Background: The dearth of effective treatment options for patients with metastatic TNBC has enabled the rapid development of more effective treatments for this condition, but research indicates that clinicians face challenges in maintaining a working knowledge of evolving data. This study was conducted to determine if an online, case-based continuing medical education (CME)/nursing continuing professional development (NCPD)–approved activity could identify and address gaps in clinicians’ knowledge regarding the personalized care of patients with metastatic TNBC. Methods: The activity, Metastatic Triple-Negative Breast Cancer: Applying Treatment Advances to Personalized Care, chaired by Sara A. Hurvitz, MD, FACP, was made accessible starting on July 23, 2021. Learners participated in a 1-hour activity that highlighted emerging therapeutic targets in TNBC, with an emphasis on current challenges and new opportunities in the management of metastatic disease. Learners completed a repeated-pairs pre- and post-activity assessment consisting of case-based questions that gauged their ability to apply emerging data to clinical decision making. Knowledge gaps and learning gains were calculated based on percentages of learners obtaining correct responses on the pre- and post-activity assessments. Significance was assessed using a chi-squared test. Results: As of February 2, 2022, 632 clinicians had completed the activity for credit. Baseline assessment data revealed gaps in knowledge regarding emerging actionable targets and management of treatment-related adverse events (Table). The activity resulted in significant gains in knowledge and competence related to these topics, with P< 0.0001 for all learning gains. Conclusions: These data indicate that a substantial knowledge gap exists regarding the latest developments in the treatment of metastatic TNBC. They also demonstrate that online, case-based CME/NCPD-approved activities can result in statistically significant improvements in clinicians’ knowledge of therapeutic advances and management of treatment-related adverse events for patients with metastatic TNBC. Acknowledgements: This activity was supported by an independent educational grant from Merck.