Delhi HC refuses patent for cancer detection method, cites diagnostic bar

Delhi High Court upheld the patent office's rejection of a Japanese firm's cancer detection method using worms, ruling it barred under patent law as a diagnostic process

The Delhi High Court has declined to interfere with the patent office’s rejection of a patent application filed by Japanese company Hirotsu Bio Science Inc for a cancer detection technique based on a worm’s reaction to odours from human biological samples.

 

Justice Tejas Karia on Saturday upheld the August 2023 order of the assistant controller of patents and designs, holding that the claimed invention is barred from patent protection under Section 3(i) of the Patents Act, 1970, which excludes diagnostic, therapeutic and treatment methods for humans or animals.

 

The court found that the method sought to be patented was not confined to a preliminary or screening-stage assessment but amounted to a general diagnostic process for detecting cancer. On that basis, it concluded that the application squarely attracted the statutory exclusion.

 

 

The patent application related to an in vitro method for cancer detection using the behaviour of the nematode Caenorhabditis elegans. The company claimed that the worms are drawn towards cancer-specific odours present in samples such as urine, enabling early identification of various forms of cancer.

 

Hirotsu argued that its invention did not constitute a diagnostic method within the meaning of the Act, as it merely indicated cancer risk and did not involve clinical judgment or treatment by medical professionals. The process, it said, operated entirely outside the human body and therefore fell outside the mischief of Section 3(i).

 

The High Court rejected this line of reasoning, holding that the applicability of the exclusion does not depend on who performs the method. The court observed that limiting Section 3(i) only to procedures carried out by medical practitioners would defeat its purpose, as even fully automated diagnostic methods would then become patentable.

 

Finding no legal infirmity in the patent office’s reasoning, the court dismissed the appeal and affirmed the refusal of the patent application.