Researchers at King's College London have developed a pioneering oral medication that could significantly improve cancer treatment outcomes by overcoming chemotherapy resistance. The drug, designated KCL-HO-1i, targets a key protein that tumors use to shield themselves from treatment, potentially transforming the therapeutic landscape for cancer patients.
Targeting Tumor Defense Mechanisms
The new drug addresses a critical limitation in cancer treatment where the body's immune system inadvertently protects tumors from chemotherapy. White blood cells called macrophages produce a protein known as heme oxygenase-1 (HO-1), which creates a protective barrier around tumors and blocks the effects of chemotherapy drugs.
Professor James Arnold, head of the tumour immunology group at King's College London, explained the mechanism: "We discovered that these macrophages in cancer play a key role in blocking chemotherapy. By targeting the enzyme they produce using KCL-HO-1i, we were able to help beneficial immune cells and chemotherapy drugs become significantly more effective."
Promising Preclinical Results
Initial trials conducted on laboratory mice demonstrated remarkable efficacy, with results published in the journal Science Translational Medicine. The studies focused on breast cancer models and showed that KCL-HO-1i made tumors more responsive to different types of chemotherapy, including cases where tumors had previously been resistant to treatment.
"In laboratory models, even chemotherapy-resistant tumours became responsive to treatment, which is a really exciting step forward," Arnold noted.
Patient-Centered Design and Clinical Timeline
The drug has been specifically designed for convenient at-home administration as a tablet that patients would take between chemotherapy sessions. This approach could potentially reduce the need for more aggressive cancer interventions while maintaining treatment effectiveness.
Researchers anticipate that human trials involving patients with breast cancer and other forms of the disease could commence within two years. Professor James Spicer, a professor of experimental cancer medicine at KCL, emphasized the clinical significance: "Chemotherapy remains a key part of treatment for many patients with cancer, but too often it is not as effective or long-lasting as we might like. This research has identified a key reason for these limitations, and discovered a drug that we are keen to test in the clinic alongside established chemotherapy drugs."
Commercial Development and Future Implications
The King's College London research team has established a spin-out company called Aethox Therapeutics to advance the drug's development. Professor Miraz Rahman, a professor of medicinal chemistry at KCL, highlighted the potential impact: "If human trials are successful, KCL-HO-1i could become a valuable companion drug to existing cancer therapies – helping more patients to benefit from the treatments that are already available and reduce the need for more aggressive cancer therapies in the future."
Research Support and Industry Perspective
The study received support from Cancer Research UK and the Medical Research Council. Tanya Hollands, research information manager at Cancer Research UK, commented on the broader implications: "Researchers are increasingly learning how to make better use of existing cancer treatments, whether it's using them differently or in combination with new medicines, like this work suggests. Using combination therapies can help bring improved treatment options to patients more quickly, safely and affordably, because some components of the treatment have already been tested and used in the clinic."
The development represents a significant advancement in combination therapy approaches, potentially offering a new strategy to enhance the effectiveness of established chemotherapy regimens while maintaining patient convenience through oral administration.
