Optimizing maribavir management: The role of health system specialty pharmacies in access, monitoring, and waste reduction.

Background: Cytomegalovirus (CMV) infection is a common complication in transplant recipients, with refractory or resistant infections making up a subset of this population. Maribavir, indicated for CMV infection that is refractory to first-line treatments, is a high-cost, limited-distribution specialty medication that requires frequent laboratory monitoring to assess efficacy.

Objective: To evaluate outcomes of health system specialty pharmacy (HSSP) management of maribavir including waste and cost avoidance, medication access, and pharmacist interventions during treatment.

Methods: This study was a single-center, retrospective cohort analysis of patients prescribed maribavir from April 1, 2022, to August 1, 2024. Included patients were prescribed maribavir for posttransplant CMV infection/disease that was refractory to treatment with ganciclovir, valganciclovir, cidofovir, or foscarnet. Outcomes included the number of dispenses that were reduced by pharmacist interventions that led to medication waste avoidance and the cost avoidance of these interventions, time to medication access, and the number of pharmacist interventions recommending laboratory tests or medication discontinuation during treatment. Descriptive statistics were used for analysis. To estimate costs avoided by pharmacy and payer, cost avoidance was calculated by multiplying the 14-day supply of maribavir that was not dispensed during the final treatment course because of pharmacist intervention by the average wholesale price (AWP), AWP minus 20% (AWP-20%), and wholesale acquisition cost (WAC).

Results: Included patients (N = 33) were predominately male (64%) with a median age of 62 years (interquartile range [IQR] = 50-66 years). Five patients were required to repeat treatment with maribavir multiple times because of CMV reactivation totaling 41 unique instances of maribavir use. The most common transplant type was kidney (n = 11), and all patients were donor CMV positive (n = 33). 29 patients were able to fill with the institution's HSSP with 36 instances of maribavir use and 113 fills of maribavir. Of these 36 instances, 12 (33%) had the final dispense of the treatment course reduced because of pharmacist intervention, amounting to a cost avoidance range of $143,421 (AWP-20%) to $179,276 (AWP). Maribavir insurance prior approval (PA) was required for 31 (76%) instances of medication use, with median PAs occurring the same day as referral (IQR = 0-2). Of the 41 instances of maribavir use, 8 (20%) required an intervention from the pharmacist recommending CMV laboratory testing be completed.

Conclusions: Pharmacists successfully obtained timely insurance PAs for maribavir. During treatment, pharmacists reduced unnecessary fills, resulting in large cost and waste avoidance. Future research is needed to evaluate the long-term effects of interventions by specialty pharmacists on maribavir patient outcomes.