The biggest biotech funding rounds in October 2025

The companies Kailera Therapeutics, Summit Therapeutics, and Tubulis bagged the biggest biotech funding rounds overall in October 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 October 2025

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

Biggest private biotech funding rounds by value

While many companies raised impressive amounts of money in October 2025, it was Kailera Therapeutics, which exited stealth just over a year ago with $400 million, that came out on top after bagging another $600 million in series B funding in one of the largest private biotech rounds of the year so far. The company said it will use the funds to support the advancement of its obesity portfolio, including a global phase 3 trial of lead candidate KAI-9531, an injectable dual GLP-1/GIP receptor agonist that could potentially challenge Eli Lilly’s Zepbound.

In second place, meanwhile, came German biotech Tubulis, which raised $361 million in series C financing. This marked another feat, as the company stated that the fundraising represented “the largest series C for a European biotechnology company and the largest financing for a private antibody-drug conjugate (ADC) developer globally.” The proceeds from this round will be used to expand the clinical development of TUB-040, Tubulis’ lead ADC candidate, into earlier lines of therapy and additional tumor indications.

And, third in the standings last month was Kardigan, which raised $254 million in series B funding. The company will use the funds from this to advance its pipeline of complementary candidates to target the underlying drivers of specific types of dilated cardiomyopathy, calcific aortic valve stenosis, and acute severe hypertension.

Private biotech funding rounds by location

When looking at the private biotech funding rounds by location last month, we can see that, once again, North American companies achieved the most rounds, with 21 in total, and also raised the most money, bringing in a total of $2.678 billion. European biotechs also performed well, bringing in $814.7 million from eight rounds. However, the Asia-Pacific region had a very disappointing month, with no significant funding rounds occurring in the region.

Private biotech funding rounds by funding type

Although there were more series A rounds (10) than any other type of financing round last month, it was series B rounds that brought in the largest total, with $1.119 billion from just five rounds. This was largely thanks to Kailera Therapeutics’ $600 million megaround.

Private biotech funding rounds by therapeutic subsector

Oncology topped the standings in October 2025 as the therapeutic subsector that attracted the most rounds and the largest amount of investment, bringing in a total of $814.7 million from eight rounds. Meanwhile, metabolic disorder companies came a close second – again, mainly thanks to Kailera Therapeutics’ series B round. And, interestingly, two companies focused specifically on hair loss also raised big last month, suggesting that some investors might be turning their focus toward a gap in a market that has very few treatment options.

Public biotech funding rounds in October 2025

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

Public biotech funding by value

In the public biotech funding landscape last month, Summit Therapeutics came out on top after raising $500 million from a private placement. The company intends to use the net proceeds from this to advance the clinical development of its lead candidate, ivonescimab, as well as for working capital needs and general corporate purposes.

Meanwhile, Apogee Therapeutics came second after raising $345 million in a public offering, which will help it achieve its goal of advancing optimized, novel biologics with potential for best-in-class profiles in the largest inflammatory and immunology (I&I) markets. Spyre Therapeutics then came third after bringing in $316.2 million from a public offering; the company is aiming to create the next generation of inflammatory bowel disease (IBD) and other immune-mediated disease products by combining best-in-class antibody engineering, dose optimization, and rational therapeutic combinations.

Public biotech funding by therapeutic subsector

Oncology players also came out on top in the public fundraising landscape last month, bringing in a total of $744.5 million from five rounds. And, in close second were immunological disease companies, raising $701.2 million from just three rounds.

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.

October 2025 turned out to be a stellar month for biotech investment. In fact, it was the best month of the year so far for both private and public fundraising, as private companies achieved a total of $3.492 billion – the best total of the year across private and public funding – and public companies bagged a total of $2.835 billion. 

The question is: could this finally suggest a turning point for the overall biotech fundraising landscape? Now, we will just have to wait and see how the final two months of the year play out.