The Lilly Ventures, GV and Bluebird Bio-backed cancer immunotherapy developer has raised at least $188m in the past three years.

US-based immuno-oncology therapy developer Gritstone Oncology has filed for an $80m initial public offering that would allow internet and technology group Alphabet and pharmaceutical company Eli Lilly to exit.

Gritstone is developing of cancer immunotherapies focusing on specific types of tumour, harnessing the body’s immune system to destroy cancer cells by helping it recognise their tumour-specific neoantigens.

The IPO proceeds will go to a phase 1/2 clinical trial for a personalised immunotherapy drug candidate known as GRANITE-001, as well…