The next big development in cancer treatments could be just drifting around in the ocean right now. Researchers have identified two new anticancer compounds inside the innocuous sea sponge, which has strong natural chemical defence capabilities.

Scientists from the Spanish biopharmaceutical firm  PharmaMar plucked the sea sponge Litho­plo­camia lithistoides from waters off the coast of Madagascar in 2005, where they found the cancer-fighting compounds. Two polyketides isolated from the extracts proved particularly potent at killing human cancer cells in a petri dish. The molecules appear to interfere with microtubules, which are structures that are integral to cell division.

Researchers have managed to synthesise their own version of the natural compound, as it cannot be gathered in large enough quantities from a sponge.

Ian Paterson, a polyketide expert at Cambridge University, said “while these are still early days, it is hoped that a successful anticancer drug emerges from this work and it stimulates further research in marine natural products for drug discovery.”