Estimation of Kidney Function in Patients With Multiple Myeloma: Implications for Lenalidomide Dosing.

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 (CGABW), ideal body weight (CGIBW), or adjusted body weight (CGAdjBW); 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 CGABW. The most common dose discordance was the decrease of a full dose of lenalidomide 25 mg when using CGABW 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 CGIBW instead of CGABW; the same trend was observed when using CGAdjBW 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 CGABW. Physicians should use CGABW when estimating renal function to dose lenalidomide.

SGLT-2 Inhibitors Versus GLP-1 Receptor Agonists Effects on Kidney and Clinical Outcomes in Veterans with Type 2 Diabetes.

BACKGROUND: The primary aim compared kidney endpoints between patients with type 2 diabetes (T2D) 36 months after initiation on a sodium-glucose cotransporter-2 inhibitor (SGLT2i) or a GLP-1 receptor agonist (GLP-1RA). Secondary aims compared estimated glomerular filtration rate (eGFR), hemoglobin A1c (HbA1c), weight, and urine albumin-to-creatinine ratio (UACR) changes. METHODS: We conducted a retrospective cohort study of propensity score matched veterans with T2D, baseline eGFR>20mL/min/1.73m2, and initiated on a SGLT2i vs GLP-1RA between 4/1/2009-9/1/2020. Cox proportional hazard models were constructed to evaluate effectiveness between both groups on composite endpoint (decline of >=40% in eGFR from baseline, ESRD event, and all-cause mortality) and its components adjusting for baseline characteristics. Spline models were constructed to evaluate eGFR change and linear mixed effects models were constructed to evaluate changes in HbA1c, weight, and UACR. We used an intent-to-treat (ITT) approach as our main analysis followed by a per-protocol (PP) approach excluding veterans who discontinued or switched therapy during the study period. RESULTS: A total of 29,146 propensity score matched veterans were included in SGLT2i and GLP-1RA groups (14,573 per group). In the ITT and PP analyses, veterans initiated on SGLT2i had a 35% (HR=0.65; 95% CI: 0.62, 0.68) and 34% (HR=0.66; 95% CI: 0.62, 0.69) reduction in the hazard of experiencing the composite endpoint compared to veterans initiated on GLP-1RA adjusting for baseline characteristics, respectively. Between 6-36 months, we found an improved chronic eGFR slope with SGLT2i compared to GLP-1RA in both ITT and PP analyses; +1.19 mL/min/1.73 m2 (95% CI: 0.93, 1.45) and +1.29 mL/min/1.73m2 (95% CI: 1.01, 1.57), respectively. The annual difference in chronic eGFR slope in both ITT and PP analyses were +0.97 mL/min/1.73m2/year (95% CI: 0.82, 1.11) and +1.08 mL/min/1.73m2/year (95% CI: 0.92, 1.25). Improved HbA1c, weight loss and UACR were reported for both groups. CONCLUSION: In this real-world study, veterans with T2D initiated on SGLT2i were associated with reduced hazard of experiencing mortality, worsening eGFR, or developing ESRD and improved glycemic, metabolic, and renal endpoints compared to GLP-1RA use.