Mirum prices $600M 2032 zero-coupon convertible notes
Mirum Pharmaceuticals issued $690.0 million of 0.00% Convertible Senior Notes due 2032 in a private 144A placement to qualified institutional buyers, including a $90.0 million overallotment option that was fully exercised.
Rhea-AI Filing Summary
Mirum Pharmaceuticals issued $690.0 million of 0.00% Convertible Senior Notes due 2032 in a private 144A placement to qualified institutional buyers, including a $90.0 million overallotment option that was fully exercised. The company estimates net proceeds of approximately $671.6 million after discounts and expenses. The notes are senior unsecured, carry no regular interest, and mature on June 1, 2032, with multiple triggers that allow conversion into cash, stock, or a mix, at Mirum’s election. The initial conversion rate is 7.1971 shares per $1,000, implying a conversion price of about $138.94 per share, a 30% premium to the $106.88 stock price on May 12, 2026, and could rise to a maximum rate of 9.3562 shares upon certain events. Mirum plans to use about $475.0 million of proceeds plus 3,220,529 shares to exchange approximately $237.2 million principal of its 4.00% Convertible Senior Notes due 2029, with the balance earmarked for general corporate purposes, including potential acquisitions.
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Insights
Mirum raises sizable zero-coupon convertible debt and refinances 2029 notes.
Mirum Pharmaceuticals is issuing $690.0 million of 0.00% Convertible Senior Notes due 2032, with an initial conversion price of about $138.94 per share, a 30.0% premium to the $106.88 stock price on May 12, 2026. The notes are senior, unsecured and carry no regular interest, limiting ongoing cash interest expense.
The company estimates net proceeds of about $671.6 million and expects to deploy roughly $475.0 million plus 3,220,529 shares to exchange $237.2 million principal of its 4.00% Convertible Senior Notes due 2029. This shifts debt toward a longer-dated, zero-coupon instrument while adding some equity issuance and potential future dilution from conversion.
Initially, a maximum of 6,455,778 shares may be issued upon conversion at the stated maximum conversion rate, and Mirum retains redemption and repurchase mechanisms tied to stock price and “fundamental change” events. Actual impact on leverage and equity mix will depend on conversion behavior, future stock performance and the extent of completed note exchange transactions disclosed in subsequent filings.
8-K Event Classification
Key Figures
Key Terms
Convertible Senior Notes financial
Rule 144A regulatory
Make-Whole Fundamental Change financial
Fundamental Change financial
Events of Default regulatory
qualified institutional buyers financial
FAQ
What type and size of financing did Mirum Pharmaceuticals (MIRM) complete?
What net proceeds does Mirum Pharmaceuticals (MIRM) expect from the 2032 convertible notes?
How will Mirum Pharmaceuticals (MIRM) use the proceeds from the 2032 notes?
What happens to Mirum Pharmaceuticals’ 4.00% convertible notes due 2029 under this transaction?
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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
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FORM
CURRENT REPORT
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| Item 1.01 | Entry Into a Material Definitive Agreement. |
Indenture and Notes
On May 15, 2026, Mirum Pharmaceuticals, Inc. (the “Company”) issued $690.0 million aggregate principal amount of its 0.00% Convertible Senior Notes due 2032 (the “Notes”), which includes the full exercise of the initial purchasers’ option to purchase up to an additional $90.0 million aggregate principal amount of Notes. The Notes were issued pursuant to, and are governed by, an indenture (the “Indenture”), dated as of May 15, 2026, between the Company and U.S. Bank Trust Company, National Association, as trustee (the “Trustee”).
The Notes are the Company’s senior, unsecured obligations. The Notes will not bear regular interest, and the principal amount of the notes will not accrete. The Notes will mature on June 1, 2032, unless earlier converted, redeemed or repurchased.
Noteholders may convert all or any portion of their Notes at their option only in the following circumstances: (i) during any calendar quarter (and only during such calendar quarter) commencing after the calendar quarter ending on September 30, 2026, if the last reported sale price per share of the Company’s common stock, $0.0001 par value per share (the “common stock”), exceeds 130% of the conversion price for each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter; (ii) during the five consecutive business days immediately after any 10 consecutive trading day period (such 10 consecutive trading day period, the “measurement period”) if the trading price per $1,000 principal amount of Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price per share of the Company’s common stock on such trading day and the conversion rate on such trading day; (iii) upon the occurrence of certain corporate events or distributions on the Company’s common stock, as described in the Indenture; (iv) if the Company calls such Notes for redemption; and (v) at any time from, and including, March 1, 2032 until the close of business on the second scheduled trading day immediately before the maturity date. The Company will settle conversions by paying or delivering, as applicable, cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock, at its election, based on the applicable conversion rate(s).
The initial conversion rate is 7.1971 shares of common stock per $1,000 principal amount of Notes, which represents an initial conversion price of approximately $138.94 per share, and is subject to adjustment upon the occurrence of certain events as described in the Indenture. If a “Make-Whole Fundamental Change” (as defined in the Indenture) occurs, then the Company will in certain circumstances increase the conversion rate for a specified period of time.
The Company may not redeem the Notes at its option at any time before June 6, 2029. The Notes will be redeemable, in whole or in part (subject to the “Partial Redemption Limitation” (as defined in the Indenture)), at the Company’s option at any time, and from time to time, on a redemption date on or after June 6, 2029 and, in the case of any partial redemption, on or before the 30th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the Notes to be redeemed, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the redemption date, but only if (i) the Notes are “Freely Tradeable” (as defined in the Indenture) as of the date the Company sends the related redemption notice and all accrued and unpaid additional interest, if any, has been paid in full as of the first interest payment date occurring on or before the date the Company sends such notice; and (ii) the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price on (1) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date the Company sends such redemption notice; and (2) the trading day immediately before the date the Company sends such notice. In addition, calling any Note for redemption will constitute a Make-Whole Fundamental Change with respect to that Note, in which case the conversion rate applicable to the conversion of that Note will be increased in certain circumstances if it is converted after it is called for redemption and on or before the second business day immediately before the related redemption date. Pursuant to the Partial Redemption Limitation, the Company may not elect to redeem less than all of the outstanding Notes unless at least $75.0 million aggregate principal amount of Notes are outstanding and not subject to redemption as of the time the Company sends the related redemption notice.
If a “Fundamental Change” (as defined in the Indenture) occurs, then, subject to limited exceptions as described in the Indenture, noteholders may require the Company to repurchase their Notes at a cash repurchase price equal to the principal amount of the Notes to be repurchased, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the fundamental change repurchase date. The definition of Fundamental Change includes certain business combination transactions involving the Company and certain de-listing events with respect to the Company’s common stock.
The Notes have customary provisions relating to the occurrence of “Events of Default” (as defined in the Indenture), which include the following: (i) certain payment defaults on the Notes (which, in the case of a default in the payment of interest, if any, on the Notes, will be subject to a 30-day cure period); (ii) the Company’s failure to send certain notices under the Indenture within specified periods of time; (iii) the Company’s failure to comply with certain covenants in the Indenture relating to the Company’s ability to consolidate with or merge with or into, or sell, lease or otherwise transfer, in one transaction or a series of transactions, all or substantially all of the assets of the Company and its subsidiaries, taken as a whole, to another person; (iv) the Company’s failure to convert a Note in accordance with the Indenture upon the exercise of the conversion right with respect thereto, if such default is not cured within five business days after its occurrence; (v) a default by the Company in its other obligations or agreements under the Indenture or the Notes if such default is not cured or waived within 60 days after notice is given in accordance with the Indenture; (vi) certain defaults by the Company or any of its “significant subsidiaries” (as defined in the Indenture) with respect to indebtedness for borrowed money with a principal amount of at least $75,000,000; and (vii) certain events of bankruptcy, insolvency and reorganization involving the Company or any of its significant subsidiaries.
If an Event of Default involving bankruptcy, insolvency or reorganization events with respect to the Company (and not solely with respect to a significant subsidiary of the Company) occurs, then the principal amount of, and all accrued and unpaid interest, if any, on, all of the Notes then outstanding will immediately become due and payable without any further action or notice by any person. If any other Event of Default occurs and is continuing, then, the Trustee, by notice to the Company, or noteholders of at least 25% of the aggregate principal amount of Notes then outstanding, by notice to the Company and the Trustee, may declare the principal amount of, and all accrued and unpaid interest, if any, on, all of the Notes then outstanding to become due and payable immediately. However, notwithstanding the foregoing, the Company may elect, at its option, that the sole remedy for an Event of Default relating to certain failures by the Company to comply with certain reporting covenants in the Indenture consists exclusively of the right of the noteholders to receive special interest on the Notes for up to 365 days at a specified rate per annum not exceeding 0.50% on the principal amount of the Notes.
The Company estimates that the net proceeds from the offering of the Notes will be approximately $671.6 million after deducting the initial purchasers’ discounts and commissions and estimated offering expenses payable by the Company. The Company expects to use a portion of the net proceeds from the offering of the Notes to pay the cash portion of the consideration in the Note Exchange Transactions as described below. The Company expects to use the remainder of the net proceeds of this offering for general corporate purposes, which may include the acquisition of complementary products, technologies, intellectual property or businesses as part of its growth strategy.
The Company expects to use approximately $475.0 million of the net proceeds from the offering of the Notes and expects to issue 3,220,529 shares of its common stock in exchange for approximately $237.2 million aggregate principal amount of the Company’s 4.00% Convertible Senior Notes due 2029 in privately negotiated transactions (the “Note Exchange Transactions”) entered into concurrently with the pricing of the offering of the Notes.
The above description of the Indenture and the Notes is a summary and is not complete. A copy of the Indenture and the form of the certificate representing the Notes are filed as Exhibits 4.1 and 4.2, respectively, to this Current Report on Form 8-K, and the above summary is qualified by reference to the terms of the Indenture and the Notes set forth in such Exhibits.
| Item 2.03 | Creation of a Direct Financial Obligation or an Off-Balance Sheet Arrangement. |
The disclosure set forth in Item 1.01 above is incorporated by reference into this Item 2.03.
| Item 3.02 | Unregistered Sales of Equity Securities. |
The disclosure set forth in Item 1.01 above is incorporated by reference into this Item 3.02. The Notes were issued to the initial purchasers in reliance upon Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”), in transactions not involving any public offering. The Notes were resold by the initial purchasers to persons whom the initial purchasers reasonably believe are “qualified institutional buyers,” as defined in, and in accordance with, Rule 144A under the Securities Act. The Company relied on these exemptions from registration based in part on representations made by the initial purchasers in the purchase agreement dated May 12, 2026 by and among the Company and the initial purchasers.
The Notes and the shares of common stock issuable upon conversion of the Notes, if any, have not been registered under the Securities Act and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements.
To the extent that any shares of common stock are issued upon conversion of the Notes, they will be issued in transactions anticipated to be exempt from registration under the Securities Act by virtue of Section 3(a)(9) thereof because no commission or other remuneration is expected to be paid in connection with conversion of the Notes and any resulting issuance of shares of common stock. Initially, a maximum of 6,455,778 shares of the Company’s common stock may be issued upon conversion of the Notes and based on the initial maximum conversion rate of 9.3562 shares of common stock per $1,000 principal amount of Notes, which is subject to customary anti-dilution adjustment provisions.
The 3,220,529 shares of the common stock being issued in connection with the Note Exchange Transactions are being issued in reliance on the exemption from the registration requirements provided by Section 4(a)(2) of the Securities Act.
| Item 8.01 | Other Events. |
On May 12, 2026, the Company issued a press release announcing the launch of the offering of the Notes. On May 12, 2026, the Company issued a press release announcing the pricing of the offering of the Notes. Copies of the press releases are filed as Exhibits 99.1 and 99.2 to this Current Report on Form 8-K and are incorporated by reference herein.
Forward-Looking Statements
This Current Report on Form 8-K includes forward-looking statements within the meaning of Section 27A of the Securities Act and Section 21E of the Securities Exchange Act of 1934, as amended, including statements concerning the use of proceeds from the offering of the Notes. Forward-looking statements represent the Company’s current expectations regarding future events and are subject to known and unknown risks and uncertainties that could cause actual results to differ materially from those implied by the forward-looking statements. Among those risks and uncertainties are market conditions, the risks relating to the Company’s business, and the risks described in the Company’s Annual Report on Form 10-K for the period ended December 31, 2025, filed with the SEC on February 25, 2026 and Quarterly Report on Form 10-Q for the period ended March 31, 2026, filed with the SEC on May 6, 2026, and the future quarterly and current reports that the Company files with the SEC. The forward-looking statements included in this Current Report on Form 8-K speak only as of the date of this Current Report on Form 8-K, and the Company does not undertake to update the statements included in this Current Report on Form 8-K for subsequent developments, except as may be required by law.
| Item 9.01 | Financial Statements and Exhibits. |
(d) Exhibits.
| Exhibit |
Description | |
| 4.1 | Indenture, dated as of May 15, 2026, between Mirum Pharmaceuticals, Inc. and U.S. Bank Trust Company, National Association, as trustee. | |
| 4.2 | Form of Note, representing the Company’s 0.00% Convertible Senior Notes due 2032 (included as Exhibit A to the Indenture filed as Exhibit 4.1). | |
| 99.1 | Press Release issued by the Company on May 12, 2026. | |
| 99.2 | Press Release issued by the Company on May 12, 2026. | |
| 104 | Cover page interactive data file (embedded within the inline XBRL document). | |
SIGNATURE
Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Company has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
| Mirum Pharmaceuticals, Inc. | ||||||
| Date: May 18, 2026 | By: | /s/ Christopher Peetz | ||||
| Christopher Peetz | ||||||
| Chief Executive Officer | ||||||
Exhibit 99.1
Mirum Pharmaceuticals Announces Proposed Convertible Senior Notes Offering
FOSTER CITY, Calif.—May 12, 2026—Mirum Pharmaceuticals, Inc. (“Mirum”) (Nasdaq: MIRM), a leading rare disease company, today announced its intention to offer, subject to market conditions and other factors, $600.0 million aggregate principal amount of convertible senior notes due 2032 (the “notes”) in a private placement (the “offering”) to persons reasonably believed to be qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). Mirum also expects to grant the initial purchasers of the notes an option to purchase, for settlement within a period of 13 days from, and including, the date the notes are first issued, up to an additional $90.0 million aggregate principal amount of notes.
The notes will be senior, unsecured obligations of Mirum and will accrue interest payable semi-annually in arrears. The notes will mature on June 1, 2032, unless earlier converted, redeemed or repurchased. Noteholders will have the right to convert their notes in certain circumstances and during specified periods. Mirum will settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at Mirum’s election. The interest rate, initial conversion rate, repurchase or redemption rights and other terms of the notes will be determined at the time of pricing of the offering.
Mirum expects to use a portion of the net proceeds from the offering to pay the cash portion of the consideration in the note exchange transactions as described below. Mirum expects to use the remainder of the net proceeds of this offering for general corporate purposes, which may include the acquisition of complementary products, technologies, intellectual property or businesses as part of its growth strategy.
Mirum expects to use a portion of the net proceeds from the offering and to issue shares of its common stock in exchange for a portion of its outstanding 4.00% convertible senior notes due 2029 (the “2029 notes”) in privately negotiated transactions (each, a “note exchange transaction”) entered into concurrently with the pricing of the offering. The terms of each note exchange transaction will depend on a variety of factors, including the market price of Mirum’s common stock and the trading price of the 2029 notes at the time of such note exchange transactions. No assurance can be given as to how much, if any, of the 2029 notes will be exchanged or the terms on which they will be exchanged. This press release is not an offer to exchange the 2029 notes, and the offering of the notes is not contingent upon the note exchange transactions.
In connection with any note exchange transaction, Mirum expects that holders of the 2029 notes who agree to have their 2029 notes exchanged and who have hedged their equity price risk with respect to such 2029 notes (the “hedged holders”) will, concurrently with, or shortly after, the pricing of the notes, unwind all or part of their hedge positions by buying Mirum’s common stock and/or entering into or unwinding various derivative transactions with respect to its common stock. The amount of Mirum’s common stock to be purchased by the hedged holders or the notional number of
shares of Mirum’s common stock underlying such derivative transactions may be substantial in relation to the historical average daily trading volume of Mirum’s common stock. This activity by the hedged holders could increase (or reduce the size of any decrease in) the market price of Mirum’s common stock, including concurrently with the pricing of the notes, resulting in a higher effective conversion price for the notes. Mirum cannot predict the magnitude of such market activity or the overall effect it will have on the price of the notes or its common stock.
The offer and sale of the notes, any shares of common stock issuable upon conversion of the notes and any shares of common stock issuable in connection with any note exchange transaction have not been, and will not be, registered under the Securities Act, any state securities laws or the securities laws of any other jurisdiction, and unless so registered, may not be offered or sold except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and any other applicable securities laws.
This press release does not constitute an offer to sell, or the solicitation of an offer to buy, any of these securities nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, sale or solicitation would be unlawful.
About Mirum Pharmaceuticals, Inc.
Mirum Pharmaceuticals (NASDAQ: MIRM) is a leading rare disease company with a global footprint of approved products and a broad pipeline of investigational medicines. Purpose-built to bring forward breakthrough medicines for people with overlooked conditions, Mirum focuses on rare liver and rare genetic diseases, where it has built deep expertise and strong connections to patient communities. The company’s commercial portfolio includes LIVMARLI® (maralixibat) for Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC), CHOLBAM® (cholic acid) for bile-acid synthesis disorders, and CTEXLI® (chenodiol) for cerebrotendinous xanthomatosis (CTX).
Mirum’s clinical-stage pipeline includes volixibat, an IBAT inhibitor in late-stage development for primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), brelovitug, a fully human monoclonal antibody in late-stage development for chronic hepatitis delta virus (HDV), zilurgisertib, an ALK2 inhibitor under regulatory review with the FDA for fibrodysplasia ossificans progressiva (FOP), and MRM-3379, a PDE4D inhibitor being evaluated for Fragile X syndrome (FXS).
Mirum’s success is driven by a team dedicated to advancing high impact medicines through strategic development, disciplined execution and purposeful collaboration across the rare disease ecosystem.
Forward-Looking Statements
Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include statements regarding, among other things, the anticipated terms of the notes being offered and the note exchange transactions, the completion, timing and size of the proposed offering and note exchange transactions, the intended use of the proceeds and the potential impact of the foregoing or related transactions on the market price of Mirum’s common stock or the price of the notes. Because such statements are subject to risks and
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uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Words such as “anticipate,” “expected,” “will,” “could,” “would,” “guidance,” “potential” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Mirum’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks and uncertainties related to associated with market conditions, including market interest rates, the trading price and volatility of Mirum’s common stock, Mirum’s business in general, the impact of geopolitical and macroeconomic events, and the other risks described in Mirum’s Quarterly Report on Form 10-Q for the period ended March 31, 2026 and subsequent filings with the Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made and are based on management’s assumptions and estimates as of such date. Mirum undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law.
Contact Information
Investor Contact:
Andrew McKibben
ir@mirumpharma.com
Media Contact:
Meredith Kiernan
media@mirumpharma.com
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Exhibit 99.2
Mirum Pharmaceuticals Prices $600.0 Million Convertible Senior Notes Offering; Refinances a Portion of 2029 Convertible Notes
FOSTER CITY, Calif.—May 12, 2026—Mirum Pharmaceuticals, Inc. (“Mirum”) (Nasdaq: MIRM), a leading rare disease company, today announced the pricing of its offering of $600.0 million aggregate principal amount of 0.00% convertible senior notes due 2032 (the “notes”) in a private placement (the “offering”) to persons reasonably believed to be qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended (the “Securities Act”). The issuance and sale of the notes are scheduled to settle on May 15, 2026, subject to customary closing conditions. Mirum also granted the initial purchasers of the notes an option to purchase, for settlement within a period of 13 days from, and including, the date the notes are first issued, up to an additional $90.0 million aggregate principal amount of notes.
The notes will be senior, unsecured obligations of Mirum. The notes will not bear regular interest and the principal amount of the notes will not accrete. The notes will mature on June 1, 2032, unless earlier converted, redeemed or repurchased. Before March 1, 2032, noteholders will have the right to convert their notes only in certain circumstances and during specified periods. From and after March 1, 2032, noteholders may convert all or any portion of their notes at any time at their election until the close of business on the second scheduled trading day immediately before the maturity date. Mirum will settle conversions by paying or delivering, as applicable, cash, shares of its common stock or a combination of cash and shares of its common stock, at Mirum’s election. The initial conversion rate is 7.1971 shares of common stock per $1,000 principal amount of notes, which represents an initial conversion price of approximately $138.94 per share of common stock. The initial conversion price represents a premium of approximately 30.0% over the last reported sale price of $106.88 per share of Mirum’s common stock on May 12, 2026. The conversion rate will be subject to adjustment upon the occurrence of certain events. If a “make-whole fundamental change” (as defined in the indenture for the notes) occurs, then Mirum will in certain circumstances increase the conversion rate for a specified period of time.
Mirum may not redeem the notes at its election at any time before June 6, 2029. The notes will be redeemable, in whole or in part (subject to a partial redemption limitation), for cash at Mirum’s option at any time, and from time to time, on a redemption date on or after June 6, 2029 and, in the case of any partial redemption, on or before the 30th scheduled trading day immediately before the maturity date, at a cash redemption price equal to the principal amount of the notes to be redeemed, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the redemption date, but only if (i) the notes are “freely tradable” (as defined in the indenture for the notes) as of the date Mirum sends the related redemption notice and all accrued and unpaid additional interest, if any, has been paid in full as of the first interest payment date occurring on or before the date Mirum sends such notice; and (ii) the last reported sale price per share of Mirum’s common stock exceeds 130% of the conversion price on (1) each of at least 20 trading days, whether or not consecutive, during the 30 consecutive trading days ending on, and including, the trading day immediately before the date Mirum sends the related redemption notice; and (2) the trading day immediately before the date Mirum sends such notice. In addition, calling any note for redemption will constitute a make-whole fundamental change with respect to that note, in which case the conversion rate applicable to the conversion of that note will be increased in certain circumstances if it is converted after it is called for redemption.
If a “fundamental change” (as defined in the indenture for the notes) occurs, then, subject to a limited exception, noteholders may require Mirum to repurchase their notes at a cash repurchase price equal to the principal amount of the notes to be repurchased, plus accrued and unpaid special interest and additional interest, if any, to, but excluding, the fundamental change repurchase date.
Mirum estimates that the net proceeds from the offering will be approximately $583.8 million (or approximately $671.6 million if the initial purchasers fully exercise their option to purchase additional notes), after deducting the initial purchasers’ discounts and commissions and Mirum’s estimated offering expenses.
Mirum expects to use a portion of the net proceeds from the offering to pay the cash portion of the consideration in the note exchange transactions as described below. Mirum expects to use the remainder of the net proceeds of this offering for general corporate purposes, which may include the acquisition of complementary products, technologies, intellectual property or businesses as part of its growth strategy.
Mirum expects to use approximately $475.0 million of the net proceeds from the offering and to issue approximately 3.2 million shares of its common stock in exchange for approximately $237.2 million aggregate principal amount of the 4.00% convertible senior notes due 2029 (the “2029 notes”) in privately negotiated transactions (each, a “note exchange transaction”) entered into concurrently with the pricing of the offering. This press release is not an offer to exchange the 2029 notes, and the offering of the notes is not contingent upon the note exchange transactions.
In connection with any note exchange transaction, Mirum expects that holders of the 2029 notes who agree to have their 2029 notes exchanged and who have hedged their equity price risk with respect to such 2029 notes (the “hedged holders”) will, concurrently with, or shortly after, the pricing of the notes, unwind all or part of their hedge positions by buying Mirum’s common stock and/or entering into or unwinding various derivative transactions with respect to its common stock. The amount of Mirum’s common stock to be purchased by the hedged holders or the notional number of shares of Mirum’s common stock underlying such derivative transactions may be substantial in relation to the historical average daily trading volume of Mirum’s common stock. This activity by the hedged holders could increase (or reduce the size of any decrease in) the market price of Mirum’s common stock. Mirum cannot predict the magnitude of such market activity or the overall effect it will have on the price of the notes or its common stock.
The offer and sale of the notes, any shares of common stock issuable upon conversion of the notes and any shares of common stock issuable in connection with any note exchange transaction have not been, and will not be, registered under the Securities Act, any state securities laws or the securities laws of any other jurisdiction, and unless so registered, may not be offered or sold except pursuant to an exemption from, or in a transaction not subject to, the registration requirements of the Securities Act and any other applicable securities laws.
This press release does not constitute an offer to sell, or the solicitation of an offer to buy, any of these securities nor shall there be any sale of these securities in any state or jurisdiction in which such an offer, sale or solicitation would be unlawful.
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About Mirum Pharmaceuticals, Inc.
Mirum Pharmaceuticals (NASDAQ: MIRM) is a leading rare disease company with a global footprint of approved products and a broad pipeline of investigational medicines. Purpose-built to bring forward breakthrough medicines for people with overlooked conditions, Mirum focuses on rare liver and rare genetic diseases, where it has built deep expertise and strong connections to patient communities. The company’s commercial portfolio includes LIVMARLI® (maralixibat) for Alagille syndrome (ALGS) and progressive familial intrahepatic cholestasis (PFIC), CHOLBAM® (cholic acid) for bile-acid synthesis disorders, and CTEXLI® (chenodiol) for cerebrotendinous xanthomatosis (CTX).
Mirum’s clinical-stage pipeline includes volixibat, an IBAT inhibitor in late-stage development for primary sclerosing cholangitis (PSC) and primary biliary cholangitis (PBC), brelovitug, a fully human monoclonal antibody in late-stage development for chronic hepatitis delta virus (HDV), zilurgisertib, an ALK2 inhibitor under regulatory review with the FDA for fibrodysplasia ossificans progressiva (FOP), and MRM-3379, a PDE4D inhibitor being evaluated for Fragile X syndrome (FXS).
Mirum’s success is driven by a team dedicated to advancing high impact medicines through strategic development, disciplined execution and purposeful collaboration across the rare disease ecosystem.
Forward-Looking Statements
Statements contained in this press release regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such forward-looking statements include statements regarding, among other things, the completion of the proposed offering and note exchange transactions, the intended use of the proceeds and the potential impact of the foregoing or related transactions on the market price of Mirum’s common stock or the price of the notes. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Words such as “anticipate,” “expected,” “will,” “could,” “would,” “guidance,” “potential” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon Mirum’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks and uncertainties related to associated with market conditions, including market interest rates, the trading price and volatility of Mirum’s common stock, Mirum’s business in general, the impact of geopolitical and macroeconomic events, and the other risks described in Mirum’s Quarterly Report on Form 10-Q for the period ended March 31, 2026 and subsequent filings with the Securities and Exchange Commission. All forward-looking statements contained in this press release speak only as of the date on which they were made and are based on management’s assumptions and estimates as of such date. Mirum undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law.
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Contact Information
Investor Contact:
Andrew McKibben
ir@mirumpharma.com
Media Contact:
Meredith Kiernan
media@mirumpharma.com
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