Characterization of Treatment Utilization in a Metabolic Genetics Clinic

Treatment plans prescribed for patients diagnosed with rare metabolic genetic disorders have evolved with the expansion of Food and Drug Administration (FDA)-approved therapies. This study aimed to characterize medication and medical formula utilization within a metabolic genetics clinic.

This was a retrospective cross-sectional study that included patients with a confirmed metabolic genetic disorder. Manual chart review collected patient diagnosis, medication use, medical formula use, and laboratory data. The primary endpoint was to describe medication and medical formula use in this population. The secondary endpoints included laboratory monitoring frequency, medication acquisition needs, and estimated annual cost, determined using the FDA Redbook.

Of the screened patients, 152 of 225 were included. The most common diagnosis was phenylketonuria (n = 63, 41.4%), and most patients were younger than 21 years old (n = 93, 61.2%). Ninety-five patients were prescribed 110 medications, and 62 patients were prescribed 77 medical formulas. Prior authorization was required for 62.7% of medications and 42.9% of medical formulas. Most medications (70%) were dispensed through specialty pharmacy. Laboratory monitoring was required for 89.1% (98/110) of medications, accounting for 94.7% (90/95) of patients. The estimated annual direct cost of medication use exceeded $100,000 in 47.2% (51/108) of patients, while 31.6% (24/76) of medical formulas exceeded an estimated annual cost of $10,000.

This study describes the treatment landscape of patients seen at a metabolic genetics clinic. Most medications require close laboratory monitoring, prior authorization, and specialty pharmacy use. These data highlight an opportunity for clinical pharmacists to impact the safe and effective use of these high-cost medications.