Mirum Pharmaceuticals prices upsize $275M convertible senior note offering

Mirum Pharmaceuticals announced the pricing of its offering of $275.0 million aggregate principal amount of 4.00% convertible senior notes due 2029 in a private offering to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended. The offering size was increased from the previously announced offering size of $200.0 million aggregate principal amount of notes. 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 $41.25 million principal amount of notes. The notes will be senior, unsecured obligations of Mirum and will accrue interest at a rate of 4.00% per annum, payable semi-annually in arrears on May 1 and November 1 of each year, beginning on November 1, 2023. The notes will mature on May 1, 2029, unless earlier converted, redeemed or repurchased by Mirum. Before January 2, 2029, noteholders will have the right to convert their notes only upon the occurrence of certain events. From and after January 2, 2029, noteholders may convert their notes at any time at their election until the close of business on the 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 31.5075 shares of common stock per $1,000 principal amount of notes, which represents an initial conversion price of approximately $31.74 per share of common stock. The initial conversion price represents a premium of approximately 35.0% over the last reported sale price of $23.51 per share of Mirum’s common stock on April 12, 2023.