Singh
- Department of Human Genetics, Emory University, Atlanta, GA, USA
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Real-world treatment, dosing, and discontinuation patterns among patients treated with pegvaliase for phenylketonuria: Evidence from dispensing data. Mol Genet Metab Rep 2022; 33:100918. [PMID: 36176956 PMCID: PMC9513695 DOI: 10.1016/j.ymgmr.2022.100918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 09/17/2022] [Indexed: 11/24/2022] Open
Abstract
Background Phenylketonuria (PKU) is an inborn metabolic error characterized by a deficiency of the enzyme required for the metabolism of phenylalanine, an essential amino acid found in most protein-containing foods. Pegvaliase (Palynziq®) is an enzyme substitution therapy approved for adults with PKU who have inadequate blood phenylalanine control (≥600 μmol/L) on existing management. Objective To characterize the treatment, discontinuation, and dosing patterns in patients treated with pegvaliase in real-world practice settings in the United States following commercial availability in 2018. Study design Retrospective cohort study using BioMarin's proprietary drug dispense database associated with the pegvaliase REMS program. Methods Sample construction identified all patients who properly initiated pegvaliase in real world settings (‘full cohort’) and a subset of patients (‘extended follow-up cohort’) with ≥12 months between first dispense of maximum dose and last pegvaliase dispense. Key outcomes were quantified across patients in both cohorts: maximum daily dose; time to maximum daily dose; maximum daily syringes; and dose escalation over time. The overall dose at discontinuation and time to discontinuation were calculated. Patients who subsequently reinitiated therapy were identified. For the extended follow-up cohort, 12-month changes in dose and syringes and dispensing gaps during the 12 months after maximum dose were quantified across all patients and were further stratified by maximum dose. Results Overall, 1596 patients associated with 33,814 dispenses were reflected in the pegvaliase dispense dataset during the study period from July 9, 2018, through December 31, 2021; 1280 patients associated with 25,973 dispenses met inclusion criteria for the full cohort, with 19.9 dispenses each on average. Of these patients, 483 patients associated with 15,149 dispenses also met the extended follow-up criteria, with an average of 31.4 dispenses. Average treatment duration in the full cohort was 82.2 weeks, including 50.8 weeks after maximum daily dose was achieved. The average maximum daily dose was 30 mg with an average time to maximum dose of 31.8 weeks: 43.0% of patients had a maximum dose of 20 mg, 31.3% a maximum dose of 40 mg, and 12.0% a maximum dose of 60 mg. At data cut-off, 289 patients (22.6%) had discontinued; within this group, 126 patients (43.6%) discontinued within the first 6 months after reaching maximum dose. The overall average treatment duration for patients in the extended follow up cohort at data cut off was 131.2 weeks, including 98.6 weeks after maximum dose was achieved. The average maximum daily dose across the cohort was 32.9 mg: 42.4% of patients had a maximum dose of 20 mg, 41.0% a maximum dose of 40 mg, and 11.2% a maximum dose of 60 mg. At 12 months after achieving maximum dose, 35% of patients had down-dosed, with a 46.8% decrease (on average) from their maximum dose. Conclusions Real-world use of pegvaliase reflects longer titration periods than in the dosing schedule based on trial experience. Over time, a substantial number of patients are able to reduce their daily dose by titrating down from their maximum dose, a finding of great interest to clinicians and patients alike.
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Abstract
PURPOSE OF REVIEW To present new therapeutic modalities for inborn errors of metabolism that are in clinical trials or recently approved by the US Food and Drug Administration (FDA) and to improve pediatricians' understanding of therapies their patients with inborn errors of metabolism receive. RECENT FINDINGS New therapies that move beyond the old standard modalities of recombinant human enzyme therapies, diet and medications have been recently approved by the US FDA to include nonhuman enzyme therapies, gene therapy and chaperone therapies. SUMMARY These new therapies offer more therapeutic options for individuals with inborn errors of metabolism. These new therapies have the potential to improve patient compliance and outcomes. Many other novel modalities are in the development pipeline, and are likely to transform the management of inborn errors of metabolism over the coming decade.
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Rohr F, Wessel A, Harding CO, Waisbren SE, Viau K, Kritzer A. Reinstitution of pegvaliase therapy during lactation. Mol Genet Metab Rep 2022; 33:100938. [DOI: 10.1016/j.ymgmr.2022.100938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/06/2022] [Accepted: 11/08/2022] [Indexed: 11/18/2022] Open
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Hollander S, Viau K, Sacharow S. Pegvaliase dosing in adults with PKU: Requisite dose for efficacy decreases over time. Mol Genet Metab 2022; 137:104-106. [PMID: 35964530 DOI: 10.1016/j.ymgme.2022.08.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/01/2022] [Accepted: 08/02/2022] [Indexed: 11/28/2022]
Abstract
Novel pharmaceutical therapies such as pegvaliase, phenylalanine ammonia lyase (PAL), have enhanced disease control for many individuals with phenylketonuria (PKU). We present a retrospective chart review to assess pegvaliase doses over time in individuals followed at the Boston Children's Hospital PAL Clinic, including those who started pegvaliase in a clinical trial ("trial patients") and those who started after drug came to market ("post-market patients"). Trial patients were on pegvaliase an average of 4.8 years longer, and their mean current pegvaliase dose was 126 ± 92 compared to 223 ± 147 mg/week for post-market patients (p = 0.0155), suggesting that the pegvaliase dose for target efficacy may decrease over time in adults with PKU. In post-market patients, we demonstrated a significant, inverse correlation with dose change and number of weeks from response (r = -0.46, p = 0.046). The entire cohort showed significant variability in terms of time to achieve a therapeutic response, response dose, and current dose. Our data suggest that patients tolerate a reduction in pegvaliase dose over time while maintaining efficacy. This is a clinically meaningful finding as it indicates that patients may reduce number of weekly injections over time on pegvaliase.
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Affiliation(s)
- Suzanne Hollander
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA; Department of Clinical Nutrition, Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA.
| | - Krista Viau
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA
| | - Stephanie Sacharow
- Division of Genetics and Genomics, Boston Children's Hospital, 300 Longwood Ave, Boston, MA 02115, USA; Department of Pediatrics, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
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Bernstein L, Hansen J, Kogelmann C, Ellerbrok M, Giżewska M, Gaughan S, Rocha JC, Belanger-Quintana A, Rohr F. Normalizing Diet in Individuals with Phenylketonuria Treated with Pegvaliase: A Case Series and Patient Perspective. NUTRITION AND DIETARY SUPPLEMENTS 2021. [DOI: 10.2147/nds.s337135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Schötz S, Reisbeck F, Schmitt AC, Dimde M, Quaas E, Achazi K, Haag R. Tunable Polyglycerol-Based Redox-Responsive Nanogels for Efficient Cytochrome C Delivery. Pharmaceutics 2021; 13:pharmaceutics13081276. [PMID: 34452237 PMCID: PMC8397965 DOI: 10.3390/pharmaceutics13081276] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 01/11/2023] Open
Abstract
The sensitivity of therapeutic proteins is a challenge for their use in biomedical applications, as they are prone to degradation and opsonization, thus limiting their potential. This demands for the development of drug delivery systems shielding proteins and releasing them at the site of action. Here, we describe the synthesis of novel polyglycerol-based redox-responsive nanogels and report on their potential as nanocarrier systems for the delivery of cytochrome C (CC). This system is based on an encapsulation protocol of the therapeutic protein into the polymer network. NGs were formed via inverse nanoprecipitation using inverse electron-demand Diels–Alder cyclizations (iEDDA) between methyl tetrazines and norbornenes. Coprecipitation of CC led to high encapsulation efficiencies. Applying physiological reductive conditions of l-glutathione (GSH) led to degradation of the nanogel network, releasing 80% of the loaded CC within 48 h while maintaining protein functionality. Cytotoxicity measurements revealed high potency of CC-loaded NGs for various cancer cell lines with low IC50 values (up to 30 μg·mL−1), whereas free polymer was well tolerated up to a concentration of 1.50 mg·mL−1. Confocal laser scanning microscopy (CLSM) was used to monitor internalization of free and CC-loaded NGs and demonstrate the protein cargo’s release into the cytosol.
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