Griswold, Cassia

Introduction: Many patients with prostate cancer have an indication for anticoagulation. This presents a pharmacokinetic dilemma as enzalutamide and apalutamide have significant effects on the metabolism of direct oral anticoagulants. To date, data on coadministration of these agents is limited to pharmacokinetic studies and post-hoc analysis, which suggest no deleterious effects. Our study seeks to elucidate whether the concomitant administration of enzalutamide or apalutamide with apixaban or rivaroxaban results in a clinically meaningful change in thromboembolic events. Methods: We conducted a retrospective, observational cohort study of adult prostate cancer patients on concomitant apalutamide or enzalutamide and apixaban or rivaroxaban for ≥ 3 months from January 1, 2018 to August 9, 2024 at all 3 tertiary sites of our care network. The primary outcome was incidence of deep vein thrombosis, pulmonary embolism, or ischemic stroke. The secondary outcomes included the incidence of switching of anticoagulant therapy or prostate-directed therapy due to concern for drug-drug interaction. The secondary outcomes were assessed in the entire cohort without exclusion. Results: A total of 500 patients were assessed for eligibility, of which 94 were included in the final analysis of primary outcome. The primary outcome occurred in 4 patients (4.3%). The switching of anticoagulant therapy occurred in 32 patients (6.4%). The switching of prostate-directed therapy occurred in 5 patients (1%). Conclusion: This study suggests that there is not an increased incidence of VTE or stroke when compared to historical controls. This study may help clinicians make risk benefit decisions regarding concurrent therapies.

Background: For patients with resected stage III colon cancer, 6 months of adjuvant fluoropyrimidine-based chemotherapy has been the standard of care. The IDEA collaboration aimed to evaluate whether 3 months of adjuvant chemotherapy was noninferior to 6 months. Despite failing to meet its primary endpoint, the subgroup analyses demonstrated noninferiority based on regimen and treatment duration when a risk-stratified approach was used. Patients and Methods: To evaluate the impact of the results of the IDEA collaboration, we evaluated adjuvant chemotherapy prescribing practice patterns, including planned adjuvant treatment regimen and duration from January 1, 2016, to January 31, 2021. The time period was selected to evaluate chemotherapy prescribing patterns prior to the abstract presentation of the IDEA collaboration in June 2017 and after full manuscript publication in March 2018. Results: A total of 399 patients with stage III colon cancer who received adjuvant chemotherapy were included in the analysis. A significant increasing trend for use of 3 months of adjuvant chemotherapy was observed after presentation of the IDEA abstract (P<.001). A significant change in CAPOX (capecitabine/oxaliplatin) prescribing was also observed, increasing from 14% of patients prior to presentation of the IDEA abstract to 48% after presentation (P<.001). Comparing 3 months of CAPOX with 6 months of FOLFOX (fluorouracil/leucovorin/oxaliplatin), 3 months of CAPOX use also steadily increased over time (adjusted odds ratio [aOR], 1.28; 95% CI, 1.20–1.37; P<.001). Among subgroups of interest, no differences in adoption of CAPOX were observed. The adoption of 3 months of CAPOX was similar in patients with low-risk cancer (aOR, 1.27; 95% CI, 1.17–1.37) and those with high-risk cancer (aOR, 1.31; 95% CI, 1.16–1.47). Conclusions: Despite the IDEA collaboration failing to demonstrate noninferiority of 3 months’ duration of adjuvant therapy compared with 6 months, the findings have influenced practice prescribing patterns, favoring CAPOX and a shorter duration of planned adjuvant treatment.