1565 Background: The onset of the COVID-19 pandemic resulted in major disruptions in enrollment and conduct of cancer clinical trials. In response, regulators allowed modifications to traditional trial processes to enable clinical research and care to continue. The American Society of Clinical Oncology and Friends of Cancer Research established a task force to evaluate how sponsors perceived the impact of these mitigation strategies on data quality and overall trial conduct. Methods: The study used a survey and live interviews of industry and National Cancer Institute (NCI) cooperative group sponsors of cancer treatment trials. Sponsors with trials active in the United States from January 2015-May 2022 were eligible. We assessed perceived impacts of the pandemic on protocol deviations, types of mitigation strategies, trial closures, dropouts, adverse events (AEs), and data integrity. Descriptive statistics were used for survey data summaries. Key findings from semi-structured interviews were described by theme. Results: Of forty-one eligible sponsors, 20 (49%; 15/36 industry and 5/5 cooperative group) completed the survey; eleven (55%; 7/15 industry and 4/5 cooperative group) were interviewed. Sixty percent of sponsors reported large portfolios (>10 trials) of phase II and/or phase III trials. The most widely adopted mitigation strategies were remote distribution of oral anticancer therapies (70%), remote consenting (65%), and remote symptom monitoring for AEs (65%). The proportion of sponsors reporting a “substantial” increase in protocol deviations compared to the pre-pandemic period dropped from 42% in the initial wave (March-April 2020) to 16% thereafter. Sponsors primarily reported “no change” in trial drop-out rates (77%), the number of trials closed due to low accrual (90%), or rates of AEs (81%) at any point during the pandemic. Overall, most (83%) respondents reported the pandemic had “minimal” (14) or “no” impact (1) on data integrity. In interviews, many sponsors reported persistent time delays in data entry related to labor shortages at sites. Conclusions: This study represents the first systematic evaluation of clinical trial sponsors about the impact of the COVID-19 pandemic on the conduct of cancer clinical trials. Remote clinical trial conduct mitigation strategies were broadly adopted. Despite an observed increase in protocol deviations, most sponsors reported the pandemic had minimal or no impact on data integrity. The COVID-19 pandemic impacted how cancer clinical trials were performed and has likely accelerated a trend towards greater flexibility in trial conduct that was already emerging, with potential benefits of reduced burden and improved access for patients and sites . Future work is planned to further quantify the impact of the pandemic and trial mitigation strategies on the quality of trial data both overall and for historically underrepresented patient groups.