Grünert SC, Derks TGJ, Mundy H, Dalton RN, Donadieu J, Hofbauer P, Jones N, Uçar SK, LaFreniere J, Contreras EL, Pendyal S, Rossi A, Schneider B, Spiegel R, Stepien KM, Wesol-Kucharska D, Veiga-da-Cunha M, and Wortmann SB
Glycogen storage disease type Ib (GSD Ib, biallelic variants in SLC37A4) is a rare disorder of glycogen metabolism complicated by neutropenia/neutrophil dysfunction. Since 2019, the SGLT2-inhibitor empagliflozin has provided a mechanism-based treatment option for the symptoms caused by neutropenia/neutrophil dysfunction (e.g. mucosal lesions, inflammatory bowel disease). Because of the rarity of GSD Ib, the published evidence on safety and efficacy of empagliflozin is still limited and does not allow to develop evidence-based guidelines. Here, an international group of experts provides 14 best practice consensus treatment recommendations based on expert practice and review of the published evidence. We recommend to start empagliflozin in all GSD Ib individuals with clinical or laboratory signs related to neutropenia/neutrophil dysfunction with a dose of 0.3-0.4 mg/kg/d given as a single dose in the morning. Treatment can be started in an outpatient setting. The dose should be adapted to the weight and in case of inadequate clinical treatment response or side effects. We strongly recommend to pause empagliflozin immediately in case of threatening dehydration and before planned longer surgeries. Discontinuation of G-CSF therapy should be attempted in all individuals. If available, 1,5-AG should be monitored. Individuals who have previously not tolerated starches should be encouraged to make a new attempt to introduce starch in their diet after initiation of empagliflozin treatment. We advise to monitor certain safety and efficacy parameters and recommend continuous, alternatively frequent glucose measurements during the introduction of empagliflozin. We provide specific recommendations for special circumstances like pregnancy and liver transplantation., Competing Interests: Declaration of competing interest All authors with exception of ELC, JlF, PH and SKU received accommodation support by Sophie's Hope Foundation. All authors report no conflict of interest related to this study. TGJD declares that he has confidentiality agreements with third parties. In the past 36 months, there have been consultation agreements (with Danone, Ultragenyx Pharmaceutical Inc, ModernaTX Inc., and Beam Therapeutics), contracts for financial research support for investigator-initiated research (NCT04311307) and sponsor-initiated research (NCT03517085, NCT03970278, NCT05139316, and NCT05196165), honoraria for lectures or presentations (by MEDTalks, Prelum, and Danone), and participations in a Data Safety Monitoring Board (NCT05095727) and Advisory Boards (Ultragenyx Pharmaceutical Inc, ModernaTX Inc., and Beam Therapeutics). For all private-public relationships, all contracts are via UMCG Contract Research Desk and all payments are to UMCG. ND declares that he is a director and minority shareholder in SpOtOn Clinical Diagnostics Ltd. KMS declares that in the last 36 months there were consultancy agreements with BioMarin, Chiesi, Takeda, Sanofi, Amicus and Immusoft Corporation. SCG declares that over the last 3 years in the area of inherited metabolic diseases she has received accommodation support from Nutricia Metabolics, honoraria for lectures from Vitaflo and Ultragenyx, and that she is an advisory board member of Ultragenyx. JL and BS declare no conflict of interest. Funding to Sophie's Hope Foundation and curegsd1b.org is by individual donors, rather than pharmaceutical or medical food industry. ELC declares no conflict of interest. C.D. Nina la Guerrera (www.ninalaguerrera.org) is a small size non-for-profit platform, whose main sources of funding are by individual donors from sectors that have no interest in biomedical research. HM declares that over the last 3 years in the area of inherited metabolic diseases she has received accommodation support from Vitaflo. honoraria for lectures from Vitaflo and Nutricia and served as a paid consultant for Ultragenyx. SBW declares that over the last 3 years in the area of inherited metabolic diseases she has received accommodation support from Nutricia Metabolics., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)