Seaport Therapeutics $254.9M IPO priced; PureTech (PRTC) retains stake

Rhea-AI Filing Summary

PureTech Health plc reports that its founded entity, Seaport Therapeutics, has priced an upsized initial public offering of 14,160,000 shares of common stock at $18.00 per share, at the top of the target range, for expected gross proceeds of $254.9 million before fees and expenses. Underwriters have a 30-day option to buy an additional 2,124,000 shares at the IPO price, less underwriting discounts and commissions. The shares are expected to begin trading on the Nasdaq Global Select Market on May 1, 2026 under the symbol “SPTX,” with closing expected on May 4, 2026 subject to customary conditions. After the offering closes, PureTech expects to hold 16,685,013 Seaport common shares.

Insights

Equity capital markets analyst

PureTech’s founded entity Seaport raises $254.9M in IPO.

Seaport Therapeutics, a PureTech-founded neuropsychiatry company, has priced an upsized IPO of 14,160,000 shares at $18.00 per share, targeting gross proceeds of $254.9 million before underwriting discounts, commissions and expenses.

The deal includes a 30-day underwriter option for 2,124,000 additional shares, which could further expand proceeds if exercised. Trading on the Nasdaq Global Select Market under ticker SPTX is expected to start on May 1, 2026, with closing on May 4, 2026, subject to customary conditions.

Following completion, PureTech Health expects to hold 16,685,013 Seaport shares, maintaining a meaningful ownership position. Future disclosures in company filings may provide more detail on how this stake contributes to PureTech’s portfolio strategy and potential value realization.

Key Figures

IPO shares offered: 14,160,000 shares IPO price: $18.00 per share Expected gross proceeds: $254.9 million +5 more

8 metrics

IPO shares offered 14,160,000 shares Upsized initial public offering of Seaport Therapeutics common stock

IPO price $18.00 per share Price to the public, at the top of the target range

Expected gross proceeds $254.9 million Gross proceeds to Seaport from the offering before fees and expenses

Underwriters’ option 2,124,000 shares 30-day option to buy additional shares at the IPO price

PureTech post-IPO holding 16,685,013 shares Seaport common stock expected to be held by PureTech upon closing

Nasdaq ticker SPTX Seaport Therapeutics trading symbol on Nasdaq Global Select Market

Trading start date May 1, 2026 Expected first trading day for Seaport Therapeutics on Nasdaq

Expected closing date May 4, 2026 Offering closing subject to satisfaction of customary conditions

Key Terms

upsized initial public offering, gross proceeds, Nasdaq Global Select Market, joint book-running managers, +2 more

6 terms

upsized initial public offering financial

"has announced the pricing of its upsized initial public offering of 14,160,000 shares"

gross proceeds financial

"The gross proceeds to Seaport from the offering, before deducting the underwriting discounts"

The total amount of cash a company receives from a financing event or sale before any fees, expenses, taxes or deductions are taken out. Investors watch gross proceeds because it shows the raw scale of new capital being raised—think of it as the paycheck amount before withholdings—which helps assess how much funding is available for operations, growth, debt payoff or how much shareholder dilution might occur once costs are removed.

Nasdaq Global Select Market market

"The shares are expected to begin trading on the Nasdaq Global Select Market on May 1, 2026"

A Nasdaq Global Select Market listing is the highest tier of stocks on the Nasdaq exchange, reserved for companies that meet the strictest financial, reporting and governance standards. For investors, it acts like a premium quality label—signaling larger, more transparent and better-governed companies that tend to offer greater liquidity and lower perceived risk compared with lower-tier listings, making it easier to buy, sell and evaluate shares.

joint book-running managers financial

"Goldman Sachs & Co. LLC, J.P. Morgan, Leerink Partners, Citigroup, and Stifel are acting as joint book-running managers"

Joint book-running managers are the lead banks or financial firms responsible for organizing and overseeing the sale of a large financial offering, such as a company’s stock or bonds. They coordinate efforts to set the price, attract investors, and ensure the offering is successful. Their role is important to investors because they help ensure the offering is well-managed, properly priced, and accessible to a wide range of buyers.

registration statement regulatory

"A registration statement relating to this offering has been filed with the Securities and Exchange Commission"

A registration statement is a formal document that companies file with a government agency to offer new shares of stock to the public. It provides essential information about the company's finances, operations, and risks, helping investors make informed decisions. Think of it as a detailed product description that ensures transparency and trust before buying into a company.

forward-looking statements regulatory

"This press release includes certain disclosures that contain “forward-looking statements,” including, without limitation, statements regarding Seaport Therapeutics’ expectations"

Forward-looking statements are predictions or plans that companies share about what they expect to happen in the future, like estimating sales or profits. They matter because they help investors understand a company's outlook, but since they are based on guesses and assumptions, they can sometimes be wrong.

Form 6-K: How Foreign Companies Report to the SEC →

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Private Issuer

Pursuant to Rule 13a-16 or 15d-16

under the Securities Exchange Act of 1934

For the month of May, 2026

Commission File Number 001-39670

PURETECH HEALTH PLC

(Translation of registrant’s name into English)

6 Tide Street, Suite 400

Boston, Massachusetts 02210

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F ☒   Form 40-F ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ☐

INFORMATION CONTAINED IN THIS REPORT ON FORM 6-K

On May 1, 2026, PureTech Health plc (LSE: PRTC, Nasdaq: PRTC) (the “Company”) issued a press release titled “PureTech Founded Entity Seaport Therapeutics Announces Pricing of Upsized Initial Public Offering.”

The press release is furnished herewith as Exhibit 99.1 and is incorporated by reference herein.

Exhibits

99.1 Press Release of PureTech Health plc, dated May 1, 2026, titled “PureTech Founded Entity Seaport Therapeutics Announces Pricing of Upsized Initial Public Offering.”

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

				PURETECH HEALTH PLC
Date: May 1, 2026				By:		/s/ Robert Lyne
						Name: Robert Lyne
						Title:  Chief Executive Officer

Exhibit 99.1

1 May 2026

PureTech Health plc

PureTech Founded Entity Seaport Therapeutics Announces Pricing of Upsized Initial Public Offering

PureTech Health plc (Nasdaq: PRTC, LSE: PRTC) (“PureTech” or the “Company”), a hub-and-spoke biotherapeutics company dedicated to giving life to science and transforming innovation into value, today announced that its Founded Entity, Seaport Therapeutics, Inc. (“Seaport”), has announced the pricing of its upsized initial public offering of 14,160,000 shares of its common stock at a price to the public of $18.00 per share, at the top of the target range. The gross proceeds to Seaport from the offering, before deducting the underwriting discounts and commissions and offering expenses, are expected to be $254.9 million. All of the shares are being offered by Seaport. In addition, Seaport has granted the underwriters a 30-day option to buy an additional 2,124,000 shares of its common stock at the initial public offering price, less underwriting discounts and commissions.

The shares are expected to begin trading on the Nasdaq Global Select Market on May 1, 2026 under the ticker symbol “SPTX.” The offering is expected to close on May 4, 2026 subject to the satisfaction of customary closing conditions.

Upon the closing of the offering, PureTech will hold 16,685,013 shares of Seaport common stock.

The full text of the announcement from Seaport is as follows:

Seaport Therapeutics Announces Pricing of Upsized Initial Public Offering

BOSTON, April 30, 2026 – Seaport Therapeutics, Inc., (Nasdaq: SPTX) (“Seaport” or the “Company”), a clinical-stage therapeutics company that is inventing and developing neuropsychiatric medicines, today announced the pricing of its upsized initial public offering of 14,160,000 shares of its common stock at a price to the public of $18.00 per share, at the top of the target range. The gross proceeds to Seaport Therapeutics from the offering, before deducting the underwriting discounts and commissions and offering expenses, are expected to be $254.9 million. All of the shares are being offered by Seaport Therapeutics. In addition, Seaport Therapeutics has granted the underwriters a 30-day option to buy an additional 2,124,000 shares of its common stock at the initial public offering price, less underwriting discounts and commissions.

The shares are expected to begin trading on the Nasdaq Global Select Market on May 1, 2026 under the ticker symbol “SPTX.” The offering is expected to close on May 4, 2026 subject to the satisfaction of customary closing conditions.

Goldman Sachs & Co. LLC, J.P. Morgan, Leerink Partners, Citigroup, and Stifel are acting as joint book-running managers for the offering.

A registration statement relating to this offering has been filed with the Securities and Exchange Commission and was declared effective on April 30, 2026. The offering is being made only by means of a prospectus. Copies of the final prospectus, when available, may be obtained from: Goldman Sachs & Co. LLC, Attention: Prospectus Department, 200 West Street, New York, NY 10282, by telephone at 1-866-471-2526, or by emailing prospectus-ny@ny.email.gs.com; J.P. Morgan Securities LLC, c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, by telephone at 866-803-9204, or

by email at prospectus-eq_fi@jpmorganchase.com; Leerink Partners LLC, Attention: Syndicate Department, 53 State Street, 40th Floor, Boston, MA 02109, by telephone at (800) 808-7525 ext. 6105, or by email at syndicate@leerink.com; Citigroup Global Markets Inc., c/o Broadridge Financial Solutions, 1155 Long Island Avenue, Edgewood, NY 11717, by telephone at 1-800-831-9146; or Stifel, Nicolaus & Company, Incorporated, Attention: Syndicate, One Montgomery Street, Suite 3700, San Francisco, CA 94104, by telephone at (415) 364-2720 or by emailing syndprospectus@stifel.com.

This press release shall not constitute an offer to sell or the solicitation of an offer to buy these securities, nor shall there be any sale of these securities in any state or jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

About Seaport Therapeutics

Seaport Therapeutics is a clinical-stage therapeutics company focused on inventing and developing new medicines for patients with depression, anxiety, and other debilitating neuropsychiatric disorders. Through its differentiated approach, the Company identifies clinically validated mechanisms with established efficacy and safety which had historically been limited by high first-pass metabolism, low bioavailability, and/or side effects. Seaport applies its proprietary Glyph^TM platform to overcome those limitations and invent innovative oral therapies. With an experienced team of industry leaders, Seaport has a proven track record in neuropsychiatry drug discovery and development and delivering successful business outcomes. Seaport aims to develop novel, leading treatment options that will make a significant impact for patients and their families.

Cautionary Note Regarding Forward-Looking Statements

This press release includes certain disclosures that contain “forward-looking statements,” including, without limitation, statements regarding Seaport Therapeutics’ expectations regarding the commencement of trading of its shares on the Nasdaq Global Select Market, the completion and timing of the closing of the offering and the anticipated gross proceeds from the offering. Forward-looking statements are based on Seaport Therapeutics’ current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict. Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties related to the satisfaction of customary closing conditions and the completion of the offering, and the risks inherent in biopharmaceutical product development. These and other risks and uncertainties are described more fully in the section titled “Risk Factors” section of the registration statement filed with the Securities and Exchange Commission. Forward-looking statements contained in this announcement are made as of this date, and Seaport Therapeutics undertakes no duty to update such information except as required under applicable law. Readers should not rely upon the information on this page as current or accurate after its publication date.

About PureTech Health

PureTech Health is a hub-and-spoke biotherapeutics company dedicated to giving life to science and transforming innovation into value. We do this through a proven, capital-efficient R&D model focused on opportunities with validated pharmacology and untapped potential to address significant patient needs. This strategy has produced dozens of therapeutic candidates, including three that have received U.S. FDA approval. By identifying, shaping, and de-risking these high-conviction assets and scaling them through dedicated structures backed by external capital, we accelerate their path to patients while creating sustainable value for shareholders.

For more information, visit www.puretechhealth.com or connect with us on LinkedIn and X (formerly Twitter) @puretechh.

Cautionary Note Regarding Forward-Looking Statements

This press release contains statements that are or may be forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation, statements regarding Seaport Therapeutics’ expectations regarding the commencement of trading of its shares on the Nasdaq Global Select Market, the completion and timing of the closing of the offering and the anticipated gross proceeds from the offering. The forward-looking statements are based on current expectations and are subject to known and unknown risks, uncertainties and other important factors that could cause actual results, performance and achievements to differ materially from current expectations, including, but not limited to, those risks, uncertainties and other important factors described under the caption “Risk Factors” in our Annual Report on Form 20-F for the year ended December 31, 2025, filed with the SEC and in our other regulatory filings. These forward-looking statements are based on assumptions regarding the present and future business strategies of the Company and the environment in which it will operate in the future. Each forward-looking statement speaks only as at the date of this press release. Except as required by law and regulatory requirements, we disclaim any obligation to update or revise these forward-looking statements, whether as a result of new information, future events or otherwise.

FAQ

What does PureTech Health’s 6-K reveal about Seaport Therapeutics’ IPO?

The 6-K shows PureTech’s founded entity Seaport Therapeutics priced an upsized IPO of 14,160,000 shares at $18.00 per share. Expected gross proceeds are $254.9 million before underwriting discounts, commissions, and expenses, with all shares sold by Seaport itself.

How large is Seaport Therapeutics’ IPO mentioned by PureTech Health (PRTC)?

Seaport Therapeutics’ IPO comprises 14,160,000 common shares priced at $18.00 each, for expected gross proceeds of $254.9 million. An additional 2,124,000 shares may be sold under a 30-day underwriters’ option at the same price, less underwriting discounts and commissions.

When will Seaport Therapeutics trade on Nasdaq and under what ticker?

Seaport Therapeutics’ common stock is expected to begin trading on the Nasdaq Global Select Market on May 1, 2026. The shares will trade under the ticker symbol “SPTX,” as disclosed in the PureTech Health Form 6-K and accompanying press release text.

What ownership in Seaport Therapeutics will PureTech Health retain after the IPO?

Upon closing of the offering, PureTech Health expects to hold 16,685,013 shares of Seaport Therapeutics common stock. This post-offering stake reflects PureTech’s continuing ownership in its founded entity following Seaport’s upsized initial public offering on Nasdaq.

Who are the joint book-running managers for Seaport Therapeutics’ IPO?

The IPO’s joint book-running managers are Goldman Sachs & Co. LLC, J.P. Morgan, Leerink Partners, Citigroup, and Stifel. These underwriters are responsible for marketing and distributing Seaport Therapeutics’ shares, including managing the 30-day option for additional shares.

Filing Exhibits & Attachments

1 document

Press Releases

• EX-99.1 EX-99.1 12.8 KB