Indian Scientists Develop 'Smart' Cancer Drug RK-251 That Activates Only Inside Tumour Cells
Researchers at the Institute of Advanced Study in Science and Technology (IASST), Guwahati, led by Dr. Asis Bala, along with Dr. K.P. Bhabak of IIT Guwahati, announced a "smart" cancer drug named RK-251 on 19 August 2026. RK-251 remains chemically inactive in healthy tissue and is triggered only inside cancer cells, which typically contain elevated levels of reactive oxygen species (ROS). On detecting high ROS levels, the compound releases a potent anticancer agent called NBDHEX directly inside the tumour cell. In preclinical laboratory studies, RK-251 showed targeted activity against aggressive triple-negative breast cancer cells while sparing healthy cells, and toxicity studies in zebrafish (Danio rerio) embryos found no obvious signs of toxicity. The findings were published in the Journal of Medicinal Chemistry, a journal of the American Chemical Society; researchers caution that extensive further testing, including human clinical trials, is required before RK-251 could become a treatment option.
IIT Guwahati is located in Assam, established in 1994 | Triple-negative breast cancer lacks oestrogen, progesterone and HER2 receptors, making it hard to target | Reactive Oxygen Species (ROS) are chemically reactive oxygen-containing molecules found at elevated levels in cancer cells