PK analyses conducted by the pharmacist consisted of entering and analyzing factor levels, and identifying and performing therapeutic optimizations. These activities consumed 30% of the pharmacist’s working time. Given these PK assessments, two types of optimizations were proposed: product substitution or dose optimization with the same drug. Once identified, possible optimizations were discussed with the physician and then proposed to the patient’s family. The pharmacist’s role was not restricted to PK analyses. The most time-consuming activity conducted by the pharmacist involved clinic attendance which represented 40% of the pharmacist’s working time. Clinic attendance activities included discussions with families, education on new product administration, and discussions with the multidisciplinary team. Furthermore, 20% of the pharmacist’s time was dedicated to administrative activities such as organization of appropriate switch days, coordinating laboratory tests and timing of PK assessments, ensuring entire supply consumption, adverse event reporting and inventory management support. Finally, the pharmacist developed practice improvement policies and trained staff 10% of the time.