Blocking Autophagy After TACE May Extend Disease Control in Colorectal Liver Metastases

Colorectal cancer is one of the most common and lethal malignancies worldwide, and liver metastases develop in roughly half of all patients with advanced disease. Once colorectal cancer has spread to the liver, options beyond second-line systemic therapy become limited, and the duration of meaningful disease control is short. Liver-directed interventions such as transarterial chemoembolization (TACE) can deliver higher local response rates than systemic therapy alone, but durable benefit has remained elusive.

The biological reason is instructive. When TACE cuts off arterial blood flow to tumors, it creates acute ischemia — but cancer cells are resourceful survivors. They activate autophagy, a process by which cells cannibalize their own organelles and proteins for energy, allowing them to endure nutrient and oxygen deprivation. Simultaneously, hypoxia-inducible factor (HIF) signaling upregulates vascular endothelial growth factor (VEGF), triggering angiogenesis that rapidly rebuilds the tumor's blood supply. The net effect is that TACE's initial damage is repaired from within.

This Phase 1 trial, sponsored by the Abramson Cancer Center at Penn Medicine, was designed to disrupt both escape routes at once. Axitinib, a potent VEGF receptor inhibitor, was paired with hydroxychloroquine, a well-known autophagy blocker, and added to standard TACE in patients with liver-dominant metastatic colorectal cancer. The primary goal was to determine safety and tolerability of the combination before advancing to efficacy endpoints.

Unfortunately, the trial was terminated before reaching its intended conclusions. The reasons for termination are not disclosed in the available abstract, which limits interpretation considerably. No efficacy data are presented, and no safety findings have been publicly summarized.

Despite termination, the mechanistic rationale remains scientifically compelling. The interplay between autophagy, HIF activation, and VEGF-driven tumor survival after ischemic therapy is a broadly relevant cancer biology question. Future trials with refined patient selection or alternative autophagy inhibitors may revisit this strategy. Clinicians and researchers working in hepatic oncology should note that the hypothesis — block survival signaling to make locoregional therapy stick — represents a rational and testable approach to a persistent clinical problem.