The biggest biotech funding rounds in May 2025

The companies Pathos AI, Taysha Gene Therapies, and Abeona Therapeutics bagged the biggest biotech funding rounds overall in May 2025 across private and public funding types. In this article, we break down last month’s private and public fundraising activity, looking at the largest rounds in more detail.

Private biotech funding rounds in May 2025

First, let’s take a look at the private biotech investments in May 2025, breaking them down by value, location, funding type, and therapeutic subsector.

Biggest private biotech funding rounds by value

In May 2025, it was Pathos AI that secured the biggest biotech fundraising of the month, after bagging a very impressive $365 million in a series D round, which also brought its post-money valuation to approximately $1.6 billion. The company said that the proceeds from the financing will support the advancement of its clinical-stage pipeline and continued investment in its proprietary AI Foundation Model that is purpose-built for oncology.

Abeona Therapeutics took second place in the private biotech fundraising standings after it managed to raise $155 million by selling its U.S. Food and Drug Administration (FDA) priority review voucher, which it gained along with the approval for its first commercial product, to an undisclosed buyer. 

Meanwhile, Azafaros wasn’t far behind Abeona, raising €132 million ($146 million) in a series B round, which will enable it to accelerate the development of its lead product nizubaglustat, scheduled to enter phase 3 studies for Niemann-Pick disease type C and GM1/GM2 gangliosidoses later this year.

Private biotech funding rounds by location

When we look at the private investments in May 2025 by location, we can see that, as expected, North American companies were the ones with the most funding rounds (12), bringing in a total of $1.193 billion from those rounds. Meanwhile, Europe wasn’t too far behind in terms of the number of rounds, as companies in the region achieved eight in total, from which $633.3 million was raised. It is also worth noting that the Asia-Pacific region outperformed its April tally (in which it didn’t achieve any major funding rounds), thanks to Singapore-based Nuevocor’s $45 million series B round.

Private biotech funding rounds by funding type

While both series A and series B rounds were the most popular funding types last month, with seven rounds of each taking place, it was series B rounds that brought in the most money with $602 million – versus the $386 million achieved from the same number of series A rounds. Interestingly, series D rounds also managed to bring in more money than series A rounds, despite there being only two series D rounds in total.

Private biotech funding rounds by therapeutic subsector

As we have come to expect, May saw oncology companies come out on top in terms of the number of rounds and the amount of money raised overall, with five rounds and $601.3 million in total. Players focused on neurological conditions came next, with $329 million raised from four rounds.

Public biotech funding rounds in May 2025

Now, let’s check out the public biotech fundraising rounds that occurred in May 2025, breaking them down by value and therapeutic subsector.

Public biotech funding by value

May 2025 saw Taysha Gene Therapies bag the biggest public biotech investment of the month, with the company pricing a $200 million public offering. The company is focused on advancing adeno-associated virus (AAV)-based gene therapies for severe monogenic diseases of the central nervous system and has a lead program in development for Rett syndrome. 

ORIC Pharmaceuticals also raised big, this time from a private placement. The oncology company brought in $125 million and intends to use the money to fund the research and development of its clinical-stage product candidates and research programs, as well as for working capital and general corporate purposes.

Public biotech funding by therapeutic subsector

Mirroring the events of last month’s private biotech funding, oncology companies also performed the best in the public fundraising landscape in May, raising $317.25 million from five rounds. Plus, the subsector of neurological conditions brought in the second-largest amount of money, thanks to Taysha Gene Therapies’ $200 million offering.

Month-to-month comparison of biotech fundraising

Below is a graph showing a month-to-month comparison of private and public biotech fundraising, looking at the total amount of money raised per month in 2025. 

May was the second-lowest month of the year so far for private biotech fundraising, with companies raising $1.8 billion – $453 million less than what was raised in April. Meanwhile, public biotech fundraising bounced back from a very disappointing month in April, in which public companies only managed to raise $202.9 million. Last month, however, $602.25 million was raised in total.