Mirum Pharmaceuticals (NASDAQ: MIRM) completes Bluejay buyout with cash, stock and milestones

Rhea-AI Filing Summary

Mirum Pharmaceuticals has completed its acquisition of Bluejay Therapeutics, using a mix of cash, stock and potential future milestone payments. At closing, Mirum acquired Bluejay’s net cash of approximately $56.6 million and agreed to pay Target security holders up to $280.8 million in cash and 4,673,597 shares of Mirum common stock as upfront consideration, plus up to $25.8 million in cash and 522,375 shares as holdback consideration. The deal also includes up to $200 million in cash milestone payments tied to net sales. Following the mergers and related private placements, 59,879,958 shares of Mirum common stock were issued and outstanding as of January 23, 2026. Certain funds affiliated with Frazier Life Sciences, linked to a Mirum director and owning more than five percent of Mirum’s stock, participated as Bluejay security holders and will receive their pro rata share of the merger consideration.

Insights

Biotech M&A and capital structure analyst

Mirum closes a sizable cash-and-stock biotech acquisition and adjusts its share base.

The transaction gives Mirum Pharmaceuticals full ownership of Bluejay Therapeutics through a two-step merger structure. Consideration includes substantial cash payments and several million Mirum shares, plus additional cash milestones of up to $200 million tied to future net sales. Mirum also acquires approximately $56.6 million of Bluejay’s net cash, which offsets a portion of the cash outlay.

The mix of upfront, holdback and milestone components spreads payments over time and links part of the cost to commercial performance. The filing notes that, immediately after the mergers and related private placements, Mirum had 59,879,958 shares outstanding, indicating a larger equity base following the cash-and-stock deal. Entities affiliated with Frazier Life Sciences IX, L.P., associated with a Mirum board member and owning more than five percent of Mirum’s stock, also receive their pro rata share of the merger consideration under the same terms, highlighting an element of related-party participation that investors may review in future disclosures.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): January 23, 2026

Mirum Pharmaceuticals, Inc.

(Exact name of Registrant as Specified in Its Charter)

Delaware		001-38981		83-1281555
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)
989 East Hillsdale Boulevard Suite 300
Foster City, California				94404
(Address of Principal Executive Offices)				(Zip Code)

Registrant’s Telephone Number, Including Area Code: (650) 667-4085

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common stock, par value $0.0001 per share		MIRM		Nasdaq Global Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.01 Completion of Acquisition or Disposition of Assets.

On January 23, 2026, Mirum Pharmaceuticals, Inc. (the “Company”) completed the previously announced acquisition of Bluejay Therapeutics, Inc., a Delaware corporation (“Target”), contemplated by the Agreement and Plan of Merger and Reorganization, dated December 6, 2025 (the “Merger Agreement”), by and among the Company, Bjork Merger Sub I, Inc., a Delaware corporation and a direct wholly owned subsidiary of the Company (“Merger Sub I”), Bjork Merger Sub II, LLC, a Delaware limited liability company and a direct wholly owned subsidiary of the Company (“Merger Sub II”), Target and Fortis Advisors LLC, a Delaware limited liability company, solely in its capacity as the representative, agent and attorney in fact of the Target security holders, pursuant to which, among other things, Merger Sub I merged with and into Target (the “First Merger”), with Target surviving the First Merger and becoming a wholly owned subsidiary of the Company, and, as part of the same overall transaction, Target, as the surviving entity of the First Merger, merged with and into Merger Sub II (the “Second Merger” and collectively with the First Merger, the “Mergers”), with Merger Sub II surviving the Second Merger as a direct wholly owned subsidiary of the Company.

Pursuant to the Merger Agreement, upon the closing of the Mergers, the Company acquired Target’s net cash of approximately $56.6 million and paid or will pay to the holders of Target’s securities up to an aggregate amount of (i) $280.8 million in cash and (ii) 4,673,597 shares of Company common stock, subject to the Company’s receipt of deliverables that are a condition to payment and deduction to satisfy applicable taxes (collectively, the “Upfront Consideration”), and will pay to the holders of Target’s securities in accordance with the Merger Agreement up to an aggregate amount of (a) $25.8 million in cash and (b) 522,375 shares of Company common stock, subject to the Company’s receipt of deliverables that are a condition to payment, deduction to satisfy applicable taxes and certain holdbacks pursuant to the terms and conditions of the Merger Agreement (the “Holdback Consideration”). Pursuant to the Merger Agreement, the Company will pay to the holders of Target’s securities, upon the achievement of certain net sales milestones, milestone payments in an aggregate amount of up to $200 million in cash (together with the Upfront Consideration and the Holdback Consideration, the “Merger Consideration”).

Under the terms of the Merger Agreement, all issued and outstanding Target capital stock (other than any cancelled shares and dissenting shares) and all outstanding Target options (whether vested or unvested) as of immediately prior to the consummation of the Mergers were cancelled in exchange for their applicable pro rata portions of the Merger Consideration as set forth in the Merger Agreement.

Entities affiliated with Frazier Life Sciences IX, L.P., which are associated with a member of the Company’s board of directors and are beneficial owners of more than five percent of the Company’s outstanding capital stock, are Target security holders and received their pro rata portion of the Upfront Consideration and are entitled to receive their pro rata portion of the remainder of the Merger Consideration, including the Holdback Consideration, in accordance with and subject to the terms of the Merger Agreement.

The foregoing description of the Merger Agreement and the Mergers does not purport to be complete and is subject to, and qualified in its entirety by, the full text of the Merger Agreement, which is filed as Exhibit 2.1 to this Current Report on Form 8-K (this “Form 8-K”) and is incorporated herein by reference.

Item 7.01 Regulation FD Disclosure.

On January 26, 2026, the Company issued a press release announcing the consummation of the Mergers, a copy of which is furnished as Exhibit 99.1 to this Form 8-K.

As provided in General Instruction B.2 of Form 8-K, the information in this Item 7.01, including Exhibit 99.1 hereto, shall not be deemed to be “filed” for purposes of, or otherwise subject to the liabilities under, Section 18 of the Securities Exchange Act of 1934, as amended, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act, whether made before or after the date hereof, regardless of any general incorporation language in such filing, except as shall be expressly set forth by specific reference in such a filing.

Item 8.01 Other Events.

Immediately following the consummation of the Mergers, the Company closed the two private placement offerings (the “Private Placements”) pursuant to the two subscription agreements entered into by the Company with the parties thereto on December 7, 2025 and December 18, 2025, as previously announced in the Company’s Current Reports on Form 8-K, filed with the U.S. Securities and Exchange Commission (the “Commission”) on December 8, 2025 and December 19, 2025. As of January 23, 2026, immediately following the consummation of the Mergers and the closing of the Private Placements, 59,879,958 shares of the Company’s common stock are issued and outstanding.

Item 9.01 Financial Statements and Exhibits.

(a) Financial statements of businesses or funds acquired.

The Company intends to file the financial statements required by Item 9.01(a) of Form 8-K by an amendment to this Form 8-K no later than 71 calendar days after the date this Form 8-K is required to be filed.

(b) Pro forma financial information.

The Company intends to file the pro forma financial information required by Item 9.01(b) of Form 8-K by an amendment to this Form 8-K no later than 71 calendar days after the date this Form 8-K is required to be filed.

(d) Exhibits.

Exhibit No.		Description
2.1*		Agreement and Plan of Merger and Reorganization, dated December 6, 2025, by and among Mirum Pharmaceuticals, Inc., Bjork Merger Sub I, Inc., Bjork Merger Sub II, LLC, Bluejay Therapeutics, Inc. and Fortis Advisors LLC (incorporated by reference to Exhibit 2.1 to the Registrant’s Current Report on Form 8-K, filed with the Commission on December 8, 2025)
99.1		Press Release, dated January 26, 2026
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

* Certain portions of this exhibit have been omitted (as marked in brackets) because it is both not material and is the type that the registrant treats as private or confidential. Schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K. The registrant undertakes to furnish supplemental copies of any of the omitted schedules upon request by the Commission.

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 hereunto duly authorized.

				Mirum Pharmaceuticals, Inc.
Date: January 26, 2026				By:		/s/ Christopher Peetz
						Christopher Peetz
						Chief Executive Officer

FAQ

What acquisition did Mirum Pharmaceuticals (MIRM) just complete?

Mirum Pharmaceuticals completed its acquisition of Bluejay Therapeutics, Inc. via a two-step merger, making Bluejay a wholly owned subsidiary and then merging it into a Mirum subsidiary.

How much is Mirum Pharmaceuticals paying for Bluejay Therapeutics?

Mirum agreed to pay Bluejay security holders up to $280.8 million in cash and 4,673,597 Mirum shares as upfront consideration, up to $25.8 million in cash and 522,375 shares as holdback consideration, plus potential $200 million in cash sales-based milestone payments.

What cash did Mirum Pharmaceuticals acquire in the Bluejay deal?

At closing, Mirum acquired Bluejay’s net cash of approximately $56.6 million, which helps offset part of the cash portion of the merger consideration.

How many Mirum Pharmaceuticals shares are now outstanding after the Bluejay merger?

As of January 23, 2026, immediately following the Bluejay mergers and the closing of the related private placements, 59,879,958 shares of Mirum’s common stock were issued and outstanding.

Are there milestone payments in the Mirum–Bluejay merger?

Yes. Mirum will pay Bluejay security holders up to $200 million in cash upon the achievement of specified net sales milestones, in addition to the upfront and holdback consideration.

Did any related parties participate in the Bluejay merger consideration?

Entities affiliated with Frazier Life Sciences IX, L.P., associated with a Mirum board member and owning more than five percent of Mirum’s stock, are Bluejay security holders and receive their pro rata share of the merger consideration.

Will Mirum Pharmaceuticals provide Bluejay financials and pro forma information?

Mirum intends to file the acquired business financial statements and pro forma financial information required by Item 9.01 of Form 8-K by amendment no later than 71 calendar days after the Form 8-K filing deadline.