Objectives: Data are limited for real-world LC-FAOD outcomes. Major clinical manifestations of LC-FAOD were assessed as primary outcomes in triheptanoin clinical trials and include rhabdomyolysis, hypoglycemia, and cardiomyopathy. This analysis aims to quantify the real-world burden of LC-FAOD in terms of major clinical manifestations by treatment periods.

Methods: Data were collected with the PicnicHealth digital record platform and included patient-level medical records in the US, supplemented with patient reported outcomes. Patients with confirmed LC-FAOD enrolled in Odyssey from August 2020 to September 2021. Manifestations were captured in all healthcare settings. Rhabdomyolysis was defined as diagnosis or physician notes of acute muscle pain or creatinine kinase level >2000U/L, hypoglycemia as diagnosis or blood glucose level <60mg/dL, and cardiomyopathy as diagnosis or ejection fraction value <55%. Major clinical events (MCEs) were defined as rhabdomyolysis-, hypoglycemia-, or cardiomyopathy-associated hospitalizations or emergency room visits. Outcomes were assessed using a cross-sectional design that compared different treatment periods (of at least 6 months duration) of triheptanoin or medium-chain triglycerides (MCT).

Results: Twenty-seven patients were analyzed, with a median of 7.6 years of data. Nineteen and 21 patients received triheptanoin and MCT, respectively. Fourteen of the triheptanoin-treated patients switched from MCT. MCEs occurred in 31% of patients during triheptanoin treatment compared with 70% during MCT treatment. In triheptanoin-treated patients versus MCT-treated patients, rhabdomyolysis was reported in 31% versus 60%, hypoglycemia in 8% versus 30%, and cardiomyopathy in 8% versus 15% of patients. Total annualized MCEs during triheptanoin and MCT treatment were 0.2 and 0.8. Average annualized inpatient days during triheptanoin and MCT treatment were 0.4 and 0.9.

Conclusions: LC-FAOD patients from the real-world Odyssey program experienced fewer MCEs overall during triheptanoin treatment compared with MCT treatment. Future analyses with larger sample sizes and longer treatment durations are planned. Detailed results for all MCEs will be presented.