Hemab Therapeutics Holdings, Inc.

(a) Recent Sales of Unregistered Equity Securities

Issuances of Share Capital

On March 30, 2026, in connection with the corporate reorganization, we issued 23,343 shares of Series Seed Preferred Stock, 225,866 shares of Series A Preferred Stock, 442,205 shares of Series B Preferred Stock, 512,991 shares of Series C Preferred Stock and 946,000 shares of common stock, to the then-existing shareholders of Hemab ApS in exchange for the same number and class of shares of Hemab ApS. No cash consideration was paid in connection with the corporate reorganization.

No underwriters were involved in the foregoing issuances of securities. The securities described above were issued to investors in reliance upon the exemption from the registration requirements of the Securities Act, as set forth in Section 4(a)(2) under the Securities Act and, in certain cases, Regulation D thereunder relative to transactions by an issuer not involving any public offering, or pursuant to Regulation S thereunder in that offers, sales and issuances were not made to persons in the United States and no directed selling efforts were made in the United States, to the extent an exemption from such registration was required. All purchasers received written disclosures that the securities had not been registered under the Securities Act and that any resale must be made pursuant to a registration statement or an available exemption from such registration.

Equity Grants

From January 4, 2026 to February 16, 2026, Hemab ApS granted to certain of its employees, directors, advisors and consultants warrants to subscribe for an aggregate of 2,294,798 ordinary shares at an exercise price of $6.00.

On March 30, 2026, in connection with the corporate reorganization, each outstanding warrant to subscribe for the purchase of ordinary shares of Hemab ApS was assumed by Hemab Therapeutics Holdings, Inc. and converted into a warrant to purchase the same number of shares of common stock of Hemab Therapeutics Holdings, Inc. As a result, following the corporate reorganization, warrants for the subscription of an aggregate of 4,372,742 shares of our common stock were outstanding. Any warrant exercise price that had been denominated in DKK prior to the corporate reorganization was converted into an exercise price in U.S. dollars at the exchange rate as in effect at the close of business on the business day prior to the corporate reorganization. These warrants become exercisable upon the schedule specified in the applicable warrant agreement.

On April 23, 2026, we granted stock options to purchase an aggregate of 306,900 shares of common stock, at an exercise price per share equal to the initial public offering price, effective upon the pricing of the IPO. These stock options become exercisable upon the schedule specified in the applicable option agreement.

The securities described above were issued pursuant to written compensatory plans or arrangements with our employees, directors, advisors, and consultants, in reliance on the exemption provided by Rule 701 promulgated under the Securities Act, or pursuant to Section 4(a)(2) under the Securities Act, relative to transactions by an issuer not involving any public offering, or pursuant to Regulation S thereunder in that offers, sales and issuances were not made to persons in the United States and no directed selling efforts were made in the United States, relative to transactions by an issuer not involving any public offering, to the extent an exemption from such registration was required. All recipients either received adequate information about our company or had access, through employment or other relationships, to such information.

On May 1, 2026, we filed a registration statement on Form

under the Securities Act to register all of the shares of our common stock subject to outstanding options and warrants and all shares of our common stock otherwise issuable pursuant to our equity compensation plans.

Issuances of Common Stock upon Conversion of Preferred Stock

On May 4, 2026, in connection with the closing of our IPO, all of our outstanding shares of preferred stock were converted into an aggregate of 26,496,910 shares of common stock. The conversion of preferred stock into common stock occurred in accordance with the terms of our certificate of incorporation and did not constitute a sale for purposes of the Securities Act.

(b) Use of Proceeds from IPO

On May 4, 2026, we closed our IPO, pursuant to which we issued and sold 19,262,500 shares of our common stock, including 2,512,500 shares sold by us pursuant to the full exercise of the underwriters’ option to purchase additional shares, at a public offering price of $18.00 per share for aggregate gross proceeds of approximately $346.7 million.

All of the shares of common stock issued and sold in the IPO were registered under the Securities Act pursuant to a Registration Statement on Form

(File

No. 333-294989),

which was declared effective by the SEC on April 30, 2026. Goldman Sachs & Co. LLC, Jefferies LLC, and Evercore Group L.L.C. acted as joint book-running managers for the IPO, and Wedbush Securities Inc. acted as lead manager for the IPO. The offering commenced on April 30, 2026 and did not terminate until the sale of all of the shares offered.

We received aggregate net proceeds from the IPO of approximately $317.2 million, after deducting underwriting discounts and commissions and other offering expenses payable by us. None of the underwriting discounts and commissions or offering expenses were paid directly or indirectly to any of our directors or officers or their associates or to persons owning ten percent or more of any class of our equity securities or to any of our affiliates.

As of March 31, 2026, we had not used any of the net proceeds from the IPO because the IPO closed on May 4, 2026. There has been no material change in our planned use of proceeds from the IPO as described in the final prospectus filed pursuant to Rule 424(b)(4) under the Securities Act with the SEC on May 1, 2026.