New Delhi, August 25: Indian researchers have developed a cancer drug candidate designed to activate primarily inside tumour cells, potentially allowing anticancer treatment to act more selectively while reducing exposure of healthy tissues. The compound, named RK-251, remains at the preclinical stage and has not yet been approved or made available for patient treatment.
The research was led by Asis Bala of the Institute of Advanced Study in Science and Technology (IASST), an autonomous institute under the Department of Science and Technology, Government of India, in collaboration with K.P. Bhabak of the Indian Institute of Technology Guwahati.
RK-251 uses a biological characteristic associated with cancer cells to trigger its activity. Cancer cells generally produce higher levels of reactive oxygen species (ROS), molecules capable of causing cellular damage. The researchers designed the drug candidate to exploit this difference between tumour and normal cells.
When RK-251 enters a cancer cell with elevated ROS levels, the mechanism is intended to activate the compound and release NBDHEX, a potent anticancer agent. NBDHEX targets proteins involved in the survival and treatment resistance of several types of cancer cells.
The approach seeks to address one of the limitations associated with conventional cancer treatment, in which drugs can affect healthy cells along with malignant cells and cause significant side effects. By making activation dependent on the cancer-cell environment, the researchers aim to concentrate the drug’s anticancer action more selectively.
Preclinical experiments showed strong activity from RK-251 against aggressive triple-negative breast cancer cells. At the same time, the candidate produced considerably less effect on healthy cells in the experiments. The findings indicated that its ROS-responsive mechanism could improve the selectivity of treatment.
Researchers also tested the candidate in zebrafish embryos (Danio rerio) as part of their preclinical evaluation. The experiments did not reveal obvious signs of toxicity. The compound also displayed the expected fluorescence when exposed to reactive oxygen species, providing additional evidence consistent with the proposed activation mechanism.
The findings, however, do not establish RK-251 as a treatment for cancer patients. The candidate remains in the laboratory research phase and will require further studies to assess its safety and effectiveness.
Before it can be considered for human use, RK-251 will need additional laboratory evaluation, safety assessments and validation through appropriate clinical trials. Its performance in preclinical experiments therefore represents an early stage of drug development rather than evidence of an available cancer therapy.
The researchers’ work centres on using the chemical environment inside cancer cells as a trigger for drug activation, with the objective of distinguishing tumour tissue from healthy tissue more effectively.
