This prospectus supplement amends and supplements the information in the prospectus dated August 6, 2025, filed as part of the registration statement on Form S-3 (File No. 333-289326). It should be read in conjunction with the ATM Prospectus, with the exception that the information herein amends or supersedes the information contained in the ATM Prospectus. The prospectus supplement is not complete without the ATM Prospectus and may only be delivered or utilized in connection with it and any future amendments or supplements thereto.
The company has entered into an amended and restated sales agreement with Leerink Partners LLC and Cantor Fitzgerald & Co. as sales agents. Under this agreement, the company may issue and sell American Depositary Shares (ADSs), each representing three ordinary shares, with a par value of $0.0001 per share. The maximum aggregate gross offering amount of ADSs that the company may offer and sell has been increased to $400,000,000. As of the date of this prospectus supplement, the company has sold approximately $58.5 million (3,040,000 ADSs) pursuant to the sales agreement, leaving a remaining capacity to sell up to $341,478,784.
The ADSs are listed on the Nasdaq Global Market under the symbol “GPCR.” On May 6, 2026, the last reported sale price of the ADSs was $40.84 per ADS. Sales of the ADSs, together with the underlying ordinary shares, may be made in sales deemed to be an "at-the-market offering" as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended. The sales agents are not required to sell any specific number or dollar amount of securities but will act as sales agents using commercially reasonable efforts consistent with their normal trading and sales practices, on mutually agreed terms among the sales agents and the company. There is no arrangement for funds to be received in any escrow, trust, or similar arrangement.
The sales agents will be entitled to a commission of up to 3.0% of the gross proceeds of any ADSs sold under the amended and restated sales agreement. In connection with the sale of the ADSs on behalf of the company, the sales agents will each be deemed to be an "underwriter" within the meaning of the Securities Act, and their compensation will be deemed to be underwriting commissions or discounts. The company has also agreed to provide indemnification and contributions to the sales agents against certain civil liabilities, including liabilities under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended.
Investing in the ADSs involves a high degree of risk. Investors should review carefully the risks and uncertainties described in the section titled "Risk Factors" beginning on page S-4 of the ATM Prospectus, and under similar headings in the documents that are incorporated by reference into this prospectus supplement and the ATM Prospectus concerning factors investors should consider before investing in the ADSs.
Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities, or passed upon the adequacy or accuracy of the disclosures in this prospectus supplement or the ATM Prospectus. Any representation to the contrary is a criminal offense.
The plan of distribution outlines the terms and conditions of the sales agreement, including the method of sales, the compensation to be paid to the sales agents, and the reporting requirements. The sales agents will offer the ADSs subject to the terms and conditions of the sales agreement on a daily basis or as otherwise agreed upon by the company and the sales agents. The company will designate the maximum number or amount of ADSs to be sold through the sales agents on a daily basis or otherwise determine such maximum number or amount together with the sales agents.
The compensation payable to the sales agents will be an amount of up to 3.0% of the gross proceeds of any ADSs sold through it pursuant to the sales agreement. The company has also agreed to reimburse the sales agents for certain of their expenses in an amount up to $100,000, in addition to certain ongoing disbursements of their legal counsel in the amount up to $25,000 in connection with certain events described in the sales agreement. The company estimates that the total expenses of the offering payable by it, excluding compensation payable to the sales agents under the sales agreement, will be approximately $1.1 million.
Settlement for sales of ADSs will occur, unless the parties agree otherwise, on the first trading day following the date on which any sales were made in return for payment of the net proceeds to the company. There is no arrangement for funds to be received in an escrow, trust, or similar arrangement. The company will report at least biannually the number of ADSs sold through the sales agents under the sales agreement, the net proceeds to the company, and the compensation paid by the company to the sales agents in connection with the sales of ADSs during the relevant period.
In connection with the sale of the ADSs on behalf of the company pursuant to the sales agreement, the sales agents will each be deemed to be an "underwriter" within the meaning of the Securities Act and the compensation paid to each sales agent will be deemed to be underwriting commissions or discounts. The sales agents and/or their affiliates have provided, and may in the future provide, various investment banking and other financial services for the company for which services they have received, and may in the future receive, customary fees.
