Osisko Development Announces Closings of Additional US$75 Million Aggregate Principal Amount of 4.125% Convertible Senior Notes Bringing Total Offering to US$300 Million

MONTREAL, June 01, 2026 (GLOBE NEWSWIRE) -- Osisko Development Corp. (NYSE: ODV, TSXV: ODV) ("Osisko Development" or the "Company") announced today the closing on May 29, 2026 of an additional US$75.0 million aggregate principal amount of 4.125% convertible senior notes due 2031 (the "Notes"), consisting of US$25.0 million aggregate principal amount of Notes sold pursuant to the full exercise of the initial purchasers' option to purchase additional notes from the Company's previously announced offering (the "Initial Purchasers' Option") and US$50.0 million aggregate principal amount of Notes sold in a concurrent private placement (the "Private Placement") with Double Zero Capital, LP ("Double Zero") (the "Double Zero Notes"). Together with the Company's closing of its offering of US$225.0 million aggregate principal amount of Notes in a private placement on May 26, 2026 (the "Base Offering," and collectively with the Initial Purchasers' Option and the Private Placement, the "Offerings") total gross proceeds from the Offerings were US$300.0 million.