Riaz, Irbaz Bin

e19503 Background: The risk of venous thromboembolic events (VTE) despite mandatory thromboprophylaxis (TPx) in patients with multiple myeloma (MM) receiving contemporary lenalidomide (Len)-based regimens is not well-defined. Methods: Medline, Embase, and CENTRAL databases were queried to identify phase 1-3 clinical trials of Len-based regimens with mandatory TPx published until April 2018. Random effects meta-analysis was performed using CMAv3 software to obtain crude, and per 100 patient-cycle incidence rate (IR). Prespecified subgroup analyses were performed to obtain IR for VTE by (1) line of treatment (newly diagnosed [ND], relapsed/refractory [RR] and maintenance [Mx] phase) and (2) different Len-based regimens. Results: We screened 1069 citations and analyzed data from 43 trials with 8696 patients, including 17 in ND, 23 in RR and 3 in Mx phase. 12 out of 43 were Phase 3 randomized controlled trials. The overall incidence of VTE in 8696 patients was 4.6% (95% CI, 3.7-5.8%), with 1.0 event (95% CI, 0.7-1.4%) per 100 patient cycles. In patients with NDMM (n = 3295), 193 (5.9%) experienced VTE with a pooled IR of 0.9 (95% CI, 0.3-2.3) per 100 patient-cycle. Among RRMM patients (n = 3981), 251 (6.3%) experienced VTE with a pooled IR of 1.0 (95% CI, 0.4-2.3) per 100 patient-cycle. The incidence of VTE was highest with the following triplet regimens: Rd + Proteasome inhibitor (PIs) and Rd + Anthracycline (Ac) [+/- Vincristine], with the latter having a high risk of VTE regardless of the treatment phase (table). With Len Mx (n = 1420), 38 (2.7%) patients had VTE, with a pooled IR of 0.2 (95% CI, 0-2.1) per 100 patient-cycle. Conclusions: Patients with MM undergoing treatment with Len-based regimens remain at risk of VTE despite current TPx strategies. The estimates of VTE IR provided by this analysis can guide clinicians in assessing treatment-related risk of VTE in this setting. [Table: see text]

709 Background: Several immunotherapy (IMT) combinations either as an IMT doublet or IMT in combination with TKIs are now available for first-line therapy of metastatic renal cell carcinoma (mRCC). In the absence of head-to-head clinical trials, we performed an indirect comparison of frontline treatment options to provide clinical guidance. Methods: Medline, Embase and Cochrane Library were searched to identify relevant trials. Hazard ratios (HR) and confidence interval (CI) for primary outcome of progression-free survival (PFS) and secondary outcome of overall survival (OS) were abstracted. Network meta-analysis was performed using a multivariate, consistency model, random-effects meta-regression. Data on Grade 3 or higher AEs was abstracted and meta-analyzed. Pre-specified subgroup analyses were performed based on risk categories (high risk vs low and intermediate vs), history of prior nephrectomy, PD-L1 positivity, age and sex. Risk for bias(RoB) was assessed using the Cochrane Collaboration’s tool. Results: Nine studies were included for PFS analysis, and 6 studies for OS analysis. Avelumab-axitinib (AA) (HR 0.69, 0.48-0.96), and Pembrolizumab-Axitinib (PA) (HR 0.89, 0.50-0.96) significantly improved PFS, while there was no significant PFS benefit with atezolizumab-bevacizumab (AB) (HR 0.83, 0.62-1.13) and nivolumab-ipilimumab (NI) (HR 0.85, 0.63-1.15) as compared to Sunitinib. PA (HR 0.53, 0.38-0.75) and NI (HR 0.63, 0.44-0.90) significantly improved OS, while AB (HR 0.93, 0.75-1.12) showed no significant OS benefit as compared to Sunitinib. NI and AB had significantly fewer grade ≥3 AE than sunitinib. No significant interaction was found by risk group, age, sex or prior nephrectomy. Significant interaction was found by PD-L1 expression(p<0.001), with significant PFS improvement in PD-L1 positive (HR 0.62, 0.53-0.73) but not in PD-L1 negative patients (HR 0.92, 0.81-1.05). Overall, RoB was low amongst included studies. Conclusions: AA improved PFS, NI improved OS, whereas PA improve both PFS and OS as compared to sunitinib monotherapy. However, no IMT combination was superior to other combinations. Cost effectiveness analysis will be reported separately.

708 Background: Patients with high risk non-metastatic renal cell cancer (RCC) are at significant risk of recurrence following nephrectomy. Previously, we reported no benefit of adjuvant tyrosine kinase inhibitor (TKI) treatment in high-risk patients. Since our most recent publication, efficacy results from the multicenter double-blind SORCE trial have become available. We updated our meta-analysis to include these additional data and performed a cumulative meta-analysis. Methods: PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched to identify relevant RCTs. A generic variance-weighted random effects model was used to derive estimates for efficacy. Heterogeneity was assessed using the Cochran Q statistic and was quantified using the I2 test. The primary outcome was disease-free survival (DFS), defined as the interval between randomization and the first recurrence, the occurrence of metastasis or a secondary cancer, or death due to any cause. Statistical analysis was performed using Comprehensive Meta-Analysis version 3 (Biostat). Results: Five phase 3 trials were identified, enrolling 6531 patients. Two trials compared sunitinib with placebo (S-TRAC and ECOG-ACRIN), two compared sorafenib with placebo (ECOG-ACRIN and SORCE) and one trial each compared pazopanib (PROTECT) and axitinib (ATLAS) vs placebo. Cumulative evidence suggests that adjuvant therapy with TKIs showed no significant improvement in (DFS) hazard ratio [HR] of 0.93 (95% CI, 0.85-1.02), compared to placebo. There was no significant heterogeneity among included trials ( I2= 52%, P= .41). Overall, the trials were at low risk of bias. Conclusions: Adjuvant vascular endothelial growth factor tyrosine kinase inhibitors in high-risk renal cell carcinoma did not improve DFS as compared to placebo. Improved patient selection using better prognostic biomarkers or scoring systems may identify subsets of patients who can benefit from adjuvant treatments. Toxicity estimates will be updated as data from SORCE trial publication becomes available.

335 Background: Network meta-analysis can provide useful evidence for relative efficacy and toxicity of different treatment options in absence of head-to-head trials. Previously, we reported no difference in efficacy between Apalutamide (APA) and Enzalutamide (ENZA). In this analysis, we provide updated indirect comparisons of all FDA approved agents (APA,ENZA, Darolutamide(DARO) for the treatment of M0CRPC with rapid PSA doubling time. Methods: MEDLINE, EMBASE and Cochrane Library were searched to identify relevant clinical trials. Hazard ratios (HR) and 95% confidence interval (CI) for Metastasis Free Survival (MFS), Overall Survival (OS) and data on grade 3 or higher AEs were abstracted. Bayesian network meta-analysis was conducted using WinBUGS 1.4.3 software (MRC Biostatistics Unit, Cambridge, UK) to perform an indirect comparisons. Risk for bias was assessed using the Cochrane Collaboration’s tool. Results: Three RCTs (SPARTAN, PROSPER and ARAMIS) compared APA, ENZA and DARO respectively in combination with ADT to ADT alone. A total of 4117 patients were included in efficacy analysis (2694 received novel hormonal agents and 1423 received ADT and placebo). There were no statistically significant differences in MFS (HR 0.97, 95% CrI 0.74 - 1.30) between APA and ENZA; however, both APA 0.69 (95% CI 0.52 -0.92) and ENZA 0.71 (95% CrI 0.53, 0.92) significantly improved MFS as compared to DARO. There were no statistically significant differences in OS between these drugs. DARO had fewer grade 3 or higher adverse events of fatigue (HR 0.09, 95% CrI 0.01 – 0.51) compared to ENZA. However other common adverse events such as hypertension, falls, coronary artery disease/myocardial infarction and diarrhea were not significantly different between treatment groups. There was low risk of bias amongst included studies. Conclusions: APNA and ENZA provide significant improved in MFS as compared to DARO in patients with M0CRPC. The drugs have similar toxicity profile except that DARO was associated with lower incidence of fatigue compared to ENZA. Cost effective analysis of these drugs will be reported separately.

PURPOSE: Gender disparity persists in academic medicine. Female faculty are underrepresented in leadership positions and have lower research output. We studied gender differences in faculty rank and departmental leadership and contributing factors among academic hematologists and oncologists in the United States. METHODS: For clinical faculty at 146 hematology or oncology fellowship programs listed in the Fellowship and Residency Electronic Interactive Database, we collected data on demographics, academic rank, and research output using the Doximity and Scopus databases. We compared unadjusted characteristics of men and women by using 2-sided t tests and χ2 tests where appropriate. To predict probability of full professorship or leadership position among men versus women, we performed multivariable logistic regression analysis adjusted for clinical experience in years, number of publications, h-index, clinical trial investigator status, National Institutes of Health funding, and workplace ranking (top 20 v not). RESULTS: Two thousand one hundred sixty academic hematologists and oncologists were included. Women composed 21.9% (n = 142) of full professors, 35.7% (n = 169) of associate professors, and 45.4% (n = 415) of assistant professors. Thirty percent (n = 70) of departmental leaders were women. Female faculty, compared with male faculty, had a lower mean h-index (12.1 v 20.9, respectively; P < .001) and fewer years of professional experience since fellowship (10 v 16 years, respectively; P < .001). After adjusting for duration of clinical experience, academic productivity, and workplace ranking, the odds of obtaining professorship (odds ratio [OR], 1.05; 95% CI, 0.71 to 1.57; P = .85) or divisional leadership (OR, 0.57; 95% CI, 0.20 to 1.58; P = .28) for female physicians were not different compared with male physicians. CONCLUSION: Gender disparity exists in senior ranks of academic hematology and oncology; however, gender is not a significant predictor in achieving professorship or department leadership position.

PURPOSE: There is a concern that influenza vaccination could increase the incidence of immune-related adverse events (irAEs) in patients with cancer receiving immune checkpoint inhibitors. The aim of our study was to determine the safety of influenza vaccination in this patient population. PATIENTS AND METHODS: We retrospectively identified patients who received at least 1 dose of pembrolizumab during any influenza season from September 2014 to August 2017 and reviewed medical records for irAEs. The primary endpoint was the incidence of irAEs. We used multivariable logistic regression and cumulative incidence curve with competing risks for comparison. RESULTS: Among 162 patients with cancer included in this study, 70 patients (43.2%) received at least 1 influenza vaccination. The vaccinated group was significantly older ( P = .002) and received more cycles of pembrolizumab ( P = .006). The incidence of any grade irAEs in the vaccinated group trended toward being lower (25.7% v 40.2%; P = .07) compared with the nonvaccinated group. Influenza vaccination was independently associated with fewer irAEs, with an odds ratio of 0.4 (95% CI, 0.2 to 0.9; P = .03) in multivariable analyses. The vaccinated group was less likely to have irAEs compared with the nonvaccinated group (24.7% v 34.4% at 12 months; P = .05), with death as a competing risk. The median irAE-free duration in the vaccinated group was longer than the nonvaccinated group (not reached v 28 months; P = .037). CONCLUSION: Influenza vaccination in patients with cancer receiving immune checkpoint inhibitor therapy was not associated with increased irAEs. This supports the safety of influenza vaccination in this patient population.

Background Thromboprophylaxis is routinely used with lenalidomide‐based regimens in multiple myeloma because of a substantial risk of venous thromboembolism (VTE). However, little is known about the incidence of VTE with contemporary lenalidomide‐based regimens. The objective of the current study was to estimate the incidence of VTE despite thromboprophylaxis with currently used lenalidomide‐based regimens in patients with myeloma. Methods The Ovid MEDLINE, Embase, and Cochrane databases were queried from study inception to January 2019 for keywords to cover the following concepts: “lenalidomide,” “venous thromboembolism,” and “multiple myeloma.” Phase 1, 2, and 3 clinical trials evaluating lenalidomide‐based regimens with thromboprophylaxis were included. The pooled incidence rate of VTE was estimated using a random‐effects model. Results The search generated 1372 citations, with 51 clinical trials and 9069 patients included for analysis. The most common thromboprophylaxis agents were aspirin, low‐molecular‐weight heparin or warfarin, administered either per risk‐stratification or at investigators' discretion. The pooled incidence of VTE in trials of patients who had newly diagnosed and relapsed/refractory myeloma was 6.2% (95% CI, 5.4%‐7.1%) over median treatment durations ranging from 2 to 34 cycles, which translated into 1.2 VTE events per 100 patient‐cycles (95% CI, 0.9‐1.7 VTE events per 100 patient‐cycles). Among contemporary regimens, the risk of VTE was low with combined lenalidomide and low‐dose dexamethasone (0.2 [95% CI, 0.1‐0.6] events/100 patient‐cycles) and lenalidomide maintenance (0.0 [95% CI, 0.0‐0.7] events per 100 patient‐cycles). VTE risk was higher with combined lenalidomide and low‐dose dexamethasone plus proteasome inhibitors (1.3 [95% CI, 0.7‐2.3] events per 100 patient‐cycles). Conclusions Despite adequate thromboprophylaxis, lenalidomide‐based regimens have a substantial risk of VTE in controlled clinical trial settings. Further studies are needed on new thromboprophylaxis strategies with regimens that have a high VTE risk.

Introduction: We have previously reported underrepresentation of female faculty at senior academic ranks in hematology/oncology (H/O). In this analysis we aimed to investigate the influence of sex in attaining leadership positions amongst academic hematologists/oncologists in United States. Methods: Faculty members were identified at 146 H/O fellowship programs listed on fellowship and residency electronic interactive database (FREIDA.) Data was collected on demographics, academic rank and research output using Doximity and Scopus databases. We compared the unadjusted characteristics of men and women by using two-sided t-tests and χ2 tests where appropriate. In primary analysis, logistic regression models were used to evaluate sex differences on probability of having full professorship (versus assistant and associate professorship) and of achieving leadership positions including division chief, Program Director (PD) and Associate Program Director (APD). Adjusted models included the following variables: clinical experience in years, number of publications, h-index, appointment at top 20 hospital, clinical trial investigator status and National Institutes of Health funding. Stratified analysis was performed adjusting for duration of clinical experience (≤15 vs >15 years) Results: Fewer women were full Professors (21.9% vs 78.1%), division chiefs (16.7% vs 83.3%), and PDs (30.5% vs 69.5) but the number was similar for Associate Program Directors (47.1% vs 52.9%). In a univariate unadjusted model, women were less likely to be full professors compared to men (OR 0.39; 95% confidence interval [CI], 0.31-0.48; P<.001). However, in the multivariable adjusted model no statistically significant sex difference in full professorship was found (OR 1.05; 95% CI 0.71, 1.57; P=.85; Table). The likelihood of full professorship was positively associated with clinical experience in years, number of first/last author publications, h-index, and being a primary investigator on at least one clinical trial.In a univariate unadjusted model, women were less likely to be division chiefs as compared to males (OR 0.35; 95% CI, 0.16, 0.80; P=.01). However, in the multivariable adjusted model, there was no statistically significant sex difference in achieving the position of division chief (OR 0.57; 95% CI 0.20, 1.58; P=.28; Table). No significant difference was found between females and males for being program directors or associate program directors in both univariate and multivariate analysis. Similarly, a stratified analysis adjusting for duration of clinical experience (≤15 vs >15 years) found no significant sex differences in attaining leadership position (Table) Conclusion: We found that women are underrepresented at higher academic ranks and in leadership positions in hematology/oncology, but that sex is not a significant negative predictor to women obtaining leadership positions after correcting for traditional predictors of academic success. However, "non-traditional" and therefore less measurable and analyzable factors such as networking, mentorship, sponsorship, gender bias, balancing work and home responsibilities and many others may contribute and should be further investigated. Disclosures No relevant conflicts of interest to declare.

Introduction Despite more robust attempts to deliver chemotherapy in the outpatient setting, certain regimens for hematologic malignancies require inpatient hospitalization for treatment and monitoring clinical status. Increased length of stay (LOS) for planned chemotherapy admissions leads to increased healthcare utilization and decreased patient satisfaction. We sought to identify potentially modifiable risk factors for increased LOS. Methods Planned chemotherapy admissions to the inpatient hematology services at Mayo Clinic (Rochester, MN) from October 2018 through March 2019 were reviewed. We included patients who had treatment plans based on four pre-specified common regimens for acute myeloid leukemia, relapsed non-Hodgkins lymphoma and multiple myeloma. Patients who remained in the hospital for lack of caregiver support were excluded. Patient characteristics, including age, malignancy type, and chemotherapy regimen were recorded. Encounter characteristics included day of week of admission, time of admission, time chemotherapy plan initiated, and whether or not all necessary procedures (labs, vascular access, chemo orders) were completed prior to admission. Primary outcome was LOS. Secondary outcome was time to treatment initiation (TTI) after admission. Results There were 100 planned admissions for patients receiving four regimens: cytarabine consolidation, EPOCH, ICE, VDT-PACE, during the six month review period. Thirty-six admissions did not occur as planned (regimen changed, rescheduled, or disease progression). Of the remaining 66 admissions, 11 outliers were excluded from primary analysis. Baseline characteristics are summarized in Table 1. Univariate analysis with independent t-test found no difference in LOS for patients who had physician chemotherapy orders in place prior to admission. To the contrary, we detected a non-significant trend toward longer mean length of stay for patients that were not seen in clinic on day of admission (Table 2). On ANOVA, there was a statistically significant difference in LOS when comparing Monday admissions 3.93 days (95% CI 3.07 to 4.79) vs Friday 5.25 days (95% CI, 4.86 to 5.64), but not between any other days. There were no statistically significant differences in TTI when comparing by day of week, physician order status, or chemotherapy regimen. Again, a non-significant trend toward increased TTI was observed for patients not seen in clinic on the same day as admission. Conclusions This study serves as a starting point towards identifying modifiable factors that are essential to delivery of safe, satisfying inpatient care to our hematological malignancy patients.Our noteworthy finding regarding patients who were admitted on Friday having a longer LOS than those admitted on Monday requires further exploration. This study is ongoing with mature data to be presented at the meeting. Disclosures No relevant conflicts of interest to declare.