Mara, Kristin C.

Background: Skeletal related events (SREs) including pathologic fractures, surgery or radiation to bone, and spinal cord compression contribute to diminished quality of life in patients with multiple myeloma. Bone modifying agents (BMA) such as denosumab or the bisphosphonates zoledronic acid and pamidronate, are used to inhibit osteoclast activity to prevent SREs. The Bone Working Group of the International Myeloma Working Group suggests monthly administration of zoledronic acid for 12 months in newly diagnosed myeloma patients. This is followed by an option to discontinue or decrease administration frequency to every 3, 6, or 12 months if a very good partial response or better is achieved. The ideal start time of BMA from diagnosis and the duration of administration has not been adequately established to optimize reduction of SREs. Methods: This was a retrospective, single-center study that included newly diagnosed myeloma patients treated at the Mayo Clinic between 9/1/2018 and 9/1/2020 who had received at least one dose of a BMA. The primary objective was to evaluate the impact of BMA dosing frequency and duration on SREs. Secondary objectives included time to BMA initiation, time to relapse or progressions following BMA start, and safety. Data was summarized using frequencies and percentages for categorical data, and medians and interquartile ranges (IQR) for continuous data. A spline plot and cut-point analysis were used to assess the association of time from multiple myeloma diagnosis to BMA initiation with skeletal related outcomes. Rates of SREs were estimated using the Aalen-Johansen method, where death was treated as a competing risk. Associations of factors with SREs were assessed using Cox proportional hazards regressions, and these associations were summarized using hazard ratios (HR) and corresponding 95% confidence intervals (CI). Variables that could change throughout follow-up including BMA frequency, cumulative BMA dose, and duration of BMA were treated as time-dependent covariates in the Cox proportional hazards models, where the information for these variables was updated each time an additional dose of BMA was given. All analyses were performed using SAS version 9.4 software (SAS Institute, Inc.; Cary, NC) and R version 4.2.2 (R Core Team, R Foundation for Statistical Computing, Vienna, Austria). Results: Sixty-seven patients were included with a median age of 65 years old. The most frequently used BMA was zoledronic acid (88.1%), followed by pamidronate (7.5%), and denosumab (4.5%). Fifty-five patients (82.1%) had bone disease at baseline. Within 2 years of starting BMA, SREs occurred in 42.2% of patients with baseline bone disease and 8.3% of patients without (p=0.054). Median time to BMA initiation after diagnosis was 45 days (IQR 14-105) in patients with baseline bone disease and 87 (IQR 32-496) in patients without. Among the 26 patients with a SRE, median time from start of BMA to SRE was 170 days (IQR 32-496). No significant association was found between time to initiation and development of a SRE (Figure 1). BMA dosing frequencies of every 3 months and 6 months had a HR for SREs of 1.67 and 0.47, respectively compared to every 1 month, (P-values >0.25). After excluding patients without baseline bone disease, compared to every 1 month dosing, dosing every 3 months and every 6 months increased the risk of SRE, although the differences were not statistically significant (3 months: HR=1.92, 95% CI 0.76-4.88, p=0.17; and 6 months: HR=1.26, 95% CI 0.14-10.94, p=0.84). Patients without bone disease at baseline remained on BMAs for a median of 1.8 years while patients with bone disease received BMAs for a median of 2 years. There was no statistically significant difference found with varying duration or cumulative dose and SRE development (Table 1). Relapse or progression occurred in 32.1% of patients within 2 years of starting BMA, while death occurred in 7.5% of patients. Osteonecrosis of the jaw occurred in 1 patient with bone disease at baseline who received zoledronic acid every 3 months for a duration of 596 days. Conclusions: No significant association between time of BMA initiation, dosing frequency, or duration on development of SREs were observed. This suggests delaying the start time of BMAs to allow for dental clearance and initial treatment would not increase risk of SREs. Prospective trials are needed to confirm these findings.

Abstract Introduction Although there are studies assessing reasons for antidepressant discontinuation, little is known about the impact of sex differences or cytochrome P450 phenotypes. Our objective is to assess discontinuation rates between males and females and whether CYP450 phenotype influences discontinuation. Methods This is a retrospective review of patients previously enrolled in the Right Drug, Right Dose, Right Time: Using Genomic Data to Individualize Treatment database with major depressive disorder. Patients were evaluated for antidepressants trialed between January 1, 2009, and September 30, 2019. Survival analyses with competing risks were used to analyze discontinuation reasons. A Kaplan-Meier estimation method was used to assess the time to discontinuation and discontinuation rates. Analyses were also completed to assess discontinuation between men and women by phenotypic groups. All tests were two-sided, and p-values ≤ .05 were considered statistically significant. Results There were 620 antidepressant discontinuation events discovered from 1015 antidepressant trials included. Overall, the median time to discontinuation for males was 2.6 years and 1.9 years for females (hazard ratio [HR] 0.97 [95% confidence interval (CI): 0.80, 1.19], p = .77). The risk of discontinuation was not different between males and females in any of the phenotype groups, which was consistent in the multivariable analyses. Concomitant use of medications that inhibited or induced antidepressant metabolism increased the overall risk of discontinuation (HR 1.45, 95% CI [1.06, 1.99], p = .020) in a time-dependent analysis. Discussion We did not detect a significant difference in risk of antidepressant discontinuation rates between males and females even when accounting for cytochrome P450 phenotype. Future studies should account for whether medications that inhibit or induce antidepressant metabolism may be a crucial factor in antidepressant discontinuation.

Abstract Background Two independent placebo-controlled clinical trials conducted prior to SARS-CoV-2 Omicron demonstrated that sotrovimab and remdesivir reduced hospitalization among high-risk outpatients with mild to moderate COVID-19. However, their effectiveness have not been directly compared. Methods This retrospective study examined all high-risk outpatients with mild to moderate COVID-19 who received either remdesivir or sotrovimab at Mayo Clinic during the Omicron BA.1 surge from January to March 2022. COVID-19-related hospitalization or death within 28 days were compared between the two treatment groups. Results Among 3,257 patients, 2,158 received sotrovimab and 1,099 received remdesivir. Patients treated with sotrovimab were younger (median age, 60 vs. 69 years) and had lower comorbidity (Monoclonal Antibody Screening Score, 5 vs. 6; Charlson Comorbidity Index, 3 vs. 4), but were more likely to be immunocompromised (47.3% vs. 30.2%) than remdesivir-treated patients. The majority (89%) had received at least one dose of COVID-19 vaccine (median, 3 doses [IQR 2-3] for both groups). COVID-19-related hospitalization (1.5% and 1.0% in remdesivir and sotrovimab groups, respectively, p=.15) and mortality within 28 days (0.4% in both groups, p=.82) were similarly low. A propensity score weighted analysis demonstrated no significant difference in the rates of COVID-related hospitalization and death within 28 days between the two groups. Conclusion This study demonstrated favorable outcomes that were not significantly different between patients treated with remdesivir or sotrovimab. As sotrovimab is no longer authorized, these results support the continued use of remdesivir for treating high-risk patients with COVID-19 during the current Omicron-predominant epoch. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria Maria Gonzalez Suarez, M.D., Ph.D., Gilead: Grant/Research Support Ravindra Ganesh, M.B.B.S., M.D., Alpaca Health: Advisor/Consultant Raymund R. Razonable, MD, Allovir: Endpoint Adjudication Committee|American Society of Transplantation: Board Member|Gilead: Grant/Research Support|Novartis: DSMB|Regeneron: Grant/Research Support|Roche: Grant/Research Support

Abstract Background Implementing effective antimicrobial stewardship interventions is an important component of antimicrobial stewardship programs. Recently, stewardship research has shown that clinician characteristics may have an impact on antimicrobial stewardship intervention methods and acceptance rates. Methods A multisite health system antimicrobial stewardship prospective audit and feedback program interventions performed by stewardship staff using a standardized electronic medical record (EMR) tool were compared by stewardship clinician profession (pharmacist, physician, or advanced practice provider, APP) from 7/1/2017 to 6/30/2022. Outcomes assessed were intervention rates, communication methods, and intervention acceptance by patient age and intensive care unit (ICU) status of patient. Generalized estimating equations utilizing logistic regression were used to assess for associations between staff. Associations were assessed both univariately and after adjusting for other factors. Results Of 69,503 prospective audit and feedback EMR based rules, there were 14,699 rules associated with an intervention. The majority of rules were reviewed by pharmacists (90.7%) followed by physician (9.2%) and APP (< 1%). Of 9,034 interventions with an outcome documented, 7326 (85.5%) pharmacist interventions were accepted and 360 (77.3%) physician interventions were accepted (adjusted p=0.047). Pharmacists intervened by direct action (ie, adjust a medication order) in 6.6% of interventions; whereas, physicians did so rarely (0.4%). Pharmacists were more likely to use synchronous communication than physicians in the adjusted model (pharmacist vs. physician: 63.8% vs 52.5%; p=0.004). Patients in the ICU had a significantly lower intervention acceptance rate (non-ICU vs. ICU: 86.6% vs. 78.0%; adjusted OR 0.57 [95% CI 0.46-0.70], p< 0.001).Table 1.Intervention Rate by Baseline Demographics of Stewardship Clinicians and Patients. *% are reported as row % **Multivariable model was also adjusted for day of week and time of day APP-Advanced practice provider; ICU-intensive care unitTable 2.Intervention Acceptance. *% are reported as row % **Multivariable model was also adjusted for day of week and time of day APP-Advanced practice provider; ICU-intensive care unit Conclusion Antimicrobial stewardship pharmacists and physicians are both effective at prospective audit and feedback but used different intervention styles. Advanced practice providers were vastly underrepresented. Patients in the ICU may benefit from tailored ASP efforts. Disclosures Sara Ausman, PharmD, Gilead: Honoraria Caitlin Brown, PharmD, Alexion: Grant/Research Support|Trevena: Advisor/Consultant Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria

Abstract Background Due to extensive protein binding, use of ceftriaxone in the setting of hypoalbuminemia may result in suboptimal drug exposure via higher concentrations of unbound drug resulting in increased volume of distribution and increased drug clearance. We aimed to evaluate the impact of hypoalbuminemia on clinical success among hospitalized adults with obesity who were treated with ceftriaxone for a bacterial infection. Methods This retrospective review included adult inpatients with weight > 100 kg or body mass index (BMI) > 40 who received ceftriaxone 2 grams intravenously every 12 hours for at least 72 hours for one of the following indications: bloodstream infection, pneumonia, urinary tract infection, non-enterococcal endocarditis, skin and soft tissue infection, or bone and joint infection. The primary outcome was clinical success, a composite of clinical cure and microbiologic cure. Clinical cure was defined as resolution of signs and symptoms compatible with active infection without need to change or extend antibiotic therapy due to inadequate effect of ceftriaxone. Microbiologic cure was defined as negative repeat sterile site cultures, if applicable. Secondary outcomes included length of stay, mortality, and 30-day readmission. Outcomes were analyzed with Mann-Whitney U tests, Pearson’s chi-squared tests, and Fisher’s exact tests (α level = 0.05). Results 137 patients were included, 34 of whom had a serum albumin ≤ 2.5 g/dL. Patients were predominantly white (94.2%) and male (69.3%) with a median BMI of 48.6 (Table 1). Clinical success, a composite of clinical and microbiologic cure, was achieved in 76.5% and 92.2% (p = 0.013) of those with and without hypoalbuminemia, respectively. Clinical cure was significantly more common among those without hypoalbuminemia (93.2%) as compared to those with hypoalbuminemia (76.5%) (p = 0.007). Death during hospitalization was more common (14.7% vs. 0%, p < 0.001) and median length of stay was longer (14 vs. 9 days, p = 0.009) in the hypoalbuminemia group. No difference was seen in 30-day readmission (23.5% vs. 11.7%, p = 0.089). Conclusion Hypoalbuminemia was associated with a lower rate of clinical success among patients with obesity who were treated with ceftriaxone 2 grams every 12 hours. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria

AbstractStudy ObjectiveTo develop and validate a model for predicting acute kidney injury (AKI) after high‐dose methotrexate (HDMTX) exposure.DesignRetrospective analysis.SettingMultisite integrated health system throughout Minnesota and Wisconsin.PatientsAdult patients with lymphoma who received HDMTX as a 4‐h infusion.Measurements and Main ResultsLASSO methodology was used to identify factors available at the outset of therapy that predicted incident AKI within 7 days following HDMTX. The model was then validated in an independent cohort. The incidence of AKI within 7 days following HDMTX was 21.6% (95% confidence interval (CI) 18.4%‐24.8%) in the derivation cohort (435 unique patients who received a total of 1642 doses of HDMTX) and 15.6% (95% CI 5.3%‐24.8%) in the validation cohort (55 unique patients who received a total of 247 doses of HDMTX). Factors significantly associated with AKI after HDMTX in the multivariable model included age ≥ 55 years, male sex, and lower HDMTX dose number. Other factors that were not found to be significantly associated with AKI on multivariable analysis, but were included in the final model, were body surface area, Charlson Comorbidity Index, and estimated glomerular filtration rate. The c‐statistic of the model was 0.72 (95% CI 0.69‐0.75) in the derivation cohort and 0.72 (95% CI 0.60‐0.84) in the validation cohort.ConclusionThis model utilizing identified sociodemographic and clinical factors is predictive of AKI following HDMTX administration in adult patients with lymphoma.

IMPORTANCE: The outcomes of critically ill adults with obesity on continuous renal replacement therapy (CRRT) are poorly characterized. The impact of CRRT dose on these outcomes is uncertain. OBJECTIVES: This study aimed to determine if obesity conferred a survival advantage for critically ill adults with acute kidney injury (AKI) on CRRT. Secondarily, we evaluated whether the dose of CRRT predicted mortality in this population. DESIGN, SETTING, AND PARTICIPANTS: A retrospective, observational cohort study performed at an academic medical center in Minnesota. The study population included critically ill adults with AKI managed with CRRT. MAIN OUTCOMES AND MEASURES: The primary outcome of 30-day mortality was compared between obese (body mass index [BMI] ≥ 30 kg/m2) and nonobese (BMI < 30 kg/m2) patients. Multivariable regression assessed was used to assess CRRT dose as a predictor of outcomes. An analysis included dose indexed according to actual body weight (ABW), adjusted body weight (AdjBW), or ideal body weight (IBW). RESULTS: Among 1033 included patients, the median (interquartile range) BMI was 26 kg/m2 (23–28 kg/m2) in the nonobese group and 36 kg/m2 (32–41 kg/m2) in the obese group. Mortality was similar between groups at 30 days (54% vs. 48%; p = 0.06) but lower in the obese group at 90 days (62% vs. 55%; p = 0.02). CRRT dose predicted an increase in mortality when indexed according to ABW or AdjBW (hazard ratio [HR], 1.2–1.16) but not IBW (HR, 1.04). CONCLUSIONS AND RELEVANCE: In critically ill adults with AKI requiring CRRT, short-term mortality appeared lower in obese patients compared with nonobese patients. Among weight calculations, IBW appears to be preferred to promote safe CRRT dosing in obese patients.

ABSTRACT Cefepime exhibits highly variable pharmacokinetics in critically ill patients. The purpose of this study was to develop and qualify a population pharmacokinetic model for use in the critically ill and investigate the impact of various estimated glomerular filtration rate (eGFR) equations using creatinine, cystatin C, or both on model parameters. This was a prospective study of critically ill adults hospitalized at an academic medical center treated with intravenous cefepime. Individuals with acute kidney injury or on kidney replacement therapy or extracorporeal membrane oxygenation were excluded. A nonlinear mixed-effects population pharmacokinetic model was developed using data collected from 2018 to 2022. The 120 included individuals contributed 379 serum samples for analysis. A two-compartment pharmacokinetic model with first-order elimination best described the data. The population mean parameters (standard error) in the final model were 7.84 (0.24) L/h for CL1 and 15.6 (1.45) L for V1. Q was fixed at 7.09 L/h and V2 was fixed at 10.6 L, due to low observed interindividual variation in these parameters. The final model included weight as a covariate for volume of distribution and the eGFR cr-cysC (mL/min) as a predictor of drug clearance. In summary, a population pharmacokinetic model for cefepime was created for critically ill adults. The study demonstrated the importance of cystatin C to prediction of cefepime clearance. Cefepime dosing models which use an eGFR equation inclusive of cystatin C are likely to exhibit improved accuracy and precision compared to dosing models which incorporate an eGFR equation with only creatinine.