A Growing Backlog Of Biotechs Haven’t Raised Funding Since The Boom

As biotech startup funding continues to decline, the backlog of funded, private companies that haven’t raised capital in several years has grown quite large.

Per Crunchbase data, more than 200 private U.S. biotechs with $50 million or more in funding to date secured their last reported financing between three and five years ago. The list includes at least 15 biotech unicorns and emerging unicorns that haven’t raised known funding for at least the past three years.

From boom to not

Part of the reason for the backlog of companies with long funding lags is the shift in investor appetite for biotech. During the boom years from 2020 through 2022, startup investors put an average of $40 billion per year into the space — well above current levels.

Some of those were truly huge financings as well. The largest, in early 2022, went to Altos Labs, a San Francisco startup focused on cellular rejuvenation that launched with $3 billion in committed capital.

The biotech IPO market was also quite happening then compared to now. This offered companies yet another avenue to raise capital to fund research and clinical trials.

This year, by contrast, is on track to come in much lower. So far in 2025, only about $17 billion has gone to U.S. biotechs, per Crunchbase data. And of that, roughly half has gone to seed and early stage startups — leaving a smaller portion for late-stage financings for well-funded companies.

High profile companies see funding lag times

A number of the companies that have gone three-plus years without a round were fairly high-profile startups as well. Many are still chugging along, likely helped by having secured large commitments when funding flowed more freely.

For example Insitro, a startup focused on applying machine learning to drug discovery and development, raised $643 million between 2018 and 2021 but hasn’t raised a known round since. This spring, the company announced a 22% workforce cut in a move it said “extends our runway into 2027.”

Agtech unicorn Pivot Bio, which develops microbial nitrogen for farms, also hasn’t secured known financing in more than four years, per Crunchbase data. However, it should be noted that its last round — a $430 million Series D in 2021 — was pretty big. The company has a number of open positions and this spring announced plans to relocate a significant portion of its operations from Berkeley, California, to the Midwest.

Ultima Genomics, developer of a low-cost sequencing platform, is another company that had a big round a few years ago and hasn’t raised since. The Newark, California-based startup launched in May 2022 with $300 in initial funding from backers including Andreessen Horowitz and Khosla Ventures. Of late, it’s been steadily announcing new partnerships.

Collectively, it’s a huge sum of commitments

If we look at all the well-funded biotechs in our query, they’ve collectively raised a tremendous amount of money.

In total, the 204 companies in our sample 1 that haven’t raised for three-plus years previously pulled in $17.9 billion. That’s roughly equivalent to all the venture money that’s gone into biotech this year.

Will investors eventually see some return on investment for these commitments? Despite having some preternatural disposition toward pessimism, I’d say the outlook is reasonably positive.

For one, while the biotech IPO market has been quiet lately, cycles do turn. And when this one does, it looks like there’s a strong pipeline of compelling companies that could pursue listings. An uptick in M&A could also be in the cards.

Of course, not all these well-funded companies will prove successful, and some will likely fold in coming quarters and years. But hopefully, some of those that do make it will succeed in a big way.