After a strong open to the year, the public markets suffered a six-month drought that led to biotech’s tightest IPO window in years.
2025 began on an encouraging note for biopharma. In addition to the flurry of high-profile deals coming out of the J.P. Morgan Healthcare Conference, January got last year’s IPO class off to a strong start.
Maze Therapeutics announced its intention to go public just over a week into the new year and seemingly opened the floodgates: four other biotechs followed in quick succession, one of which had already established a name for itself as a rising star in obesity and ended the year with a dramatic exit. From all indications, 2025 was shaping up to be a healthy year for IPOs, on track to meet a 2024 prediction from William Blair of 30 public market debuts.
Analysts were cautious about it, but were nevertheless hopeful.
“A robust IPO market is very important for innovative drug developers to access capital to fund later-stage (more expensive) clinical trials and to give earlier investors exit opportunities,” Michael Rachlin, Senior Managing Director at FTI Consulting’s Corporate Finance & Restructuring unit, told BioSpace in an email.
But then a drought hit, and the industry went for six months without any IPO action. Finally, LB Pharma picked things up with a successful offering in August. Overall, eight biotechs completed an IPO last year, as per BioSpace’s tally, a marked decrease from 19 in 2024, 13 in 2023 and 17 in 2022.
In hindsight, this slowdown—despite the sector already having undergone years of correction—makes sense, Rachlin said, noting that since the pandemic boom, investors have grown more judicious with their spending.
“We are likely in/entering a more discerning IPO marketplace where drug innovators with proven, later-stage assets/programs will have the necessary support to go public,” he said. Still, he continued, IPOs will remain a crucial part of a healthy biopharma industry. Overall he was optimistic.
“The development and commercialization of novel and innovative drugs will continue to be a cornerstone of health and wellness, and a robust IPO market will continue to be an important factor for drug innovators to access capital and liquidity,” Rachlin said.
In this piece, BioSpace looks back on what turned out to be a slow year for IPOs.
Maze Therapeutics
Public Market Debut Date: January 31
Proceeds: $140 million
2025 Performance: 10%
Leading 2025’s IPO class is Maze Therapeutics, which announced that it would go public in early January. The biotech, which was looking to raise money for its lead assets being tested for chronic kidney disease (CKD), closed its offering a few weeks later, counting $140 million in proceeds.
Despite being the first company to brave the IPO waters last year, the market’s reception to Maze was largely muted, according to a Jan. 31 report from Reuters. In its debut trading session, the biotech’s shares rose a meager 1% to $16.12 a pop, versus its IPO price of $16. Over the course of the entire year, however, Maze’s value shot up more than 150%.
Much of the excitement around the biotech has been driven by MZE782, an oral blocker of the amino acid transporter SLC6A19, which in September blew past Maze’s own expectations for it. In its first-in-human study, a 960-mg daily dose of MZE782 elicited a 39-fold and 55-fold increase in phenylalanine and glutamine excretion, respectively, over 24 hours—pointing to its potential to treat CKD and phenylketonuria.
Alongside this early-stage readout, Maze announced an oversubscribed private placement worth $150 million, providing capital to further develop its pipeline.
Metsera
Public Market Debut Date: Feb. 5
Proceeds: $316.2 million
2025 Performance: 54%
Arguably the biggest name that went public last year is Metsera, which in January announced its aspirations to trade on the Nasdaq Global Market—just nine months after launching. A few weeks later, Metsera closed its offering with gross proceeds of $316.2 million, higher than its initial target of $250 million.
It isn’t difficult to see why the industry is so excited for Metsera. In the months leading up to its IPO, the New York biotech released a stream of impressive data from its weight loss pipeline. In September 2024, for instance, the company’s long-acting GLP-1 injectable MET-097 lowered body weight by 7.5% at 36 days in a Phase I study. Then, days before announcing its IPO, injectable MET-097 again impressed observers with 11.3% weight reduction at 12 weeks in a mid-stage trial. Metsera planned to put much of its IPO haul behind MET-097 and take the candidate into late-stage development.
Months later, the biotech found itself in the middle of one of pharma’s most public and high-profile—not to mention messiest—bidding wars. After initially agreeing to be acquired by Pfizer for $4.9 billion, Metsera received an unsolicited rival bid from Novo Nordisk, offering $8.5 billion—a proposal that Metsera found attractive enough to call it a “superior” bid.
This set off a chain of increasingly tense exchanges between the three companies, including lawsuits from Pfizer, a provocation by Novo from the White House and a letter from the Federal Trade Commission. Ultimately, Pfizer won the tug-of-war and snagged Metsera for around $9.8 billion.
Sionna Therapeutics
Public Market Debut Date: Feb. 7
Proceeds: $191 million
2025 Performance: 56%
Just days behind Metsera is Sionna Therapeutics, which also launched its Nasdaq bid in mid-January, riding the JPM high. The IPO closed a few weeks later, with a gross haul of $191 million.
Sionna funneled the IPO raise into its cystic fibrosis pipeline, according to its prospectus filed Jan. 17. In cystic fibrosis, mutations to the CFTR protein leave it dysfunctional; Sionna is targeting the protein’s NBD1 domain. Leading Sionna’s pipeline is the NBD1 stabilizer SION-719, which the biotech is testing in combination with standard-of-care. A Phase IIa study for this regimen launched in October 2025.
Sionna is also working on SION-451, another NBD1 stabilizer. The biotech is studying SION-451 as part of two proprietary doublets, for which the first patient in a Phase I trial was dosed in August last year.
Before announcing its IPO, Sionna had raised $182 million during its series C round in March 2024. In June that same year, the company licensed two cystic fibrosis candidates from AbbVie, both of which Sionna is still advancing.
Ascentage Pharma
Public Market Debut Date: Jan. 24
Proceeds: $126.4 million
2025 Performance: 17%
Also in January, China’s Ascentage Pharma sought to debut on the U.S.’ public markets with an IPO to raise funds for its leukemia therapy lisaftoclax, according to an SEC document filed at the time.
The fundraising window was relatively short—Ascentage filed its prospectus on Jan. 21 and closed the IPO on Jan. 28—and proceeds fell below target. The company had initially eyed $133.9 million in net IPO earnings but ultimately brought in only $126.4 million.
Lisaftoclax, an orally available BCL-2 inhibitor, is Ascentage’s second lead asset that’s being developed for several hematological malignancies. In its prospectus, the biotech said that it intended to use $50 to $60 million of its IPO proceeds to advance the drug through approval for chronic lymphocytic leukemia (CLL) in China and prepare for its commercial launch. This came to pass in July 2024, when Chinese regulators greenlit lisaftoclax for CLL and small lymphocytic leukemia (SLL). In the U.S., lisaftoclax is currently in late-stage development for CLL/SLL, multiple myeloma and acute myeloid leukemia.
Ascentage also earmarked a substantial chunk of its IPO haul to advance its second lead asset, the tyrosine kinase inhibitor olverembatinib, in the U.S., where it is in Phase III development for acute lymphocytic leukemia, chronic myeloid leukemia and gastrointestinal stromal tumors
Aardvark Therapeutics
Public Market Debut Date: Feb. 13
Proceeds: $94.2 million
2025 Performance: -6%
Closing out the industry’s early-year streak is Aardvark Therapeutics, which in late January started its journey toward the Nasdaq. Like Metsera, Aardvark was riding the industry-wide wave of optimism around obesity. Unlike its buzzier New York-based counterpart, though, Aardvark’s IPO came up short of its expectations. In mid-February, the California company closed its offering after bringing in just over $94 million, well below the $103 million it had hoped to raise.
As outlined in its SEC prospectus filed Jan. 23, Aardvark said that it would use the IPO earnings to drive the development of lead asset ARD-101, which targets certain receptors in the gut but acts differently than the commonly-exploited GLP-1 pathway. After aligning with the FDA on a late-stage design in October, the biotech dosed its first patient in December in the Phase III HERO trial testing ARD-101 for hyperphagia in Prader-Willi syndrome.
The IPO also helped Aardvark push its other asset ARD-201, which according to the biotech’s website is poised for mid-stage development in obesity. Preclinical data in August last year pointed to a roughly 19% weight reduction in mice after 30 days.
LB Pharma
Public Market Debut Date: Sept. 11
Proceeds: $285 million
2025 Performance: 15%
After the rush in January, biotech’s IPO scene entered a months-long lull, which was broken in late August by LB Pharma. The Pennsylvania-based neuropsychiatric specialist was looking to advance its antipsychotic drug candidate LB-102 into late-stage development for schizophrenia.
The biotech had originally aimed to raise some $263 million, according to its prospectus filed on Sept. 8, but it ended up with an oversized haul of $285 million after selling 19 million shares at $15 a pop.
LB planned to use the bulk of its IPO earnings to advance LB-102, according to its SEC filing at the time, particularly to push it through a Phase III schizophrenia trial and accomplish other studies to support a new drug application. Another chunk of the money would be used to develop the asset in bipolar depression.
A month after its IPO, LB came to the 38th European Congress of Neuropsychopharmacology and presented mid-stage schizophrenia data for LB-102, touting significant cognitive improvements versus placebo. The company is gearing up to launch a late-stage schizophrenia study for the asset in the first quarter of 2026, with topline data in the back half of 2027. A Phase II bipolar depression trial is also slated for the first quarter of 2026.
MapLight Therapeutics
Public Market Debut Date: Oct. 27
Proceeds: $296.3 million
2025 Performance: 10%
Following in LB Pharma’s steps is MapLight Therapeutics, which in mid-September launched its Nasdaq bid in an IPO that aimed to raise $227.3 million, with the possibility of bringing that up to $262.3 million if underwriters exercise all options. Weeks later, the California company announced that it exceeded both of its initial targets, hitting $296.3 million in gross proceeds.
MapLight will use its IPO haul to advance its current programs, according to its Sept. 19 prospectus. The biotech’s pipeline is led by ML-007C-MA, an M1/M4 muscarinic receptor agonist being trialed for Alzheimer’s disease psychosis and schizophrenia. A few days before announcing its IPO, MapLight launched a Phase II study for the asset in Alzheimer’s disease psychosis, which will deliver topline findings in the back half of 2027.
ML-007C-MA is likewise in mid-stage development for schizophrenia, with topline data expected in the latter half of 2026. MapLight is also working on ML-004, a Phase II investigational therapy for autism spectrum disorder.
Months before it went public, MapLight secured $372.5 million in its series D round in July, which at the time the company said will also primarily go toward ML-007C-MA.
Evommune
Public Market Debut Date: Nov. 6
Proceeds: $172.5 million
2025 Performance: -26%
Closing out the 2025 IPO class is Evommune, which launched its offering in late October amid the federal shutdown, looking to raise from $140 million to $160 million.
Because the government was locked down at the time, Evommune relied on Section 8(a) of the Securities Act to see its IPO through to completion. This statute provides that offerings take effect not shorter than 20 days after a filing is made. That came to pass a few days later, with Evommune debuting Nov. 6 on the New York Stock Exchange with $172.5 million in gross proceeds.
The primary purpose of Evommune’s IPO was to “increase our financial flexibility,” according to its Oct. 17 prospectus. The money will also help move along the company’s most advanced asset, EVO756, an oral small-molecule blocker of the MRGPRX2 receptor found on peripheral neurons and immune cells. This mechanism, according to Evommune’s website, addresses inflammatory dysfunction that drives several diseases.
A month before its IPO, Evommune reported Phase II data for EVO756 in chronic inducible urticaria, touting a 93% clinical response rate at four weeks and a rapid onset of improvements. Two Phase IIb readouts in chronic spontaneous urticaria and atopic dermatitis are expected next year.
Editor’s Note: Aktis Oncology also filed for an IPO on December 19. You can read about that announcement here.
