Patient and physician preferences for third-line or later (3L+) treatments of metastatic colorectal cancer (mCRC).

61 Background: When considering later-line treatments for mCRC, patients and physicians balance survival gains with adverse events (AEs) and quality of life. As new treatment options emerge, this study aimed to evaluate patient and physician preferences for 3L+ mCRC treatments to inform clinical decision making. Methods: Patients with self-reported mCRC who received ≥2 prior lines of treatment, and physicians (≈80% oncologists) who treated ≥10 patients with mCRC in the past year, completed an online survey with a multidimensional thresholding (MDT) exercise. The survey was developed based on evidence review, stakeholder engagement, and qualitative interviews. The MDT included treatment benefits (overall survival [OS], 3‐month progression‐free survival [PFS]), AEs (severe hand‐foot syndrome [HFS], diarrhea, severe neutropenia, mild‐to‐moderate hypertension [HTN], fatigue), and treatment regimens. Data were analyzed using a Dirichlet regression. Model estimates were used to quantify acceptable tradeoffs between median months of OS and other attributes. Results: 51 patients (53% 3L; 22% 4L) and 151 physicians completed the survey. Physicians practiced in academic/university settings (36%), community hospitals (30%), or group practices (34%). Overall, both patients (43%) and physicians (64%) most frequently ranked improvement in OS as the most important attribute, followed by improvement in PFS; the next priority was improvement in fatigue for patients and neutropenia for physicians. Patients and physicians both preferred the oral-only regimens vs oral+ intravenous (IV); patients were willing to accept greater reductions in OS for oral-only treatment regimens vs physicians (0.91-1.05 months vs 0.23-0.35 months) (Table). Both groups valued reducing the risk of AEs. For example, to have a treatment with 0% vs 40% risk of severe neutropenia, patients were willing to forgo 1.6 months and physicians 1 month of OS. For a 0% vs 40% risk of HTN, patients were willing to forgo 1.4 months and physicians 0.24 months of OS. Conclusions: When considering potential 3L+ mCRC treatments, patients and physicians differ in their willingness to make trade-offs, with patients accepting a potential incremental reduction in OS in favor of being able to take an oral-only regimen or lower risk of AEs. These findings highlight the importance of incorporating patient preferences into treatment decision-making in mCRC, including the 3L+ setting. Median months of OS equivalent to a change (trade-off) in another attribute. Patients (n=51)Median months of OS Physicians (n=151)Median months of OS 10% change in probability Diarrhea 0.41 0.14 Neutropenia 0.40 0.25 HTN 0.36 0.06 HFS 0.64 0.32 Fatigue 0.60 0.09 3-month PFS 0.75 0.38 2 pills PO QD → 3 pills PO BID2 pills PO QD → 3 pills PO BID + IV Q2W3 pills PO BID → 3 pills PO BID + IV Q2W 0.141.050.91 0.120.350.23 PO, by mouth; QD, once daily; BID, twice daily; Q2W, every 2 weeks.