The IPO window for biotech companies appears to be reopening. Last week ended with three biotech companies hitting the public markets, a flurry of activity that helped make April the biggest month for biotech IPOs since March 2021, according to Renaissance Capital.
Hemab Therapeutics and Seaport Therapeutics began negotiations on Friday. These companies followed respiratory-disorder biotech Avalyn Pharma, which began trading Thursday after its own IPO. Earlier this month, obesity drug biotechnology Kailera Therapeutics raised $625 million during its IPO. The four companies together raised $1.5 billion. Investors have shown strong interest in these clinical-stage biotechnologies. Everyone was able to increase their trade size and each saw their stock prices skyrocket during their first day of trading.
Here’s a look at the two new biotech companies that joined Nasdaq on Friday.
Hemab IPO Raises $301M for Crucial Test of Drug for Rare Platelet Disorders
Hemab develops drugs for rare bleeding disorders. The Company’s primary target disease is Glanzmann’s thomboasthenia, a genetic disorder that results in platelet dysfunction. No medication is available for this disease. Although platelet transfusion offers a therapeutic option, it requires patients to visit a transfusion center regularly for life. These treatments may lose their effectiveness if the body develops antibodies against the infused platelets.
Hemab’s lead drug candidate, sutacimig (formerly HMB-001), is a bispecific antibody designed to bind to factor VII circulating in the blood and TREML1, a receptor expressed exclusively on activated platelets. Binding to both targets aims to facilitate clotting. In phase 1/2 testing, Hemab reported a significant reduction in treated annualized bleeding rate, according to IPO filing. Sutacimig’s phase 3 study is expected to begin in the second half of this year. A phase 2 test of sutacimig is underway in a different disorder, factor VII deficiency. Hemab plans to release clinical data from this study late this year or early next year.
Hemab’s next drug candidate, HMB-002, is being developed as a prophylactic treatment for von Willebrand disease, a disease in which patients have low levels of von Willebrand factor (VWF). This clotting protein ensures that platelets adhere to damaged blood vessel walls and serves as a support for another protein called factor VIII, protecting it from premature breakdown and elimination. The antibody drug Hemab targets VWF in its inactive conformation, stabilizing the protein and extending its half-life. Therefore, circulating levels of VWF are expected to increase.
In preliminary Phase 1/2 testing results, Hemab reported a 1.5-fold increase in VWF and Factor VIII. Additional data is expected late this year or early next year. The Company’s pipeline has additional assets in preclinical development. Hemab plans to bring the first of these assets into the clinic in the second half of this year. Data from this drug candidate are expected by mid-2027.
Since its founding in 2020, Hemab has raised $346 million as a private company. The most recent funding was a $157 million Series C round last October led by Sofinnova Partners. Hemab’s largest shareholder is RA Capital Management with an 11.4% stake post-IPO, followed by Novo Holdings’ 9.85% stake.
At the end of 2025, Hemab said its cash and marketable securities totaled $185.5 million. With this capital and IPO proceeds, Hemab plans to spend between $120 million and $130 million on clinical testing of sutacimig in Glanzmann thrombasthenia and factor VII deficiency; $60 million to $70 million for clinical testing of HMB-002 for von Willebrand disease; and $25 million to $35 million for other programs. Hemab expects its capital to last until 2029.
In his preliminary conditions for IPOHemab planned to offer 15 million shares in a range of $16 to $18 each. Hemab finished price 16.75 million shares at the top of the target price range. These stocks trade on Nasdaq under the ticker symbol “COAG”.
Seaport Therapeutics launches on public markets
Seaport Therapeutics has raised $254.9 million to support its portfolio of neuropsychiatric drugs aimed at overcoming the limitations of currently available therapies. Its main indication is major depressive disorder (MDD). The market for depression medications is crowded, but available therapies still leave room for improvement in effectiveness and tolerability.
One of the limitations of orally administered medications is high first-pass metabolism, meaning that much of a drug is metabolized by the liver or intestines before it even enters the body’s circulation. Seaport’s drugs come from its proprietary Glpyh platform that leverages the lymphatic system for delivery, which the company calls “Glyphing.” Its therapies are prodrugs, compounds that transform into active medicine in the body. This approach aims to overcome high first-pass metabolism.
Seaport’s lead drug candidate is GlyphAllo (formerly SPT-300), an oral prodrug of allopregnanolone. This molecule, naturally present in the body, reduces stress. The allopregnanolone analogs developed by Sage Therapeutics became the postpartum depression (PPD) drugs Zulresso and Zurzuvae. Despite the clinical and regulatory success of PPD, Sage was unsuccessful in obtaining FDA approval for these drugs in MDD.
Seaport attempts to succeed where Sage failed. In the IPO Filingthe company says its drug is designed to overcome the bioavailability limitations of allopregnanolone to provide rapid and long-lasting effectiveness. In phase 1 testing, Seaport reported that GlyphAllo achieved therapeutically relevant exposure in the body with oral administration. In phase 2a testing, the study drug demonstrated early proof of concept and a favorable tolerability profile in healthy volunteers. A phase 2b study is underway in patients with MDD; preliminary data is expected in the first half of 2027.
Seaport’s next drug candidate, GlpyhAgo (formerly SPT-320), is an oral Glyphed prodrug of agomelantine, a molecule that has clinical validation for applications in the treatment of anxiety and depression. GlyphAgo is being developed for generalized anxiety disorder. In phase 1 testing, Seaport reported that its drug had higher bioavailability and body exposure than unmodified agomelantine. The study drug was also well tolerated, with no liver-related adverse effects. Seaport plans to launch a Phase 2a trial, GlyphAgo, to evaluate the drug’s potential sleep benefits in patients with anxiety and sleep disorders; preliminary data are expected in early 2028. In parallel, Seaport is planning a Phase 2b study evaluating this drug in generalized anxiety disorder; preliminary data is expected by the end of 2028.
Seaport was created in 2024 by PureTech Health, a company that builds startups around platform technologies. According to the IPO filing, Seaport had raised $325 million in its history prior to the IPO. Its last financing was a $225 million Series B round in 2024 led by Arch Venture Partners and Sofinnova Investments. PureTech is Seaport’s largest shareholder with a 32.9% stake post-IPO, followed by Arch’s 10.3% stake, according to the filing.
At the end of 2025, Seaport said its cash position stood at $233.6 million. Along with the IPO proceeds, Seaport plans to spend approximately $121 million to advance GlyphAllo through Phase 2b testing and Phase 3. An additional $97 million is planned to advance GlyphAgo through Phase 2a testing and preliminary Phase 2b data readout. The company said it expects its capital to last until 2029.
Seaport initially planned to offer 11.8 million shares at a range of $16 to $18 each. The company ended up price 14.16 million stocks at the top of the target price range. These stocks trade on Nasdaq under the ticker symbol “SPTX”.
Photo: Stephanie Keith/Bloomberg, via Getty Images
