Opinion

E. Shyam P. Reddy: New Oral Drug Targets Tumor Defense to Overcome Chemotherapy Resistance

E. Shyam P. Reddy/LinkedIn

Aug 13, 2025, 13:26

E. Shyam P. Reddy: New Oral Drug Targets Tumor Defense to Overcome Chemotherapy Resistance

E. Shyam P. Reddy, Professor and Director of the Cancer Biology Program, Department of Obstetrics and Gynecology at Morehouse School of Medicine, shared on LinkedIn:

“A cancer drug could enhance how patients respond to chemotherapy even in treatment-resistant tumors. The drug works by disarming a key defense mechanism that tumors use to protect themselves from treatment. In preclinical models, it has already shown promise in making chemotherapy-resistant cancers more responsive to therapy.

Chemotherapy is one of the most widely used cancer treatments, but it doesn’t always work as effectively as hoped. One major reason is that a specific group of the body’s own immune cells act as a barrier around tumors.

These white blood cells, known as macrophages, surround the blood vessels inside tumors and act like gatekeepers, blocking helpful immune cells from entering and doing their job in supporting the responses to chemotherapy.

The King’s College London scientists, who have launched a spinout company, Aethox Therapeutics, found that these macrophages make a protein called heme oxygenase-1 (HO-1), which helps shield the tumor from the immune system and block the effects of chemotherapy. The new drug, KCL-HO-1i, targets this protein.

The research is published in the journal Science Translational Medicine.

Professor James Arnold, Head of Tumor Immunology Group, King’s College London, said, ‘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. In laboratory models, even chemotherapy-resistant tumors became responsive to treatment, which is a really exciting step forward.’

Unlike many cancer treatments that require hospital visits, KCL-HO1i is designed to be taken at home as a tablet between chemotherapy sessions. This makes it easier for patients to incorporate into their treatment plans without adding extra hospital burdens.

In early tests using mouse models of breast cancer, the drug made tumors more responsive to a range of commonly used chemotherapies. These promising results suggest it could be used across a wide variety of cancer types and chemotherapy treatments.

The researchers hope that with funding, clinical trials on breast and other cancers could begin within two years.

Professor James Spicer, Professor of Experimental Cancer Medicine, King’s College London, said, “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.’

This breakthrough is the result of a multidisciplinary collaboration between researchers including Professors James Arnold, James Spicer, and Miraz Rahman and their research teams at King’s College London.”

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