For the past few years it was not unusual for a company to ipo within 12 months of raising a seed round in biotech. In my experience, biotech investors are still using 5 year fund horizons etc which make them far far more impatient than tech investors. Tech has had private markets willing to pour billions in to allow companies to stay private for over a decade (airbnb, uber, etc) at huge valuations, while biotechs have been pushed to IPO ASAP