Delhi High Court Says Cancer Detection Methods Cannot Be Patented Under Indian Law
The Delhi High Court has refused to grant patent protection to a Japanese company for a cancer detection technique that uses worms to identify cancer-related smells in human samples.
Justice Tejas Karia upheld the decision of the patent office and ruled that the invention is barred under Section 3(i) of the Patents Act. This provision clearly excludes diagnostic, preventive, or treatment methods for humans or animals from being patented.
The case was filed by Hirotsu Bio Science Inc, a Japanese firm that challenged the rejection of its patent application by the Assistant Controller of Patents and Designs in August 2023. The company had developed an in vitro cancer detection method that relies on the behaviour of a tiny worm called Caenorhabditis elegans. According to the firm, these worms are attracted to cancer-specific odours present in biological samples such as urine, making early detection of multiple cancers possible.
Hirotsu Bio Science argued that its invention was only a preliminary screening tool and not a medical diagnosis. It claimed that proper diagnosis requires clinical judgement by doctors, while its method merely indicated cancer risk and worked completely outside the human body.
The Court rejected this argument. It observed that the method was not limited to pre-screening but amounted to a general diagnostic technique for cancer. Justice Karia also clarified that it does not matter who performs the method. Even if a process is fully automated and not conducted by medical professionals, it would still fall under Section 3(i) if it serves a diagnostic purpose.
The Court concluded that allowing such patents would defeat the intent of the law, as diagnostic methods could otherwise be patented simply by removing human involvement. As a result, the appeal was dismissed, and the patent office’s rejection was upheld.
