S13 Ep24: Biomarker-Directed Therapies Improve Outlooks for the mCRC Treatment Arsenal: With Chandler Park, MD; and Midhun Malla, MD

In this episode of MedNews Week's Oncology Unplugged, host Chandler Park, MD, a medical oncologist at Norton Cancer Institute in Louisville, Kentucky, was rejoined by Midhun Malla, MD, of the University of Alabama at Birmingham, to discuss therapeutic options for patients with metastatic colorectal cancer (mCRC), particularly in the third-line setting and beyond.

In the final part of this 3-part episode miniseries, Drs Park and Malla explored the challenges faced by community oncologists, especially in rural or underserved areas, in accessing clinical trials, which remain a preferred disease management approach due to their role in advancing novel therapies. However, in the absence of trial availability or when patients are ineligible, they emphasized the importance of evidence-based, FDA-approved agents for later lines of therapy.

Three primary agents were discussed for patients who have progressed on first-line FOLFOX (folinic acid, fluorouracil, and oxaliplatin) and second-line FOLFIRI (folinic acid, fluorouracil, and irinotecan) regimens: trifluridine/tipiracil (TAS-102; Lonsurf) plus bevacizumab (Avastin); fruquintinib (Fruzaqla); and regorafenib (Stivarga). These agents offer viable treatment pathways in biomarker-unselected patient populations. However, direct comparisons between these agents are lacking, as most were tested against placebo controls. The choice among them is often individualized based on patient performance status, prior exposure to biologics, and toxicity profiles.

TAS-102 plus bevacizumab has generated promising results, though real-world data may show diminished efficacy due to frequent prior exposure to 5-fluorouracil and bevacizumab in US patients. Fruquintinib offers a VEGF-targeted approach with a more favorable hematologic toxicity profile, whereas regorafenib is associated with notable adverse effects, including hypertension, gastrointestinal toxicity, and mucositis. Park and Malla emphasized the importance of treatment sequencing, toxicity management, and individualized patient-centered care, including consideration of dose modifications to preserve quality of life in later-line settings.

In addition to later-line options, the conversation also touched on emerging frontline therapies. Notable investigational agents include zanidatimab-hrii (Ziihera) and KRAS G12C–directed therapies. Additionally, a novel integrin-targeted cytotoxin is currently under evaluation at the University of Alabama at Birmingham in patients with treatment-naive mCRC. This agent induces apoptosis via caspase-8 activation and has demonstrated encouraging preclinical activity. Overall, the discussion highlighted a nuanced, biomarker-informed, and patient-tailored approach to mCRC management, emphasizing both the value of clinical trials and the importance of optimizing currently available therapies.