Saunders, Ila Maewal

Background Lenalidomide is an immunomodulatory drug used to treat multiple myeloma that requires renal dosing adjustment based on Cockcroft-Gault (CG). Various equations to estimate kidney function exist and pose a potential issue with lenalidomide dosing. Objective The objective of this analysis was to evaluate the impact of estimating kidney function in newly diagnosed multiple myeloma patients with CG, Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and their potential impact on lenalidomide dosing. Methods Data from 1121 multiple myeloma patients at the time of diagnosis acquired from the Mayo Clinic were used to calculate creatinine clearance (CrCl) using Cockcroft-Gault with actual body weight (CG ABW ), ideal body weight (CG IBW ), or adjusted body weight (CG AdjBW ); MDRD; and CKD-EPI for each subject. Discordances in dosing were then analyzed, and lenalidomide exposure was calculated for each subject to assess impact on pharmacokinetics of lenalidomide for patients who received discordant doses. Results Overall, approximately 16% of patients received a discordant dose when using MDRD or CKD-EPI instead of CG ABW . The most common dose discordance was the decrease of a full dose of lenalidomide 25 mg when using CG ABW down to 10 mg and when using MDRD or CKD-EPI with 53.8% to 55.6% of all discordances in this category. When assessing different body weights, the most common discordance was a decrease from 25 to 10 mg when using CG IBW instead of CG ABW ; the same trend was observed when using CG AdjBW instead as well. Patients were also at risk of over- or underexposure based on area under the concentration versus time curve (AUC) for discordant dosing. Conclusion and Relevance A significant proportion of patients are at risk of under- or overdose of lenalidomide if CKD-EPI or MDRD are used instead of CG ABW . Physicians should use CG ABW when estimating renal function to dose lenalidomide.

Background Current workforce shortages within the hematopoietic stem cell transplant field necessitate capitalizing on the role of oncology-trained pharmacists. Working within an agreed-upon protocol, pharmacists are able to expand patient care delivery through optimal medication therapy management. Methods An electronic survey was developed by the Advocacy & Policy Working Committee of the American Society for Blood and Marrow Transplantation Pharmacy Special Interest Group and distributed to pharmacists involved in the care of hematopoietic stem cell transplant patients. The primary objective was to assess the current state of collaborative practice agreements in the hematopoietic stem cell transplant setting. Results Forty-eight responses representing 41 institutions were returned. Respondents were mostly female (67%) and practiced in the adult setting (83%). Reponses represented a range of practice experience in hematopoietic stem cell transplant with the majority of the hematopoietic stem cell transplant positions (83%) funded by the department of pharmacy at an academic medical center. Of the 48 responses, 22 (46%) respondents reported having collaborative practice agreements in place; 10 (21%) respondents did not currently have collaborative practice agreements, but were planning to implement them; and 16 (33%) respondents did not have collaborative practice agreements at their institution. Clinical activities performed under a collaborative practice agreement included medication selection and dosing modifications, therapeutic drug monitoring, supportive care management, and management of comorbid conditions and chronic diseases. The most commonly cited barrier to establishing collaborative practice agreements was the inability to secure reimbursement for services provided. No respondents reported a negative impact on job satisfaction. Conclusions The results of this survey provide the pharmacy community with a robust understanding of the current landscape of hematopoietic stem cell transplant pharmacy collaborative practice agreements.