Immunosuppressant adherence in adult outpatient hematopoietic cell transplant recipients

Introduction: Medication nonadherence continues to be challenging for allogeneic hematopoietic cell transplant (HCT) recipients. The risk and severity of chronic graft-versus-host disease (GVHD) are associated with low immunosuppressant concentrations (which can be improved with model-informed precision dosing (MIPD)) and with immunosuppressant nonadherence (which can be improved with acceptable interventions). Methods: With the goals of improving adherence and achieving therapeutic concentrations of immunosuppressants to eliminate GVHD, we characterized the feasibility of using the Medication Event Monitoring (MEMS^®) Cap in adult HCT recipients. Results: Of the 27 participants offered the MEMS^® Cap at the time of hospital discharge, 7 (25.9%) used it, which is below our a priori threshold of 70%. These data suggest the MEMS^® Cap is not feasible for HCT recipients. The MEMS^® Cap data were available for a median of 35 days per participant per medication (range: 7–109 days). The average daily adherence per participant ranged from 0 to 100%; four participants had an average daily adherence of over 80%. Conclusions: MIPD may be supported by MEMS^® technology to provide the precise time of immunosuppressant self-administration. The MEMS^® Cap was used by only a small percentage (25.9%) of HCT recipients in this pilot study. In accordance with larger studies using less accurate tools to evaluate adherence, immunosuppressant adherence varied from 0% to 100%. Future studies should establish the feasibility and clinical benefit of combining MIPD with newer technology, specifically the MEMS^® Button, which can inform the oncology pharmacist of the time of immunosuppressant self-administration.