Introduction:
Introduction: Long-chain fatty acid oxidation disorders (LC-FAOD) are a group of rare inborn errors of metabolism that lead to energy depletion and major clinical events (MCEs), including rhabdomyolysis, hypoglycemia, and cardiomyopathy. Current LC-FAOD management strategies include diet and exercise restrictions, avoidance of fasting, and treatment with triheptanoin. Triheptanoin is the first and only FDA-approved treatment for children and adults with LC-FAOD. This retrospective cohort study assessed MCEs and healthcare resource use (HRU) among commercially insured patients with LC-FAOD treated with triheptanoin.

Methods:


Methods: The IQVIA PharMetrics^® Plus database was searched for patients who initiated triheptanoin after FDA approval (30 June 2020) to the end of September 2023. Patients with LC-FAOD treated with triheptanoin had confirmed diagnosis of LC-FAOD defined as at least one ICD-10-CM Diagnosis Code E71.310 in any billing position of a claim in the database and evidence of a triheptanoin prescription starting from 01 July 2020 (identified using NDC code 69794005050). The first date of a triheptanoin claim was defined as the index date. Patients had at least 12 months of medical and pharmacy continuous enrollment before the index date, and at least 6 months of medical and pharmacy continuous enrollment after the index date. Patients were excluded from the study if there was any evidence of participation in clinical trial with ICD-10-CM Diagnosis Code Z00.6, any evidence of pregnancy, or any evidence of long-term hospitalization. Complications and medical history were assessed during all time periods available before the index date and were identified using ICD-10-CM Diagnosis Codes in any care setting. MCEs were defined as rhabdomyolysis, hypoglycemia, and/or cardiomyopathy in an inpatient and/or emergency room setting identified using ICD-10 Diagnosis Codes. MCEs and HRU of all disease related diagnoses were assessed up to 18 months before the baseline period and at least 6 months after triheptanoin initiation. Annualized event rates and durations were calculated.

Results:


Results: Of 34 triheptanoin-treated patients, 23 (67.6%) were pediatric and 11 (32.4%) were female. 65.2% of pediatrics and 72.7% of adults had history of rhabdomyolysis, hypoglycemia, and/or cardiomyopathy diagnoses. Before receiving triheptanoin, the annualized average total MCE rate was 0.52 versus 0.17 after triheptanoin initiation. Reductions were observed in all three MCEs: rhabdomyolysis decreased from 0.29 to 0.11, hypoglycemia from 0.06 to 0.00, and cardiomyopathy from 0.22 to 0.08. Annualized average MCE durations decreased from 4.4 to 0.9 days for all MCEs. Annualized average number of hospitalizations was 0.58 before triheptanoin versus 0.26 after triheptanoin initiation. MCE and hospitalization reductions were observed in both pediatric and adult patients.

Conclusion:
Conclusions: This study demonstrated that patients with LC-FAOD experienced fewer MCEs and fewer inpatient visits after receiving triheptanoin. Future studies comparing a no-treatment disease cohort are needed to better understand the triheptanoin treatment effect.